Question: Re-wiring an adapter for an Astatic 636L mike for a Cobra 142 GTL Base Station

[glenn11209]

Hello Forum!

I have a Cobra 142 GTL 40 channel AM base station radio with upper and lower sidebands.

I am using an Astatic 636L handheld mike for it:

Astatic 636L CB Microphone

Use the Astatic 636L Noise-Canceling Dynamic Microphone for CB, amateur radio and SSB communications. Fast Shipping, 120% Satisfaction Guarantee!

www.rightchannelradios.com

I needed to purchase a Workman C4PHR5C 4-Pin Cobra / Uniden to 5-Pin HR CB Radio Microphone Adapter which I have now:

Amazon.com: Workman C5P4C Adapter - 5 pin SSB CB mic to 4 Pin - Compatible/Replacement for CB Radio: Sports & Outdoors

Buy Workman C5P4C Adapter - 5 pin SSB CB mic to 4 Pin - Compatible/Replacement for CB Radio: Electronics - Amazon.com ✓ FREE DELIVERY possible on eligible purchases

www.amazon.com

In keying the mike on the CB THEN then audio is engaged. I have to let go of keying the mike and them the audio turns off.

***THIS IS THE ADAPTER I NEED TO RE-WIRE. I AM NOT RE-WIRING THE MIKE BECAUSE I USE IT ON A REALISTIC TRC 221 HANDELD 40 CHANNEL CB AND THE MIKE WIRING FITS THAT RADIO, SO INSTEAD I AM RE-WIRING THE ADAPTER TO BE ABLE TO USE THE SAME MIKE FOR THE COBRA 142 GTL.***

Any help as to how to properly change thr wiring would be greatly appreciated

.

 

[K4EET]

glenn11209, hello and welcome to Radio Reference!

I believe that your answer can be derived from this webpage:

Cobra 142GTL

and by studying how that Adapter is wired. Does that help you out?

Cheers! Dave

 

[glenn11209]

glenn11209, hello and welcome to Radio Reference!

I believe that your answer can be derived from this webpage:

Cobra 142GTL

and by studying how that Adapter is wired. Does that help you out?

Cheers! Dave

Hello Dave! Thanks for your reply! The information you shared with me is for the MIKE re-wiring, NOT the ADAPTER re-wiring that I mentioned in my original post.

 

[K4EET]

Hello Dave! Thanks for your reply! The information you shared with me is for the MIKE re-wiring, NOT the ADAPTER re-wiring that I mentioned in my original post.

Hmmm... but I was thinking that given the schematics and the two microphone pin-outs combined with your own ringing-out of how that adapter is wired pin-to-pin (couldn't find a schematic on that item), you would be able to figure out what wires needed to be moved to where on what pins inside the adapter. At least that was my thought process... What do you think?

Dave

 

[glenn11209]

The pictures of of the ADAPTER not the Mike. I need help configuring the ADAPTER. If I reconfigure the MIKE I cannot use it on my CB handheld.

 

[glenn11209]

I will review it Dave and see if I can figure it out and get back to you! Thank you.

 

[K4EET]

The pictures of of the ADAPTER not the Mike. I need help configuring the ADAPTER. If I reconfigure the MIKE I cannot use it on my CB handheld.

I understand that. I just cannot tell from the pictures what color wires go to what pin numbers and where the 5th pin on the Astatic mic goes to.

 

[glenn11209]

Astatic (4 wire)
1- White
2- N/C
3- Black
4- Shield
5- Red

Now, when I open the adapter there are two wires I need to switch from the 5 jack end. AM I correct in switching the Number 3 from the black wire to the Number 5 and the Number 5 black to red?

 

[glenn11209]

No, I am wrong. I will try reversing 1 and 2 on the 5 pin end of the adapter.

 

[glenn11209]

From what I can see all I need to do is reverse 1 and 2.

 

[K4EET]

Sorry for the delay in getting back to you. I have gotten distracted a 100 times today. LOL!

Sooooooo... You are suggesting to reverse pins 1 and 2 on the 5 pin plug end. What I am still a little confused about, what is the actual wiring plan of the adapter? I still have not been able to determine that. What I would like to see (and this is an example only) is this:

4 PIN END - - - - - -5 PIN END
Pin 1 -------------> Pin 3
Pin 2 -------------> Pin 5
Pin 3 -------------> Pin 1 and Pin 4
Pin 4 -------------> Pin 2

Then we can make sure that the microphone wires goes to the right places on the radio's microphone input connector.

Dave

 

[glenn11209]

From the 5 pin end of the adapter pin 1 is black, 2 is red, 3 is blue, 4 is blank without any wire, 5 is blank without any wire also.

From the 4 pin side of the adapter there are only 3 wires attached and one pin is blank without a wire. There are NO numbers on the 4 pin side.

 

[K4EET]

Pull up this PDF:

http://www.cbtricks.com/radios/cobra/142gtl/graphics/cobra_142gtl_om.pdf

On Page 18 is the Cobra 142GTL microphone wiring.

I am trying to figure out how this is going to work with the Adapter Plug and the Astatic Mic.

 

[K4EET]

Here is the Astatic 636L Wiring Diagram...

Microphone Wiring Diagram

This resource lists various CB microphone wiring information for different brands. CB mic wiring can be frustrating enough, but this guide will help!

www.wearecb.com

 

[glenn11209]

Ok thank you Dave! Its only 3 wires that we are dealing with on the adapter as you know are aware.

 

[K4EET]

So here is what has to happen. One caveat though. In the Cobra, the shield and ground are isolated whereas in the Astatic, the shield and ground are tied together. I do not know if this will cause any problems...

COBRA PIN - - - - ASTATIC PIN
1 ---------------> 2
2 ---------------> 1
3 ---------------> 4
4 ---------------> 1 ?
5 ---------------> 3

Try that and see if the tied together shield and ground cause any problems.

Dave

 

[ThomasB3131]

What kind of mic jack is on the other end of the adapter? Is the mic plug on the 636L a radio shack din plug or a normal 4 pin plug?

 

[glenn11209]

First is the Astatic mike end:



That end is plugged into this end of the adapter:





This is the other side on the adapter which is 5 pin:





That end goes into this plug in the radio:

 

[ThomasB3131]

Ok, well what you could do is figure out how the mic is wired by using your multimeter to probe between the different holes on the microphone. Once you figure that out, you can then figure the wiring on the radio by using the said method above and match the two wiring patterns together. The changes will be on the 4 pin end of the adapter. You won't have to change the wiring on the 5 pin side of the adapter since it is already correctly wired for the 142 gtl.

Here is a link to a well explained video on how to find the wiring for a microphone and for a radio, just in case you need a visual reference.

 

[glenn11209]

I do not have a multimeter which is ine reason I posted this thread. What does help is your suggestion that I figure out which wites to alternate on the 4 pin side of the adapter alone.

I will reverse red and black and see what happens.