Robert, if you are using the external mic connector to key the radio, you will have to "key" the mic line by using a resistor to ground versus directly to ground. The radio goes into TX mode when current is pulled through the mic line. If you are paralleling the internal PTT switch, this does not apply. You can search for one of the sites with the old ACC controller info, and there is an appnote on hooking the 2-, 3-, and 4- radios to their units that shows PTT and mic audio connections. ACC used the FC-1 board to interface the controller logic to the radio.
Mike - w5jr - via arrl.net - Milton, GA
