Question about Cobra 29 LTD CB Radio

1 Answer

Cobra 29 LTD classic when turned on it shuts off

When you turn the raido on the needle swings the led comes on and then the whole thing shuts off it has ben in the same set up and always talked good ive got a 4 ft fiberglass whip on the roof of my truck and its about 12ft off the ground total i have not changed the set up but i did clip (D11) or (D12) not sure but the raido woorked good for about a year and would out talk most high $ raidos need help

Posted by on

1 Answer

  • Level 3:

    An expert who has achieved level 3 by getting 1000 points

    All-Star:

    An expert that got 10 achievements.

    MVP:

    An expert that got 5 achievements.

    Guru:

    An expert who has written 7 tips or uploaded 3 video tips

  • Master
  • 773 Answers

Well I hope you didn't clip D12. D11 makes sense to me. If you clip that you are disabling the AMC, automatic modulation circuit. This will allow the radio to modulate at full modulation all the time, which isn't always good. You can over driver your final and possibly blow it.

Most of the time you can just turn up VR4. thats the AMC adjustment. It will raise your modulation to the max but will not over modulate it.

You probably blew the final and or more components as well. Your going to have to take it to a radio tech. This is no simple fix.

Posted on Feb 08, 2009

1 Suggested Answer

6ya6ya
  • 2 Answers

SOURCE: I have freestanding Series 8 dishwasher. Lately during the filling cycle water hammer is occurring. How can this be resolved

Hi,
a 6ya expert can help you resolve that issue over the phone in a minute or two.
best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.
the service is completely free and covers almost anything you can think of (from cars to computers, handyman, and even drones).
click here to download the app (for users in the US for now) and get all the help you need.
goodluck!

Posted on Jan 02, 2017

Add Your Answer

Uploading: 0%

my-video-file.mp4

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

×

Loading...
Loading...

Related Questions:

1 Answer

Why is the swing on my cobra 29 ltd with bt swinging backwards with i talk


because when you tried to modify the radio for more power and audio you turned the wrong coil and can.

Aug 01, 2012 | Cobra 29 LTD CB Radio

1 Answer

Hello i own a cobra 29 ltd classic from 1993 today i was talkin skip like crazy!! running about 100 watts out of a texas star modulator!! i left for a while came back talked for a while everything was good...


sounds like the amp got hot and shorted on the bias.. and is keyed up a few watts. to fix you will have to have the amp repaired. new power transistor. to fix. 3174269649 Texas.

Dec 12, 2010 | Cobra 29 LTD CB Radio

1 Answer

COBRA 29 WX NW ST


have somebody look and see if there are any bad solder joints inside the radio...

Jan 10, 2009 | Cobra 29 LTD CB Radio

1 Answer

Cobra 29 LTD Classic not transmitting or receiving


ant. light should only come on if you have a high vswr a bad thing did you check that cb/pa switch is set to cb check your swr this is not a good place to mount ant. as it is close to metal of back of cab

Dec 20, 2008 | Cobra 29 LTD CB Radio

2 Answers

Cobra classic 29 ltd


Had fixed the same problem yesterday. My cobra worked when it wanted to, when it didn't it looked like you explained. I found out that on my cobra the blue wire on the mike connector was broken. When it disconnects, no sound. after soldering, everything works fine.

Dec 04, 2008 | Cobra 29 LTD CB Radio

1 Answer

Cobra 29 Ltd


Hi,

Appreciate the direct "Ask Me" again.

The initial posting would still hold true, best would be:
  • remove TR18;
  • replace 2SC2069 with 2SC1969; and
  • adjust L12, 13 & 14.
Hope this be of initial help/idea. Pls post back how things turned up or should you need additional information.

Good luck and kind regards. Thank you for using FixYa.

Sep 07, 2008 | Cobra 29 LTD CB Radio

2 Answers

Cobra 29 Ltd Classic


In most cases just turning up VR4 is more then enough. Replacing the final, tr14 with another transistor requires changing many more parts to get it to work.

With a new 29, there is no need to change the final. Just turn vr4 all the way up and you will see around 20 - 25 watts. L13 won't gain you a single watt. L12 will raise the dead key, and usually you want a lower dead key for good swing. L14 will gain you a few watts, but don't adjust this unless you have a watt meter. You turn it out to increase wattage, but too much will over bias the final and shorten its life.

You hook it to a watt meter with a dummy load. Then say a steady AHHHH into the mic while keyed. Turn the slug out until the needle stops going up, then back it down to where it stopped.

The easy thing to do, and you will be pleased is just to turn VR4 up. Now, Up is counter clockwise. Its a variable resistor, so the less resistance, the more modulation. So you want to turn the VR down.

that will be more then enough.

Sep 06, 2008 | Cobra 29 LTD CB Radio

Not finding what you are looking for?
Cobra 29 LTD CB Radio Logo

145 people viewed this question

Ask a Question

Usually answered in minutes!

Top Cobra Radio Communications Experts

AnyMHz.com
AnyMHz.com

Level 2 Expert

489 Answers

Iron
Iron

Level 3 Expert

3018 Answers

Brad Brown

Level 3 Expert

13794 Answers

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

Answer questions

Manuals & User Guides

Loading...