Cobra 29 LTD CB Radio - Answered Questions & Fixed issues

follow these steps to adjust the
standing wave ratio(SWR).
1. Turn on the CB.
2. Set S/RF/SWR/CAL to CAL.
3. Key the Mic and rotate SWR CAL so the meter points
to CAL.
4. Unkey Mic.
5. Set S/RF/SWR/CAL to SWR.
6. Key Mic again and note the actual measurement on
the SWR scale. Refer to the following table to interpret
the reading.

1:1 - 1.5 Great
1.5 - 2:1 OK
2:1 - 3:1 Not So Good
Higher than 3.1:1 Terrible

d23 a 1n4004 diode second component from pa speaker port inside radio has failed. It is most likely that neg/pos polarity has been switched shorting this diode. It is there to protect your radio from reverse polarity as so it is names the "protection diode." 2 solutions first not recommended.

1. Cut the diode this will stop the directed grounding that is continuing to blow your fuse.
2. Go get a pack of 1n4004 and rosin core silver solder from radio shack and replace it paying attention to the direction it is installed.

just a side note the solder trace often burns in this area so a jumper wire soldered in around this bad area solder side maybe needed.

Check to see if the meter needle is swinging backwards when you key up. If it does your final may be bad. If the needle goes forward and others say they see your keying up but no sound your audio chip may be bad; especially if you have tried so many mics and antennas. If your radio has a swr warning light and it comes on this could extremely limit your range and others may not hear you and contiued use will damage your radio. Good luck!!!

simple,just chech the input resistance and out put...they should have even small resistance always example .5ohms .3 ohms it counts...

Recommend contacting Cobra directly here Support Cobra Electronics Corporation

Try this Support Cobra Electronics Corporation

Cobra technical support here: Support Cobra Electronics Corporation

Honestly you can purchase a nicer unit these days. Otherwise contact Cobra here: Support Cobra Electronics Corporation

Check speaker and plug external one in if you have it.

swap mic could be a broke wire or bad switch in handset.

check antenna and coax connections.

i know checks sound basic but they could save you a lot of headaches later

would need to know the mic wire code you going to use. but half moon cut out at top as you look at it is top left 1-4 next row left side 2-3. 1 is cable/ unshield (common). 2 is MOD 3 is TX 4is RX... 1 is wire with no cover 2 is with cover rapped round wire RX is received TX is transmit, hope this helps. newer mic have different code wires so check with meter, red green and blue and shield is on some of the new wiring.

Try a hand mic with the set, there may be a short within the radio.If not your problem is with the audio amp in the radio itself.Repair should be about $15.00.

First, make sure that the CAL/SWR/RF switch is set to CAL. If you still can't move the needle, check the RF output. If the needle moves to the far right, you at least have output power, and something is wrong with the SWR circuitry. Does the needle move with incoming signals?? If the needle doesn't move, then you either have a damaged meter. If the needle moves on rec eived signals but not when you transmit and the switch is set to RF, then you most likely have a damaged transmitter output stage.

Look , I don't speak a forign language but I can get what you are saying . ford rangers from 1993 to 2003 should all have interchangeable parts ,Mine does.

The problem may be in the audio output chip mounted on the chassis, also! there is also a small capacitor located next to the audio chip that has known to be a problem, finally sub the speaker for another, often a source of trouble.

if the antenna warning indicator is lighting during transmission then the antenna is either located and.or installed improperly or a defect exists in the antenna mount or the feedline itself, including connectors.

contact Connex ,see if they have one they can send to you . Maybe even a photocopy.

get it away from the ext . speaker. They are cheap enough ,buy another one and see if it still squeals. If it does then you may have to jump the mic with resistors ,turn down your mic gain, check for talk back on rear where your pa. and external speaker hooks to inside the radio. If you see a resister connecting them then you have talk back . Mainly its a Keep the mic away from the speaker deal that makes them squeal. Try other cobra mics with the same pin out and see if it still happens . easy fix just have to be patient .

If your asking about a Cobra radio then these links will have the pin-outs plus wiring color code for different mic's. I had to guess what you was asking for as your question was kinda vague. And a Cobra 29 is a 4 pin mike, not 5 pin. The 148 - 142 were 5 pin. I'll include it also. http://www.cbtricks.com/radios/cobra/148gtl/index.htm Cobra 29LTD ST 29WX ST

YOU GOT A CB INSTALLED ON YOUR LAWN MOWER?

no tx,no dx. Did you check the fuse? Turn the squelch to the left all the way and the RF gain all the way to the right. you should be able to hear a hiss.Check to see that the radio is on CB and not PA. If you hear a hiss then check to see that your antenna is attached properly and that the antenna is matched to the radio . You should be hearing something now. Check to see that the antenna is grounded properly also .