GeneralG4D11
How close to the upper edge of a band’s phone segment should your displayed carrier frequency be when using 3 kHz wide USB?
B
Answer
Amateur station equipment
Type
A
At least 3 kHz above the edge of the band
B
At least 3 kHz below the edge of the band
C
At least 1 kHz above the edge of the segment
D
At least 1 kHz below the edge of the segment
Answer Notes
In Upper Sideband (USB) operation, your transmitted voice signal occupies the frequency space directly above your displayed carrier frequency. When transmitting a 3 kHz wide USB signal, your actual RF energy extends up to 3 kHz higher than the frequency shown on your display.
To prevent your signal from crossing outside the allowed frequency privileges, you must position your carrier frequency at least 3 kHz below the upper edge of the band or phone segment.
Failing to leave this 3 kHz buffer means the higher audio frequencies of your voice will create an out-of-band emission. Options suggesting tuning above the edge or leaving only a 1 kHz gap are incorrect because they do not accommodate the full width of the sideband.
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How close to the lower edge of a band’s phone segment should your displayed carrier frequency be when using 3 kHz wide LSB?
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