GME TX821 and Cobra CB radios

[RadioKid]

G'day all,
Just bought 2 second hand CBs from a junkyard for $10 each
A GME TX821 and a Cobra 23 channel(not sure of model, has 19m on front)
They both havent got mics. The cobra has a 4 pin socket (tried a Uniden UHF mic, not very good), and the GME has a 5 pin socket. Both radios dont have audio coming from the speakers. Is that normal?
Any ideas for where i can get mics compatible mics for them, and will a simple 27MHz whip antenna from Jaycar work?
Thanks, Mathew

[Scannersplitterguy]

No audio from the speaker, without a microphone plugged in is normal for many 27 MHz cb radios.
The PTT (push to talk) switch in the mic switches the receive audio on.
I used to repair these radios over 20 years ago
For the GME the pins on the mic socket should be as follows:
Pin 1. Mic audio
Pin 2. Ground
Pin 3. Receive (connect pins 2&3 and you should hear background static)
Pin 4. Transmit (connect pins 2&4 and the radio transmits)
Pin 5. CH.8 select. The original mic had a separate button that locked the radio to CH.8 (road/truckies channel)

Can't help with the Cobra specifically, but being a 4 pin socket, it should be ... ground/mic audio/receive/transmit.
You'll need a multimeter to work out which pin is ground, from there it's easy to work out the rest.
You can buy generic mics on ebay or Jaycar, just need the right plug and maybe a soldering iron if you have to rewire things.