LESSON 14

relationship between frequency and wavelength,
identification of bands, names of frequency ranges, types of waves

Though all AC produces electromagnetic radiation normally the start of the electromagnetic spectrum starts with Very Low Frequency (VLF) radio waves which would be 3 to 30 KHz though 20 KHz is considered the lowest radio frequency wave. The wave length of 20 KHz is 15 Km. The spectrum goes up to Low Frequency (LF) Radio Waves 30 to 300 KHz is called Low Frequency radio waves. The spectrum goes up by powers of ten so that 300 KHz to 3 MHz is Medium Frequency (MF), 3 to 30 MHz is High Frequency (HF), 30 to 300 MHz Very High Frequency (VHF), 300 to 3,000 MHz Ultra High Frequency (UHF), 3,000 to 30,000 Extremely High Frequency (EHF) though most frequencies above 1,000 MHz are usually referred to as Microwave. The electromagnetic wave spectrum does not stop at microwave but continues up through infrared to visible light with a wave length of 400 - 700 nanometers and on up Ultra violet, X-ray, and Gamma ray. So the only difference between light and radio waves is the frequency or wave length. Electromagnetic radiation all travel at the same speed so radio waves and light travel at the same speed 3000,000,000 meters per second thus a wavelength in meters equals 300 divided by frequency in megahertz.

The number of cycles per second at which an alternating current flows is the frequency measured in Hertz (Hz). Thus 60 Hz means the there are 60 complete cycles per second.

As the frequency gets higher the wave length becomes shorter thus 50 MHz equals 6 meters and 150 MHz equals 2 meters.

The different ham bands are usually referred to by their wave length though the exact wave length may not be in that band. 50 MHz is an amateur frequency and is the bottom end of the 6 meter band. The 6 meter band goes from 50 to 54 MHz. Then as mentioned above 150 MHz is 2 meters long but the 2 meter band is from 144 to 148 MHz. 420 to 450 MHz is the 70 centimeter band while 428.57 is the approximate frequency of 70 centimeters.

Sound waves are not only lower in frequency but they are mechanical waves while radio waves are electromagnetic. Sound waves travel at 1,100 feet per second at sea level air pressure. Voice frequencies are considered to be between 300 to 3000 Hz.

relationship between frequency and wavelength,
identification of bands, names of frequency ranges, types of waves

Though all AC produces electromagnetic radiation normally the start of the electromagnetic spectrum starts with Very Low Frequency (VLF) radio waves which would be 3 to 30 KHz though 20 KHz is considered the lowest radio frequency wave. The wave length of 20 KHz is 15 Km. The spectrum goes up to Low Frequency (LF) Radio Waves 30 to 300 KHz is called Low Frequency radio waves. The spectrum goes up by powers of ten so that 300 KHz to 3 MHz is Medium Frequency (MF), 3 to 30 MHz is High Frequency (HF), 30 to 300 MHz Very High Frequency (VHF), 300 to 3,000 MHz Ultra High Frequency (UHF), 3,000 to 30,000 Extremely High Frequency (EHF) though most frequencies above 1,000 MHz are usually referred to as Microwave. The electromagnetic wave spectrum does not stop at microwave but continues up through infrared to visible light with a wave length of 400 - 700 nanometers and on up Ultra violet, X-ray, and Gamma ray. So the only difference between light and radio waves is the frequency or wave length. Electromagnetic radiation all travel at the same speed so radio waves and light travel at the same speed 3000,000,000 meters per second thus a wavelength in meters equals 300 divided by frequency in megahertz.

The number of cycles per second at which an alternating current flows is the frequency measured in Hertz (Hz). Thus 60 Hz means the there are 60 complete cycles per second.

As the frequency gets higher the wave length becomes shorter thus 50 MHz equals 6 meters and 150 MHz equals 2 meters.

The different ham bands are usually referred to by their wave length though the exact wave length may not be in that band. 50 MHz is an amateur frequency and is the bottom end of the 6 meter band. The 6 meter band goes from 50 to 54 MHz. Then as mentioned above 150 MHz is 2 meters long but the 2 meter band is from 144 to 148 MHz. 420 to 450 MHz is the 70 centimeter band while 428.57 is the approximate frequency of 70 centimeters.

Sound waves are not only lower in frequency but they are mechanical waves while radio waves are electromagnetic. Sound waves travel at 1,100 feet per second at sea level air pressure. Voice frequencies are considered to be between 300 to 3000 Hz.

1. T4B01 (C)
What is the name for the distance a radio wave travels during one complete cycle?
A. Wave speed
B. Waveform
C. Wavelength
D. Wave spread
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2. T4B02 (D)
What term describes the number of times that an alternating
current flows back and forth per second?
A. Pulse rate
B. Speed
C. Wavelength
D. Frequency
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3. T4B03 (B)
What does 60 hertz (Hz) mean?
A. 6000 cycles per second
B. 60 cycles per second
C. 6000 meters per second
D. 60 meters per second
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4. T4B04 (C)
Electromagnetic waves that oscillate more than 20,000 times per second as they travel through space are generally referred to as what?
A. Gravity waves
B. Sound waves
C. Radio waves
D. Gamma radiation
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5. T4B05 (A)
How fast does a radio wave travel through space?
A. At the speed of light
B. At the speed of sound
C. Its speed is inversely proportional to its wavelength
D. Its speed increases as the frequency increases
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6. T4B06 (B)
How does the wavelength of a radio wave relate to its frequency?
A. The wavelength gets longer as the frequency increases
B. The wavelength gets shorter as the frequency increases
C. There is no relationship between wavelength and frequency
D. The wavelength depends on the bandwidth of the signal
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7. T4B07 (D)
What is the formula for converting frequency to wavelength in meters?
A. Wavelength in meters equals frequency in Hertz multiplied by 300
B. Wavelength in meters equals frequency in Hertz divided by 300
C. Wavelength in meters equals frequency in megahertz divided by
300
D. Wavelength in meters equals 300 divided by frequency in
megahertz
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8. T4B08 (C)
What are sound waves in the range between 300 and 3000 Hertz called?
A. Test signals
B. Ultrasonic waves
C. Voice frequencies
D. Radio frequencies
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9. T4B09 (A)
What property of a radio wave is often used to identify the
different bands amateur radio operators use?
A. The physical length of the wave
B. The magnetic intensity of the wave
C. The time it takes for the wave to travel one mile
D. The voltage standing wave ratio of the wave
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10. T4B10 (A)
What is the frequency range of the 2 meter band in the United States?
A. 144 to 148 MHz
B. 222 to 225 MHz
C. 420 to 450 MHz
D. 50 to 54 MHz
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11. T4B11 (D)
What is the frequency range of the 6 meter band in the United States?
A. 144 to 148 MHz
B. 222 to 225 MHz
C. 420 to 450 MHz
D. 50 to 54 MHz
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12. T4B12 (C)
What is the frequency range of the 70 centimeter band in the United States?
A. 144 to 148 MHz
B. 222 to 225 MHz
C. 420 to 450 MHz
D. 50 to 54 MHz

Answers: C D B C A B D C A A D C