APX 8500 CPS Volume Adjustment Question

[innokuous1]

I've been asked to troubleshoot an audio volume complaint on a fire truck..

The radio is a remote mounted APX 8500 with two control heads, one
inside by the officer seat and one outside by the pump panel.

The outside head has a palm mic and external speaker.

The inside head has a palm mic, a telephone handset speaker/mic and an external speaker. Audio also passes through the speaker in the head. The telephone handset is made by Motorola with just a PTT button on it, no model number that I can find. The handset cradle has no wiring, it just supports the handset.

The complaint is the audio coming through the handset is too loud so the volume knob on the head gets turned down.
The resulting problem is when the handset is no longer being used the volume coming through the other speakers is low and
transmissions are missed unless someone remembers to turn the volume on the head back up.

My question is, using the CPS can I turn down the audio volume going just to the handset?

I'm looking at the CPS in "Radio Ergo Config">"Radio Profiles">"Default">"Audio Settings">"Speaker/RX Settings" and I'm not
sure if I'm in the right place to solve the problem and if I am in the right place, what to change.

Any thoughts on this would be appreciated.

 

[buddrousa]

What happens when if you turn up the volume control at the pump panel or is this a problem with audio only in the cab of the Firetruck.

 

[ramal121]

So in the cab you have both a palm mic and a handset? Okaaaay. Who rigged this up and how is this all connected?

The handset you describe is the newer style from Motorola. You state the earpiece volume goes up and down when adjusted from the head. This means the handset is connected to the speaker output and this is not where the earpiece is designed to pick up its audio. Much too hot for it. That handset needs to be connected to the lower constant receive audio that is available either at the mic connector or the 26 pin accessory connector. The volume in the earpiece stays the same and the speaker is set with the volume control. You can also have the speaker mute when the handset is removed from the cup when it is installed correctly.

Now the older G style handsets (all the wiring is in the hangup cup) do operate off of the speaker output and the earpiece can handle that volume level.

Where does your handset connect to the radio?

The only other alternative is to pad down the receive audio to the handset with an appropriate dropping resistor.