Radius Encoder Install Question

[ccomm911]

Hello All. We have a VHF Radius mobile radio with a 5 pin accy. connector. We need to install a Communications Specialists ST-804 Two Tone encoder in the Radius. The encoder will be triggered by an external source. There will NOT be a microphone connected in this application. Where inside of the radio can we get the PTT and the point to tie in the audio from the encoder to TX audio? I see a test point on the board, just under the big ignition jumper that is labeled TXA. Can we tie in there? Or, since there is no mic attached, can we just make a new RJ45 plug and use the PTT and Audio in there? It has been a very long time since we have done one of these, just can't remember how. Please be specific with any instructions you might have. Thank you very much in advance for your assistance.

[Batwings21]

Use the mic connector.
http://batlabs.com/images/maxrad.gif