That’s the essence of my question Mr. Crowley. The PS15 manual reads :
“The AUDIO COUPLING jack may also be used to input a
signal into the system. Use at least a 2.2 kilohm resistor in
series with the signal source to prevent loading of the RTS
Systems intercom line. Use an audio isolation transformer
to prevent ground loops.”
So in theory it could work with the proper attenuation/isolation as you mentioned.
There is also this interface device from Eartec:
http://eartec.com/SLTalk%20Interface/sltinterface.html
Which could serve the same purpose.
Chuck
