XPR7550 - CH ACT?

[Mackinaw]

Hi all,

I'm trying to interface an XPR7550 with another radio. The XPR will send its received audio to an XTL for re-transmission. Normally, I would prefer to complete a project like this solely with mobile radios, but I have to deal with what I have on hand for this temporary project.

I am presently trying to determine how to activate the XTL's PTT when audio is passed from the XPR7550. On mobile versions of the XPR, such as the 5550, I believe there is a pin which represents the CH ACT status. Is there anything that would act similarly on the XPR7550's accessory connector? I have done a little research and haven't found much information how to accomplish this. Perhaps I'm simply overthinking it.

Thanks in advance for your suggestions.

 

[Mocom30]

Hi
Use home made solution. Speaker + and Speaker - are on 0 Volt level at standby, on Rx audio, the speaker + and - are on 1/2 supply voltage.
See drawing below.