BasicB-008-004-002
What are harmonic emissions?
A
Answer
Safety
Type
A
Unwanted signals at frequencies which are multiples of the fundamental (operating) frequency
B
Signals which cause skip propagation to occur
C
Unwanted signals that are combined with a 60 Hz hum
D
Unwanted signals caused by mixing with a nearby transmitter
Answer Notes
In radio electronics, a harmonic is an emission whose frequency is an exact integer multiple of the fundamental (operating) frequency. For example, if you are transmitting at 7 MHz, your second harmonic is 14 MHz, and your third harmonic is 21 MHz.
These unwanted signals are generated by non-linearities in the transmitter's amplifier stages. Distractors such as signals combined with a 60 Hz hum refer to power supply issues, while mixing with nearby transmitters describes intermodulation, not harmonic emissions.
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If a neighbour reports television interference on one or two channels only when you transmit on 15 metres, what is probably the cause of the interference?
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Why are harmonic emissions from an amateur radio station not wanted?