Question about Cobra Radio Communications

1 Answer

I have a Cobra 29 LTD that dosn't have any volume. I can see that it is transmitting and recieving by the meter, but it has no squelch or volume through either the speaker or an external speaker.

Posted by on

1 Answer

  • Level 1:

    An expert who has achieved level 1.

    MVP:

    An expert that got 5 achievements.

    Scholar:

    An expert who has written 20 answers of more than 400 characters.

    Hot-Shot:

    An expert who has answered 20 questions.

  • Contributor
  • 38 Answers

Try a different microphone. If the mic is bad or a wire is broken it will cause this problem.

Posted on Nov 17, 2013

6 Suggested Answers

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

  • 200 Answers

SOURCE: cobra 29 nw ltd won't transmit

Have you cracked the radio open yet?  check for loose connections etc.  get back to me if that doesnt yeild any results

Posted on Jan 22, 2009

  • 773 Answers

SOURCE: cobra 29 ltd classic antenna calibration ??

Wow. That's not at all a solution to what this guy is asking. And why all the caps??

The one point jm77437 has that is correct is that you do not set the radio, you set the antenna. The rest is blah blah.

Here is how you tune your antenna for you radio. First off it depends on what kind of antenna you have. most fiberglass antennas have a tunable tip to adjust the height of the antenna. Metal whips either have a collar at the base that the whip will either slide up or down in to adjust the height. The other type of metal whip's you have to physically clip to shorten the antenna, you must be careful with this type because once its clipped, that's it. You cannot add what you cut off.

I am going to give this example using a metal whip with an adjustable collar.

First after your radio is hooked up in the vehicle, drive to an open lot. Buildings and other structures can cause extra reflection. turn to channel 1. Flip the meter to CAL. Key the mic without talking. Now turn the CAL knob up until the needle reaches the little upside down triangle all the way to the right marked CAL. Now you have just celebrated your radio for your setup to measure you SWR. Now while still holding the key, flip the meter switch to SWR. The needle will move, and where it stops is your SWR reading. The lower the better. Anything under 1.5 is considered really good. But still, the lower the better.

Make note of what your SWR was on ch 1.

Now flip to channel 40. Repeat the SWR process. You must recalabrate each time you take a reading.

Now like jm77437 said. If your SWR reading is higher on 40 then 1, then your antenna is too long, and you must make it shorter. Loosen the collar and lower the antenna in the collar 1/4 inch at a time. check the swr each time you adjust the antenna.

If your SWR reading is higher on channel 1, then your antenna is too short. You must make your antenna longer. Do this by loossening the collar and pulling the antenna upward in the collar 1/4 inch at a time, again checking the swr each time you adjust the antenna.

What you want to achieve is having the same SWR reading on channel 1 and 40. then you have the best match you are going to get with that antenna.

If your swr is under 1.5 on all channels, you don't need to fuss unless you are a perfectionist. then by all means go ahead.

If your reading is higher then 3, or your ant light comes on, something is really wrong. Make sure your antenna is connected all the way, and the coax is not damaged.

Its important to have an appropriate SWR because if you do not, you are reflecting too much signal back into the radio, and eventually you will burn out your final transistor, and your radio will be toast.

Some tips: make sure you check the swr with the doors and windows shut. Make sure you are in an open lot. Remember to calabrate ecah time you take a reading. If you have had your radio peaked by a radio shop, and they have lowered your dead key, or have done a swing modification, then the meter in your radio will not work when taking an SWR reading and you will have to use an external meter.

Posted on Apr 24, 2009

  • 773 Answers

SOURCE: cobra 29 ltd classic antenna calibration ??

You should not calibrate the antenna before you install it on the car!! the antenna needs to be calibrated on the vehicle that it is going to be on. Type of vehicle, different mounts, and many other variables can change the amount of reflection you will get.

j0hn9999 did a much better job but left some info out.

Take your SWR readings on channel 1, then on channel 40.... NOW, if your SWR is higher on ch 40 then ch 1, then your antenna is too long and it needs to be shortened. Refer to the antenna instructions on how to shorten the antenna.

If your SWR is higher on ch 1 then on ch 40 then your antenna is too short. You must lengthen the antenna. Again refer to your antenna instructions on how to lengthen your antenna.

You must calibrate each time you take a reading.

Make sure your doors and windows are shut when taking a reading

Make sure you are in an open lot when taking a reading as buildings, trees and other structures can cause reflection and give you an inaccurate reading.

If you adjust the length of your antenna on another vehicle and then put it on yours, the SWR will be off. It will need to be tuned again.

An external meter is better then the one in the radio, but will need to be hooked up in the vehicle you have the antenna on.

If you are not running any kind of power, or do not have a swing kit installed, and the radio is stock, the meter in the radio is more then enough to get a correct SWR reading.

Posted on Apr 24, 2009

riceski
  • 1851 Answers

SOURCE: 29 ltd classic wont transmit

Hi,
Great radio when it works.
If you have your settings on CB - not PA - -be sure that your Cobra has that setting selected.
If CB -is selected and still nothing - be sure you have a working mic. These wires are fragile and can break internally. One easy way to check is to borrow a cobra mic or even drop by a CB repair shop and ask them to do a mic check with the mic - it is free.

If you have a bad mic replace it and all should be well.
If your mic is good and it still doesn't transmit you will need to replace the finals in the unit. It is common that these burn out of you got too close to someone with too powerful a radio. The CB shop will need to look at it further and repairs should not be over about 40.00.

Good luck with your Cobra.

Posted on Mar 31, 2010

  • 773 Answers

SOURCE: 29 cobra ltd c.b. wont transmit or receive

make sure the RF gain is all the way up, and the dynamic is all the way up or most of the way up.

When you say the antenna is good, have you checked the SWR's and or have tuned the antenna to be the correct length for the radio? If this has not been done ever, your radio could be a brick.

Also, make sure the PA/CB switch is on CB. if its on PA(public address) it will not receive or transmit because it is on PA mode, which if you have one hooked up, a PA speaker, then you can talk to people through it out side your car.

Also, make sure the S/RF SWR CAL switch, its the first one on the left, is all the way up on S/RF. this is your signal/ receive setting for the meter. When you hold the key, does this needle swing forward? As well does the RX/TX light turn red? If it does, then the radio is transmitting.

There is another light on the radio under the TX/RX light. It is the Antenna warning light. If this light comes on when you transmit, or has come on all the time during transmit, and now it doesn't then the radio is a brick. That is a warning light. It means that the antenna is not matched, or has not been tuned to the radio. If this has not been done ever, you have killed the radio.

Here is why. When you transmit, you are sending off a radio wave. This radio wave, at 27mhz, is about 36 feet long. In order for the wave to radiate off the antenna, the length of the antenna has to match the length of the radio wave. Now it does not have to be a full 36 feet. It can be an exact multiple of 36 feet. In other words it can be 1/4( one quarter) or 5/8(five eights) of a wave in length. 1/4 of a wave is 108 inches, or 9 feet long. Your antenna is still probably does not seem 9 feet long, but there is usually a loading coil that is not exposed making up the rest of the length of antenna, so that it matches the length of the radio waves electrically. If you were to stretch the coil out with the antenna whip, it would be 9 feet long.

When the antenna does not match the wave length, part of the RF energy does not leave the antenna, and goes back down the feed line(coax) and hits the transmit transistor. Prolonged reflection to the transmit transistor, otherwise known as the final will blow it out. As well depending on how bad the length was off, the more off, the more reflect energy, the more RF energy you are blasting back into the radio, and this causes more things then just the transmit to blow out. Some time the receive goes along with it when it finally goes.

So if the RF gain is up all the way, which by the way is basically how much receive you have, and there really is no reason to have it down at all, and the CB/PA switch is on CB and the needle does not swing forward when its on the S/RF setting, chances are that the radio is now no good.

It is fixable, but if there are no CB shops near you then you will have to send it out. And Cobra will not cover this under warranty because its stated in their warranty that they do not cover damage due to high SWR.

Posted on Apr 06, 2010

Add Your Answer

Uploading: 0%

my-video-file.mp4

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

×

Loading...
Loading...

Related Questions:

1 Answer

Cobra 29 LTD LX LE vr pots


vr1 "s" 9 setting on the tx meter vr2 voltage setting vr3 squelch vr4 amc vr5 p4 display on tx signal meter.

Mar 22, 2013 | Cobra 29 LTD CB Radio

1 Answer

What is wrong with a cobra 29 ltd when the meter sticks when you transmit and will not recieve


could be a mic problem. try using a process of elimination to solve you problem.

Sep 06, 2012 | Cobra 29 LTD CB Radio

1 Answer

Unknown if transmits, does not recieve


I LOST POWER ON MY 29 COBRA 29 LTD

Feb 01, 2011 | Cobra 29 LTD CB Radio

1 Answer

Cb has power but no squelch,can't recieve or transmit


Begin with
  • Volume knob 12 o'clock position
  • Squelch knob full counter clockwise
  • RF gain knob full clockwise
  • Pa/CB switch to CB
  • Mic plugged in
  • Check coax and antenna connections.
  • Make sure your antenna gommet/insulator is installed correctly or it will directed gound. Treat antenna shaft as it is the positive portion of circuit.
If you have another CB check the antenna system with that rig. To verify it is a radio issue. Then dig deeper Microphone, PLL chip, Audio chip etc.

Jan 11, 2011 | Cobra 29 LTD CB Radio

1 Answer

Cant recieve or output , I bought a new cable and antenna plus a swr meter.


With an antenna connected, volume set to 1/4 from minimum, squelch / RF squelch fully counter-clockwise (or minimum) - do you hear anything from the speaker? If not - plug an earphone / external speaker into the external speaker jack on the rear - any sound? If not, do you see the S/RF meter needle moving (not resting on 0 or 1)? If not - find a channel with activity on as indicated by the S/RF meter first.

Try with another antenna connected if possible, or transmit with another CB radio on the same channel nearby - and try again.

If you aren't able to receive sound (not just static) - or indicated signals on the S/RF meter, the radio *MAY* need to be professionally serviced. Make sure you get an estimate for the work before authorizing - otherwise you may be spending more on a repair than the radio is worth. It is not uncommon to have to pay a diagnostic fee - that most shop will put toward the repair if allowed to do the work.

Good luck!

Sep 07, 2010 | Cobra 29 LTD CB Radio

1 Answer

Cobra 29ltd CLassic, TX power and audio is ok, volume from spkr is good, squelch works but no cb recieve.


Try a new Mic. Make sure its a working mic. If you have a bad mic, the receive will not work.

Aug 22, 2010 | Cobra 29 LTD CB Radio

1 Answer

Low volume and problems with squelch


Check your speaker for a short.

Jul 06, 2008 | Cobra 29 LTD CB Radio

Not finding what you are looking for?
Radio Communications Logo

Related Topics:

137 people viewed this question

Ask a Question

Usually answered in minutes!

Top Cobra Radio Communications Experts

AnyMHz.com
AnyMHz.com

Level 2 Expert

500 Answers

Steve

Level 3 Expert

3287 Answers

Brad Brown

Level 3 Expert

15478 Answers

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

Answer questions

Manuals & User Guides

Loading...