I obviously opened a can of worms with this topic. My only intent was to
draw attention to strict instructions when installing radio equipment - not
just VHF transceivers but any device sensitive to small signals.
I have no quarrel with fellow builders but the last correspondent mentioned
"noisy grounds" and "quiet grounds". The 'forest of tabs' I found to be an
excellent organiser of various aircraft ground return paths - and have used
it since the day I saw it. This can be a 'noisy' ground because it is
subject to all the noise (strobes, large on/off selections and even received
radio signals) - that's because they are meant to be DC sources.
Ah, but the 'quiet' ground probably sits somewhere on the radio set. It is
designed to absorb the noise created and then subject it to circuitry before
unleashing it on the aircraft ground. If the coax is to be grounded ( and
thus be free of interference) it goes to the quiet ground first.
All I wanted to say was - be sure to follow the radio installation
instructions to the letter. The fault lies with the use of "ground or earth"
for both points. We need another term for radio ground - maybe "quiet"
works?
Cheers, Ferg
P.S: I heartily endorse Bob Nuckolls' (AeroElectric) advice - I invited him
to conduct a well-attended lecture at our hangar
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