Diesel, After much searching here is the exact mic pin layout for the 73v
Type 4-2
1 : Ground / Common
2 : Audio
3 : Transmit
4 : Receive
If you have a test meter you should be able to tell which wires are what on your Astatic :
Relay Switching" radios such as Connex/Galaxy/Superstar "export" units do not need any "receive" connection; (they hear with the mic disconnected); to use a M4 mic rewire it: pin 1=shield& white, pin 2=red(audio), pin 3=black(transmit) pin 4=not used.
Unfortunately there is no standard color coding for microphones. Two leads are easy to identify. One: The shield is the ground lead. Two: The wire with the shield wrapped around it is the audio lead. (Often the audio wire is white; however it may be yellow or red or some other color).
To identify the other wires: you can either look at the switch inside the mic or do some testing with an "ohm-meter" continuity tester. If you have a four wire mic: check between the shield & each unidentified wire to see which connects to the shield in receive & which connects in transmit (PTT switch button pushed in).
If there are 5 wires: do a little experimentation to see which wires connect for receive & which connect for transmit. The wire that connects to each of the other wires (one in receive & the other in transmit) is "common," the others are "receive" & transmit."
Many ASTATIC 6-wire mics have the following colors: White=Audio, Shield=Ground, Blue=Common (put with ground for 4-wire hookups), Red=Transmit, Black=Receive, (Yellow--do not use for most CB's).
God bless you all !
CDX-897
OT-897
WV-897
CM-2368
American Kangaroo-1897</p>
