CDM control station speaker issue

[kb1qwb]

I've got a CDM-750 installed in a CDM-Series control station. The radio's internal speaker is disabled as to not compete with the station speaker. The problem is that when I plug in a headset, while the headset works fine, the station speaker also continues producing audio.

I called Motorola tech support, was given a callback ticket, and eventually told that the unit is working as it should be, and my only option is to turn the radio volume all the way down while using the headset. Unfortunately, that doesn't bring the volume nearly low enough - it would still be clearly audible to other users in the room, which is what I'm trying to avoid. I've searched the Professional software (and Google) and it seems the CDM has no minimum volume setting that I can lower.

The settings in the control station are set by a series of Dip switches in the back of the unit, none of which have helped the problem. Thank you in advance for any ideas!

 

[cabletech]

The only way to disable the speaker, is to install a on/off switch in line with the speaker or do like I do
and cut the speacker line and install a second speaker jack that when you plug in the headset, it will
automaticlly disable the normal speaker.

 

[mmckenna]

You will likely need to design something yourself. I set up some Peiker radio handsets (like a phone handset) to work on a bus fleet. This was with Kenwood NX-900 radios, but the general interface is the same.

The handset cradle has a hook switch in it that senses if the handset is hung up on the cradle or not. When the handset is hung up, I've set up the speaker audio to route through the switch to a loudspeaker that is built into the handset cradle. When the handset goes off hook, the speaker audio is routed to the handset speaker and the one in the cradle is disconnected.

The Kenwood's allow you to set them up to allow both the hand mic and the external mic input on the DB25 of the back of the radio to work at the same time. This allowed the bus drivers to use the regular hand mic for most of their traffic, and only use the handset when dispatch tells them to for passing traffic they don't want everyone on the bus to hear.

Pei Tel HA10 is the specific model. HA10 - Handset with thumb guard, one button and cradle | pei tel Communications GmbH | menschen. entwickeln. sicherheit.

I've never used the Motorola handset for the CDM's, but I can't imagine there isn't a way to do this using the connector on the back of the radio. Next time I'm programming one, I'll take a look.

 

[cmdrwill]

Look for the handset option in the programming.

 

[kb1qwb]

Thanks for your replies, everyone.

N1NCI found a solution, which is to solder a 10k resister between Q2 and pin 5 on the board. Q2 goes to ground when a headset is plugged in, and pin 5 is speaker mute.