Love the photo - you have to stay put for some "disasters"???

I don't think this is a difficult problem, but a schematic or system wiring diagram showing the components in place, their interconnections, and boxes for the circuit(s) will speed things along.

Also, you mention 4 control tones; do you have to detect each one individually, or just pick off anything that looks and smells like a control tone?

ak

Firstly, thanks to everyone for helping out! I'm headed to Chicago this morning, and when I get settled in I will get some more info posted. All of the tones and any voice on the PA line are just audio to me. I need to grab that audio and send it through my radio out into the RF world. This part is not so bad. Recognize there is audio present and trigger contact closure to ground my PTT pin. The situation gets even more convoluted if I try to get audio from RF INTO the PA system. I will try to explain later this evening why thats difficult, and post drawings as well as radio pinouts to explain. Providing audio from the radio system into the PA creates problems, in part due to the nature of the radio programming. It may end up that I don't need to provide that functionality, but I really want it. It's going to get thick in here, so I applaud anyone who sticks around !

 

First pic is the oscillator. It is doing all 4 tones. Next pic are the relays. Top 3 are A, B, C zones. The rest correspond to tones. These are triggering from the control room buttons. No issues here, just showing some ancient tech!

 

I have 2 pins in the rear accessory port for audio + and -.

Is this mic-level or line-level audio?

 

Is this mic-level or line-level audio?

Line level. I am entering the system before any Amps.

 

I think everyone is making this more complicated that it is.

As I understand it, he wants to detect ANY audio output on the PA system, feed this into the audio input of the radio and pull the key input of the radio low. All the questions about the nature of the tones or where they come from are redundant.

I believe all that is needed is a peak detector, set for some (unknown) level on the PA output, that pulls the key pin low. The PA audio can be connected to the radio input always since it will be ignored when the key input is high.

Bob

 

I think everyone is making this more complicated that it is.

As I understand it, he wants to detect ANY audio output on the PA system, feed this into the audio input of the radio and pull the key input of the radio low. All the questions about the nature of the tones or where they come from are redundant.

I believe all that is needed is a peak detector, set for some (unknown) level on the PA output, that pulls the key pin low. The PA audio can be connected to the radio input always since it will be ignored when the key input is high.

Bob

Sorry crew, this has been established in a side-bar conversation. I was waiting on s follow up from the OP.

Peak detector (differential input) with a few seconds of time constant should do it (with comparator switch to pull aux pin to ground.

 

I think everyone is making this more complicated that it is.

As I understand it, he wants to detect ANY audio output on the PA system, feed this into the audio input of the radio and pull the key input of the radio low. All the questions about the nature of the tones or where they come from are redundant.

I believe all that is needed is a peak detector, set for some (unknown) level on the PA output, that pulls the key pin low. The PA audio can be connected to the radio input always since it will be ignored when the key input is high.

Bob

Correct

 

Sorry for the delay guys. Chicago trip is consuming much more time than I'd like!

 

Ended up with this, although I really wanted to make my own! Time got the best of the situation.

 

Ended up with this, although I really wanted to make my own! Time got the best of the situation.View attachment 138128

Probably a much better solution for a safety-related device in a commercial/industrial environment.