Spectra speaker lead voltage

[n9upc]

Greetings,

I am trying to get a core sense off of a dash mount spectra and heard that the speaker leads carry voltage on them and that could be able to drive a relay for a COR/COS set-up.

My question I have is that if I use one of the leads for voltage to drive a relay what is the BEST method to get audio to drive the mic input on the other radio - factoring in that the mic input has a mic hi (+) and a mic lo (-).

Any help would be great!!!

[lm2032]

What you're wanting to do is not a problem. Here's a post with a schematic to make a Spectra repeater interface.

http://batboard.batlabs.com/viewtopic.php?p=245306

Check out the in-band schematic for the details on the relay connections. The relay is a 250 ohm, 5 volt reed relay. I've build this circuit and it works fine. You can also substitute a transistor or an opto for the relay depending on how much current you need to switch.

[Jim202]

UNDER NO CIRCUMSTANCES DO YOU WANT TO GROUND EITHER SIDE OF THE SPEAKER WIRES. With that
said, if you do ground either wire, you will blow the audio output amp.

Parts are starting to get hard to obtain for these radios.

Jim

Greetings,

I am trying to get a core sense off of a dash mount spectra and heard that the speaker leads carry voltage on them and that could be able to drive a relay for a COR/COS set-up.

My question I have is that if I use one of the leads for voltage to drive a relay what is the BEST method to get audio to drive the mic input on the other radio - factoring in that the mic input has a mic hi (+) and a mic lo (-).

Any help would be great!!!

[Will]

UNDER NO CIRCUMSTANCES DO YOU WANT TO GROUND EITHER SIDE OF THE SPEAKER WIRES. With that
said, if you do ground either wire, you will blow the audio output amp.

Parts are starting to get hard to obtain for these radios.

I have a good supply of the audio amp ICs for Spectras and Astro Spectras.

[Will]

My question I have is that if I use one of the leads for voltage to drive a relay what is the BEST method to get audio to drive the mic input on the other radio - factoring in that the mic input has a mic hi (+) and a mic lo (-).

The Mic audio in that circuit is obtained thru the 2.2 uF non polarized capacitor in series with a 2.2 K resistor going to the Mic input on pin 15 of the transmit radio.