On (19 Feb 98) Ed Kriston wrote to All...
 EK> I have a Swan 500C HF radio that doesn't have a mic attached.  The
 EK> connector looks like it is a stereo 1/4 inch plug, that's my guess.
 EK> Does anyone know the wiring for this radio?
Lots of older radios used a "stereo" plug for this purpose. I don't have
specific knowledge of the 500C but I would bet it is like all the
others. The "tip" is for the microphone input. The "ring" (just behind
the "tip") is for press-to-talk and both use the remaining portion for a
ground. Generally the mike cord is a two conductor shielded cable. The
shield is connected to the longest part of the plug, which is ground.
You should be able to confirm this by simply pluging in a (cordless)
stereo plug, turn on the power to the radio, and briefly "short" across
the "ring" and "ground" connections on the plug which should in
turn cause the press-to-talk relay to activate. The only other way it
*could* be connected is by exchanging the tip and ring connections
since they are both "above ground". Ground would *still* be ground.
... It's always darkest just before you step on the cat.
--- PPoint 2.00
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