Re: All about CB radio
I'm noticing that one of the major difficulties facing anyone just starting to get into CB repairs is the lack of a suitable RF signal generator. Synthesised AM/FM signal generators aren't cheap, even when they are quite old and second hand.
The old standby back in the day was to use another radio set to low power and running into a dummy load but in truth, the output level from that setup was always far too strong for the intended purpose.
If you took a very battered but working mobile radio and completely disabled the transmitter leaving only the initial output from the VCO, that would give a much weaker signal. It might even be possible to build a switchable attenuator inside a diecast box and put it inside the 'host' unit and take the output from that to the SO239 socket on the rear of the unit. The main problem would be stopping stray radiation coming out of the unit, along the power leads for example. On an 'ideal' test signal generator the only place the signal should be coming out of is the output socket, and nowhere else.
If you picked something with a sine-wave roger bleep (ie, Amstrad chassis) you could arrange for the beep tone to be either continuously on or continuously off, giving the option to modulate the output signal with a sinewave test tone.
It wouldn't begin to approach the low RF leakage and fully variable level output from a 'proper' purpose made generator, but it might be better than trying to tune up on a local transmitter or on off-air signals.
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