Question about Cobra 29 WX NW ST 40-Channels Base CB Radio

1 Answer

RED TX and ANT light, Cobra 29

Hi there, as the subject line says, I key in the mike and get 2 red lights. It will rec signals fine but will not transmit. I assume that since I don't have 18 ft of coax that this is the best place to start??

Posted by on

1 Answer

  • Level 3:

    An expert who has achieved level 3 by getting 1000 points


    An expert that got 10 achievements.


    An expert that got 5 achievements.

    Brigadier General:

    An expert that has over 10,000 points.

  • Master
  • 6,966 Answers
Re: RED TX and ANT light, Cobra 29


Your post of 2 lights; 1 is to indicate that you are transmitting when keying the mic is normal. The 2nd indicating an antenna warning (or SWR) should be corrected. You are right in starting with the coaxial cable which of course would include the PL259 connector. Verify that there are no breaks, over-bended loop, exposed ground/shield and that the solder of the center wire as well as the braided shield/ground is in order.

If it is a mobile setup, further verify that the antenna mount (except when magnetic) is properly grounded to the body of the vehicle and free from rust/corrosion. In some instances, it is the antenna itself that need checking or even possibly replacement.

Alternately, if the needle doesn't swing to the right side of the meter when the mic is keyed, it is possible that your finals (2SC1306) needs replacement.

Hope this be of some help/idea. Pls post back how things turned out or should you need additional information.

Good luck and kind regards.

Posted on Dec 06, 2007

Add Your Answer

0 characters

Uploading: 0%


Complete. Click "Add" to insert your video. Add


3 Points

Related Questions:

3 Answers

Red lights come on tx n rx and antenna come on when I key up the cb radio and the swr meter doesn't move

if a mod has been done to the cobra 29 (all 29,s)the light will come on just find vr6 audio the radio as it comes on adjust vr6 untill it goes away,,,,always trust your watt meter(s.w.r scale)over the flashing light its really easy to do it beats paying a shop $10-$15

Jan 13, 2013 | Cobra 29 LTD CB Radio

1 Answer

When i key in both green lights turn red. is this normal ?

One of the lights is marked RX/TX. This light normally turns red when you press the mike key. The other light indicates a bad SWR if internal circuits are properly aligned. If someone has turned the pot which sets the level at which the light comes on, it may come on when you press the mike key. Check your SWR with an external meter to see if you have problems in the antenna system. The way I set this light in my shop is to put a 150 ohm resistor on the antenna connector and set the control so that the ANT light just comes on.

Jun 15, 2011 | Cobra 29 LTD CB Radio

1 Answer

My rx/tx light is green untill i push on the mike. then the light turns red. and the antenna led theres nothing. whats could be the cause and the fix...and the swr metter goes into the red all the way to...

Its working alright then...what the antenna light is for in case the SWR is too high. If it does not come on---Then it means your antenna works good.

May 16, 2011 | Cobra 29 LTD CB Radio

1 Answer

Key to tx-green lite out-no output power or red lite rec ok

It could be small transistors--in the back where the light and transmit hook up. One small transistor will shut down transmit & possibly receive. Get it serviced at a radio repair shop. if you know how do it yourself. Change all small transistors to 2sc3904 or 2sc 3906 at "Radio Shack."

Apr 30, 2011 | Cobra 29 LTD CB Radio

1 Answer

Red RX/TX and red ANT light on my CB

Well,first hand ,some cobra radio,s have red some have green RX/TX lights, but are you modulating? Some green lights turn red. What is your standing Wave on the antenna,s? You need to check it and the output of the radio. To do this you need a watt or field strenth meter. Can get one at Radio Shack. Your standing Wave is ok as long as it is below a 2. That has to be done on the antenna. ..hope this helps...

Mar 11, 2010 | Cobra 29 LTD CB Radio

2 Answers

When i key up the mike the tx/rx light and the ant

your swr setting are off wack fix your swr

Oct 02, 2009 | Cobra 29 LTD CB Radio

1 Answer

The ant light and the other light light up red when i key the kic

the tx/rx liight is green when your radio is recieving signals and turns red when you are sending signals. the ANT light is red when your SWR is too high (over 3)

1. turn the knob labeled swr cal all the way counter clockwise
2. set the rf swr cal switch to the CAL position
3 key up the mic and hold it while you rotate the swr cal knob until the needle reaches the swr cal postition
4. set the swr cal rf switch to the swr position
5. key up the mic while on chanel one (record the the number)
6. switch to chanel 40 key up the mic (record the number)
if the number on chanel one is lower than the number on chanel 40 then your antenna is too long.

Sep 14, 2009 | Cobra 29 LTD CB Radio

1 Answer

I have a cobra 29 NW ST LE. When I key the mike, the needle in the gauge does not move, but the light is on. I don't know if I am heard or not. The RX/TX indicator does change to red though. Could that be...

Check all of the switchs on the radio,
if all are were they belong then the meter is
bad,but you need to try to find someone to
give you a radio check onair.
Maybe this helped.

Aug 23, 2009 | Cobra CB Radios

1 Answer

Cobra 29GTL Won't Transmit

if the red ant light comes on this means that you have antenna trouble either in the antenna itself or the coax but this should not have anything to do with the radio not transmitting. it sounds to me that you have a bad audio chip or a bad power output transistor. in either case you should really take it to a cb shop and let the professionals solve your problem, good luck!!

Aug 16, 2007 | Cobra 148 GTL 120-Channels Base CB Radio

Not finding what you are looking for?
Cobra 29 WX NW ST 40-Channels Base CB Radio Logo

344 people viewed this question

Ask a Question

Usually answered in minutes!

Top Cobra CB Radios Experts

Level 2 Expert

489 Answers


Level 3 Expert

3018 Answers


Level 2 Expert

204 Answers

Are you a Cobra CB Radio Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides