Your audio isn’t what it used to be and its time to replace the mic on your CB but upgrading will mean more choice and quality than the basic mic that you bought with your CB.

The choice of new or used is never an easy one but if you are a purist and want to have the mic to match your CB the age of the set will make that decision for you. The one problem with buying a used mic is they are usually the most handled part of the rig and in between spending years clasped in a sweaty palm and being dropped on a regular basis means some of the used ones up for sale can be in poor condition.

Modulation Limits

CB Radios have preset limits on the amount of modulation that can be applied to the outgoing radio signal (as do most commercial available two way radios), this is set as a requirement in the type of license issued to make their production and sale possible.

If these limits were not controlled imagine the utter chaos on a channelized system like CB, its bad enough sometimes when another transmitter near by bleeds over 2 channels either side but take away modulation presets and things would be a lot worse.

The only way to remove these preset limits is to physically bypass this circuit inside the CB altogether (but that’s another web page altogether).

When choosing a replacement mic the frequency response is an important factor, not enough response down at the low end of the sound frequency and your voice will lack any bass.

One recommendation if you think that your mic might be letting you down is to borrow one in the short term and compare the audio against the one your are thinking of replacing as your mic may not be the problem and something else could be destroying the audio output of your setup.

Don’t fear the plug!

Even if you cant find what you want in the pin out style for your CB these things can easily be fixed with little knowledge and skill needed to change the plug or the wiring as all mics are of the same basic design.

The internet is full of information about making these changes and any good dealer will have some idea about what you should do to adapt your new mic or at least be able to point you in the right direction.

What ever CB radio you use finding a mic to fit it or adapting another for your rig is easy enough.

Click here to see a range of replacement CB mics

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17 Responses to Replacement CB Microphones

  1. Mike says:

    Hi Carl, I’ve been out of town since last contact. It seems my last message to you disappeared. I’m not on facebook or twitter but you can use my email as I check it numerous times daily. If that’s okay let me know. Thanks again, Mike

    • Carl says:

      Hi Mike

      I took down the comments as I sent you an email for the first steps in getting the mic wired. Are you sure its not in your inbox?

      I’ll resend it from a gmail account anyway, which tends to be more reliable then the ones I pay for 🙂

  2. Mike says:

    On the 4 pin side of the MC-50 mic adapter, with the notch facing down, working counter clockwise starting with the bottom right pin. 1. White and Shield 2. Red 3. Violet/Purple 4. Yellow. Hope that helps…I hope you can solve this puzzle. Thanks again, Mike

    • Carl says:

      Hey Mike can we move this over to social media?, the instant messaging is going to make things much quicker if I need to send you web links.

      Let me know your preference and I’ll email you a link.

  3. Mike says:

    Thanks Carl….I know your busy so whenever you have time is fine. I’m just happy that your looking it up for me, so no big hurry….thanks again Mike

    • Carl says:

      Ok Mike try this….

      On the 142gtl

      Pin 1 Yellow
      Pin 2 Braid
      Pin 3 Voilet/Purple
      Pin 4 No connection
      Pin 5 Red

      I,m assuming these are the color wires you now have on the end of the MC 50 lead.

      • Mike says:

        Okay that is the wires coming from the 142 gtl side. They are all correct but there is also a white wire and i’m assuming then that the white wire is not connected and just cut off? Now what pins do these attach to on the adapter on the MC 50 side as the MC 50 plug has only 4 pins or am I missing something? Thanks Mike

        • Carl says:

          OK Mike, sorry for the confusion. I was working on the idea that you had cut the plug off the MC-50 and we were dealing with the bare wires on that cord.

          Lets take a small step back and you explain how you wish to attach the mic and 142 GTL together (the general mechanics and not the wiring layout).

          I know this has been slow going but its crazy SOTA season this time of year and I’m never in the house, all back to normal now.

          • Mike says:

            Hi Carl, I think that I caused the confusion. I bought (from ebay) a 5 pin adapter cable that is wired for the 142 gtl radio mic and at the other end of the adapter cable is a 4 pin male that was supposed to allow me to plug in my MC-50 microphone, however the MC-50 side was not wired correctly so it wouldn’t work. I un-soldered the wires from the 4 pin side in an attempt to re-wire it correctly but so far my hit and miss approach has not worked. This is the boom mic that you helped me with. All 5 wires you described are correct on the Cobra side. I know your busy so whenever you get a chance to answer is fine. Thanks again Mike

            • Carl says:

              Hey Mike, I,m with you now.

              I,m going to need to know which of the wires coming from the adapter are going to what pins on the MC-50 connector.

  4. Mike says:

    Hi Carl, I was just wondering if you had time to find wiring diagrams for my mic problem. I can re wire the plug. I already have unsoldered the wires from the 4 prong plug as I was using trial and error method……got only error unfortunately. Thanks again for all your help. Mike

    • Carl says:

      Sorry Mike, I’ve not forgotten about you 🙂 , this time of year is ultra busy for me and I don’t spend much time in front of the computer.

      I’ve already had a look and am halfway to a solution, today is an ‘off day’ and will dig into it for you.

  5. Mike says:

    Hi Carl, I haven’t had a chance to get back to you (busy summer). I did as you said and pulled the bottom off the mic base and I used a coiled wire from another mic and wired it in….works beautifully. So now I have my boom mic but now I would like to use it on a different radio-my Cobra 142 GTL. It has a 5 pin male and the Kenwood MC-50 has a 4 pin male. I have an adapter wire that I purchased that plugs into the Cobra and then into the MC-50 mic wire, however it is not wired correctly as they promised. I’ve ordered 2 different adapters that were supposed to be right. I have tried different wiring diagrams but having trouble going from 5 wires to 4 wires. You have been a fountain of information in the past and I was wondering if you could help. Thanks Mike

    • Carl says:

      Hi Mike

      Your adapter problem is not uncommon as they are very broad based and have trouble when it comes to mics like the MC-50. I’ve just got back from a camping trip and need some sleep 🙂 but I’ll pull some circuit diagrams up later and see if we can’t get you going.

      It may be a case of doing a bit of rewiring and put a brand new plug on the end of the mic, unless you lucky enough to alter one of the adapters.

  6. Mike says:

    Hi Carl, Thanks for the come back. I’ll have to get some wire and look into your solution. Sounds like a plan. the audio should be fine as the coiled wire running from the radio to the mic base is about 5 feet when stretched out. The wire running from the base to the mic is only about a foot long and that’s the one I need to make longer. I will let you know how it turns out as I’ll have to probably order the wire unless I can find an electronics store in the area that would have it. Thanks Mike

  7. Mike says:

    Hi Carl, You have helped me more than you will ever know. I do have a new question. I purchased a Kenwood MC-50 Microphone and it really works great but due to my limited space on my desk I would like to convert it to a boom mic. I have the boom but I need about 4 ft of wire to connect the microphone to base, which I can leave on my desk to key with. I’m not sure where to purchase the cable and I would like if I could get it pre wired. The mic and base have a 5 pin plug. Any suggestions or ideas??? Thanks Mike

    • Carl says:

      Hey Mike

      OK, I’ve had a look and couldn’t find anything that would solve your problem (in way of an extension lead). You may be able to get one made, but it looks like the connectors are non standard and may be a pain to get hold of.

      So, I’m going to approach this as if I was solving the problem myself (which may not be up your street but here goes)

      I would open up the mic base and unplug the connector inside, desolder or unwire the connector and reconnect once its outside the base (please make a note of where everything goes).

      Find 2 corresponding connectors that will plug into the one you’ve just removed and into the connector inside the mic base, add a length of 5 core CB mic wire (coiled or not, you should get your 4 foot) or some decent multicore audio cable.

      If things are a little loose in the hole in the base, add a grommet to tighten it up and maybe a tie wrap or two inside to stop any pulling at the point where the connector plugs into the circuit board.

      At least this way its easy to go back to the original mic configuration and saves you cutting any of the wires.

      One point I’d like to make is have you tested the audio through the CB with the microphone so far away from you?

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