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Microphone Wiring

We created this page to help people understand that not all microphones are wired the same way. For example, just because two different microphones are 4 pin does not mean that they are wired the same, even if they are the same brand! Different manufacturers may wire their microphones differently. Generally, a radio manufacturer will wire their microphones the same so that the microphones are interchangeable between their radios, however, this is not always the case.

For example, Cobra 4 Pin radios are wired 1) Shield 2) Audio 3) Transmit 4) Receive while Midland 4 Pin radios are wired 1) Audio 2) Shield 3) Receive 4) Transmit. There are some radio brands that have the same general wiring (such as Cobra and Uniden) but that is not always the case.

The list below offers some microphone wiring information. Mic wiring can be frustrating enough, but when you can't find the right wiring info, it is just impossible. We will continue to try to get all the information that we can listed on this page.

Radio Mic Wiring Diagram

CB Microphone Wiring (Galaxy)

The chart and image above are correct for these models:

(Extra NOTE: The popular Astatic 636L-DX1X is compatible with these)

Galaxy CB Radios

  • DX919
  • DX929
  • DX939
  • DX949
  • DX959
  • DX979
  • DX44V
  • DX55V
  • DX66V
  • DX77V

Cobra CB Radios

  • 19 DX IV
  • 148 GTL
  • 18 WX ST II
  • 19 DX IV Camo
  • 25 LTD
  • 25 LX
  • 25 NW LTD
  • 25 WX NW ST
  • 29 LTD Chrome
  • 29 LTD Classic
  • 29 LTD DE
  • 29 LX
  • 29 LX Camo
  • 29 NW LTD
  • 29 WX NW ST

Uniden CB Radios

  • PC68LTW
  • PC68XL
  • PC78LTW
  • PC78XL
  • PRO505XL
  • PRO510XL
  • PRO520XL

Midland CB Radios

  • 1001LWX
  • 5001
  • 9001Z

Wiring for the C29 LX MAX and the C29LTDBT:

  • 1) Ground
  • 2) Audio
  • 3) Transmit
  • 4) Receive
  • 5) BT Button
  • 6) BT Microphone


Pin-End Views

Cobra 4 Pin Mic Wiring Diagram
Cobra 4 Pin


TX = White, MOD = Red, REC = Blue, Shield/Common = Braid/Black

Midland 4 Pin Microphone Wiring Diagram
Midland 4 Pin
TX = ?, MOD = ?, REC = ?, Shield/Common = ?
Cobra 5 Pin Microphone Wiring Diagram
Cobra 5 Pin


TX = White, MOD = Red, REC = Blue, Shield = Braid, Common = Black


Wiring Color Codes for Astatic 6 Wire Microphones:

  • White - Audio
  • Shield - Ground
  • Blue - Common for Switching
  • Red - Push to Talk (Transmit)
  • Black - Receive
  • Yellow - Receive Ground (not normally used)

NEW information - 6/26/18

6 Pin President Microphone DNC520 Microphone Wiring:

1. Modulation
2. RX
3. TX (Up/Down)
5. Ground
6. Power Supply

DNC520 Microphone Wiring Diagram

Having troubles with your microphone?

  • Make sure the connections are tightened.
  • Ensure that the microphone pins on the radio are making a connection with the microphone plug.  If need be, you can very gently spread the pins with a small flathead screwdriver.
  • Make sure your CB mic is plugged in securely. Check for breaks or damage to the plug and cord. Check the pins in the radio for damage as well.
  • Be sure you are pressing the CB microphone button all the way in.
  • If it is a power mic or echo mic, make sure there is a battery in it!
  • Visit our Troubleshooting Radios Article for other helpful information.


that's great, but what's the pin pattern on a Superstar120FM I have the radio, but no mic

CB World Response: We only have information on the Superstar 120 and we are not sure if the wiring is the same for the 120FM. From the information that we have, wiring for the 120 is as follows: 1) Shield 2) Audio 3) Transmit 4) Receive If this is the case for your 120FM, this wiring is standard 4 pin Cobra/Uniden wiring so you could select a microphone such as the 636L series or KCBMIC. We hope that helps!
I dug out my Uniden PC 66 with the D104 M6B. You can't beat that mic for clarity if you can set up the mic adjustment and the mic setting on the radio right. The mic itself is about a 3. Tape over that so it stays. The issue is the rubber jacket on the D104 started falling apart and the company does not sell parts so I have to rewire with a new cord. But it is worth the trouble as some of these factory mics sound like garbage.
So I have this Pro com ll amplified Mic think made by Telex. It was wired for my Pres HR2510 and worked really good. I want to wire for my cobra 4 pin (cobra 25 and 29) but can't seem to figure out . . . Any help would be appreciated. Had a wiring booklet but misplaced it. Thanks in advance.


Thank you for contacting us!  Here is the information that we have.

The HR2510 is wired as follows:
1- Audio
2- Shield
3- Transmit
4- CH
5- CH

The Cobra radios are wired as follows:
1- Shield
2- Audio
3- Transmit
4- Receive

You might also consider the C4PHR5C adapter.
We hope that helps!
I have a cobra 29 lx max. All my wires in my mic broke off and i need to put it back together but i can not find a wire diagram any where for it. Its a 6 pin. CB World Response: Wiring for the C29 LX MAX and the C29LTDBT:

1) Ground
2) Audio
3) Transmit
4) Receive
5) BT Button
6) BT Microphone
Will a stock cobra 29 mic work on a magnum s 380 radio
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