Question about Cobra 18 WX ST 40-Channels Base CB Radio

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Cobra 18wx st II, not working...

I recently bought a Cobra from a friend to use for work. When he pulled it out of his pickup it was working. When I installed it in my company semi that I drive daily it will not work. I can get sound out of the speaker for the weather channels, but when I try to broadcast I get nothing. The power meter will go up when you cue up the mic but I get no response. Would it be the antenna thats mounted on the truck is bad or what??? Please help.

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  • busman2 Sep 22, 2008

    I have a cobra 18wxst11. I can hear everydody clear but when I send they tell me my mike sreeches.

  • cruiser guy Sep 27, 2008

    Hello, mine is doing the same problem.  Fine reception, on transmission only annoying "buzz" over the recipient's speaker.  My friend thinks its my mic.  What do you guys think?

  • yxlasse Mar 01, 2009

    Cobra 18wx st II, not working sending ok but reciving nothing
    only when WX option is on u can hear sound from speaker
    what to do?


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I would agree that it can be the mic if the radio seems to be going into transmit. If it was a antenna problem you would still hear people talking on ch 19 and you would still talk but your distance would be greatly cut back. These radio's have a very common issue with vibration causing the solder in the radio to crack more commonly called a cold solder joint. I have repaired many of these myself over the years. You will need to have a tech look at it maybe a good cbshop. Hope this helps

Posted on Jun 26, 2009

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Yes it is the twig, it is either the wire is broken on the plug center pin. the magmount centre pin or a bad earth on the mount. ask a friend with a rig to copy you close up. you should rx and tx. if it is your twig dont hold the key down long or you will take out the output can soon see if you have by keying the rig and the needle does not move.

Posted on May 28, 2009

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For the 1st and last one I'd have to say to check the antenna system and coax out real well first. For cruiser guy there's a good chance that it is a mic problem or a broken mic wire. Let me know,,, Mechanic

Posted on Nov 05, 2008

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Related Questions:

1 Answer

Can i peak and tune a cobra 18wx st

technically , yes legally , no. besides this is a false statement. A radio is already tuned when you get it by the factory. now the true part is the it should be tuned to specs otherwise you are possiably interferring with other operators on the amature bands 4 watts is max and 95% mod will give you plenty of swing.

Mar 11, 2012 | Cobra 18 WX ST II 40-Channels Base CB...

1 Answer

I don't know how I copied and pasted so much sorry about that. But my question is I have orange and red wires with fuses and black wire without do I hook both red and orange to hot and black to ground?

it depends on what radio if you have a cobra 18wx style or maxon's, or a radioshack type the red is constant power 12v, orange is a switched 12v.. IE key like a stereo, and black is ground. if you have a 25 or 29 ltd types or exports they only have 2 wires red 12v and black ground. but you do find some power cords that have all three, and the orange on the 25 / exports are not used.

Feb 09, 2011 | Cobra 25 WX-NW-ST 40-Channels Base CB...

1 Answer

What is the DW button/switch for on the Cobra 18 WX ST II?

It is dual watch. you can set it to have two channels monitored. like ch 1 and ch 13 it will flip between those two channels. but if you use say 6, 19, 26 along with another ch it will stay on the channel with the most noise. and you would have to turn up the squelch to compensate.

Dec 13, 2010 | Cobra 18 WX ST II 40-Channels Base CB...

1 Answer

I have a red orange and black wire i need to know what the orange wire is

hello, in my Cobra 18 WX ST II the orange wire goes to "mic2" on the circuit board the other end runs to pin # 2 on the mic jack

May 21, 2010 | Cobra 18 WX ST II 40-Channels Base CB...

1 Answer

No sound

Its, either a broken wire in the mic or the internal speaker blew. Try an external speaker then the mic

Jan 24, 2009 | Cobra 18 WX ST II 40-Channels Base CB...

1 Answer

CB keeps blowing fuses

There are a few common reasons the fuse keeps blowing:

1. The transmitter final transistor is bad, it usually is directly connected to the 12v source and not switched by the power switch.
2. The power wires were accidentally reversed I.E. positive to ground, neg to 12v. There is a protection diode on the circuit board that did its job and is now shorted. it will keep blowing fuses until its replaced.

Dec 30, 2008 | Cobra 18 WX ST 40-Channels Base CB Radio

1 Answer

Not real sure

Make sure that the mike gain & RF gain controls are turned clockwise & the squelch is counter-clockwise.

Jun 07, 2008 | Cobra 29 WX NW ST 40-Channels Base CB...

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