Those issues used to come in my shop at least several times a week , the 25 LTD's also have audio chip on the side.... When people do away with the inside rubber spacers for the bracket , they have to tighten the knobs a extra half turn or more and that pulls the pins from the PC board....
Someone gave me a box of these Cobra 29's all with different conditions but none fully working. When my Stryker 955's audio started slowly dying one day at work I came home that evening and put a PA switch out of the radio that wouldn't even power on and put it in the one with a wobbling PA switch and no receive and it worked. I got it going just in time. The last day I ran the Stryker I could barely hear anyone on it with everything cranked wide open. So I finished out the day with the backup Cobra 19. Much better than nothing but definitely not my favorite. I use CB in my dump truck to talk to scale houses, loaders and other trucks. Its part of a normal dump truckers job to have a CB. I'm quite pleased with the Cobra 29 LTD Classic. The Stryker though gives me battery voltage readout 13.8V with the alternator working, crystal clear audio, a little echo and delay and just flat out looks great. I keep it set at 4 watts which is 1/4 up on power on this radio.😀
I see this on my bench monthly .it's the ic ..and glue all around it... The ic with hair dry and boom u will have reciever. Remove the glue away from the chip and ocilator
Sometime I find the issue at the pll chip.the glue and wax...also ocilator circuit 5 out of 10 times ....your great at what u do ...good job ..9lb hammer Oklahoma
troubleshooting is always the hardest part of any repair. Anyone can replace parts, but knowing which to replace and why is the trick. Nice trick with the external S-meter.
I got to disagree with the "anyone can replace parts" gadget. I have seen some real butchery on boards where people who didn't know how waded on in! Your right though that experience and troubleshooting skills sure beats hunt and peck!
+Darryl Landry Hey Darryl. Two different ways of doing it. Drill tiny holes in each section and spray cleaner in the hole. Have to be very carful not to drill in to far. Other way is remove switch from board, cut the tabs off the backing plate, then slid each section off and clean. Reinstall and drill a through hole to accept a 4.40 1 1/4th inch screw. Next time I do one I will video it.
I have a cobra 29 ltd classic that does this sometimes it will recieve great then just go dead. Smack the top then goes back to receiving again. I'm thinking it's the same problem that you describe here. What should I look for thanks in advance. Great video by the way
mine doed same thing it wod b nice if he wod show how to fix it. i cant find a cb shop anywhere. well, i foind 1 but the guy is never open left messages on voicemail & got ignored.
Hi I got a cobra 29 and every time you de keyed the speaker would pop i put a 470 uf capacitor across the speaker terminals and it went.Its like the audio was way to loud its alot softer now.
My brother has a Uniden with a similar issue. very low volume from the speaker. Time to open it back up and look for cold solders ... By the way, I've learned so much from your FT-101 videos that I decided to start looking at this older stuff.
Sounds like a plan. I plugged in headphones last night and could hear some chatter (sounded like a traffic warning) on 19, but very faint. I really appreciate the advice and videos.
Good video I have a Cobra 29 LTD that received really well but will not transmit the needle moves when I key up but no one hears me try different mics same problem. do you have any advice
Michael R I have the same problem with my radio. I key up and speak and the meter goes to 5 and sits there while I talk. I have audio output on PA and CB mode when I hook up an external speakers. But no one responds when I ask for radio check, even though I can hear people talking and their signal shows its good on my meter. Have you solved the problem?
I tried the "external" signal meter and it doesn't move at all. What would you look at next then? Any suggestions on a Cobra 25 LTD Classic (made in 1990) that doesn't have transmit/receive? I've tested the pa/cb switch, cold solder joints and capacitors. If you don't mind a couple questions, would the audio chip (if bad) do this? The audio chip does make noise if I rub my finger across it. Also, the 25 has three transistors...I know which transistor is the final. What is the transistor in the very back corner (near the final) and which is the one mounted on the frame next to the on/off/volume knob? Is the one near the final the driver or the am regulator? Anything helps. Bought this 25 cheap, just a little project I'm trying to get up and running again. The finals, etc., is the stock final on the 25's a C2075, C1969? Thanks!
Those issues used to come in my shop at least several times a week , the 25 LTD's also have audio chip on the side.... When people do away with the inside rubber spacers for the bracket , they have to tighten the knobs a extra half turn or more and that pulls the pins from the PC board....
Someone gave me a box of these Cobra 29's all with different conditions but none fully working. When my Stryker 955's audio started slowly dying one day at work I came home that evening and put a PA switch out of the radio that wouldn't even power on and put it in the one with a wobbling PA switch and no receive and it worked. I got it going just in time. The last day I ran the Stryker I could barely hear anyone on it with everything cranked wide open. So I finished out the day with the backup Cobra 19. Much better than nothing but definitely not my favorite.
I use CB in my dump truck to talk to scale houses, loaders and other trucks. Its part of a normal dump truckers job to have a CB.
I'm quite pleased with the Cobra 29 LTD Classic. The Stryker though gives me battery voltage readout 13.8V with the alternator working, crystal clear audio, a little echo and delay and just flat out looks great. I keep it set at 4 watts which is 1/4 up on power on this radio.😀
Thanks for sharing
I need a new *bub* in my radio too!
I'm thinking about a green led.
Thanks for the great vid
I see this on my bench monthly
.it's the ic ..and glue all around it... The ic with hair dry and boom u will have reciever.
Remove the glue away from the chip and ocilator
Sometime I find the issue at the pll chip.the glue and wax...also ocilator circuit 5 out of 10 times ....your great at what u do ...good job
..9lb hammer Oklahoma
Thats a great tip for intial testing. Thanks! I apreciate the videos and help
troubleshooting is always the hardest part of any repair. Anyone can replace parts, but knowing which to replace and why is the trick. Nice trick with the external S-meter.
Very true gadget73. Troubleshooting is the most important process in any repair. And the more you learn the quicker the job can get. Thanks
I got to disagree with the "anyone can replace parts" gadget. I have seen some real butchery on boards where people who didn't know how waded on in! Your right though that experience and troubleshooting skills sure beats hunt and peck!
+HM Dickson Anyone can (try) replace parts, how well they try or how much solder skill is another question.
+HM Dickson Fair point. I've definitely seen some terrible solder jobs.
Would've liked to see how you fix the channel selector. Thanks for sharing
+Darryl Landry Hey Darryl. Two different ways of doing it. Drill tiny holes in each section and spray cleaner in the hole. Have to be very carful not to drill in to far. Other way is remove switch from board, cut the tabs off the backing plate, then slid each section off and clean. Reinstall and drill a through hole to accept a 4.40 1 1/4th inch screw. Next time I do one I will video it.
Great repair thanks for the s meter tip
+DENNIS N Thanks Dennis, good to see my old videos are helpful.
Wow..great ..I usually see this issue do to the glue and wax....cool find at the ic
I have a cobra 29 ltd classic that does this sometimes it will recieve great then just go dead. Smack the top then goes back to receiving again. I'm thinking it's the same problem that you describe here. What should I look for thanks in advance. Great video by the way
mine doed same thing it wod b nice if he wod show how to fix it. i cant find a cb shop anywhere. well, i foind 1 but the guy is never open
left messages on voicemail & got ignored.
I have a cobra LTD 29 the thing stays on when the buttons even turned off
Hi I got a cobra 29 and every time you de keyed the speaker would pop i put a 470 uf capacitor across the speaker terminals and it went.Its like the audio was way to loud its alot softer now.
Awesome! You’re the best, thanks buddy
Can you do a video on how to operate a signal generator?
Where are you located inbox me I have a cobra 29 needs repair ?
My brother has a Uniden with a similar issue. very low volume from the speaker. Time to open it back up and look for cold solders ... By the way, I've learned so much from your FT-101 videos that I decided to start looking at this older stuff.
I would check capacitors around the audio chip. Glad you are liking the videos
Sounds like a plan. I plugged in headphones last night and could hear some chatter (sounded like a traffic warning) on 19, but very faint. I really appreciate the advice and videos.
Good video I have a Cobra 29 LTD that received really well but will not transmit the needle moves when I key up but no one hears me try different mics same problem. do you have any advice
Sounds like the final is gone. You will need a bit of test gear to confirm.
Is there a way I could check the final with just a multimeter?
Yes there is. Google how to test bipolar transistor with a DMM. you will find hundreds of tutorials on that.
Michael R I have the same problem with my radio. I key up and speak and the meter goes to 5 and sits there while I talk. I have audio output on PA and CB mode when I hook up an external speakers. But no one responds when I ask for radio check, even though I can hear people talking and their signal shows its good on my meter. Have you solved the problem?
The Radio Shop what final would cause this problem? Do you have the location of the part of the part Number? I have a cobra 29 NW ST
I tried the "external" signal meter and it doesn't move at all. What would you look at next then? Any suggestions on a Cobra 25 LTD Classic (made in 1990) that doesn't have transmit/receive? I've tested the pa/cb switch, cold solder joints and capacitors. If you don't mind a couple questions, would the audio chip (if bad) do this? The audio chip does make noise if I rub my finger across it. Also, the 25 has three transistors...I know which transistor is the final. What is the transistor in the very back corner (near the final) and which is the one mounted on the frame next to the on/off/volume knob? Is the one near the final the driver or the am regulator? Anything helps. Bought this 25 cheap, just a little project I'm trying to get up and running again. The finals, etc., is the stock final on the 25's a C2075, C1969? Thanks!
Good video but I couldn't hear what you were saying with the tester sqealing
You might want to change that 220 mf 10v decoupling cap off that last pin of the audio IC or it will "hybernate" again on you :) LOL!
rock trucks have this problem too many rocky roads
+Rick Gunther Yes you are correct. They will beat the radios to death.
not good with headphones on
If you like to discuss this jump over to gokarters.com/smf/index.php?topic=2408.new#new