Feeding Audio into a Motorola Mobile

[K6PYR]

I have a need to feed audio directly into a Motorola mobile radio. (not via the microphone)
I'm looking for either a pre-made device that I can put a connector on and connect to a Motorola mobile or a circuit that I can build. I need to be able to bring headphone level audio down to whatever Motorola expects to see at the mike or auxiliary input connectors. I imagine it would have a potentiometer on it somewhere to adjust the incoming gain.

Currently I use a Motorola Radius type mobile, but I'm open to swapping radios if one model is better for this than another. They are not terribly expensive on the used market. I've got to build up three of these, so no matter what, I've got to purchase some more radios.

I've looked for a commercial device and have not found one. Surely one of you Motorola experts out there might have seen such a thing in the past and can send me in the right direction?

Thanks.

 

[SteveC0625]

Check out ebay seller mre1032. He has what you want.

 

[mmckenna]

CDM-750's are going for dirt cheap on e-Bay. They have a 20 pin rear connector (will accept the 16pin connectors, the other 4 pins are not needed for what you are doing).
MRE1032 is a good seller of this stuff on e-Bay, he's got some premade cables. But if you are cranking out a bunch of these on your own, you can buy just the connectors and pins to do what you want.

You'll need to pad down the audio to the Motorola specs and figure out a PTT circuit. Easy to do.
Batlabs has the info you need on the pinouts: HT750/1250/1550/PRO5150/7150/9150/GP320/340/360/380/ GP318/338/GP640/680/1280/CDM750/CDM1250/CDM1550,etc.

This might handle your headphone level to to mic level input adaptation: https://www.rdlnet.com/downloads/datasheets/st-mx2.pdf
RDL makes some pretty decent products we've used for this sort of stuff in the past. RDL Homepage

 

[K6PYR]

Thanks. I'll look into both.

 

[cmdrwill]

You'll need to pad down the audio to the Motorola specs

Most Motorola mobile radios need at least 180 mill a volts mic audio.

Need a little more info on your "headphone level audio".