Fascinating. Being from the ham world this is all new to me. Seems like an odd system to me, when you have the mic off the hook and tone squelch doesn't work then you hear all traffic?
Yeah, for the amateur radio crowd, this part of commercial radios might seem confusing.
Think about the old days where 2 way radios were much more common since there were no cell phones. Most contractors/service providers used some sort of radio for dispatch. Since small companies couldn't usually afford their own repeater systems, they'd rent service from a radio shop. That shop might have a repeater on a tall mountain, one channel, but they'd put in a bunch of different CTCSS and/or DCS tones. Each company would have their own tone so that their people would only need to hear the traffic intended for them. Since it would be easy for someone to talk over someone else if they didn't monitor first, the easy solution was to do this off hook tone disable. When they took the mic off hook, they'd hear any/all traffic on the repeater and know they had to wait their turn.
Much better solution that expecting a user to remember to push a button to check the channel before transmitting.
Other option was to use a "busy channel lock out", that basically kept them from transmitting if the repeater was in use.
No, the mic isn't on the hook. In fact, the mic isn't even plugged into it, just an adapter plug I made to pick off the PTT and mic input. So, which wire in the plug needs to be grounded?
Thanks, this just might be the break I need! I am at work for a 48 hour shift but will test the minute I get home on Wednesday and let you know.
OK, got it.
On the mic jack on the front of the radio, the following pins are used:
Pin # Name Function
1 MBL MIC backlight control
2 PSB 13.6vdc
3 GND Ground
4 PTT/TXD Push To Talk (Transmit Data for programming)
5 ME MIC Ground
6 MIC MIC signal input
7 HOOK/RXD Hook Detection (Receive Data for programming)
8 CM MIC data detection
So, what you need to do is to run a jumper in the RJ-45 plug that connects pin 3 (ground) to pin 7 (Hook).
That should make it look like the microphone is hung up.
Or, you can just program the radio to not use the function. I don't have the programming software in front of me, so I can't assist there, but look for a function with a term like Off-hook Decode, or something similar.