Power calculations, units, kilo, mega, milli, micro - 1 exam
question
Power in electronics is expressed in Watts so the basic unit of electrical power is one Watt. The power dissipated by a circuit is equal to the voltage (E) multiplied by the current (I) (EI=P). Thus 1 volt through a 1 Ohm resistor will draw 1 ampere of current which means that 1 Watt of power will be dissipated.
In earlier lessons it was stated that a MHz (Megahertz) was a million Hertz and a Kilohertz (KHz) was one thousand Hertz it also follows that a Megawatt (MW) is one million watts and a kilowatt (KW) is one thousand watts. One Kilowatt running for one hour is one Kilowatt Hour (KWH) which is an expression of power used while KW or Watt is an expression of power being used at any one instant in time. So if 2 watts were to be consumed for 15 minuets it would mean that a total of one half watt hours would have been used (.25 hours times 2 watts equals one half).
Along with Mega and Kilo there is also Giga which is one thousand million thus 1 Gigahertz is equal to 1,000 Megahertz. Power, voltage, and current is sometimes expressed in less then one complete unit. These expressions are milli (.001), Micro (.000001) and pico (.000,000,001).
The total power being drawn by a transmitter while transmitting can be calculated by measuring the DC voltage at the transceiver and multiply by the current drawn. This formula will account for total power used by all stages inside the unit but when we refer to how much power a transmitter is normally this is a reference to either the final input power (Volts applied time current drawn by the final amplifier alone) or the output power (Watts measured out of the transmitter) which will be less then the power input. Remember the power input to a transmitter is DC power and power output is RF power.
RF power input to RF power output is a reference to gain of an amplifier which is not being considered in this lesson.
Pico= million millionth Micro= millionth Milli= thousandth
Kilo= thousand Mega= Million Giga= Thousand Million
P=IE E=P/I I=P/E
T4E01
What unit is used to describe electrical power?
A. Ohm
B. Farad
C. Volt
D. Watt
~~
T4E02
What is the formula used to calculate electrical power in a DC circuit?
A. Power (P) equals voltage (E) multiplied by current (I)
B. Power (P) equals voltage (E) divided by current (I)
C. Power (P) equals voltage (E) minus current (I)
D. Power (P) equals voltage (E) plus current (I)
~~
T4E03
How much power is represented by a voltage of 13.8 volts DC and a current of 10 amperes?
A. 138 watts
B. 0.7 watts
C. 23.8 watts
D. 3.8 watts
~~
T4E04
How much power is being used in a circuit when the voltage is 120 volts DC and the current is 2.5 amperes?
A. 1440 watts
B. 300 watts
C. 48 watts
D. 30 watts
~~
T4E05
How can you determine how many watts are being drawn by your transceiver when you are transmitting?
A. Measure the DC voltage and divide it by 60 Hz
B. Check the fuse in the power leads to see what size it is
C. Look in the Radio Amateur's Handbook
D. Measure the DC voltage at the transceiver and multiply by the current drawn when you transmit
~~
T4E06
How many amperes are flowing in a circuit when the applied voltage is 120 volts DC and the load is 1200 watts?
A. 20 amperes
B. 10 amperes
C. 120 amperes
D. 5 amperes
~~
T4E07
How many milliamperes is the same as 1.5 amperes?
A. 15 milliamperes
B. 150 milliamperes
C. 1500 milliamperes
D. 15000 milliamperes
~~
T4E08
What is another way to specify the frequency of a radio signal that is oscillating at 1,500,000 Hertz?
A. 1500 kHz
B. 1500 MHz
C. 15 GHz
D. 150 kHz
~~
T4E09
How many volts are equal to one kilovolt?
A. one one-thousandth of a volt
B. one hundred volts
C. one thousand volts
D. one million volts
~~
T4E10
How many volts are equal to one microvolt?
A. one one-millionth of a volt
B. one million volts
C. one thousand kilovolts
D. one one-thousandth of a volt
~~
T4E11
How many watts does a hand-held transceiver put out if the output power is 500 milliwatts?
A. 0.02 watts
B. 0.5 watts
C. 5 watts
D. 50 watts
Answers to today's Questions
D A A B D B C A C A B
Saturday, September 22, 2007
LESSON 19
Operating controls
By the time most amateur radio operators receive their amateur call sign they already have their shack (place where the station is located) set up. In the earlier days of Ham radio there were usually many knobs on both the transmitter and the receiver and each served a purpose which had to be understood before going on the air.
Most modern ham equipment has fewer knobs but they are not necessarily less difficult to operate or at least set up to operate. They usually have an on off switch which may be included in the volume control, a squelch control, and a frequency control. There are also usually switches which include RIT, +/- or Shift Key, Power Level, and a Hexadecimal Touch Tone Pad. The best way to understand how to use all of these is to read the owner’s manual.
While the owner’s manual will describe your unit functions some general function control information is necessary for the amateur radio exam.
In older equipment the transmit frequency and receive frequency was controlled by a variable capacitor. That allowed a nice smooth operation across the frequencies but today most transmitters and receivers use a Phase Lock Loop to control the frequency which changes frequency in jumps of several kilohertz at a time. Maybe it changes at 5 or 10 KHz per click. If the receiver is capable of receiving SSB the missing carrier frequency must be reinserted at the same frequency, plus or minus only a few cycles, as the suppressed carrier frequency in the transmitter. Though both the transmitting station’s transmitter and the receiving stations receiver might read the same frequency there will most likely be a slight difference in the true frequency so some adjustment in receiver frequency will be necessary. This is the purpose of the RIT (Receiver Incremental Tuning) control.
The transmitter output and the receiver input frequency of a repeater are not the same. Most repeater have a 600 KHz either plus or minus offset in frequency between the receiver and the transmitter. The modern transceiver is provided with a shift control function so the transmitter will transmit on the repeater input frequency and the receiver will receive the repeater’s output frequency.
There may also be a step menu on a transceiver to set the tuning rate when changing frequencies. If one repeater input frequency is 146.865 MHz and another repeater input is 146.65 MHz and the transceiver has a 10 KHz step rate then it must be changed to allow for the 5 KHz change when using the 146.865 MHz repeater.
FM receivers are very noisy when no signal is being received. This noise, known as white noise, is very annoying so a squelch control is placed on FM receivers so as to quiet the unit when no signal is being received.
To allow for easy frequency shifting up/down buttons are used on many transceivers usually located on the microphone key pad.
The key pad or VFO knob might be used to set the transceiver on the desired frequency but for commonly used frequencies is quicker to put the desired frequencies in memory which will allow a change to the desired frequency with a minimal operation. Along with transmit and receive frequency the memory may also store the power level and the CTCSS tone frequency. CTCSS is short Continuous Tone-Coded Squelch System and it is a sub-tone frequency used to prevent the receiver audio from opening except when it is present or to prevent a repeater from transmitting without it being on the received signal. Most of the time in ham operations CTCSS is used only in repeater input to reduce interference problems.
An alternative action for some controls is accessed by the “F”, function, key.
If a transmission signal is distorted and unreadable it may be due to the microphone gain control being set to high.
1. T5B01
What may happen if a transmitter is operated with the microphone gain set too high?
A. The output power will be too high
B. It may cause the signal to become distorted and unreadable
C. The frequency will vary
D. The SWR will increase
~~
2. T5B02
What kind of information may a VHF/UHF transceiver be capable of storing in memory?
A. Transmit and receive operating frequency
B. CTCSS tone frequency
C. Transmit power level
D. All of these answers are correct
~~
3. T5B03
What is one way to select a frequency on which to operate?
A. Use the keypad or VFO knob to enter the correct frequency
B. Turn on the CTCSS encoder
C. Adjust the power supply ripple frequency
D. All of these answers are correct
~~
4. T5B04
What is the purpose of the squelch control on a transceiver?
A. It is used to set the highest level of volume desired
B. It is used to set the transmitter power level
C. It is used to adjust the antenna polarization
D. It is used to quiet noise when no signal is being received
~~
5. T5B05
What is a way to enable quick access to a favorite frequency on your transceiver?
A. Enable the CTCSS tones
B. Store the frequency in a memory channel
C. Disable the CTCSS tones
D. Use the scan mode to select the desired frequency
~~
6. T5B06
What might you do to improve the situation if the station you are listening to is hard to copy because of ignition noise interference?
A. Increase your transmitter power
B. Decrease the squelch setting
C. Turn on the noise blanker
D. Use the RIT control
~~
7. T5B07
What is the purpose of the buttons labeled "up" and "down" on many microphones?
A. To allow easy frequency or memory selection
B. To raise or lower the internal antenna
C. To set the battery charge rate
D. To upload or download messages
~~
8. T5B08
What is the purpose of the "shift" control found on many VHF/UHF transceivers?
A. Adjust transmitter power level
B. Change bands
C. Adjust the offset between transmit and receive frequency
D. Change modes
~~
9. T5B09
What does RIT mean?
A. Receiver Input Tone
B. Receiver Incremental Tuning
C. Rectifier Inverter Test
D. Remote Input Transmitter
~~
10. T5B10
What is the purpose of the "step" menu function found on many transceivers?
A. It adjusts the transmitter power output level
B. It adjusts the modulation level
C. It sets the earphone volume
D. It sets the tuning rate when changing frequencies
~~
11. T5B11
What is the purpose of the "function" or "F" key found on many transceivers?
A. It turns the power on and off
B. It selects the autopatch access code
C. It selects an alternate action for some control buttons
D. It controls access to the memory scrambler
Answers to today’s Questions
Answers:~B D A D B C A C B D C
By the time most amateur radio operators receive their amateur call sign they already have their shack (place where the station is located) set up. In the earlier days of Ham radio there were usually many knobs on both the transmitter and the receiver and each served a purpose which had to be understood before going on the air.
Most modern ham equipment has fewer knobs but they are not necessarily less difficult to operate or at least set up to operate. They usually have an on off switch which may be included in the volume control, a squelch control, and a frequency control. There are also usually switches which include RIT, +/- or Shift Key, Power Level, and a Hexadecimal Touch Tone Pad. The best way to understand how to use all of these is to read the owner’s manual.
While the owner’s manual will describe your unit functions some general function control information is necessary for the amateur radio exam.
In older equipment the transmit frequency and receive frequency was controlled by a variable capacitor. That allowed a nice smooth operation across the frequencies but today most transmitters and receivers use a Phase Lock Loop to control the frequency which changes frequency in jumps of several kilohertz at a time. Maybe it changes at 5 or 10 KHz per click. If the receiver is capable of receiving SSB the missing carrier frequency must be reinserted at the same frequency, plus or minus only a few cycles, as the suppressed carrier frequency in the transmitter. Though both the transmitting station’s transmitter and the receiving stations receiver might read the same frequency there will most likely be a slight difference in the true frequency so some adjustment in receiver frequency will be necessary. This is the purpose of the RIT (Receiver Incremental Tuning) control.
The transmitter output and the receiver input frequency of a repeater are not the same. Most repeater have a 600 KHz either plus or minus offset in frequency between the receiver and the transmitter. The modern transceiver is provided with a shift control function so the transmitter will transmit on the repeater input frequency and the receiver will receive the repeater’s output frequency.
There may also be a step menu on a transceiver to set the tuning rate when changing frequencies. If one repeater input frequency is 146.865 MHz and another repeater input is 146.65 MHz and the transceiver has a 10 KHz step rate then it must be changed to allow for the 5 KHz change when using the 146.865 MHz repeater.
FM receivers are very noisy when no signal is being received. This noise, known as white noise, is very annoying so a squelch control is placed on FM receivers so as to quiet the unit when no signal is being received.
To allow for easy frequency shifting up/down buttons are used on many transceivers usually located on the microphone key pad.
The key pad or VFO knob might be used to set the transceiver on the desired frequency but for commonly used frequencies is quicker to put the desired frequencies in memory which will allow a change to the desired frequency with a minimal operation. Along with transmit and receive frequency the memory may also store the power level and the CTCSS tone frequency. CTCSS is short Continuous Tone-Coded Squelch System and it is a sub-tone frequency used to prevent the receiver audio from opening except when it is present or to prevent a repeater from transmitting without it being on the received signal. Most of the time in ham operations CTCSS is used only in repeater input to reduce interference problems.
An alternative action for some controls is accessed by the “F”, function, key.
If a transmission signal is distorted and unreadable it may be due to the microphone gain control being set to high.
1. T5B01
What may happen if a transmitter is operated with the microphone gain set too high?
A. The output power will be too high
B. It may cause the signal to become distorted and unreadable
C. The frequency will vary
D. The SWR will increase
~~
2. T5B02
What kind of information may a VHF/UHF transceiver be capable of storing in memory?
A. Transmit and receive operating frequency
B. CTCSS tone frequency
C. Transmit power level
D. All of these answers are correct
~~
3. T5B03
What is one way to select a frequency on which to operate?
A. Use the keypad or VFO knob to enter the correct frequency
B. Turn on the CTCSS encoder
C. Adjust the power supply ripple frequency
D. All of these answers are correct
~~
4. T5B04
What is the purpose of the squelch control on a transceiver?
A. It is used to set the highest level of volume desired
B. It is used to set the transmitter power level
C. It is used to adjust the antenna polarization
D. It is used to quiet noise when no signal is being received
~~
5. T5B05
What is a way to enable quick access to a favorite frequency on your transceiver?
A. Enable the CTCSS tones
B. Store the frequency in a memory channel
C. Disable the CTCSS tones
D. Use the scan mode to select the desired frequency
~~
6. T5B06
What might you do to improve the situation if the station you are listening to is hard to copy because of ignition noise interference?
A. Increase your transmitter power
B. Decrease the squelch setting
C. Turn on the noise blanker
D. Use the RIT control
~~
7. T5B07
What is the purpose of the buttons labeled "up" and "down" on many microphones?
A. To allow easy frequency or memory selection
B. To raise or lower the internal antenna
C. To set the battery charge rate
D. To upload or download messages
~~
8. T5B08
What is the purpose of the "shift" control found on many VHF/UHF transceivers?
A. Adjust transmitter power level
B. Change bands
C. Adjust the offset between transmit and receive frequency
D. Change modes
~~
9. T5B09
What does RIT mean?
A. Receiver Input Tone
B. Receiver Incremental Tuning
C. Rectifier Inverter Test
D. Remote Input Transmitter
~~
10. T5B10
What is the purpose of the "step" menu function found on many transceivers?
A. It adjusts the transmitter power output level
B. It adjusts the modulation level
C. It sets the earphone volume
D. It sets the tuning rate when changing frequencies
~~
11. T5B11
What is the purpose of the "function" or "F" key found on many transceivers?
A. It turns the power on and off
B. It selects the autopatch access code
C. It selects an alternate action for some control buttons
D. It controls access to the memory scrambler
Answers to today’s Questions
Answers:~B D A D B C A C B D C
Thursday, September 20, 2007
LESSON 20
Repeaters; repeater and simplex operating techniques,
offsets, selective squelch, open and closed repeaters, linked
repeaters
During the 1950’s business two way radio using VHF repeaters became popular. As the popularity increased it became apparent that there was not enough room on the VHF band so they were forced to operate simplex (transmitting and receiving on the same frequency) on VHF and go to UHF for repeater. This along with the rapidly developing technology made used out of date repeaters available for Amateur radio use at reasonable prices. This also meant that vehicle radios and base stations were becoming available also for reasonable prices. A little conversion and tweaking frequencies and they became ham radios.
So during the late 1960 and into the 1970 amateur radio repeaters were growing in numbers daily. The purpose of the repeater is to extend the range of mobile and low-power stations. Under ideal conditions normally maximum mobile to mobile communications would be less then 14 miles (distance to horizon) and most of the time is actually less then 5 miles because of objects blocking the signals. Using the Sutter Buttes repeater mobile communications between Lodi and Reading California are possible under normal conditions of operation. That is a distance of over 120 miles.
As the number of repeater increased it became necessary to establish a local frequency coordinator. The local coordinator should approve the frequency of all new repeaters before they are installed to minimize interference between repeaters and make the most efficient use of the available frequencies.
Many times a repeater will have a courtesy tone which is a beep that occurs when the transmitting station unkeys the mike so the receiving station will know it is ok to transmit without having to wait for the repeater to drop out or stop transmitting. There are some repeater that require the operators to wait for the repeater to stop transmitting before starting a new transmission
A repeater’s input frequency (the frequency the repeater’s receiver) and the output frequency (the frequency of the repeater’s transmitter) are not the same. An operator must know what these two frequencies are before operation is possible. Most of the times the input and output frequencies of a repeater on the 2 meter band are separated by .6 MHz (600 KHz) and the 70 CM repeaters are normally separated by 5 MHz.
Repeaters are usually shared by many hams in the area and you will not become popular on a repeater if you “Hog” the repeater for yourself. Always give a little time after the station being worked has stopped transmitting so if any other station would like to break in and use the repeater it will be possible.
Not all repeaters are open to all amateur radio operators; access to any repeater may be limited to club members or some other special group by the repeater owner. These repeaters are officially known as an auxiliary station but more commonly called closed repeaters.
If simplex operation is possible then it should be used to avoid tying up the repeater when direct contact is possible. Initials contact can be made on the repeater then move to a simplex frequency that is not a local repeater. If it is questionable if simplex communications is possible or not check the repeater’s input frequency to see if the other station can be heard.
To increase the coverage to an even greater range sometimes repeater can be linked together into a system known as a “Linked repeater system”.
1. T5C01 (B)
What is one purpose of a repeater?
A. To cut your power bill by using someone else's higher power
system
B. To extend the usable range of mobile and low-power stations
C. To transmit signals for observing propagation and reception
D. To communicate with stations in services other than amateur
~~
2. T5C02 (B)
What is a courtesy tone?
A. A tone used to identify the repeater
B. A tone used to indicate when a transmission is complete
C. A tone used to indicate that a message is waiting for someone
D. A tone used to activate a receiver in case of severe weather
~~
3. T5C03 (A)
Which of the following is the most important information to know before using a repeater?
A. The repeater input and output frequencies
B. The repeater call sign
C. The repeater power level
D. Whether or not the repeater has an autopatch
~~
4. T5C04 (C)
Why should you pause briefly between transmissions when using a repeater?
A. To let your radio cool off
B. To reach for pencil and paper so you can take notes
C. To listen for anyone wanting to break in
D. To dial up the repeater's autopatch
~~
5. T5C05 (A)
What is the most common input/output frequency offset for
repeaters in the 2-meter band?
A. 0.6 MHz
B. 1.0 MHz
C. 1.6 MHz
D. 5.0 MHz
~~
6. T5C06 (D)
What is the most common input/output frequency offset for
repeaters in the 70-centimeter band?
A. 600 kHz
B. 1.0 MHz
C. 1.6 MHz
D. 5.0 MHz
~~
7. T5C07 (A)
What is meant by the terms input and output frequency when
referring to repeater operations? A
A. The repeater receives on one frequency and transmits on another
B. The repeater offers a choice of operating frequencies
C. One frequency is used to control the repeater and another is
used to retransmit received signals
D. The repeater must receive an access code on one frequency
before it will begin transmitting
~~
8. T5C08 (A)
What is the meaning of the term simplex operation? A
A. Transmitting and receiving on the same frequency
B. Transmitting and receiving over a wide area
C. Transmitting on one frequency and receiving on another
D. Transmitting one-way communications
~~
9. T5C09 (B)
What is a reason to use simplex instead of a repeater? B
A. When the most reliable communications are needed
B. To avoid tying up the repeater when direct contact is possible
C. When an emergency telephone call is needed
D. When you are traveling and need some local information
~~
10. T5C10 (A)
How might you find out if you could communicate with a station using simplex instead of a repeater?
A. Check the repeater input frequency to see if you can hear the other station
B. Check to see if you can hear the other station on a different frequency band
C. Check to see if you can hear a more distant repeater
D. Check to see if a third station can hear both of you
~~
11. T5C11 (C)
What is the term for a series of repeaters that can be connected to one another to provide users with a wider coverage?
A. Open repeater system
B. Closed repeater system
C. Linked repeater system
D. Locked repeater system
~~
12. T5C12 (A)
What is the main reason repeaters should be approved by the local frequency coordinator before being installed?
A. Coordination minimizes interference between repeaters and makes the most efficient use of available frequencies
B. Coordination is required by the FCC
C. Repeater manufacturers have exclusive territories and you could be fined for using the wrong equipment
D. Only coordinated systems will be approved by the officers of the local radio club
~~
13. T5C13 (B)
Which of the following statements regarding use of repeaters is true?
A. All amateur radio operators have the right to use any repeater at any time
B. Access to any repeater may be limited by the repeater owner
C. Closed repeaters must be opened at the request of any amateur wishing to use it
D. Open repeaters are required to use CTCSS tones for access
~~
14. T5C14 (D)
What term is used to describe a repeater when use is restricted to the members of a club or group?
A. A beacon station
B. An open repeater
C. A auxiliary station
D. A closed repeater
Answers to today’s questions.
B B A C A D A A B A C A B D
offsets, selective squelch, open and closed repeaters, linked
repeaters
During the 1950’s business two way radio using VHF repeaters became popular. As the popularity increased it became apparent that there was not enough room on the VHF band so they were forced to operate simplex (transmitting and receiving on the same frequency) on VHF and go to UHF for repeater. This along with the rapidly developing technology made used out of date repeaters available for Amateur radio use at reasonable prices. This also meant that vehicle radios and base stations were becoming available also for reasonable prices. A little conversion and tweaking frequencies and they became ham radios.
So during the late 1960 and into the 1970 amateur radio repeaters were growing in numbers daily. The purpose of the repeater is to extend the range of mobile and low-power stations. Under ideal conditions normally maximum mobile to mobile communications would be less then 14 miles (distance to horizon) and most of the time is actually less then 5 miles because of objects blocking the signals. Using the Sutter Buttes repeater mobile communications between Lodi and Reading California are possible under normal conditions of operation. That is a distance of over 120 miles.
As the number of repeater increased it became necessary to establish a local frequency coordinator. The local coordinator should approve the frequency of all new repeaters before they are installed to minimize interference between repeaters and make the most efficient use of the available frequencies.
Many times a repeater will have a courtesy tone which is a beep that occurs when the transmitting station unkeys the mike so the receiving station will know it is ok to transmit without having to wait for the repeater to drop out or stop transmitting. There are some repeater that require the operators to wait for the repeater to stop transmitting before starting a new transmission
A repeater’s input frequency (the frequency the repeater’s receiver) and the output frequency (the frequency of the repeater’s transmitter) are not the same. An operator must know what these two frequencies are before operation is possible. Most of the times the input and output frequencies of a repeater on the 2 meter band are separated by .6 MHz (600 KHz) and the 70 CM repeaters are normally separated by 5 MHz.
Repeaters are usually shared by many hams in the area and you will not become popular on a repeater if you “Hog” the repeater for yourself. Always give a little time after the station being worked has stopped transmitting so if any other station would like to break in and use the repeater it will be possible.
Not all repeaters are open to all amateur radio operators; access to any repeater may be limited to club members or some other special group by the repeater owner. These repeaters are officially known as an auxiliary station but more commonly called closed repeaters.
If simplex operation is possible then it should be used to avoid tying up the repeater when direct contact is possible. Initials contact can be made on the repeater then move to a simplex frequency that is not a local repeater. If it is questionable if simplex communications is possible or not check the repeater’s input frequency to see if the other station can be heard.
To increase the coverage to an even greater range sometimes repeater can be linked together into a system known as a “Linked repeater system”.
1. T5C01 (B)
What is one purpose of a repeater?
A. To cut your power bill by using someone else's higher power
system
B. To extend the usable range of mobile and low-power stations
C. To transmit signals for observing propagation and reception
D. To communicate with stations in services other than amateur
~~
2. T5C02 (B)
What is a courtesy tone?
A. A tone used to identify the repeater
B. A tone used to indicate when a transmission is complete
C. A tone used to indicate that a message is waiting for someone
D. A tone used to activate a receiver in case of severe weather
~~
3. T5C03 (A)
Which of the following is the most important information to know before using a repeater?
A. The repeater input and output frequencies
B. The repeater call sign
C. The repeater power level
D. Whether or not the repeater has an autopatch
~~
4. T5C04 (C)
Why should you pause briefly between transmissions when using a repeater?
A. To let your radio cool off
B. To reach for pencil and paper so you can take notes
C. To listen for anyone wanting to break in
D. To dial up the repeater's autopatch
~~
5. T5C05 (A)
What is the most common input/output frequency offset for
repeaters in the 2-meter band?
A. 0.6 MHz
B. 1.0 MHz
C. 1.6 MHz
D. 5.0 MHz
~~
6. T5C06 (D)
What is the most common input/output frequency offset for
repeaters in the 70-centimeter band?
A. 600 kHz
B. 1.0 MHz
C. 1.6 MHz
D. 5.0 MHz
~~
7. T5C07 (A)
What is meant by the terms input and output frequency when
referring to repeater operations? A
A. The repeater receives on one frequency and transmits on another
B. The repeater offers a choice of operating frequencies
C. One frequency is used to control the repeater and another is
used to retransmit received signals
D. The repeater must receive an access code on one frequency
before it will begin transmitting
~~
8. T5C08 (A)
What is the meaning of the term simplex operation? A
A. Transmitting and receiving on the same frequency
B. Transmitting and receiving over a wide area
C. Transmitting on one frequency and receiving on another
D. Transmitting one-way communications
~~
9. T5C09 (B)
What is a reason to use simplex instead of a repeater? B
A. When the most reliable communications are needed
B. To avoid tying up the repeater when direct contact is possible
C. When an emergency telephone call is needed
D. When you are traveling and need some local information
~~
10. T5C10 (A)
How might you find out if you could communicate with a station using simplex instead of a repeater?
A. Check the repeater input frequency to see if you can hear the other station
B. Check to see if you can hear the other station on a different frequency band
C. Check to see if you can hear a more distant repeater
D. Check to see if a third station can hear both of you
~~
11. T5C11 (C)
What is the term for a series of repeaters that can be connected to one another to provide users with a wider coverage?
A. Open repeater system
B. Closed repeater system
C. Linked repeater system
D. Locked repeater system
~~
12. T5C12 (A)
What is the main reason repeaters should be approved by the local frequency coordinator before being installed?
A. Coordination minimizes interference between repeaters and makes the most efficient use of available frequencies
B. Coordination is required by the FCC
C. Repeater manufacturers have exclusive territories and you could be fined for using the wrong equipment
D. Only coordinated systems will be approved by the officers of the local radio club
~~
13. T5C13 (B)
Which of the following statements regarding use of repeaters is true?
A. All amateur radio operators have the right to use any repeater at any time
B. Access to any repeater may be limited by the repeater owner
C. Closed repeaters must be opened at the request of any amateur wishing to use it
D. Open repeaters are required to use CTCSS tones for access
~~
14. T5C14 (D)
What term is used to describe a repeater when use is restricted to the members of a club or group?
A. A beacon station
B. An open repeater
C. A auxiliary station
D. A closed repeater
Answers to today’s questions.
B B A C A D A A B A C A B D
LESSON 21
Recognition and correction of problems, symptoms of overload
and overdrive, distortion, over and under modulation, RF feedback,
off frequency signals, fading and noise, problems with digital
communications links
Most modern radio receivers are composed of at least one RF (radio frequency) amplifier a mixer which changes the frequency from the selected input frequency to a new frequency called the IF (interment frequency). If the RF or Mixer is saturated with a very strong signal even though the receiver is not tuned to that frequency it can cause that stage to not function properly. Interference caused by a very strong signal from a nearby source is known as front-end overload or fundamental overload.
Interference can also be caused by spurious emission (frequencies other then the fundamental frequency generated by the transmitter) and harmonics (multiples of the transmitter’s fundamental frequency).
When a transmitter and receiver are moving towards each other by the movement of either one or both the wave length will appear to the receiver to be shorter. If they are moving apart the wave length will appear longer and the greater the velocity the greater the effect. A longer wave length appears as a lower frequency and visa versa but the closing velocity or the separating velocity would have to be extremely high to cause sufficient frequency change to cause interference. The effect that causes this to happen is known as the Doppler Effect.
Strong RF signals can also be picked up by a telephone line acting like an antenna. The telephone may act like a radio receiver and thus the strong RF signal interferes with the phone’s operation. The telephone must have an RF filter to prevent this type of interference.
If a neighbor reports amateur transmissions are interfering with their radio or television the station owner should check to see that the transmitter is operating properly and that it does not interfere with the station owner’s TV set. The transmitter needs a good grounding system to avoid interference so that too should be checked. It is the station owner’s responsibility to Check the station and make sure it meets the standards of good amateur practice.
Some of the things that can be done to reduce or eliminate interference are use snap-on ferrite chokes on power cords and other non-antenna cords of both the transmitter and device being interfered with and/or use RF filters which include Low-pass, High-pass, Notch, and Band-pass filters.
The FCC allows very low power transmitting devices on the AM and FM broadcast bands under Part 15 of the FCC rules and regulations. If these devices are causing interference with an amateur radio stations the amateur radio operator should first check to make sure his station meets the standards of good amateur practice. If the station checks ok then working with the neighbor to identify the offending device would be the second step to take and if the problem persists politely inform the neighbor about the rules that require him to stop using the device if it causes interference.
Sometimes a mobile amateur station will have a whine or high pitch sound included in its transmission. This tone will raise and lower according to the speed of the vehicle’s engine. This is caused by the ham station picking up the noise from the vehicle’s electrical system, more specifically from the alternator. This can usually be salved by tapping the radio’s plus voltage directly from the vehicle’s battery. If this does not cure the problem a filter in the power line may be necessary.
As was mentioned earlier a transmitter needs a good ground system. But not only the transmitter but all components of the station should be grounded. One common problem of a poor ground on the transmitter is RF getting into the microphone which can cause a SSB transmission to sound garbled or break up.
A week or distorted signal being reported when a station is using a repeater could be caused by a bad location. This can also be caused if the transmitter is slightly off frequency or if the batteries are running low.
Digital signals are used by some hams instead of an analogue signal because many digital systems can automatically correct errors caused by noise and interference.
1. T5D01
What is meant by fundamental overload in reference to a receiver?
A. Too much voltage from the power supply
B. Too much current from the power supply
C. Interference caused by very strong signals from a nearby source
D. Interference caused by turning the volume up too high
~~
2. T5D02
Which of the following is NOT a cause of radio frequency
interference?
A. Fundamental overload
B. Doppler shift
C. Spurious emissions
D. Harmonics
~~
3. T5D03
What is the most likely cause of telephone interference from a nearby transmitter?
A. Harmonics from the transmitter
B. The transmitter's signals are causing the telephone to act like a radio receiver
C. Poor station grounding
D. Improper transmitter adjustment
~~
4. T5D04
What is a logical first step when attempting to cure a radio frequency interference problem in a nearby telephone?
A. Install a low-pass filter at the transmitter
B. Install a high-pass filter at the transmitter
C. Install an RF filter at the telephone
D. Improve station grounding
~~
5. T5D05
What should you do first if someone tells you that your
transmissions are interfering with their TV reception?
A. Make sure that your station is operating properly and that it does not cause interference to your own television
B. Immediately turn off your transmitter and contact the nearest FCC office for assistance
C. Tell them that your license gives you the right to transmit and nothing can be done to reduce the interference
D. Continue operating normally because your equipment cannot possibly cause any interference
~~
6. T5D07
Which of the following may be useful in correcting a radio
frequency interference problem?
A. Snap-on ferrite chokes
B. Low-pass and high-pass filters
C. Notch and band-pass filters
D. All of these answers are correct
~~
7. T5D08
What is the proper course of action to take when a neighbor
reports that your radio signals are interfering with something in his home?
A. You are not required to do anything
B. Contact the FCC to see if other interference reports have been filed
C. Check your station and make sure it meets the standards of good amateur practice
D. Change your antenna polarization from vertical to horizontal
~~
8. T5D09
What should you do if a "Part 15" device in your neighbor’s home is causing harmful interference to your amateur station?
A. Work with your neighbor to identify the offending device
B. Politely inform your neighbor about the rules that require him to stop using the device if it causes interference
C. Check your station and make sure it meets the standards of good amateur practice
D. All of these answers are correct
~~
9. T5D10
What could be happening if another operator tells you he is
hearing a variable high-pitched whine on the signals from your mobile transmitter?
A. Your microphone is picking up noise from an open window
B. You have the volume on your receiver set too high
C. You need to adjust your squelch control
D. The power wiring for your radio is picking up noise from the vehicle's electrical system
~~
10. T5D11
What may be the problem if another operator reports that your SSB signal is very garbled and breaks up?
A. You have the noise limiter turned on
B. The transmitter is too hot and needs to cool off
C. RF energy may be getting into the microphone circuit and
causing feedback
D. You are operating on lower sideband
~~
11. T5D12
What might be the problem if you receive a report that your signal through the repeater is distorted or weak?
A. Your transmitter may be slightly off frequency
B. Your batteries may be running low
C. You could be in a bad location
D. All of these answers are correct
~~
12. T5D13
What is one of the reasons to use digital signals instead of analog signals to communicate with another station?
A. Digital systems are less expensive than analog systems
B. Many digital systems can automatically correct errors caused by noise and interference
C. Digital modulation circuits are much less complicated than any other types
D. All digital signals allow higher transmit power levels
~~
Answers: C B B C A D C D D C D B
and overdrive, distortion, over and under modulation, RF feedback,
off frequency signals, fading and noise, problems with digital
communications links
Most modern radio receivers are composed of at least one RF (radio frequency) amplifier a mixer which changes the frequency from the selected input frequency to a new frequency called the IF (interment frequency). If the RF or Mixer is saturated with a very strong signal even though the receiver is not tuned to that frequency it can cause that stage to not function properly. Interference caused by a very strong signal from a nearby source is known as front-end overload or fundamental overload.
Interference can also be caused by spurious emission (frequencies other then the fundamental frequency generated by the transmitter) and harmonics (multiples of the transmitter’s fundamental frequency).
When a transmitter and receiver are moving towards each other by the movement of either one or both the wave length will appear to the receiver to be shorter. If they are moving apart the wave length will appear longer and the greater the velocity the greater the effect. A longer wave length appears as a lower frequency and visa versa but the closing velocity or the separating velocity would have to be extremely high to cause sufficient frequency change to cause interference. The effect that causes this to happen is known as the Doppler Effect.
Strong RF signals can also be picked up by a telephone line acting like an antenna. The telephone may act like a radio receiver and thus the strong RF signal interferes with the phone’s operation. The telephone must have an RF filter to prevent this type of interference.
If a neighbor reports amateur transmissions are interfering with their radio or television the station owner should check to see that the transmitter is operating properly and that it does not interfere with the station owner’s TV set. The transmitter needs a good grounding system to avoid interference so that too should be checked. It is the station owner’s responsibility to Check the station and make sure it meets the standards of good amateur practice.
Some of the things that can be done to reduce or eliminate interference are use snap-on ferrite chokes on power cords and other non-antenna cords of both the transmitter and device being interfered with and/or use RF filters which include Low-pass, High-pass, Notch, and Band-pass filters.
The FCC allows very low power transmitting devices on the AM and FM broadcast bands under Part 15 of the FCC rules and regulations. If these devices are causing interference with an amateur radio stations the amateur radio operator should first check to make sure his station meets the standards of good amateur practice. If the station checks ok then working with the neighbor to identify the offending device would be the second step to take and if the problem persists politely inform the neighbor about the rules that require him to stop using the device if it causes interference.
Sometimes a mobile amateur station will have a whine or high pitch sound included in its transmission. This tone will raise and lower according to the speed of the vehicle’s engine. This is caused by the ham station picking up the noise from the vehicle’s electrical system, more specifically from the alternator. This can usually be salved by tapping the radio’s plus voltage directly from the vehicle’s battery. If this does not cure the problem a filter in the power line may be necessary.
As was mentioned earlier a transmitter needs a good ground system. But not only the transmitter but all components of the station should be grounded. One common problem of a poor ground on the transmitter is RF getting into the microphone which can cause a SSB transmission to sound garbled or break up.
A week or distorted signal being reported when a station is using a repeater could be caused by a bad location. This can also be caused if the transmitter is slightly off frequency or if the batteries are running low.
Digital signals are used by some hams instead of an analogue signal because many digital systems can automatically correct errors caused by noise and interference.
1. T5D01
What is meant by fundamental overload in reference to a receiver?
A. Too much voltage from the power supply
B. Too much current from the power supply
C. Interference caused by very strong signals from a nearby source
D. Interference caused by turning the volume up too high
~~
2. T5D02
Which of the following is NOT a cause of radio frequency
interference?
A. Fundamental overload
B. Doppler shift
C. Spurious emissions
D. Harmonics
~~
3. T5D03
What is the most likely cause of telephone interference from a nearby transmitter?
A. Harmonics from the transmitter
B. The transmitter's signals are causing the telephone to act like a radio receiver
C. Poor station grounding
D. Improper transmitter adjustment
~~
4. T5D04
What is a logical first step when attempting to cure a radio frequency interference problem in a nearby telephone?
A. Install a low-pass filter at the transmitter
B. Install a high-pass filter at the transmitter
C. Install an RF filter at the telephone
D. Improve station grounding
~~
5. T5D05
What should you do first if someone tells you that your
transmissions are interfering with their TV reception?
A. Make sure that your station is operating properly and that it does not cause interference to your own television
B. Immediately turn off your transmitter and contact the nearest FCC office for assistance
C. Tell them that your license gives you the right to transmit and nothing can be done to reduce the interference
D. Continue operating normally because your equipment cannot possibly cause any interference
~~
6. T5D07
Which of the following may be useful in correcting a radio
frequency interference problem?
A. Snap-on ferrite chokes
B. Low-pass and high-pass filters
C. Notch and band-pass filters
D. All of these answers are correct
~~
7. T5D08
What is the proper course of action to take when a neighbor
reports that your radio signals are interfering with something in his home?
A. You are not required to do anything
B. Contact the FCC to see if other interference reports have been filed
C. Check your station and make sure it meets the standards of good amateur practice
D. Change your antenna polarization from vertical to horizontal
~~
8. T5D09
What should you do if a "Part 15" device in your neighbor’s home is causing harmful interference to your amateur station?
A. Work with your neighbor to identify the offending device
B. Politely inform your neighbor about the rules that require him to stop using the device if it causes interference
C. Check your station and make sure it meets the standards of good amateur practice
D. All of these answers are correct
~~
9. T5D10
What could be happening if another operator tells you he is
hearing a variable high-pitched whine on the signals from your mobile transmitter?
A. Your microphone is picking up noise from an open window
B. You have the volume on your receiver set too high
C. You need to adjust your squelch control
D. The power wiring for your radio is picking up noise from the vehicle's electrical system
~~
10. T5D11
What may be the problem if another operator reports that your SSB signal is very garbled and breaks up?
A. You have the noise limiter turned on
B. The transmitter is too hot and needs to cool off
C. RF energy may be getting into the microphone circuit and
causing feedback
D. You are operating on lower sideband
~~
11. T5D12
What might be the problem if you receive a report that your signal through the repeater is distorted or weak?
A. Your transmitter may be slightly off frequency
B. Your batteries may be running low
C. You could be in a bad location
D. All of these answers are correct
~~
12. T5D13
What is one of the reasons to use digital signals instead of analog signals to communicate with another station?
A. Digital systems are less expensive than analog systems
B. Many digital systems can automatically correct errors caused by noise and interference
C. Digital modulation circuits are much less complicated than any other types
D. All digital signals allow higher transmit power levels
~~
Answers: C B B C A D C D D C D B
Sunday, September 16, 2007
LESSON 22
Modulation modes, descriptions and bandwidth (AM, FM, SSB) –
For this lesson I recommend restudying the notes at the bottom of lessons 12 and 13 which deal with modulation.
An amplitude modulated carrier will normally contain a carrier frequency and two sidebands. If the carrier and one of the side bands is removed the result will be known as Single Sideband transmission or SSB. It is still a form of Amplitude Modulation (AM).
Voice transmissions by radio (phone transmissions) can increase their effective range by using SSB. Upper Sideband is normally used on all ham bands above 40 meters while Lower Sideband is the most common mode used on 40 meters and below. Because VHF and UHF bands are above 40 meter USB is normally used.
While SSB is the most common mode used for voice communications where long distance or weak signal communications are being worked on VHF and UHF FM is the most common form of modulation for repeater use. One of the major advantages of SSB over FM is a narrower band width. SSB has a bandwidth of 3 to 6 KHz while band width of FM used on the amateur bands is between 5 and 15 KHz. CW has a bandwidth much narrower then any voice communications while Television has the greatest band width. Amateur TV uses a 6 MHz band width on the 70 Centimeter band.
One of the newest additions to amateur radio operations are the gateway sites. These are amateur radio stations that use the internet to contact other amateur radio stations.
T6A01 (C)
What are phone transmissions?
A. The use of telephones to set up an amateur radio contact
B. A phone patch between amateur radio and the telephone system
C. Voice transmissions by radio
D. Placing the telephone handset near a radio transceiver's
microphone and speaker to relay a telephone call
~~
T6A02 (C)
Which of the following is a form of amplitude modulation?
A. Frequency modulation
B. Phase modulation
C. Single sideband
D. Phase shift keying
~~
T6A03 (A)
What name is given to an amateur radio station that is used to connect other amateur stations to the Internet?
A. A gateway
B. A repeater
C. A digipeater
D. A beacon station
~~
T6A04 (C)
Which type of voice modulation is most often used for long
distance and weak signal contacts on the VHF and UHF bands?
A. FM
B. AM
C. SSB
D. PM
~~
T6A05 (D)
Which type of modulation is most commonly used for VHF and UHF voice repeaters?
A. AM
B. SSB
C. PSK
D. FM
~~
T6A06 (C)
Which emission type has the narrowest bandwidth?
A. FM voice
B. SSB voice
C. CW
D. Slow-scan TV
~~
T6A07 (A)
Which sideband is normally used for VHF and UHF SSB
communications?
A. Upper sideband
B. Lower sideband
C. Suppressed sideband
D. Inverted sideband
~~
T6A08 (C)
What is the primary advantage of single sideband over FM for voice transmissions?
A. SSB signals are easier to tune in than FM signals
B. SSB signals are less likely to be bothered by noise
interference than FM signals.
C. SSB signals use much less bandwidth than FM signals
D. SSB signals have no advantages at all in comparison to other modes.
~~
T6A09 (D)
What is the approximate bandwidth of a single-sideband voice signal?
A. 1 kHz
B. 2 kHz
C. Between 3 and 6 kHz
D. Between 2 and 3 kHz
~~
T6A10 (C)
What is the approximate bandwidth of a frequency-modulated voice signal?
A. Less than 500 Hz
B. About 150 kHz
C. Between 5 and 15 kHz
D. More than 30 kHz
~~
T6A11 (B)
What is the normal bandwidth required for a conventional fast-scan TV transmission using combined video and audio on the 70-centimeter band?
A. More than 10 MHz
B. About 6 MHz
C. About 3 MHz
D. About 1 MHz
~~
Answers: C C A C D C A C D C B
For this lesson I recommend restudying the notes at the bottom of lessons 12 and 13 which deal with modulation.
An amplitude modulated carrier will normally contain a carrier frequency and two sidebands. If the carrier and one of the side bands is removed the result will be known as Single Sideband transmission or SSB. It is still a form of Amplitude Modulation (AM).
Voice transmissions by radio (phone transmissions) can increase their effective range by using SSB. Upper Sideband is normally used on all ham bands above 40 meters while Lower Sideband is the most common mode used on 40 meters and below. Because VHF and UHF bands are above 40 meter USB is normally used.
While SSB is the most common mode used for voice communications where long distance or weak signal communications are being worked on VHF and UHF FM is the most common form of modulation for repeater use. One of the major advantages of SSB over FM is a narrower band width. SSB has a bandwidth of 3 to 6 KHz while band width of FM used on the amateur bands is between 5 and 15 KHz. CW has a bandwidth much narrower then any voice communications while Television has the greatest band width. Amateur TV uses a 6 MHz band width on the 70 Centimeter band.
One of the newest additions to amateur radio operations are the gateway sites. These are amateur radio stations that use the internet to contact other amateur radio stations.
T6A01 (C)
What are phone transmissions?
A. The use of telephones to set up an amateur radio contact
B. A phone patch between amateur radio and the telephone system
C. Voice transmissions by radio
D. Placing the telephone handset near a radio transceiver's
microphone and speaker to relay a telephone call
~~
T6A02 (C)
Which of the following is a form of amplitude modulation?
A. Frequency modulation
B. Phase modulation
C. Single sideband
D. Phase shift keying
~~
T6A03 (A)
What name is given to an amateur radio station that is used to connect other amateur stations to the Internet?
A. A gateway
B. A repeater
C. A digipeater
D. A beacon station
~~
T6A04 (C)
Which type of voice modulation is most often used for long
distance and weak signal contacts on the VHF and UHF bands?
A. FM
B. AM
C. SSB
D. PM
~~
T6A05 (D)
Which type of modulation is most commonly used for VHF and UHF voice repeaters?
A. AM
B. SSB
C. PSK
D. FM
~~
T6A06 (C)
Which emission type has the narrowest bandwidth?
A. FM voice
B. SSB voice
C. CW
D. Slow-scan TV
~~
T6A07 (A)
Which sideband is normally used for VHF and UHF SSB
communications?
A. Upper sideband
B. Lower sideband
C. Suppressed sideband
D. Inverted sideband
~~
T6A08 (C)
What is the primary advantage of single sideband over FM for voice transmissions?
A. SSB signals are easier to tune in than FM signals
B. SSB signals are less likely to be bothered by noise
interference than FM signals.
C. SSB signals use much less bandwidth than FM signals
D. SSB signals have no advantages at all in comparison to other modes.
~~
T6A09 (D)
What is the approximate bandwidth of a single-sideband voice signal?
A. 1 kHz
B. 2 kHz
C. Between 3 and 6 kHz
D. Between 2 and 3 kHz
~~
T6A10 (C)
What is the approximate bandwidth of a frequency-modulated voice signal?
A. Less than 500 Hz
B. About 150 kHz
C. Between 5 and 15 kHz
D. More than 30 kHz
~~
T6A11 (B)
What is the normal bandwidth required for a conventional fast-scan TV transmission using combined video and audio on the 70-centimeter band?
A. More than 10 MHz
B. About 6 MHz
C. About 3 MHz
D. About 1 MHz
~~
Answers: C C A C D C A C D C B
LESSON 23
Voice communications, EchoLink and IRLP
Voice over Internet protocol(VoIP) is used for two types of amateur radio related operations, these are Echolink and Internet Radio Linking Project abbreviated IRLP.
Echolink is a Microsoft Windows computer program which allows, for at least part of the communication path, amateur radio operators to communicate with each other via the internet VoIP. An amateur radio license is the only requirement to use the Echolink system.
IRLP uses a worldwide network of dedicated servers and nodes to provide an inexpensive yet reliable way to link amateur radio systems using ViIP and the internet without the use of RF links, leased lines, or satellites. It will allow a simplex station or repeater site to link with other similar sites or to be accessed via computer around the world. Simply put IRLP is a method of linking two or more amateur radio stations together using the internet.
T6B01 (C)
How is information transmitted between stations using Echolink?
A. APRS
B. PSK31
C. Internet
D. Atmospheric ducting
~~
T6B02 (A)
What does the abbreviation IRLP mean?
A. Internet Radio Linking Project
B. Internet Relay Language Protocol
C. International Repeater Linking Project
D. International Radio Linking Project
~~
T6B03 (B)
Who may operate on the Echolink system?
A. Only club stations
B. Any licensed amateur radio operator
C. Technician class licensed amateur radio operators only
D. Any person, licensed or not, who is registered with the
Echolink system
~~
T6B04 (A)
What technology do Echolink and IRLP have in common?
A. Voice over Internet protocol
B. Ionospheric propagation
C. AC power lines
D. PSK31
~~
T6B05 (C)
What method is used to transfer data by IRLP?
A. VHF Packet radio
B. PSK31
C. Voice over Internet protocol
D. None of these answers are correct
~~
T6B06 (B)
What does the term IRLP describe?
A. A method of encrypting data
B. A method of linking between two or more amateur stations using the Internet
C. A low powered radio using infra-red frequencies
D. An international logging program.
~~
T6B07 (B)
Which one of the following allows computer-to-radio linking for voice transmission?
A. Grid modulation
B. EchoLink
C. AMTOR
D. Multiplex
~~
T6B08 (C)
What are you listening to if you hear a brief tone and then a station from Russia calling CQ on a 2-meter repeater?
A. An ionospheric band opening on VHF
B. A prohibited transmission
C. An Internet linked DX station
D. None of these answers are correct
~~
T6B10 (C)
Where might you find a list of active nodes using VoIP?
A. The FCC Rulebook
B. From your local emergency coordinator
C. A repeater directory or the Internet
D. The local repeater frequency coordinator
~~
T6B11 (D)
When using a portable transceiver how do you select a specific IRLP node?
A. Choose a specific CTCSS tone
B. Choose the correct DSC tone
C. Access the repeater autopatch
D. Use the keypad to transmit the IRLP node numbers
~~
RESEARCH
ECHOLINK
Echolink is a computer program that runs under Microsoft Windows to allow radio amateurs to communicate with one another using Voice over IP (VoIP) technology on the internet for at least part of the path between them. It was designed by Jonathan Taylor, a radio amateur with callsign K1RFD.
The program allows reliable worldwide connections to be made between radio amateurs, greatly enhancing Amateur Radio's communications capabilities. In essence it is the same as other VoIP applications (such as Skype), but with the unique addition of the ability to link to an amateur radio station's transceiver.
Before using the system it is necessary for a prospective user's callsign to be validated.
Radio amateurs using the Echolink software can operate it in one of two modes:
• Single User Mode. If they have an internet-connected computer, they can use the computer's microphone and speakers to connect to (or through - see below) other Echolink-enabled computers over the internet and talk to the amateur at the other end.
• Sysop Mode. This entails connecting their own VHF or UHF transceiver to their internet-connected PC with a specially-designed hardware interface. Doing this enables another radio amateur with their own transceiver, who is within radio range of this station, to communicate with (or through) any other Echolink-equipped station anywhere in the world. This is the unique feature of Echolink.
Radio amateurs without the Echolink software or a computer connected to the internet can take advantage of the Echolink network if they are within radio range of a sysop mode Echolink station. It is also possible to link a sysop mode Echolink station to a local repeater, further enhancing the communication possibilities.
Internet Radio Linking Project
The aim of this project is to reliably and inexpensively link amateur radio systems without the use of RF links, leased lines, or satellites.
The IRLP uses Voice-Over-IP (VoIP) custom software and hardware. Coupled with the power of the Internet, IRLP will link your repeater site or simplex station to the world in a simple and cost effective way.
IRLP operates a worldwide network of dedicated servers and nodes offering very stable worldwide voice communications between hundreds of towns and cities. All this with unsurpassed uptimes and the full dynamic range of telephone quality audio.
Voice over Internet protocol(VoIP) is used for two types of amateur radio related operations, these are Echolink and Internet Radio Linking Project abbreviated IRLP.
Echolink is a Microsoft Windows computer program which allows, for at least part of the communication path, amateur radio operators to communicate with each other via the internet VoIP. An amateur radio license is the only requirement to use the Echolink system.
IRLP uses a worldwide network of dedicated servers and nodes to provide an inexpensive yet reliable way to link amateur radio systems using ViIP and the internet without the use of RF links, leased lines, or satellites. It will allow a simplex station or repeater site to link with other similar sites or to be accessed via computer around the world. Simply put IRLP is a method of linking two or more amateur radio stations together using the internet.
T6B01 (C)
How is information transmitted between stations using Echolink?
A. APRS
B. PSK31
C. Internet
D. Atmospheric ducting
~~
T6B02 (A)
What does the abbreviation IRLP mean?
A. Internet Radio Linking Project
B. Internet Relay Language Protocol
C. International Repeater Linking Project
D. International Radio Linking Project
~~
T6B03 (B)
Who may operate on the Echolink system?
A. Only club stations
B. Any licensed amateur radio operator
C. Technician class licensed amateur radio operators only
D. Any person, licensed or not, who is registered with the
Echolink system
~~
T6B04 (A)
What technology do Echolink and IRLP have in common?
A. Voice over Internet protocol
B. Ionospheric propagation
C. AC power lines
D. PSK31
~~
T6B05 (C)
What method is used to transfer data by IRLP?
A. VHF Packet radio
B. PSK31
C. Voice over Internet protocol
D. None of these answers are correct
~~
T6B06 (B)
What does the term IRLP describe?
A. A method of encrypting data
B. A method of linking between two or more amateur stations using the Internet
C. A low powered radio using infra-red frequencies
D. An international logging program.
~~
T6B07 (B)
Which one of the following allows computer-to-radio linking for voice transmission?
A. Grid modulation
B. EchoLink
C. AMTOR
D. Multiplex
~~
T6B08 (C)
What are you listening to if you hear a brief tone and then a station from Russia calling CQ on a 2-meter repeater?
A. An ionospheric band opening on VHF
B. A prohibited transmission
C. An Internet linked DX station
D. None of these answers are correct
~~
T6B10 (C)
Where might you find a list of active nodes using VoIP?
A. The FCC Rulebook
B. From your local emergency coordinator
C. A repeater directory or the Internet
D. The local repeater frequency coordinator
~~
T6B11 (D)
When using a portable transceiver how do you select a specific IRLP node?
A. Choose a specific CTCSS tone
B. Choose the correct DSC tone
C. Access the repeater autopatch
D. Use the keypad to transmit the IRLP node numbers
~~
RESEARCH
ECHOLINK
Echolink is a computer program that runs under Microsoft Windows to allow radio amateurs to communicate with one another using Voice over IP (VoIP) technology on the internet for at least part of the path between them. It was designed by Jonathan Taylor, a radio amateur with callsign K1RFD.
The program allows reliable worldwide connections to be made between radio amateurs, greatly enhancing Amateur Radio's communications capabilities. In essence it is the same as other VoIP applications (such as Skype), but with the unique addition of the ability to link to an amateur radio station's transceiver.
Before using the system it is necessary for a prospective user's callsign to be validated.
Radio amateurs using the Echolink software can operate it in one of two modes:
• Single User Mode. If they have an internet-connected computer, they can use the computer's microphone and speakers to connect to (or through - see below) other Echolink-enabled computers over the internet and talk to the amateur at the other end.
• Sysop Mode. This entails connecting their own VHF or UHF transceiver to their internet-connected PC with a specially-designed hardware interface. Doing this enables another radio amateur with their own transceiver, who is within radio range of this station, to communicate with (or through) any other Echolink-equipped station anywhere in the world. This is the unique feature of Echolink.
Radio amateurs without the Echolink software or a computer connected to the internet can take advantage of the Echolink network if they are within radio range of a sysop mode Echolink station. It is also possible to link a sysop mode Echolink station to a local repeater, further enhancing the communication possibilities.
Internet Radio Linking Project
The aim of this project is to reliably and inexpensively link amateur radio systems without the use of RF links, leased lines, or satellites.
The IRLP uses Voice-Over-IP (VoIP) custom software and hardware. Coupled with the power of the Internet, IRLP will link your repeater site or simplex station to the world in a simple and cost effective way.
IRLP operates a worldwide network of dedicated servers and nodes offering very stable worldwide voice communications between hundreds of towns and cities. All this with unsurpassed uptimes and the full dynamic range of telephone quality audio.
LESSON 24
Non-voice communications - image communications, data, CW,
packet, PSK31, Morse code techniques, Q signals
In the beginning of radio communications was Morse code. Morse code was first established for wire communications but Marconi found a way to use it in a wireless mode. A message is sent by Morse code by sending a series of impulses which expressed as either on or off thus it is a form of digital communications.
As time passed voice was added to radio communications. First Amplitude Modulation (AM) was used to impose voice on the radio frequency signal then Frequency Modulation (FM) became another technique of adding information to the electromagnetic spectrum. There is another form of modulation called Phase Modulation (PM) which, as far as the technical knowledge for the technician class license is concerned, is just a form of FM. (If you shift the frequency you shift the phase and if you shift the phase you shift the frequency and if you don’t have the slightest idea what I am talking about don’t worry about it because you don’t need to understand yet.)
So for all practical purposes it could be said there are three forms of placing intelligence on a radio signal. They are digital, AM, and FM. Sometimes a transmission may be a combination of these. Television is one example because the voice is normally FM while the video is AM. Single Sideband is a form of Amplitude Modulation.
As computers became more common in our homes it was natural that this technology would be used by some hams in association with their amateur radio activities. Computers can communicate with each other using digital communicating codes and hams found that they could link their computers together on the ham radio. A system was developed where messages could be passed from one ham station to another in a manor similar to teletype but by using groups called packets which could be sent to the receiving station and then sent back to the transmitting station to assure accuracy. This system of digital communications became known as Packet Radio.
T6C01 (D)
Which of the following is an example of a digital communications method?
A. Single sideband voice
B. Amateur television
C. FM voice
D. Packet radio
~~
T6C02 (A)
What does the term APRS mean?
A. Automatic Position Reporting System
B. Associated Public Radio Station
C. Auto Planning Radio Set-up
D. Advanced Polar Radio System
~~
T6C03 (D)
What item is required along with your normal radio for sending automatic location reports?
A. A connection to the vehicle speedometer
B. A connection to a WWV receiver
C. A connection to a broadcast FM sub-carrier receiver
D. A global positioning system receiver
~~
T6C04 (C)
What type of transmission is indicated by the term NTSC?
A. A Normal Transmission mode in Static Circuit
B. A special mode for earth satellite uplink
C. A standard fast scan color television signal
D. A frame compression scheme for TV signal
~~
T6C05 (B)
What emission mode may be used by a Technician class operator in the 219 - 220 MHz frequency range?
A. Slow-scan television
B. Point-to-point digital message forwarding
C. FM voice
D. Fast-scan television
~~
T6C06 (B)
What does the abbreviation PSK mean?
A. Pulse Shift Keying
B. Phase Shift Keying
C. Packet Short Keying
D. Phased Slide Keying
~~
T6C07 (D)
What is PSK31?
A. A high-rate data transmission mode used to transmit files
B. A method of reducing noise interference to FM signals
C. A type of television signal
D. A low-rate data transmission mode that works well in noisy conditions
~~
T6C08 (C)
What sending speed is recommended when using Morse code?
A. Only speeds below five WPM
B. The highest speed your keyer will operate
C. Any speed at which you can reliably receive
D. The highest speed at which you can control the keyer
~~
T6C09 (D)
What is a practical reason for being able to copy CW when using repeaters?
A. To send and receive messages others cannot overhear
B. To conform with FCC licensing requirements
C. To decode packet radio transmissions
D. To recognize a repeater ID sent in Morse code
~~
T6C10 (A)
What is the "Q" signal used to indicate that you are receiving interference from other stations?
A. QRM
B. QRN
C. QTH
D. QSB
~~
T6C11 (B)
What is the "Q" signal used to indicate that you are changing frequency?
A. QRU
B. QSY
C. QSL
D. QRZ
Answers: D A D C B B D C D A B~~
packet, PSK31, Morse code techniques, Q signals
In the beginning of radio communications was Morse code. Morse code was first established for wire communications but Marconi found a way to use it in a wireless mode. A message is sent by Morse code by sending a series of impulses which expressed as either on or off thus it is a form of digital communications.
As time passed voice was added to radio communications. First Amplitude Modulation (AM) was used to impose voice on the radio frequency signal then Frequency Modulation (FM) became another technique of adding information to the electromagnetic spectrum. There is another form of modulation called Phase Modulation (PM) which, as far as the technical knowledge for the technician class license is concerned, is just a form of FM. (If you shift the frequency you shift the phase and if you shift the phase you shift the frequency and if you don’t have the slightest idea what I am talking about don’t worry about it because you don’t need to understand yet.)
So for all practical purposes it could be said there are three forms of placing intelligence on a radio signal. They are digital, AM, and FM. Sometimes a transmission may be a combination of these. Television is one example because the voice is normally FM while the video is AM. Single Sideband is a form of Amplitude Modulation.
As computers became more common in our homes it was natural that this technology would be used by some hams in association with their amateur radio activities. Computers can communicate with each other using digital communicating codes and hams found that they could link their computers together on the ham radio. A system was developed where messages could be passed from one ham station to another in a manor similar to teletype but by using groups called packets which could be sent to the receiving station and then sent back to the transmitting station to assure accuracy. This system of digital communications became known as Packet Radio.
T6C01 (D)
Which of the following is an example of a digital communications method?
A. Single sideband voice
B. Amateur television
C. FM voice
D. Packet radio
~~
T6C02 (A)
What does the term APRS mean?
A. Automatic Position Reporting System
B. Associated Public Radio Station
C. Auto Planning Radio Set-up
D. Advanced Polar Radio System
~~
T6C03 (D)
What item is required along with your normal radio for sending automatic location reports?
A. A connection to the vehicle speedometer
B. A connection to a WWV receiver
C. A connection to a broadcast FM sub-carrier receiver
D. A global positioning system receiver
~~
T6C04 (C)
What type of transmission is indicated by the term NTSC?
A. A Normal Transmission mode in Static Circuit
B. A special mode for earth satellite uplink
C. A standard fast scan color television signal
D. A frame compression scheme for TV signal
~~
T6C05 (B)
What emission mode may be used by a Technician class operator in the 219 - 220 MHz frequency range?
A. Slow-scan television
B. Point-to-point digital message forwarding
C. FM voice
D. Fast-scan television
~~
T6C06 (B)
What does the abbreviation PSK mean?
A. Pulse Shift Keying
B. Phase Shift Keying
C. Packet Short Keying
D. Phased Slide Keying
~~
T6C07 (D)
What is PSK31?
A. A high-rate data transmission mode used to transmit files
B. A method of reducing noise interference to FM signals
C. A type of television signal
D. A low-rate data transmission mode that works well in noisy conditions
~~
T6C08 (C)
What sending speed is recommended when using Morse code?
A. Only speeds below five WPM
B. The highest speed your keyer will operate
C. Any speed at which you can reliably receive
D. The highest speed at which you can control the keyer
~~
T6C09 (D)
What is a practical reason for being able to copy CW when using repeaters?
A. To send and receive messages others cannot overhear
B. To conform with FCC licensing requirements
C. To decode packet radio transmissions
D. To recognize a repeater ID sent in Morse code
~~
T6C10 (A)
What is the "Q" signal used to indicate that you are receiving interference from other stations?
A. QRM
B. QRN
C. QTH
D. QSB
~~
T6C11 (B)
What is the "Q" signal used to indicate that you are changing frequency?
A. QRU
B. QSY
C. QSL
D. QRZ
Answers: D A D C B B D C D A B~~
Saturday, September 15, 2007
LESSON 25
Operating in the field, radio direction finding, radio
control, contests, special event stationsHam radio is something a person can do on a rainy Sunday afternoon while relaxing in the comfort of his shack or it can be a very active in the field type of activity.
Many hams like to participate in contest like field day or CQ DX contest where points are earned by contacting other stations. The idea of a contest is to contact as many stations as possible during a specified period of time.
There are also times in which an amateur radio operator may be participating in an emergency operation. These operations, when in the field, usually involve low power portable, mobile, or handheld units. A 1500 watt linear amplifier would probably not be very useful to include in an emergency response kit. The station power source is a very important consideration and in the case of a handheld unit it is a good idea to carry one or two fully charged spare battery packs. Also when using a handheld unit a flexible antenna usually referred to as a “Rubber Duck” which inherently is very inefficient; so if the signal strength of a handheld unit is needed to be increased an external antenna is one way of effectively doing this.
Community events like parades, races, bike rides, etc are frequently assisted by ham radio operators. There will frequently be a lot of noise at such events so a combination headset and microphone can be a very useful device to include with your station equipment. . If that community activity has a very special significance a Special Events station may be operated.
A Special Events Station is a temporary licensed station that operates in conjunction with an activity of special significance.
“Fox Hunts” where a transmitting station (the fox) hides and other stations try to find him. It is not only fun but a very useful way to hone the skills and equipment of hams in an area to find interfering stations that might be operating in their area by a process known as “Radio Direction Finding”. This is normally done by attaching a directional antenna to the receiver being used to search for the hidden unit.
Radio controlled boats, airplanes, or cars are enjoyed by many not hams but only licensed ham radio can legally use amateur frequencies to enhance this hobby. Hams are allowed to use up to 1 Watt of transmitting power. The only identification required is the transmitter must have a label indicating the licensee’s call sign and address on it.
Normally when two ham radio operators establish contact with each other for the first time they each tell the other where they are located. How precise those locations are can very but usually include city and state or province. A grid locator, which is a letter-number designator assigned to a geographical location, has recently joined the ranks of revealing the location of an amateur station.
What is a grid locator?
A. A letter-number designator assigned to a geographic location
1. T7A01
What is a good thing to have when operating a hand-held
transceiver away from home?
A. A selection of spare parts
B. A programming cable to load new channels
C. One or more fully charged spare battery packs
D. A dummy load
~~
2. T7A02
Which of these items would probably not be very useful to include in an emergency response kit?
A. An external antenna and several feet of connecting cable
B. A 1500 watt output linear amplifier
C. A cable and clips for connecting your transceiver to an
external battery
D. A listing of repeater frequencies and nets in your area
~~
3. T7A03
How can you make the signal from a hand-held radio stronger when operating in the field?
A. Switch to VFO mode
B. Use an external antenna instead of the rubber-duck antenna
C. Stand so there is a metal building between you and other
stations
D. Speak as loudly as you can
~~
4. T7A04
What would be a good thing to have when operating from a location that includes lots of crowd noise?
A. A portable bullhorn
B. An encrypted radio
C. A combination headset and microphone
D. A pulse noise blanker
~~
5. T7A05
What is a method used to locate sources of noise interference or jamming?
A. Echolocation
B. Doppler radar
C. Radio direction finding
D. Phase locking
~~
6. T7A06
Which of these items would be the most useful for a hidden
transmitter hunt?
A. Binoculars and a compass
B. A directional antenna
C. A calibrated noise bridge
D. Calibrated SWR meter
~~
7. T7A07
What is a popular operating activity that involves contacting as many stations as possible during a specified period of time?
A. Contesting
B. Net operations
C. Public service events
D. Simulated emergency exercises
~~
8. T7A09
What is a grid locator?
A. A letter-number designator assigned to a geographic location
B. Your azimuth and elevation
C. Your UTC location
D. The 4 digits that follow your ZIP code
~~
9. T7A10
What is a special event station?
A. A station that sends out birthday greetings
B. A station that operates only on holidays
C. A temporary station that operates in conjunction with an
activity of special significance
D. A station that broadcasts special events
~~
10. T7A11 [97.215(c)]
What is the maximum power allowed when transmitting telecommand signals to radio controlled models?
A. 500 milliwatts
B. 1 watt
C. 25 watts
D. 1500 watts
~~
11. T7A12 [97.215(a)]
What is the station identification requirement when sending
commands to a radio control model using amateur requencies?
A. Voice identification must be transmitted every 10 minutes
B. Morse code ID must be sent once per hour
C. A label indicating the licensee's call sign and address must be affixed to the transmitter
D. There is no station identification requirement for this service
(Note: T7A08 is no longer in the question pool.)
Answers: C B B C C B A A C B C
control, contests, special event stationsHam radio is something a person can do on a rainy Sunday afternoon while relaxing in the comfort of his shack or it can be a very active in the field type of activity.
Many hams like to participate in contest like field day or CQ DX contest where points are earned by contacting other stations. The idea of a contest is to contact as many stations as possible during a specified period of time.
There are also times in which an amateur radio operator may be participating in an emergency operation. These operations, when in the field, usually involve low power portable, mobile, or handheld units. A 1500 watt linear amplifier would probably not be very useful to include in an emergency response kit. The station power source is a very important consideration and in the case of a handheld unit it is a good idea to carry one or two fully charged spare battery packs. Also when using a handheld unit a flexible antenna usually referred to as a “Rubber Duck” which inherently is very inefficient; so if the signal strength of a handheld unit is needed to be increased an external antenna is one way of effectively doing this.
Community events like parades, races, bike rides, etc are frequently assisted by ham radio operators. There will frequently be a lot of noise at such events so a combination headset and microphone can be a very useful device to include with your station equipment. . If that community activity has a very special significance a Special Events station may be operated.
A Special Events Station is a temporary licensed station that operates in conjunction with an activity of special significance.
“Fox Hunts” where a transmitting station (the fox) hides and other stations try to find him. It is not only fun but a very useful way to hone the skills and equipment of hams in an area to find interfering stations that might be operating in their area by a process known as “Radio Direction Finding”. This is normally done by attaching a directional antenna to the receiver being used to search for the hidden unit.
Radio controlled boats, airplanes, or cars are enjoyed by many not hams but only licensed ham radio can legally use amateur frequencies to enhance this hobby. Hams are allowed to use up to 1 Watt of transmitting power. The only identification required is the transmitter must have a label indicating the licensee’s call sign and address on it.
Normally when two ham radio operators establish contact with each other for the first time they each tell the other where they are located. How precise those locations are can very but usually include city and state or province. A grid locator, which is a letter-number designator assigned to a geographical location, has recently joined the ranks of revealing the location of an amateur station.
What is a grid locator?
A. A letter-number designator assigned to a geographic location
1. T7A01
What is a good thing to have when operating a hand-held
transceiver away from home?
A. A selection of spare parts
B. A programming cable to load new channels
C. One or more fully charged spare battery packs
D. A dummy load
~~
2. T7A02
Which of these items would probably not be very useful to include in an emergency response kit?
A. An external antenna and several feet of connecting cable
B. A 1500 watt output linear amplifier
C. A cable and clips for connecting your transceiver to an
external battery
D. A listing of repeater frequencies and nets in your area
~~
3. T7A03
How can you make the signal from a hand-held radio stronger when operating in the field?
A. Switch to VFO mode
B. Use an external antenna instead of the rubber-duck antenna
C. Stand so there is a metal building between you and other
stations
D. Speak as loudly as you can
~~
4. T7A04
What would be a good thing to have when operating from a location that includes lots of crowd noise?
A. A portable bullhorn
B. An encrypted radio
C. A combination headset and microphone
D. A pulse noise blanker
~~
5. T7A05
What is a method used to locate sources of noise interference or jamming?
A. Echolocation
B. Doppler radar
C. Radio direction finding
D. Phase locking
~~
6. T7A06
Which of these items would be the most useful for a hidden
transmitter hunt?
A. Binoculars and a compass
B. A directional antenna
C. A calibrated noise bridge
D. Calibrated SWR meter
~~
7. T7A07
What is a popular operating activity that involves contacting as many stations as possible during a specified period of time?
A. Contesting
B. Net operations
C. Public service events
D. Simulated emergency exercises
~~
8. T7A09
What is a grid locator?
A. A letter-number designator assigned to a geographic location
B. Your azimuth and elevation
C. Your UTC location
D. The 4 digits that follow your ZIP code
~~
9. T7A10
What is a special event station?
A. A station that sends out birthday greetings
B. A station that operates only on holidays
C. A temporary station that operates in conjunction with an
activity of special significance
D. A station that broadcasts special events
~~
10. T7A11 [97.215(c)]
What is the maximum power allowed when transmitting telecommand signals to radio controlled models?
A. 500 milliwatts
B. 1 watt
C. 25 watts
D. 1500 watts
~~
11. T7A12 [97.215(a)]
What is the station identification requirement when sending
commands to a radio control model using amateur requencies?
A. Voice identification must be transmitted every 10 minutes
B. Morse code ID must be sent once per hour
C. A label indicating the licensee's call sign and address must be affixed to the transmitter
D. There is no station identification requirement for this service
(Note: T7A08 is no longer in the question pool.)
Answers: C B B C C B A A C B C
LESSON 26
Satellite operation, Doppler shift, satellite sub bands,
LEO, orbit calculation, split frequency operation, operating
protocols, AMSAT, ISS communications
Amateur radio operations provide many exciting opportunities. One area of operation provided by the amateur radio license is satellite communications. There are amateur radio satellites which allows any licensed amateur radio operator who can legally transmit on the satellite’s uplink frequency use the satellite to communicate with other amateurs even in other countries.
AMSAT is the organization which is responsible for organizing and launching most of the amateur radio satellites.
Satellite tracking programs are available to determine when a satellite will be available for use in a certain area. Some information about a satellite is contained in satellite’s beacon.
The portion of an amateur radio band where a satellite is allowed to operate is known as a “satellite sub band”. The 70 cm band is 30 MHz wide, 420 to 450 MHz, but the satellite sub band is only 3 MHz wide, 435 to 438 MHz.
A lot of power is not required to communicate via a satellite and the minimum amount of power required to complete a contact should be used. While the minimum amount of power necessary to communicate is true with all areas of amateur radio communications it is much more critical when using satellites.
The acronym LEO, when associated with an amateur radio satellite, means “low earth orbit”.
Satellite operations include CW and SSB which are very sensitive to frequency shift. As the satellite is moving towards the receiving station the frequency at the receiving site will appear higher then the actual transmitted frequency but after is passes by and is moving away from the receiver the frequency will appear lower then the actual transmitted frequency. This phenomena is known as “Doppler Shift” and while it may cause the need to adjust the receiver frequency the transmit frequency should not be changed.
Amateur radio operators stationed on the International Space Station will sometimes use the amateur radio frequencies to communicate with hams on earth. Any amateur operator with a technician license or higher is allowed to communicate with these hams.
1. T7B01 (D)
What class of license is required to use amateur satellites?
A. Only Extra class licensees can use amateur radio satellites
B. General or higher class licensees who have a satellite operator certification
C. Only persons who are AMSAT members and who have paid their dues
D. Any amateur whose license allows them to transmit on the
satellite uplink frequency
~~
2. T7B02 (B)
How much power should you use to transmit when using an amateur satellite?
A. The maximum power of your transmitter
B. The minimum amount of power needed to complete the contact
C. No more than half the rating of your linear amplifier
D. Never more than 1 watt
~~
3. T7B03 (D)
What is something you can do when using an amateur radio
satellite?
A. Listen to the Space Shuttle
B. Get global positioning information
C. Make autopatch calls
D. Talk to amateur radio operators in other countries
~~
4. T7B04 (B)
Who may make contact with an astronaut on the International Space Station using amateur radio frequencies?
A. Only members of amateur radio clubs at NASA facilities
B. Any amateur with a Technician or higher class license
C. Only the astronaut's family members who are hams
D. You cannot talk to the ISS on amateur radio frequencies
~~
5. T7B05 (D)
What is a satellite beacon?
A. The primary transmit antenna on the satellite
B. An indicator light that that shows where to point your antenna
C. A reflective surface on the satellite
D. A signal that contains information about a satellite
~~
6. T7B06 (D)
What should you use to determine when you can access an amateur satellite?
A. A GPS receiver
B. A field strength meter
C. A telescope
D. A satellite tracking program
~~
7. T7B07 (C)
What is Doppler shift?
A. A change in the satellite orbit
B. A mode where the satellite receives signals on one band and transmits on another
C. A change in signal frequency caused by motion through space
D. A special digital communications mode for some satellites
~~
8. T7B08 (C)
What is the name of the group that coordinates the building and/or launch of the largest number of amateur radio satellites?
A. NSA
B. USOC
C. AMSAT
D. FCC
~~
9. T7B09 (C)
What is a satellite sub-band?
A. A special frequency for talking to submarines
B. A frequency range limited to Extra Class licensees
C. A portion of a band where satellite operations are permitted
D. An obsolete term that has no meaning
~~
10. T7B10 (B)
What is the satellite sub-band on 70-CM?
A. 420 to 450 MHz
B. 435 to 438 MHz
C. 440 to 450 MHz
D. 432 to 433 MHz
~~
11. T7B11 (C)
What do the initials LEO tell you about an amateur satellite?
A. The satellite battery is in Low Energy Operation mode
B. The satellite is performing a Lunar Ejection Orbit maneuver
C. The satellite is in a Low Earth Orbit
D. The satellite uses Light Emitting Optics
Answers: D B D B D D C C C B C
LEO, orbit calculation, split frequency operation, operating
protocols, AMSAT, ISS communications
Amateur radio operations provide many exciting opportunities. One area of operation provided by the amateur radio license is satellite communications. There are amateur radio satellites which allows any licensed amateur radio operator who can legally transmit on the satellite’s uplink frequency use the satellite to communicate with other amateurs even in other countries.
AMSAT is the organization which is responsible for organizing and launching most of the amateur radio satellites.
Satellite tracking programs are available to determine when a satellite will be available for use in a certain area. Some information about a satellite is contained in satellite’s beacon.
The portion of an amateur radio band where a satellite is allowed to operate is known as a “satellite sub band”. The 70 cm band is 30 MHz wide, 420 to 450 MHz, but the satellite sub band is only 3 MHz wide, 435 to 438 MHz.
A lot of power is not required to communicate via a satellite and the minimum amount of power required to complete a contact should be used. While the minimum amount of power necessary to communicate is true with all areas of amateur radio communications it is much more critical when using satellites.
The acronym LEO, when associated with an amateur radio satellite, means “low earth orbit”.
Satellite operations include CW and SSB which are very sensitive to frequency shift. As the satellite is moving towards the receiving station the frequency at the receiving site will appear higher then the actual transmitted frequency but after is passes by and is moving away from the receiver the frequency will appear lower then the actual transmitted frequency. This phenomena is known as “Doppler Shift” and while it may cause the need to adjust the receiver frequency the transmit frequency should not be changed.
Amateur radio operators stationed on the International Space Station will sometimes use the amateur radio frequencies to communicate with hams on earth. Any amateur operator with a technician license or higher is allowed to communicate with these hams.
1. T7B01 (D)
What class of license is required to use amateur satellites?
A. Only Extra class licensees can use amateur radio satellites
B. General or higher class licensees who have a satellite operator certification
C. Only persons who are AMSAT members and who have paid their dues
D. Any amateur whose license allows them to transmit on the
satellite uplink frequency
~~
2. T7B02 (B)
How much power should you use to transmit when using an amateur satellite?
A. The maximum power of your transmitter
B. The minimum amount of power needed to complete the contact
C. No more than half the rating of your linear amplifier
D. Never more than 1 watt
~~
3. T7B03 (D)
What is something you can do when using an amateur radio
satellite?
A. Listen to the Space Shuttle
B. Get global positioning information
C. Make autopatch calls
D. Talk to amateur radio operators in other countries
~~
4. T7B04 (B)
Who may make contact with an astronaut on the International Space Station using amateur radio frequencies?
A. Only members of amateur radio clubs at NASA facilities
B. Any amateur with a Technician or higher class license
C. Only the astronaut's family members who are hams
D. You cannot talk to the ISS on amateur radio frequencies
~~
5. T7B05 (D)
What is a satellite beacon?
A. The primary transmit antenna on the satellite
B. An indicator light that that shows where to point your antenna
C. A reflective surface on the satellite
D. A signal that contains information about a satellite
~~
6. T7B06 (D)
What should you use to determine when you can access an amateur satellite?
A. A GPS receiver
B. A field strength meter
C. A telescope
D. A satellite tracking program
~~
7. T7B07 (C)
What is Doppler shift?
A. A change in the satellite orbit
B. A mode where the satellite receives signals on one band and transmits on another
C. A change in signal frequency caused by motion through space
D. A special digital communications mode for some satellites
~~
8. T7B08 (C)
What is the name of the group that coordinates the building and/or launch of the largest number of amateur radio satellites?
A. NSA
B. USOC
C. AMSAT
D. FCC
~~
9. T7B09 (C)
What is a satellite sub-band?
A. A special frequency for talking to submarines
B. A frequency range limited to Extra Class licensees
C. A portion of a band where satellite operations are permitted
D. An obsolete term that has no meaning
~~
10. T7B10 (B)
What is the satellite sub-band on 70-CM?
A. 420 to 450 MHz
B. 435 to 438 MHz
C. 440 to 450 MHz
D. 432 to 433 MHz
~~
11. T7B11 (C)
What do the initials LEO tell you about an amateur satellite?
A. The satellite battery is in Low Energy Operation mode
B. The satellite is performing a Lunar Ejection Orbit maneuver
C. The satellite is in a Low Earth Orbit
D. The satellite uses Light Emitting Optics
Answers: D B D B D D C C C B C
Thursday, September 13, 2007
LESSON 27
FCC declarations of an emergency, use of non-amateur
equipment and frequencies, use of equipment by unlicensed persons,
tactical call signs
Amateur radio stations are normally not allowed to communicate directly with stations in other radio services. There are two exceptions. One is when the FCC authorizes such communications which may be part of a special events operation the other is during an actual emergency.
Sometimes while in contact with another amateur radio station an emergency call may be heard. This may be in the form of a Mayday or SOS or it may be a station requesting a break declaring it is an emergency. When an emergency call is heard first assume that the call is real; all other communications should cease and attention should be given to the station declaring the emergency.
It should be noted here that false distress signals are serious violations of the law and can result in legal actions of any or all of the following, prison time, stiff fine, and lose of amateur radio license. The offending station may also be required to pay the cost of any assistance went out as result of that distress call.
An emergency is declared on radio telephone operations by repeating the word “Mayday” three times followed by “any station come in please” and then the station identifications is given.
Sometimes in a disaster situation the FCC will declare a temporary state of communications emergency. This declaration can only be given by the FCC and will include any special conditions and rules to be observed during the emergency. After such a declaration has been made by the FCC all frequencies associated with the relief operations need to be avoided by any ham not directly involved in such operations.
For more efficient operations during emergency “Tactical Call Signs” may be used. These may be “Command Center” or “Weather Center” or any other designation of an area of operation. By using a Tactical Call Sign it is not necessary to remember who is at which station. If the operator changes the call sign remains the same. When using Tactical Call Signs these call signs do not replace standard amateur radio identifications and such identification is still required.
If the FCC has not declared a communications emergency no one has exclusive rights to any frequency. But it should be remembered that Emergency communications always holds priority over any other communications on all frequencies.
1. T8A01 [97.401(b)]
What information is included in an FCC declaration of a temporary state of communication emergency?
A. A list of organizations authorized to use radio communications in the affected area
B. A list of amateur frequency bands to be used in the affected area
C. Any special conditions and rules to be observed during the Emergency
D. An operating schedule for authorized amateur emergency stations
~~
2. T8A02 [97.111(a)]
Under what conditions are amateur stations allowed to communicate with stations operating in other radio services?
A. When communicating with the space shuttle
B. When specially authorized by the FCC, or in an actual emergency
C. When communicating with stations in the Citizens Radio Service
D. When a commercial broadcast station is reporting news during a natural disaster
~~
3. T8A03
What should you do if you are in contact with another station and an emergency call is heard?
A. Tell the calling station that the frequency is in use
B. Direct the calling station to the nearest emergency net
frequency
C. Disregard the call and continue with your contact
D. Stop your contact immediately and take the emergency call
~~
4. T8A04
What are the restrictions on amateur radio communications after the FCC has declared a communications emergency?
A. The emergency declaration prohibits all communications
B. There are no restrictions if you have a special emergency certification
C. You must avoid those frequencies dedicated to supporting
the emergency unless you are participating in the relief effort
D. Only military stations are allowed to use the amateur radio frequencies during an emergency
~~
5. T8A05
What is one reason for using tactical call signs such as "command post" or "weather center" during an emergency?
A. They help to keep the general public informed
B. They are more efficient and help coordinate public-service communications
C. They are required by the FCC
D. They increase goodwill and sound professional
~~
6. T8A06 [97.401(b)]
What is legally required to restrict a frequency to emergency-only communication?
A. An FCC declaration of a communications emergency
B. Determination by the designated net manager for an emergency net
C. Authorization by an ARES/RACES emergency coordinator
D. A Congressional declaration of intent
~~
7. T8A07
Who has the exclusive use of a frequency if the FCC has not
declared a communication emergency?
A. Any net station that has traffic
B. The station first occupying the frequency
C. Individuals passing health and welfare communications
D. No station has exclusive use in this circumstance
~~
8. T8A08
What should you do if you hear someone reporting an emergency?
A. Report the station to the FCC immediately
B. Assume the emergency is real and act accordingly
C. Ask the other station to move to a different frequency
D. Tell the station to call the police on the telephone
~~
9. T8A09
What is an appropriate way to initiate an emergency call on
amateur radio?
A. Yell as loudly as you can into the microphone
B. Ask if the frequency is in use and wait for someone to
give you permission to go ahead before proceeding
C. Declare a communications emergency
D. Say "Mayday, Mayday, Mayday" followed by "any station come in please" and identify your station
~~
10. T8A10
What are the penalties for making a false emergency call?
A. You could have your license revoked
B. You could be fined a large sum of money
C. You could be sent to prison
D. All of these answers are correct
~~
11. T8A11 [97.101(c)]
What type of communications has priority at all times in the Amateur Radio Service?
A. Repeater communications
B. Emergency communications
C. Simplex communications
D. Third-party communications
~~
12. T8A12 [97.101(c)]
When must priority be given to stations providing emergency
communications?
A. Only when operating under RACES
B. Only when an emergency has been declared
C. Any time a net control station is on the air
D. At all times and on all frequencies
~~
Answers: C B D C B A D B D D B D
equipment and frequencies, use of equipment by unlicensed persons,
tactical call signs
Amateur radio stations are normally not allowed to communicate directly with stations in other radio services. There are two exceptions. One is when the FCC authorizes such communications which may be part of a special events operation the other is during an actual emergency.
Sometimes while in contact with another amateur radio station an emergency call may be heard. This may be in the form of a Mayday or SOS or it may be a station requesting a break declaring it is an emergency. When an emergency call is heard first assume that the call is real; all other communications should cease and attention should be given to the station declaring the emergency.
It should be noted here that false distress signals are serious violations of the law and can result in legal actions of any or all of the following, prison time, stiff fine, and lose of amateur radio license. The offending station may also be required to pay the cost of any assistance went out as result of that distress call.
An emergency is declared on radio telephone operations by repeating the word “Mayday” three times followed by “any station come in please” and then the station identifications is given.
Sometimes in a disaster situation the FCC will declare a temporary state of communications emergency. This declaration can only be given by the FCC and will include any special conditions and rules to be observed during the emergency. After such a declaration has been made by the FCC all frequencies associated with the relief operations need to be avoided by any ham not directly involved in such operations.
For more efficient operations during emergency “Tactical Call Signs” may be used. These may be “Command Center” or “Weather Center” or any other designation of an area of operation. By using a Tactical Call Sign it is not necessary to remember who is at which station. If the operator changes the call sign remains the same. When using Tactical Call Signs these call signs do not replace standard amateur radio identifications and such identification is still required.
If the FCC has not declared a communications emergency no one has exclusive rights to any frequency. But it should be remembered that Emergency communications always holds priority over any other communications on all frequencies.
1. T8A01 [97.401(b)]
What information is included in an FCC declaration of a temporary state of communication emergency?
A. A list of organizations authorized to use radio communications in the affected area
B. A list of amateur frequency bands to be used in the affected area
C. Any special conditions and rules to be observed during the Emergency
D. An operating schedule for authorized amateur emergency stations
~~
2. T8A02 [97.111(a)]
Under what conditions are amateur stations allowed to communicate with stations operating in other radio services?
A. When communicating with the space shuttle
B. When specially authorized by the FCC, or in an actual emergency
C. When communicating with stations in the Citizens Radio Service
D. When a commercial broadcast station is reporting news during a natural disaster
~~
3. T8A03
What should you do if you are in contact with another station and an emergency call is heard?
A. Tell the calling station that the frequency is in use
B. Direct the calling station to the nearest emergency net
frequency
C. Disregard the call and continue with your contact
D. Stop your contact immediately and take the emergency call
~~
4. T8A04
What are the restrictions on amateur radio communications after the FCC has declared a communications emergency?
A. The emergency declaration prohibits all communications
B. There are no restrictions if you have a special emergency certification
C. You must avoid those frequencies dedicated to supporting
the emergency unless you are participating in the relief effort
D. Only military stations are allowed to use the amateur radio frequencies during an emergency
~~
5. T8A05
What is one reason for using tactical call signs such as "command post" or "weather center" during an emergency?
A. They help to keep the general public informed
B. They are more efficient and help coordinate public-service communications
C. They are required by the FCC
D. They increase goodwill and sound professional
~~
6. T8A06 [97.401(b)]
What is legally required to restrict a frequency to emergency-only communication?
A. An FCC declaration of a communications emergency
B. Determination by the designated net manager for an emergency net
C. Authorization by an ARES/RACES emergency coordinator
D. A Congressional declaration of intent
~~
7. T8A07
Who has the exclusive use of a frequency if the FCC has not
declared a communication emergency?
A. Any net station that has traffic
B. The station first occupying the frequency
C. Individuals passing health and welfare communications
D. No station has exclusive use in this circumstance
~~
8. T8A08
What should you do if you hear someone reporting an emergency?
A. Report the station to the FCC immediately
B. Assume the emergency is real and act accordingly
C. Ask the other station to move to a different frequency
D. Tell the station to call the police on the telephone
~~
9. T8A09
What is an appropriate way to initiate an emergency call on
amateur radio?
A. Yell as loudly as you can into the microphone
B. Ask if the frequency is in use and wait for someone to
give you permission to go ahead before proceeding
C. Declare a communications emergency
D. Say "Mayday, Mayday, Mayday" followed by "any station come in please" and identify your station
~~
10. T8A10
What are the penalties for making a false emergency call?
A. You could have your license revoked
B. You could be fined a large sum of money
C. You could be sent to prison
D. All of these answers are correct
~~
11. T8A11 [97.101(c)]
What type of communications has priority at all times in the Amateur Radio Service?
A. Repeater communications
B. Emergency communications
C. Simplex communications
D. Third-party communications
~~
12. T8A12 [97.101(c)]
When must priority be given to stations providing emergency
communications?
A. Only when operating under RACES
B. Only when an emergency has been declared
C. Any time a net control station is on the air
D. At all times and on all frequencies
~~
Answers: C B D C B A D B D D B D
Tuesday, September 11, 2007
LESSON 28
Preparation for emergency operations, RACES/ARES, safety of
life and property, using ham radio at civic events, compensation
prohibited
Emergencies can come at any time anywhere. For hams who plan to participate in emergency operations it is important that they be ready at all times. Some things you can do to assure readiness are: 1. At least twice a year check to make sure all your emergency response equipment is available and know where it is; 2. Make sure you have a way to run your equipment if there is a power failure in your area; 3. Participate in drills that test your ability to set up and operate in the field.
Some alternate sources of power which may be used during an emergency are the truck or car battery, a bicycle generator, and portable solar panels
Membership in emergency response groups like RACES and ARES should be considered. RACES’ primary functions are restricted to serving local, state, and federal government emergency management agencies while ARES primarily support agencies like the Red Cross, Salvation Army, and National Weather service.
Amateurs wishing to participate with RACES must register with the responsible civil defense organization before they will be able to do so. ARES only requires its members have a valid Amateur Radio license.
Time and effort should be spent to learn proper operating procedures during emergency operation. During such times the operations become much more formal then normal day to day amateur activities. Casual conversation between stations during a public service or emergency operation should be avoided because idle chatter may interfere with important traffic.
In times of genuine emergencies many rules which seem hard and fast at other times may alter. One of these changes involves the use of non-amateur frequencies or equipment to call for help. If immediate danger to life or property is involved you may use any means at your disposal to call for help on any frequency. This would include modifying an amateur radio transceiver to operate on local fire department frequencies.
An amateur radio station may transmit an SOS or Mayday when there is an immediate threat to human life or property. False distress messages are serious infractions of the law and can result in prison and/or stiff fines.
~~
It should always be remembered that amateur radio communications are not to be for the purpose of profit for anyone even during disasters. Sometimes it requires careful scrutiny on the part of an amateur to know if a piece of traffic is legitimate. A reporter may ask you to use your amateur station to make a news report but reporters and the news media are profit making businesses and thus the reporter should be advised that the FCC prohibits such use. The reporter may not have knowledge of such prohibition so tell them kindly but firmly.
1. T8B01 (D)
What can you do to be prepared for an emergency situation where your assistance might be needed?
A. Check at least twice a year to make sure you have all of your emergency response equipment and know where it is
B. Make sure you have a way to run your equipment if there is a power failure in your area
C. Participate in drills that test your ability to set up and operate in the field
D. All of these answers are correct
~~
2. T8B02 (C) [97.403]
When may you use your amateur station to transmit a "SOS" or "MAYDAY" signal?
A. Only when you are transmitting from a ship at sea
B. Only at 15 and 30 minutes after the hour
C. When there is immediate threat to human life or property
D. When the National Weather Service has announced a weather warning
~~
3. T8B03 (A)
What is the primary function of RACES in relation to emergency activities?
A. RACES organizations are restricted to serving local, state, and federal government emergency management agencies
B. RACES supports agencies like the Red Cross, Salvation
Army, and National Weather Service
C. RACES supports the National Traffic System
D. RACES is a part of the National Emergency Warning System
~~
4. T8B04 (B)
What is the primary function of ARES in relation to emergency activities?
A. ARES organizations are restricted to serving local, state, and federal government emergency management agencies
B. ARES supports agencies like the Red Cross, Salvation
Army, and National Weather Service
C. ARES groups work only with local school districts
D. ARES supports local National Guard units
~~
5. T8B05 (C) [97.407(a)]
What organization must you register with before you can
participate in RACES activities?
A. A local amateur radio club
B. A local racing organization
C. The responsible civil defense organization
D. The Federal Communications Commission
~~
6. T8B06 (B)
What is necessary before you can join an ARES group?
A. You are required to join the ARRL
B. You must have an amateur radio license
C. You must have an amateur radio license and have Red Cross CPR training
D. You must register with a civil defense organization
~~
7. T8B07 (D)
What could be used as an alternate source of power to operate radio equipment during emergencies?
A. The battery in a car or truck
B. A bicycle generator
C. A portable solar panel
D. All of these answers are correct
~~
8. T8B08 (B) [97.403, 97.405(a),(b)]
When can you use non-amateur frequencies or equipment to call for help in a situation involving immediate danger to life or property?
A. Never; your license only allows you to use the frequencies authorized to your class of license
B. In a genuine emergency you may use any means at your disposal to call for help on any frequency
C. When you have permission from the owner of the set
D. When you have permission from a police officer on the scene
~~
9. T8B09 (C)
Why should casual conversation between stations during a public service event be avoided?
A. Such chatter is often interesting to bystanders
B. Other listeners might overhear personal information
C. Idle chatter may interfere with important traffic
D. You might have to change batteries more often
~~
10. T8B10 (B)
What should you do if a reporter asks to use your amateur radio transceiver to make a news report?
A. Allow the use but give your call sign every 10 minutes
B. Advise them that the FCC prohibits such use
C. Tell them it is OK as long as you do not receive compensation
D. Tell the reporter that you must approve the material beforehand
~~
11. T8B11 (C) [97.403, 97.405(a),(b)]
When can you use a modified amateur radio transceiver to transmit on the local fire department frequency?
A. When you are helping the Fire Department raise money
B. Only when the Fire Department is short of regular equipment
C. In a genuine emergency you may use any means at your disposal to call for help on any frequency
D. When the local Fire Chief has given written permission
Answers: D C A B C B D B C B C
life and property, using ham radio at civic events, compensation
prohibited
Emergencies can come at any time anywhere. For hams who plan to participate in emergency operations it is important that they be ready at all times. Some things you can do to assure readiness are: 1. At least twice a year check to make sure all your emergency response equipment is available and know where it is; 2. Make sure you have a way to run your equipment if there is a power failure in your area; 3. Participate in drills that test your ability to set up and operate in the field.
Some alternate sources of power which may be used during an emergency are the truck or car battery, a bicycle generator, and portable solar panels
Membership in emergency response groups like RACES and ARES should be considered. RACES’ primary functions are restricted to serving local, state, and federal government emergency management agencies while ARES primarily support agencies like the Red Cross, Salvation Army, and National Weather service.
Amateurs wishing to participate with RACES must register with the responsible civil defense organization before they will be able to do so. ARES only requires its members have a valid Amateur Radio license.
Time and effort should be spent to learn proper operating procedures during emergency operation. During such times the operations become much more formal then normal day to day amateur activities. Casual conversation between stations during a public service or emergency operation should be avoided because idle chatter may interfere with important traffic.
In times of genuine emergencies many rules which seem hard and fast at other times may alter. One of these changes involves the use of non-amateur frequencies or equipment to call for help. If immediate danger to life or property is involved you may use any means at your disposal to call for help on any frequency. This would include modifying an amateur radio transceiver to operate on local fire department frequencies.
An amateur radio station may transmit an SOS or Mayday when there is an immediate threat to human life or property. False distress messages are serious infractions of the law and can result in prison and/or stiff fines.
~~
It should always be remembered that amateur radio communications are not to be for the purpose of profit for anyone even during disasters. Sometimes it requires careful scrutiny on the part of an amateur to know if a piece of traffic is legitimate. A reporter may ask you to use your amateur station to make a news report but reporters and the news media are profit making businesses and thus the reporter should be advised that the FCC prohibits such use. The reporter may not have knowledge of such prohibition so tell them kindly but firmly.
1. T8B01 (D)
What can you do to be prepared for an emergency situation where your assistance might be needed?
A. Check at least twice a year to make sure you have all of your emergency response equipment and know where it is
B. Make sure you have a way to run your equipment if there is a power failure in your area
C. Participate in drills that test your ability to set up and operate in the field
D. All of these answers are correct
~~
2. T8B02 (C) [97.403]
When may you use your amateur station to transmit a "SOS" or "MAYDAY" signal?
A. Only when you are transmitting from a ship at sea
B. Only at 15 and 30 minutes after the hour
C. When there is immediate threat to human life or property
D. When the National Weather Service has announced a weather warning
~~
3. T8B03 (A)
What is the primary function of RACES in relation to emergency activities?
A. RACES organizations are restricted to serving local, state, and federal government emergency management agencies
B. RACES supports agencies like the Red Cross, Salvation
Army, and National Weather Service
C. RACES supports the National Traffic System
D. RACES is a part of the National Emergency Warning System
~~
4. T8B04 (B)
What is the primary function of ARES in relation to emergency activities?
A. ARES organizations are restricted to serving local, state, and federal government emergency management agencies
B. ARES supports agencies like the Red Cross, Salvation
Army, and National Weather Service
C. ARES groups work only with local school districts
D. ARES supports local National Guard units
~~
5. T8B05 (C) [97.407(a)]
What organization must you register with before you can
participate in RACES activities?
A. A local amateur radio club
B. A local racing organization
C. The responsible civil defense organization
D. The Federal Communications Commission
~~
6. T8B06 (B)
What is necessary before you can join an ARES group?
A. You are required to join the ARRL
B. You must have an amateur radio license
C. You must have an amateur radio license and have Red Cross CPR training
D. You must register with a civil defense organization
~~
7. T8B07 (D)
What could be used as an alternate source of power to operate radio equipment during emergencies?
A. The battery in a car or truck
B. A bicycle generator
C. A portable solar panel
D. All of these answers are correct
~~
8. T8B08 (B) [97.403, 97.405(a),(b)]
When can you use non-amateur frequencies or equipment to call for help in a situation involving immediate danger to life or property?
A. Never; your license only allows you to use the frequencies authorized to your class of license
B. In a genuine emergency you may use any means at your disposal to call for help on any frequency
C. When you have permission from the owner of the set
D. When you have permission from a police officer on the scene
~~
9. T8B09 (C)
Why should casual conversation between stations during a public service event be avoided?
A. Such chatter is often interesting to bystanders
B. Other listeners might overhear personal information
C. Idle chatter may interfere with important traffic
D. You might have to change batteries more often
~~
10. T8B10 (B)
What should you do if a reporter asks to use your amateur radio transceiver to make a news report?
A. Allow the use but give your call sign every 10 minutes
B. Advise them that the FCC prohibits such use
C. Tell them it is OK as long as you do not receive compensation
D. Tell the reporter that you must approve the material beforehand
~~
11. T8B11 (C) [97.403, 97.405(a),(b)]
When can you use a modified amateur radio transceiver to transmit on the local fire department frequency?
A. When you are helping the Fire Department raise money
B. Only when the Fire Department is short of regular equipment
C. In a genuine emergency you may use any means at your disposal to call for help on any frequency
D. When the local Fire Chief has given written permission
Answers: D C A B C B D B C B C
LESSON 29
Net operations, responsibilities of the net control station,
message handling, interfacing with public safety officials
Emergency or distress traffic is one area in amateur radio, or any other form of communications, that neither the FCC nor any other authority takes lightly. If a distress call is given or heard it will take priority over all other communications.
If emergency traffic is being conducted on an amateur radio frequency then only those operators who are directly involved in the emergency and those who are directly involved in assistance should transmit. All other stations should not transmit. To minimize disruption of an emergency traffic net participating operators should not transmit on net frequency until asked to do so by the net control station.
During net operations if there is a break in with emergency traffic the net control station should stop all other net activity until the emergency traffic has been handled.
Emergency traffic must include the name of the person originating the message and if transmitted over amateur radio frequencies it should not include personal information concerning victims. Some messages are best not transmitted by voice transmissions to prevent casual listeners from receiving. Non voice methods of transmission such as packet or CW are better ways to handle such traffic. Never encrypt messages because it is a violation of FCC regulations to do such on the amateur radio frequencies.
If a large scale emergency has just happened and there is no net control operator available any amateur station operator should immediately open a net and ask for check-ins. It is important that a net control station have a strong and clear signal so if the station which starts an emergency net does not have such a signal that operator should, if possible, relinquish the net control position to another station which can perform the function more effectively.
The preamble of any message is the information needed to track a message as it passes through the amateur radio traffic handling system. The preamble includes a “check” which is a count of the number of words in the message. There should be no more then 25 words included in the text of an emergency message.
1. T8C01 (A)
Which type of traffic has the highest priority?
A. Emergency traffic
B. Priority traffic
C. Health and welfare traffic
D. Routine traffic
~~
2. T8C02 (B)
What type of messages should not be transmitted over amateur radio frequencies during emergencies?
A. Requests for supplies
B. Personal information concerning victims
C. A schedule of relief operators
D. Estimates of how much longer the emergency will last
~~
3. T8C03 (C)
What should you do to minimize disruptions to an emergency traffic net once you have checked in?
A. Whenever the net frequency is quiet, announce your call sign and location
B. Move 5 kHz away from the net's frequency and use high power to ask other hams to keep clear of the net frequency
C. Do not transmit on the net frequency until asked to do so by the net control station
D. Wait until the net frequency is quiet, then ask for any
emergency traffic for your area
~~
4. T8C04 (B)
What is one thing that must be included when passing emergency messages?
A. The call signs of all the stations passing the message
B. The name of the person originating the message
C. A status report
D. The message title
~~
5. T8C05 (A)
What is one way to reduce the chances of casual listeners
overhearing sensitive emergency traffic?
A. Pass messages using a non-voice mode such as packet radio or Morse code
B. Speak as rapidly as possible to reduce your on-air time
C. Spell out every word using phonetics
D. Restrict transmission of messages to the hours between midnight and 4:00 AM
6. T8C06 (C)
What is of primary importance for a net control station?
A. A dual-band transceiver
B. A network card
C. A strong and clear signal
D. The ability to speak several languages
~~
7. T8C07 (B)
What should the net control station do if someone breaks in with emergency traffic?
A. Ask them to wait until the roll has been called
B. Stop all net activity until the emergency has been handled
C. Ask the station to call the local police and then resume
normal net activities
D. Ask them to move off your net frequency immediately
~~
8. T8C08 (C)
What should you do if a large scale emergency has just occurred and no net control station is available?
A. Wait until the assigned net control station comes on the air and pass your traffic when called
B. Transmit a call for help and hope someone will hear you
C. Open the emergency net immediately and ask for check-ins
D. Listen to the local NOAA weather broadcast to find out how long the emergency will last
~~
9. T8C09 (D)
What is the preamble of a message?
A. The first paragraph of the message text
B. The message number
C. The priority handling indicator for the message
D. The information needed to track the message as it passes
through the amateur radio traffic handling system
~~
10. T8C10 (A)
What is meant by the term "check" in reference to a message?
A. The check is a count of the number of words in the message
B. The check is the value of a money order attached to the message
C. The check is a list of stations that have relayed the message
D. The check is a box on the message form that tells you the message was received
~~
11. T8C11 (B)
What is the recommended guideline for the maximum number of words to be included in the text of an emergency message?
A. 10 words
B. 25 words
C. 50 words
D. 75 words
Answers: A B C B A C B C D A B
message handling, interfacing with public safety officials
Emergency or distress traffic is one area in amateur radio, or any other form of communications, that neither the FCC nor any other authority takes lightly. If a distress call is given or heard it will take priority over all other communications.
If emergency traffic is being conducted on an amateur radio frequency then only those operators who are directly involved in the emergency and those who are directly involved in assistance should transmit. All other stations should not transmit. To minimize disruption of an emergency traffic net participating operators should not transmit on net frequency until asked to do so by the net control station.
During net operations if there is a break in with emergency traffic the net control station should stop all other net activity until the emergency traffic has been handled.
Emergency traffic must include the name of the person originating the message and if transmitted over amateur radio frequencies it should not include personal information concerning victims. Some messages are best not transmitted by voice transmissions to prevent casual listeners from receiving. Non voice methods of transmission such as packet or CW are better ways to handle such traffic. Never encrypt messages because it is a violation of FCC regulations to do such on the amateur radio frequencies.
If a large scale emergency has just happened and there is no net control operator available any amateur station operator should immediately open a net and ask for check-ins. It is important that a net control station have a strong and clear signal so if the station which starts an emergency net does not have such a signal that operator should, if possible, relinquish the net control position to another station which can perform the function more effectively.
The preamble of any message is the information needed to track a message as it passes through the amateur radio traffic handling system. The preamble includes a “check” which is a count of the number of words in the message. There should be no more then 25 words included in the text of an emergency message.
1. T8C01 (A)
Which type of traffic has the highest priority?
A. Emergency traffic
B. Priority traffic
C. Health and welfare traffic
D. Routine traffic
~~
2. T8C02 (B)
What type of messages should not be transmitted over amateur radio frequencies during emergencies?
A. Requests for supplies
B. Personal information concerning victims
C. A schedule of relief operators
D. Estimates of how much longer the emergency will last
~~
3. T8C03 (C)
What should you do to minimize disruptions to an emergency traffic net once you have checked in?
A. Whenever the net frequency is quiet, announce your call sign and location
B. Move 5 kHz away from the net's frequency and use high power to ask other hams to keep clear of the net frequency
C. Do not transmit on the net frequency until asked to do so by the net control station
D. Wait until the net frequency is quiet, then ask for any
emergency traffic for your area
~~
4. T8C04 (B)
What is one thing that must be included when passing emergency messages?
A. The call signs of all the stations passing the message
B. The name of the person originating the message
C. A status report
D. The message title
~~
5. T8C05 (A)
What is one way to reduce the chances of casual listeners
overhearing sensitive emergency traffic?
A. Pass messages using a non-voice mode such as packet radio or Morse code
B. Speak as rapidly as possible to reduce your on-air time
C. Spell out every word using phonetics
D. Restrict transmission of messages to the hours between midnight and 4:00 AM
6. T8C06 (C)
What is of primary importance for a net control station?
A. A dual-band transceiver
B. A network card
C. A strong and clear signal
D. The ability to speak several languages
~~
7. T8C07 (B)
What should the net control station do if someone breaks in with emergency traffic?
A. Ask them to wait until the roll has been called
B. Stop all net activity until the emergency has been handled
C. Ask the station to call the local police and then resume
normal net activities
D. Ask them to move off your net frequency immediately
~~
8. T8C08 (C)
What should you do if a large scale emergency has just occurred and no net control station is available?
A. Wait until the assigned net control station comes on the air and pass your traffic when called
B. Transmit a call for help and hope someone will hear you
C. Open the emergency net immediately and ask for check-ins
D. Listen to the local NOAA weather broadcast to find out how long the emergency will last
~~
9. T8C09 (D)
What is the preamble of a message?
A. The first paragraph of the message text
B. The message number
C. The priority handling indicator for the message
D. The information needed to track the message as it passes
through the amateur radio traffic handling system
~~
10. T8C10 (A)
What is meant by the term "check" in reference to a message?
A. The check is a count of the number of words in the message
B. The check is the value of a money order attached to the message
C. The check is a list of stations that have relayed the message
D. The check is a box on the message form that tells you the message was received
~~
11. T8C11 (B)
What is the recommended guideline for the maximum number of words to be included in the text of an emergency message?
A. 10 words
B. 25 words
C. 50 words
D. 75 words
Answers: A B C B A C B C D A B
Sunday, September 9, 2007
LESSON 30
Antenna types – vertical, horizontal, concept of gain,
common portable and mobile antennas, losses with short antennas,
relationships between antenna length and frequency, dummy loads
A great transmitter and an outstanding receiver combined with a poor antenna system will result in a poor communications station. The antenna is the direct link between the transmitting and the receiving stations.
Antenna are sometimes designed with a single element mounted perpendicular to the Earth’s surface so they are known as vertical antennas while a simple dipole antenna is mounted so the elements are parallel to the Earth’s surface so it is a horizontal antenna. By using other antenna elements to concentrate the signal in one direction these antennas become known as beam antennas or directional antennas. Three types of directional antennas are the quad, the Yagi, and the dish antennas.
When the elements are vertical to the Earth’s surface the radiation is vertically polarized and when the elements are horizontal to the Earth’s surface the radiation is horizontally polarized.
The simple vertical antenna and simple dipole, like the wave length of the RF signal, become shorter as the frequency is increased and become longer as the frequency decreases. The formula for determining the length of a half wave antenna is length = 5616/Frequency (Frequency in MHz and length in inches). Thus a half wave 6 meter antenna would be approximately 112 inches. A half wave antenna can be made into a quarter wave antenna by dividing the length by 2 thus a quarter wave 2 meter antenna would be approximately 19 inches.
Frequently hand held radios use a short wide and usually black antenna called affectionately referred to as a “Rubber Duck” antenna. These antennas are convenient from a physical stand point but are not as efficient as a full size antenna for transmitting or receiving.
A magnetic mount vertical antenna provides an effective mobile antenna that is to install and remove. Using a magnetic mount antenna while operating a hand held antenna inside a vehicle will greatly improve its performance. Using just a “Rubber Duck” antenna on a hand held radio inside a vehicle can reduce its efficiency 10 to 20 times (10 to 13 DB loss).
A quarter wave antenna is commonly used for mobile purposes but by using a five eights wave antenna the angle of radiation can be lowered and an additional 3 DB of gain can be realized.
Sometimes it is desired to test a transmitter while not radiating a signal. A transmitter should never be operated with out a load so if it is not desirable to radiate a signal a dummy load should be used in place of the antenna.
1. T9A01 (C)
What is a beam antenna?
A. An antenna built from metal I-beams
B. An antenna that transmits and receives equally well in all directions
C. An antenna that concentrates signals in one direction
D. An antenna that reverses the phase of received signals
~~
2. T9A02 (C)
What is an antenna that consists of a single element mounted perpendicular to the Earth's surface?
A. A conical monopole
B. A horizontal antenna
C. A vertical antenna
D. A traveling wave antenna
~~
3. T9A03 (B)
What type of antenna is a simple dipole mounted so the elements are parallel to the Earth's surface?
A. A ground wave antenna
B. A horizontal antenna
C. A rhombic antenna
D. A vertical antenna
~~
4. T9A04 (A)
What is a disadvantage of the "rubber duck" antenna supplied with most hand held radio transceivers?
A. It does not transmit or receive as effectively as a full sized antenna
B. It is much more expensive than a standard antenna
C. If the rubber end cap is lost it will unravel very quickly
D. It transmits a circular polarized signal
~~
5. T9A05 (C)
How does the physical size of half-wave dipole antenna change with operating frequency?
A. It becomes longer as the frequency increases
B. It must be made larger because it has to handle more power
C. It becomes shorter as the frequency increases
D. It becomes shorter as the frequency decreases
~~
6. T9A06 (B)
What is the advantage of 5/8 wavelength over 1/4 wavelength vertical antennas?
A. They are easier to match to the feed line than other types
B. Their radiation pattern concentrates energy at lower angles
C. They pick up less noise
D. Their radiation pattern concentrates energy at higher angles
~~
7. T9A07 (A)
What is the primary purpose of a dummy load?
A. It does not radiate interfering signals when making tests
B. It will prevent over-modulation of your transmitter
C. It keeps you from making mistakes while on the air
D. It is used for close in work to prevent overloads
~~
8. T9A08 (C)
What type of antennas are the quad, Yagi, and dish?
A. Antennas invented after 1985
B. Loop antennas
C. Directional or beam antennas
D. Antennas that are not permitted for amateur radio stations
~~
9. T9A09 (D)
What is one type of antenna that offers good efficiency when operating mobile and can be easily installed or removed?
A. A microwave antenna
B. A quad antenna
C. A traveling wave antenna
D. A magnet mount vertical antenna
~~
10. T9A10 (A)
What is a good reason not to use a "rubber duck" antenna inside your car?
A. Signals can be 10 to 20 times weaker than when you are outside of the vehicle
B. RF energy trapped inside the vehicle can distort your signal
C. You might cause a fire in the vehicle upholstery
D. The SWR might increase
~~
11. T9A11 (C)
What is the approximate length, in inches, of a quarter-wavelength vertical antenna for 146 MHz?
A. 112 inches
B. 50 inches
C. 19 inches
D. 12 inches
~~
12. T9A12 (C)
What is the approximate length, in inches, of a 6-meter 1/2
wavelength wire dipole antenna?
A. 6 inches
B. 50 inches
C. 112 inches
D. 236 inches
Answers: C C B A C B A C D A C C
common portable and mobile antennas, losses with short antennas,
relationships between antenna length and frequency, dummy loads
A great transmitter and an outstanding receiver combined with a poor antenna system will result in a poor communications station. The antenna is the direct link between the transmitting and the receiving stations.
Antenna are sometimes designed with a single element mounted perpendicular to the Earth’s surface so they are known as vertical antennas while a simple dipole antenna is mounted so the elements are parallel to the Earth’s surface so it is a horizontal antenna. By using other antenna elements to concentrate the signal in one direction these antennas become known as beam antennas or directional antennas. Three types of directional antennas are the quad, the Yagi, and the dish antennas.
When the elements are vertical to the Earth’s surface the radiation is vertically polarized and when the elements are horizontal to the Earth’s surface the radiation is horizontally polarized.
The simple vertical antenna and simple dipole, like the wave length of the RF signal, become shorter as the frequency is increased and become longer as the frequency decreases. The formula for determining the length of a half wave antenna is length = 5616/Frequency (Frequency in MHz and length in inches). Thus a half wave 6 meter antenna would be approximately 112 inches. A half wave antenna can be made into a quarter wave antenna by dividing the length by 2 thus a quarter wave 2 meter antenna would be approximately 19 inches.
Frequently hand held radios use a short wide and usually black antenna called affectionately referred to as a “Rubber Duck” antenna. These antennas are convenient from a physical stand point but are not as efficient as a full size antenna for transmitting or receiving.
A magnetic mount vertical antenna provides an effective mobile antenna that is to install and remove. Using a magnetic mount antenna while operating a hand held antenna inside a vehicle will greatly improve its performance. Using just a “Rubber Duck” antenna on a hand held radio inside a vehicle can reduce its efficiency 10 to 20 times (10 to 13 DB loss).
A quarter wave antenna is commonly used for mobile purposes but by using a five eights wave antenna the angle of radiation can be lowered and an additional 3 DB of gain can be realized.
Sometimes it is desired to test a transmitter while not radiating a signal. A transmitter should never be operated with out a load so if it is not desirable to radiate a signal a dummy load should be used in place of the antenna.
1. T9A01 (C)
What is a beam antenna?
A. An antenna built from metal I-beams
B. An antenna that transmits and receives equally well in all directions
C. An antenna that concentrates signals in one direction
D. An antenna that reverses the phase of received signals
~~
2. T9A02 (C)
What is an antenna that consists of a single element mounted perpendicular to the Earth's surface?
A. A conical monopole
B. A horizontal antenna
C. A vertical antenna
D. A traveling wave antenna
~~
3. T9A03 (B)
What type of antenna is a simple dipole mounted so the elements are parallel to the Earth's surface?
A. A ground wave antenna
B. A horizontal antenna
C. A rhombic antenna
D. A vertical antenna
~~
4. T9A04 (A)
What is a disadvantage of the "rubber duck" antenna supplied with most hand held radio transceivers?
A. It does not transmit or receive as effectively as a full sized antenna
B. It is much more expensive than a standard antenna
C. If the rubber end cap is lost it will unravel very quickly
D. It transmits a circular polarized signal
~~
5. T9A05 (C)
How does the physical size of half-wave dipole antenna change with operating frequency?
A. It becomes longer as the frequency increases
B. It must be made larger because it has to handle more power
C. It becomes shorter as the frequency increases
D. It becomes shorter as the frequency decreases
~~
6. T9A06 (B)
What is the advantage of 5/8 wavelength over 1/4 wavelength vertical antennas?
A. They are easier to match to the feed line than other types
B. Their radiation pattern concentrates energy at lower angles
C. They pick up less noise
D. Their radiation pattern concentrates energy at higher angles
~~
7. T9A07 (A)
What is the primary purpose of a dummy load?
A. It does not radiate interfering signals when making tests
B. It will prevent over-modulation of your transmitter
C. It keeps you from making mistakes while on the air
D. It is used for close in work to prevent overloads
~~
8. T9A08 (C)
What type of antennas are the quad, Yagi, and dish?
A. Antennas invented after 1985
B. Loop antennas
C. Directional or beam antennas
D. Antennas that are not permitted for amateur radio stations
~~
9. T9A09 (D)
What is one type of antenna that offers good efficiency when operating mobile and can be easily installed or removed?
A. A microwave antenna
B. A quad antenna
C. A traveling wave antenna
D. A magnet mount vertical antenna
~~
10. T9A10 (A)
What is a good reason not to use a "rubber duck" antenna inside your car?
A. Signals can be 10 to 20 times weaker than when you are outside of the vehicle
B. RF energy trapped inside the vehicle can distort your signal
C. You might cause a fire in the vehicle upholstery
D. The SWR might increase
~~
11. T9A11 (C)
What is the approximate length, in inches, of a quarter-wavelength vertical antenna for 146 MHz?
A. 112 inches
B. 50 inches
C. 19 inches
D. 12 inches
~~
12. T9A12 (C)
What is the approximate length, in inches, of a 6-meter 1/2
wavelength wire dipole antenna?
A. 6 inches
B. 50 inches
C. 112 inches
D. 236 inches
Answers: C C B A C B A C D A C C
LESSON 31
Propagation, fading, multipath distortion, reflections,
radio horizon, terrain blocking, wavelength vs. penetration,
antenna orientation
When considering VHF and UHF propagation sometimes it helps to remember that radio waves and light waves are both electro magnetic waves. The only difference between radio waves and light is their frequency or wave length (wave length is indirectly proportional to frequency that is the higher the frequency the shorter the wave length.)
VHF, UHF and higher frequencies are normally considered line of sight communication frequencies. This means when the signal reaches the horizon, the point at which the curvature of the earth blocks the signal, it continues off into space. Because of the longer wave length of VHF and UHF signals the horizon, known as radio horizon, for these signals is about one third longer then visual horizon.
Directional antennas (beams) are used to increase the transmitted signal in a given direction while reducing the signal in all other directions. When the beam is being used to receive it increases the received signal level in one direction while reducing the signal level in all other directions. The advantage of this phenomenon is more then just the simple point to point signal increase. VHF and UHF signals reflect more readily from objects like buildings, mountains, or other physical structures then do their HF counter parts. This reflection can cause multipathing which means the signal can be coming in from more then one direction. Because these reflected signals travel different distances they will most likely arrive at different phase angels which will cause the signal to interfere with itself. Beams can be used to increase the strongest signal while reducing all the others thus reducing the results of multipathing.
Sometimes a station which is blocked by an object can be reached by a VHF or UHF signals by reflecting the signals off a structure. This means the strongest signal may be in a direction away from the physical location of the other station.
The blocking of signals and multipathing can cause a fluttering sound to mobiles using VHF and UHF. This is frequently referred to as picket fencing. This same problem is sometimes observed when using a handheld unit by reports of a strong signal being changed to a weak signal though no appreciable change has take place. Because of the lower transmit power of the handheld the receive signal may not change noticeably. The best thing to do in such an event is to move around to look for a place where the signal is again improved.
Repeaters usually use vertically polarized antennas because they are easy to make omni-directional (radiate in all directions equally) then horizontally polarized antenna systems. For the same reason most mobile antenna systems are vertically polarized. When a two stations are trying to communicate with one having a horizontal antenna and the other having a vertical antenna as much as a 10 DB (100 times) loss can be produced. For this reason when using a handheld unit and working a distant repeater the antenna should be held as close to vertical as possible.
UHF signal will normally out perform VHF signals when being operated from within a building because The shorter wavelength of UHF signals allows them to more easily penetrate urban areas and buildings.
HF signals can be heard from stations even from as far as the other side of the world because HF signals can reflect off the ionosphere. VHF and UHF signals are not normally reflected by the ionosphere but sometimes a sporadic reflection from the E layer of the ionosphere will allow long distance VHF communications possible.
Strong VHF or UHF signals which overload the receiver will sometimes cause undesired signals to be heard. This can cause sudden bursts of tones or fragments of different conversations to be heard which interfere with the desired signal.
1. T9B01 (C)
Why are VHF/UHF signals not normally heard over long distances?
A. They are too weak to go very far
B. FCC regulations prohibit them from going more than 50 miles
C. VHF and UHF signals are usually not reflected by the ionosphere
D. They collide with trees and shrubbery and fade out ~~
2. T9B02 (D)
What might be happening when we hear a VHF signal from long distances?
A. Signals are being reflected from outer space
B. Someone is playing a recording to us
C. Signals are being reflected by lightning storms in our area
D. A possible cause is sporadic E reflection from a layer in the ionosphere
~~
3. T9B03 (B)
What is the most likely cause of sudden bursts of tones or fragments of different conversations that interfere with VHF or UHF signals?
A. The batteries in your transceiver are failing
B. Strong signals are overloading the receiver and causing undesired signals to be heard
C. The receiver is picking up low orbit satellites
D. A nearby broadcast station is having transmitter problems
~~
4. T9B04 (A)
What is the radio horizon?
A. The point where radio signals between two points are blocked by the curvature of the Earth
B. The distance from the ground to a horizontally mounted antenna
C. The farthest point you can see when standing at the base of your antenna tower
D. The shortest distance between two points on the Earth's surface
~~
5. T9B05 (D)
What should you do if a station reports that your signals were strong just a moment ago, but now they are weak or distorted?
A. Change the batteries in your radio to a different type
B. Speak more slowly so he can understand your better
C. Ask the other operator to adjust his squelch control
D. Try moving a few feet, random reflections may be causing multipath distortion.
~~
6. T9B06 (B)
Why do UHF signals often work better inside of buildings than VHF signals?
A. VHF signals lose power faster over distance
B. The shorter wavelength of UHF signals allows them to more easily penetrate urban areas and buildings
C. This is incorrect; VHF works better than UHF inside buildings
D. UHF antennas are more efficient than VHF antennas
~~
7. T9B07 (C)
What is a good thing to remember when using your hand-held VHF or UHF radio to reach a distant repeater?
A. Speak as loudly as possible to help your signal go farther
B. Keep your transmissions short to conserve battery power
C. Keep the antenna as close to vertical as you can
D. Turn off the CTCSS tone
~~
8. T9B08 (B)
What can happen if the antennas at opposite ends of a VHF or UHF line of sight radio link are not using the same polarization?
A. The modulation sidebands might become inverted
B. Signals could be as much as 100 times weaker
C. Signals have an echo effect on voices
D. Nothing significant will happen
~~
9. T9B09 (B)
What might be a way to reach a distant repeater if buildings or obstructions are blocking the direct line of sight path?
A. Change from vertical to horizontal polarization
B. Try using a directional antenna to find a path that reflects signals to the repeater
C. Ask the repeater owners to repair their receiver
D. Transmit on the repeater output frequency
10. T9B10 (B)
What term is commonly used to describe the rapid fluttering sound sometimes heard from mobile stations that are moving while transmitting?
A. Flip-flopping
B. Picket fencing
C. Frequency shifting
D. Pulsing
~~
11. T9B11 (C)
Why do VHF and UHF Radio signals usually travel about a third farther than the visual line of sight distance between 2 stations?
A. Radio signals move somewhat faster than the speed of light and travel farther in the same amount of time
B. Radio waves are not blocked by dust particles
C. The Earth seems less curved to radio waves than to light
D. Radio waves are blocked by dust particles
Answers: C D B A D B C B B B C
radio horizon, terrain blocking, wavelength vs. penetration,
antenna orientation
When considering VHF and UHF propagation sometimes it helps to remember that radio waves and light waves are both electro magnetic waves. The only difference between radio waves and light is their frequency or wave length (wave length is indirectly proportional to frequency that is the higher the frequency the shorter the wave length.)
VHF, UHF and higher frequencies are normally considered line of sight communication frequencies. This means when the signal reaches the horizon, the point at which the curvature of the earth blocks the signal, it continues off into space. Because of the longer wave length of VHF and UHF signals the horizon, known as radio horizon, for these signals is about one third longer then visual horizon.
Directional antennas (beams) are used to increase the transmitted signal in a given direction while reducing the signal in all other directions. When the beam is being used to receive it increases the received signal level in one direction while reducing the signal level in all other directions. The advantage of this phenomenon is more then just the simple point to point signal increase. VHF and UHF signals reflect more readily from objects like buildings, mountains, or other physical structures then do their HF counter parts. This reflection can cause multipathing which means the signal can be coming in from more then one direction. Because these reflected signals travel different distances they will most likely arrive at different phase angels which will cause the signal to interfere with itself. Beams can be used to increase the strongest signal while reducing all the others thus reducing the results of multipathing.
Sometimes a station which is blocked by an object can be reached by a VHF or UHF signals by reflecting the signals off a structure. This means the strongest signal may be in a direction away from the physical location of the other station.
The blocking of signals and multipathing can cause a fluttering sound to mobiles using VHF and UHF. This is frequently referred to as picket fencing. This same problem is sometimes observed when using a handheld unit by reports of a strong signal being changed to a weak signal though no appreciable change has take place. Because of the lower transmit power of the handheld the receive signal may not change noticeably. The best thing to do in such an event is to move around to look for a place where the signal is again improved.
Repeaters usually use vertically polarized antennas because they are easy to make omni-directional (radiate in all directions equally) then horizontally polarized antenna systems. For the same reason most mobile antenna systems are vertically polarized. When a two stations are trying to communicate with one having a horizontal antenna and the other having a vertical antenna as much as a 10 DB (100 times) loss can be produced. For this reason when using a handheld unit and working a distant repeater the antenna should be held as close to vertical as possible.
UHF signal will normally out perform VHF signals when being operated from within a building because The shorter wavelength of UHF signals allows them to more easily penetrate urban areas and buildings.
HF signals can be heard from stations even from as far as the other side of the world because HF signals can reflect off the ionosphere. VHF and UHF signals are not normally reflected by the ionosphere but sometimes a sporadic reflection from the E layer of the ionosphere will allow long distance VHF communications possible.
Strong VHF or UHF signals which overload the receiver will sometimes cause undesired signals to be heard. This can cause sudden bursts of tones or fragments of different conversations to be heard which interfere with the desired signal.
1. T9B01 (C)
Why are VHF/UHF signals not normally heard over long distances?
A. They are too weak to go very far
B. FCC regulations prohibit them from going more than 50 miles
C. VHF and UHF signals are usually not reflected by the ionosphere
D. They collide with trees and shrubbery and fade out ~~
2. T9B02 (D)
What might be happening when we hear a VHF signal from long distances?
A. Signals are being reflected from outer space
B. Someone is playing a recording to us
C. Signals are being reflected by lightning storms in our area
D. A possible cause is sporadic E reflection from a layer in the ionosphere
~~
3. T9B03 (B)
What is the most likely cause of sudden bursts of tones or fragments of different conversations that interfere with VHF or UHF signals?
A. The batteries in your transceiver are failing
B. Strong signals are overloading the receiver and causing undesired signals to be heard
C. The receiver is picking up low orbit satellites
D. A nearby broadcast station is having transmitter problems
~~
4. T9B04 (A)
What is the radio horizon?
A. The point where radio signals between two points are blocked by the curvature of the Earth
B. The distance from the ground to a horizontally mounted antenna
C. The farthest point you can see when standing at the base of your antenna tower
D. The shortest distance between two points on the Earth's surface
~~
5. T9B05 (D)
What should you do if a station reports that your signals were strong just a moment ago, but now they are weak or distorted?
A. Change the batteries in your radio to a different type
B. Speak more slowly so he can understand your better
C. Ask the other operator to adjust his squelch control
D. Try moving a few feet, random reflections may be causing multipath distortion.
~~
6. T9B06 (B)
Why do UHF signals often work better inside of buildings than VHF signals?
A. VHF signals lose power faster over distance
B. The shorter wavelength of UHF signals allows them to more easily penetrate urban areas and buildings
C. This is incorrect; VHF works better than UHF inside buildings
D. UHF antennas are more efficient than VHF antennas
~~
7. T9B07 (C)
What is a good thing to remember when using your hand-held VHF or UHF radio to reach a distant repeater?
A. Speak as loudly as possible to help your signal go farther
B. Keep your transmissions short to conserve battery power
C. Keep the antenna as close to vertical as you can
D. Turn off the CTCSS tone
~~
8. T9B08 (B)
What can happen if the antennas at opposite ends of a VHF or UHF line of sight radio link are not using the same polarization?
A. The modulation sidebands might become inverted
B. Signals could be as much as 100 times weaker
C. Signals have an echo effect on voices
D. Nothing significant will happen
~~
9. T9B09 (B)
What might be a way to reach a distant repeater if buildings or obstructions are blocking the direct line of sight path?
A. Change from vertical to horizontal polarization
B. Try using a directional antenna to find a path that reflects signals to the repeater
C. Ask the repeater owners to repair their receiver
D. Transmit on the repeater output frequency
10. T9B10 (B)
What term is commonly used to describe the rapid fluttering sound sometimes heard from mobile stations that are moving while transmitting?
A. Flip-flopping
B. Picket fencing
C. Frequency shifting
D. Pulsing
~~
11. T9B11 (C)
Why do VHF and UHF Radio signals usually travel about a third farther than the visual line of sight distance between 2 stations?
A. Radio signals move somewhat faster than the speed of light and travel farther in the same amount of time
B. Radio waves are not blocked by dust particles
C. The Earth seems less curved to radio waves than to light
D. Radio waves are blocked by dust particles
Answers: C D B A D B C B B B C
Saturday, September 8, 2007
LESSON 32
Feedlines types, losses vs. frequency, SWR concepts,
measuring SWR, matching and power transfer, weather protection,
feedline failure modes
One of the most common pieces of test equipment in the ham shack is the SWR meter. The SWR meter is used to measure how well a load is matched to the transmitter’s output. While it does not give a complete analysis of the antenna system it is a good indicator of problems in the antenna or feed line. A perfect match between the antenna and feed line is 1 to 1. A directional watt meter can be used in place of the SWR meter.
A low SWR is important for efficient operation of the antenna system. A high SWR means there is an impedance mismatch that results in poor transfer of power.
A loose connection or poor solder joint might be the cause of erratic changes in SWR readings.
While the old tube transmitter could tolerate higher SWR then the newer solid state equipment so most modern transmitters have a protection circuit which can detect the SWR and start to shut the power down at approximately 2 to 1 ratio.
Antenna feed lines should be checked frequently. Coax that is exposed to weather will experience greater losses over the years of operation. Age will deteriorate coax cable due to temperature extremes, moisture, and sunlight this deterioration will result in higher losses which will be converted to heat along the length of the cable. Moisture contamination is the most common cause for coax cable failure which usually comes in at the connectors if they are not sealed against the weather. Coax cable’s outer insulation is usually black because black will provide the best protection against ultraviolet light.
Because of the ease of installation with much less special installation considerations coax cable is the most common feed line used by amateur radio operators. While various impedances of coax cable are available most amateur radio installations use 50 ohm coax.
1. T9C01 (A)
What, in general terms, is standing wave ratio (SWR)?
A. A measure of how well a load is matched to a transmitter
B. The ratio of high to low impedance in a feed line
C. The transmitter efficiency ratio
D. An indication of the quality of your station ground connection
~~
2. T9C02 (C)
What reading on a SWR meter indicates a perfect impedance match between the antenna and the feed line?
A. 2 to 1
B. 1 to 3
C. 1 to 1
D. 10 to 1
~~
3. T9C03 (B)
What might be indicated by erratic changes in SWR readings?
A. The transmitter is being modulated
B. A loose connection in your antenna or feedline
C. The transmitter is being over modulated
D. Interference from other stations is distorting your signal
~~
4. T9C04 (A)
What is the SWR value where the protection circuits in most solidstate transmitters begin to reduce transmitter power?
A. 2 to 1
B. 1 to 2
C. 6 to 1
D. 10 to 1
~~
5. T9C05 (C)
What happens to the power lost in a feed line?
A. It increases the SWR
B. It comes back into your transmitter and could cause damage
C. It is converted into heat by losses in the line
D. It can cause distortion of your signal
~~
6. T9C06 (D)
What instrument other than a SWR meter could you use to determine if your feedline and antenna are properly matched?
A. Voltmeter
B. Ohmmeter
C. Iambic pentameter
D. Directional wattmeter
~~
7. T9C07 (A)
What is the most common reason for failure of coaxial cables?
A. Moisture contamination
B. Gamma rays
C. End of service life
D. Overloading
~~
8. T9C08 (B)
Why is it important to have a low SWR in an antenna system that uses coaxial cable feedline?
A. To reduce television interference
B. To allow the efficient transfer of power and reduce losses
C. To prolong antenna life
D. To keep your signal from changing polarization
~~
9. T9C09 (C)
What can happen to older coaxial cables that are exposed to
weather and sunlight for several years?
A. Nothing, weather and sunlight do not affect coaxial cable
B. The cable can shrink and break
C. Losses can increase dramatically
D. It will short-circuit
~~
10. T9C10 (D)
Why is the outer sheath of most coaxial cables black in color?
A. It is the cheapest color to use
B. To see nicks and cracks in the cable
C. Black cables have less loss
D. Black provides protection against ultraviolet damage
~~
11. T9C11 (B)
What is the impedance of the most commonly used coaxial cable in typical amateur radio installations?
A. 8 Ohms
B. 50 Ohms
C. 600 Ohms
D. 12 Ohms
~~
12. T9C12 (A)
Why is coaxial cable used more often than any other feed line for amateur radio antenna systems?
A. It is easy to use and requires few special installation
considerations
B. It has less loss than any other type of feedline
C. It can handle more power than any other type of feedline
D. It is less expensive than any other types of line
Answers: A C B A C D A B C D B A
measuring SWR, matching and power transfer, weather protection,
feedline failure modes
One of the most common pieces of test equipment in the ham shack is the SWR meter. The SWR meter is used to measure how well a load is matched to the transmitter’s output. While it does not give a complete analysis of the antenna system it is a good indicator of problems in the antenna or feed line. A perfect match between the antenna and feed line is 1 to 1. A directional watt meter can be used in place of the SWR meter.
A low SWR is important for efficient operation of the antenna system. A high SWR means there is an impedance mismatch that results in poor transfer of power.
A loose connection or poor solder joint might be the cause of erratic changes in SWR readings.
While the old tube transmitter could tolerate higher SWR then the newer solid state equipment so most modern transmitters have a protection circuit which can detect the SWR and start to shut the power down at approximately 2 to 1 ratio.
Antenna feed lines should be checked frequently. Coax that is exposed to weather will experience greater losses over the years of operation. Age will deteriorate coax cable due to temperature extremes, moisture, and sunlight this deterioration will result in higher losses which will be converted to heat along the length of the cable. Moisture contamination is the most common cause for coax cable failure which usually comes in at the connectors if they are not sealed against the weather. Coax cable’s outer insulation is usually black because black will provide the best protection against ultraviolet light.
Because of the ease of installation with much less special installation considerations coax cable is the most common feed line used by amateur radio operators. While various impedances of coax cable are available most amateur radio installations use 50 ohm coax.
1. T9C01 (A)
What, in general terms, is standing wave ratio (SWR)?
A. A measure of how well a load is matched to a transmitter
B. The ratio of high to low impedance in a feed line
C. The transmitter efficiency ratio
D. An indication of the quality of your station ground connection
~~
2. T9C02 (C)
What reading on a SWR meter indicates a perfect impedance match between the antenna and the feed line?
A. 2 to 1
B. 1 to 3
C. 1 to 1
D. 10 to 1
~~
3. T9C03 (B)
What might be indicated by erratic changes in SWR readings?
A. The transmitter is being modulated
B. A loose connection in your antenna or feedline
C. The transmitter is being over modulated
D. Interference from other stations is distorting your signal
~~
4. T9C04 (A)
What is the SWR value where the protection circuits in most solidstate transmitters begin to reduce transmitter power?
A. 2 to 1
B. 1 to 2
C. 6 to 1
D. 10 to 1
~~
5. T9C05 (C)
What happens to the power lost in a feed line?
A. It increases the SWR
B. It comes back into your transmitter and could cause damage
C. It is converted into heat by losses in the line
D. It can cause distortion of your signal
~~
6. T9C06 (D)
What instrument other than a SWR meter could you use to determine if your feedline and antenna are properly matched?
A. Voltmeter
B. Ohmmeter
C. Iambic pentameter
D. Directional wattmeter
~~
7. T9C07 (A)
What is the most common reason for failure of coaxial cables?
A. Moisture contamination
B. Gamma rays
C. End of service life
D. Overloading
~~
8. T9C08 (B)
Why is it important to have a low SWR in an antenna system that uses coaxial cable feedline?
A. To reduce television interference
B. To allow the efficient transfer of power and reduce losses
C. To prolong antenna life
D. To keep your signal from changing polarization
~~
9. T9C09 (C)
What can happen to older coaxial cables that are exposed to
weather and sunlight for several years?
A. Nothing, weather and sunlight do not affect coaxial cable
B. The cable can shrink and break
C. Losses can increase dramatically
D. It will short-circuit
~~
10. T9C10 (D)
Why is the outer sheath of most coaxial cables black in color?
A. It is the cheapest color to use
B. To see nicks and cracks in the cable
C. Black cables have less loss
D. Black provides protection against ultraviolet damage
~~
11. T9C11 (B)
What is the impedance of the most commonly used coaxial cable in typical amateur radio installations?
A. 8 Ohms
B. 50 Ohms
C. 600 Ohms
D. 12 Ohms
~~
12. T9C12 (A)
Why is coaxial cable used more often than any other feed line for amateur radio antenna systems?
A. It is easy to use and requires few special installation
considerations
B. It has less loss than any other type of feedline
C. It can handle more power than any other type of feedline
D. It is less expensive than any other types of line
Answers: A C B A C D A B C D B A
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