"Mike McAuley" wrote in message
nk.net...
Thanks again Greg for the info, but I guess what I'm looking for, is a way
to trigger the LED with just speaker level voltage. I don't really want to
run a separate wire to the speaker or tamper with any of the circuitry
inside the radio.

This doesn't sound much like rocket science, although it strikes me as more
hassle than it should be. First, you want to sample the audio with a high
impedance -- probably an op amp would do here. Then, you rectify the noise
and feed a comparator, or maybe just a transistor. Use that to drive a LED.

The actual mechanics of getting a wire to sample each speaker and then
placing an LED near each radio, or in some sort of arrangement that helps
you know what radio, seems to be as much of a hassle as the electronics.
Maybe you have a box that connects to each radio and then from there to the
speakers. If you make each LED a different color you would eventually
associate the color with the radio. Might work better than getting used to
the position if the LEDs are all close.

Interesting problem though. Practically all of my radios have either an LED
or an indication on the LCD that the squelch is open. Could be because I
tend to favor Icoms. But it doesn't seem to help remind me to engage brain
and think about what radio is talking before I pick up the mike!

--McD