Batboard

I have an APX 7500 Dual Band Radio. I am attempting to add a 2nd Control head. I have changed the Codeplug to allow Multi Control Heads with up to 2 heads. Both control heads are 03s. When I flash the code plug I get the following error "CH ID # ERR".

Any suggestions?

Yes, there is a procedure to put the control heads into a test mode of sorts, and you need to assign each control head with a unique CH#. I will try to remember to post the instructions tomorrow when I'm back in the office.

Ok thank you! I have not been able to find those instructions.

Don't think this will be happening with O3 heads?? From ECAT:

What is an APX 7500 O5 Multiple Control Head Configuration?

The APX 7500 mobile radio and the O5 control head can be configured in a multi control head configuration to support up to 4 control heads on a single transceiver. This allows control of a single APX 7500 transceiver from up to 4 different control head locations. The O5 control head is the only control head that supports multiple control head configurations with up to 4 control heads.

escomm is right, only confirmed on O5 (O2/O7/O9 still TBD, well at least I can't get an answer).

Ah, I missed the fact it was O3 control heads the OP was using. Oh well, here is the procedure for future reference...this is for the XTL2500 BTW...not sure if it transfers to the APX line or not. Hopefully it helps someone out at some point.


- Connect 1 control head to radio as normal
- Connect the 2nd control head with power & data cable to head only (not to radio)...and yes, plug the data cable into the head, or otherwise it won't go into the proper test mode.
- Turn on power while holding the orange button and the lower left grey buttons in
- When the radio turns on CH ID 1 should be on the display then turn the channel selector to the CH ID 2 , then turn the power off to radio and connect the blue data cable to the radio and power on the radio and displays should power up properly.

Although it doesn't solve the OP issue... there is an updated eCat..

The APX 7500 mobile radio and the O5 control head can be configured in a multi control head configuration to support up to 4 control heads on a single transceiver. This allows control of a single APX 7500 transceiver from up to 4 different control head locations. The O5, O2 and O7 control heads are the only control head that supports multiple control head configurations with up to 4 control heads.

Thanks TPG