Well, Gerald sent me the schematic for the Master Decoder modules I have. I compared connections on the card I have (thanks to his schematic) against what the newer card provides. Here are the comparisons:
Pin 1 - Ground = OK Pin 2 - PL Tone to Modulator = OK Pin 3 - To Audio Amplifier on Audio Board - Not called out on newer card - "No Connection" on newer card Pin 4 - PL Disable (Receiver #1, to Audio Board) = "Binary PL Out" on newer card Pin 5 - From PL Disable Switch = Not called out on newer card - "No Connection" on newer card Pin 6 - From Volume Control = Not called out on newer card - "No Connection" on newer card Pin 7 - PL Tone Out (to 4-User Module) = OK Pin 10 - Quieting Indicator = "Binary PL Gate Key" on newer card (This signal is on Pin 19 on newer card) Pin 11 - Detector Emitter Bias = OK Pin 12 - A+ = OK Pin 16 - PL Indicator = OK Pin 17 - Switched Ground from 4-User Control = Not called out on newer card - "Tone PL Detect" on newer card Pin 18 - Detector Base Bias = OK Pin 22 - PL Tone Input from Discriminator = "Binary PL Retransmit Input" on newer card (This signal is on Pin 23 on newer card) Pin 23 - Receiver Audio Switch on Audio Board = Not called out on newer card - "Tone PL Retransmit Input" on newer card Pin 24 - Exciter Ground = Not called out on newer card - "No Connection" on newer card As you can see, there are a LOT of signals that would need to be re-routed for this card to work properly... and others that appear not to be needed at all. I wonder if it is worth the effort. If I can't find the proper card, I think I'll have to resort to an external repeater controller/tone board, like either a Zetron or a Com-Spec get the station to operate properly. That is if I can find the interconnect wiring diagram. So, I ask again - if ANYONE has a TRN6165A Master Decoder card they are not using and would like to put to good use, PLEASE CONTACT ME. Mark - N9WYS
