Thanks to the people who posted the link. I had seen that page earlier but didn't follow the signal off the board.
The pot in the control head seems to have its arm and one end connected to ground. The other end goes through some resistors before leaving the control head. I can see the effect of turning the pot down at pin 9 of the control cable; it varies from about 3-5 kOhms. I thought it was just a DC signal or just a varying resistance to ground. The schematic posted doesn't show the wiring from the audio board out to the pot on the control head. I'm guessing that the signal coming into the squelch pot on the audio board is detected audio, since it then feeds the internal squelch pot which sets the gain and threshold of the squelch circuit. I'll have to rethink and evaluate this new information. Bob M. ====== --- sgreact47 <[EMAIL PROTECTED]> wrote: > Bob, > > Look here for the modified audio board. > > http://www.batlabs.com/images/marsqsch.jpg > > The squelch control circuit is there, uses the > Micor, MSF, high > speed squelch. > > "Bob M." <[EMAIL PROTECTED]> wrote: > > > > I'm working on a 42-50 MHz MaraTrac with the A7 > > advanced head that has a squelch pot on it. The > > squelch is open all the time, and neither the > control > > head pot or the pot inside the radio will close > the > > squelch. ____________________________________________________________________________________ Never miss a thing. Make Yahoo your home page. http://www.yahoo.com/r/hs
