Keying a relay with a 4 or 5 pin mic ?

[338_MtRushmore]

Mouser is full of reed relays. Why didn't you tell me about them sooner, that could be handy.

 

[543_Dallas]

Anyone out there ever try to key a 12v or 5 volt relay with a cobra 4 or 5 pin mic external to the radio.

Like doing a project that needs a relay to key it up when the mic is keyed. I have the circuit of a 1 second pulse to key the relay and shut back off in 1 second.

Problem is on the cobra 4 pin mics on pin 3 there is 8 volts and when the mic is keyed the voltage disappears. No Voltage and comes back when mic is released.

I need the opposite 8 volts when the mic is keyed and pulsed for the 1 second and shut off.

Like i mentioned i have the 1 second circuit a transistor capacitor resistor and relay works great with external power.

When I try on a 4 pin cobra mic like I mentioned the voltage problem needing the volts when radio is keyen and not in the receive mode.

thanks for any suggestions/help

I've done this with 12 volt relays on a cobra 148 and smt uniden 78ltd. I honestly never measured open circuit voltage on the mic jack.