Batboard

I have a Syntor/Mitrek vintage DTMF mic and want to move it to a GTX/Maxtrac; I looked at the pinouts on the website and didn't see anywhere that it supplies +12V to the mic jack. Does the GTX/Maxtrac DTMF mic use +5V and if so, what pin is it on?

I think it is 5v on pin 5 of the Maxtrac.
You could measure it.
I have to find my DTMF mic manual....
More info here;
http://www.batlabs.com/dtmf.html
Most of that vintage mics are all very similar inside, just a matter of wiring the cable up right. I have made Mostar DTMF mics work on Maxtracs...

Max-trac wrote:I think it is 5v on pin 5 of the Maxtrac.
You could measure it.

I could, but I'm just as likely to attempt to wire the mike to a source of +5V only to discover it's an output for something ... =)

Switched B=, A+, or 5V are NOT used on the DTMF enc mics. (+12 v was used only for backlight on Syntor DTMF mics)

They get the voltage nessary to run the DTMF encoder thru the mic bias on the MIC HI wire. Yes this does have 9 to 12 volts on it from the radio without any load, there is a 560 ohm resistor in series with the voltage =MIC bias. http://www.batlabs.com/images/mcxmict1.gif

http://www.batlabs.com/images/mcxmict2.gif


http://www.batlabs.com/images/mcxmict3.gif

Switched B=, A+, or 5V are NOT used on the DTMF enc mics. (+12 v was used only for backlight on Syntor DTMF mics)

They get the voltage nessary to run the DTMF encoder thru the mic bias on the MIC HI wire. Yes this does have 9 to 12 volts on it from the radio without any load, there is a 560 ohm resistor in series with the voltage =MIC bias. http://www.batlabs.com/images/mcxmict1.gif

http://www.batlabs.com/images/mcxmict2.gif


http://www.batlabs.com/images/mcxmict3.gif