Amateur ExtraE1A03
What is the highest legal carrier frequency on the 20-meter band for transmitting a 2.8 kHz wide USB data signal?
C
Answer
Extra class rules and station restrictions
Type
A
14.0708 MHz
B
14.1002 MHz
C
14.1472 MHz
D
14.3490 MHz
Answer Notes
On the 20-meter band, the data and RTTY segment for Extra class operators is allocated from 14.000 to 14.150 MHz. Any data transmission must be kept entirely within this sub-band.
In Upper Sideband (USB) mode, the transmitted signal extends upward in frequency from the carrier. Because the requested signal is 2.8 kHz wide, its highest frequency component will be 2.8 kHz (or 0.0028 MHz) above the carrier frequency.
To calculate the highest legal carrier frequency, you must subtract the bandwidth from the top edge of the data segment: 14.1500 MHz - 0.0028 MHz = 14.1472 MHz. Operating any higher would cause the top of your data signal to illegally cross into the phone segment.
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When using a transceiver that displays the carrier frequency of phone signals, which of the following displayed frequencies represents the lowest frequency at which a properly adjusted LSB emission will be totally within the band?
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May an Extra class operator answer the CQ of a station on 3.601 MHz LSB phone?