Why not use the same DB9 pinout as ARCOM and Link Comm?
We’re open to ideas, but in this case I like our pinout better. The other scheme has TX audio on 4 and RX audio on 5, which are adjacent pins in a DB-9. Ours has RX audio on 1 and TX audio on 5, which are as far apart as you can get in a DB-9. The pins adjacent to RX audio are COR and ground, and the pins adjacent to TX audio are PTT and ground, so only DC signals are near the audio pins. The TX CTCSS tone output (another “audio” pin) is near the center of the DB-9 and is surrounded by PTT and RX CTCSS, both DC signals. It’s really important to isolate RX and TX audio. Long-time listmembers will recall that we’ve solved complaints about partial DTMF muting and other audio feedthrough problems by having the customer replace a multiple-conductor shielded cable with individually-shielded cables. What is the connector pinout for the I/O connector? I’ve been asked to provide the pinout of the I/O connector, so it appears below. The connector is a DB-25F, and it handles the eight logic outpu
