CB radio not receiving

[MountainGoat]

Hey all,

I recently picked up a Uniden pc78xl cb radio from a garage sale and it's not receiving, from what I can tell. It is confirmed to transmit. After opening it up, nothing immediately stands out to me or to my navy electrician friend (he straightened a capacitor, that's it). What should my trouble shooting steps be to get this thing to receive?

I've run through all the channels and I expect to get at least something while being in town is Colorado springs. I'll attach some photos of the guts and see if anyone more familiar with these spots anything.

Thanks!

 

[suicideking]

Honestly, I'd toss it in the trash and buy a GMRS radio. Nobody around here uses CB anymore. I took mine out of my Jeep about 2 years ago. Haven't had anyone request to use CB on a run since.

If you must fix it, receiving is likely a problem with the antenna. Check your coax. Quickest is to buy a new coax and a cheap antenna. You can get a coax for around $11. This is the coax I bought for my GMRS. Works well.

https://www.amazon.com/dp/B001JT0CGI?tag=wranglerorg-20

 

[rasband]

Honestly, I'd toss it in the trash and buy a GMRS radio. Nobody around here uses CB anymore. I took mine out of my Jeep about 2 years ago. Haven't had anyone request to use CB on a run since.

If you must fix it, receiving is likely a problem with the antenna. Check your coax. Quickest is to buy a new coax and a cheap antenna. You can get a coax for around $11. This is the coax I bought for my GMRS. Works well.

https://www.amazon.com/dp/B001JT0CGI?tag=wranglerorg-20

I was thinking the same thing, unless it's just for a "fun" project to try and fix it.

 

[DavidBT]

I also have GMRS in both my rigs. I've also installed 10 meter radios tuned for 11 meter. Just this year alone, the CB has helped while traveling with our travel trailer. Both systems are really quiet for the most part. I really like having SSB on the 10 meter radio.

 

[SkylinesSuck]

If you turn the squelch down all the way, do you get static?

 

[OilSpot74]

Unless it’s a hobby thing, I’d have to agree with the GMRS switch. Far more powerful, especially handy in the mountains where line of sight is practically non existent. I use a 10w handheld and it’s never let me down. Whole set up $43.

 

[Harold&Cat]

You might try resoldering the antenna connections inside the radio . If that doesn't fix it , I would probably trash it and buy a new radio or a known working used one .
Having CB frequencies can come in handy at times , however off-road most use FRS or GMRS . I run CB , Ham and GMRS in all of my vehicles .

 

[Zorba]

I run CB , Ham and GMRS in all of my vehicles .

Ditto that (for the Jeep).

 

[JackalopeWrangler]

Your unit is apparently a cobra 29 clone, excellent radio.
Here is a link to the manual: https://www.cbradio.nl/uniden/Manual_Uniden_PC78_XL_ENG.pdf
I hear there's not many people using in Jeeps for trail com anymore, still good on the highway especially as you can hear the truckers when there is snarl talk about it, usually without having to talk and get a clue on what is up.
Wouldn't spend too much time as they are pretty cheap these days and the new ones have FM as well which I think might really be nice for trail rides.
Cheers

 

[OilSpot74]

My handheld GMRS setup was 43$ and is 10w. Works flawlessly in the mountains where line of sight can be a challenge for traditional CB

 

[Harold&Cat]

I believe the new cb radios with FM would work great on the trails , however GMRS is the new norm . You can even get a cb with tone capability that allows you to tune out unwanted radio signals . GMRS has the advantage of good range , excellent clarity and easily talks to the FRS radios which makes it easier for communication in a larger group where some might not have GMRS radios . Also GMRS doesn't need a large antenna to get good range .

I am looking at this radio for my truck .
https://www.walcottradio.com/presid...356pjtb9l2IXjsAj2YLALV7UYNnO3NGRoCxyUQAvD_BwE

 

[Mr. Bills]

Honestly, I'd toss it in the trash and buy a GMRS radio. Nobody . . . uses CB anymore.

I run CB , Ham and GMRS in all of my vehicles .

Ditto that (for the Jeep).

Just this year alone, the CB has helped while traveling with our travel trailer.

Although CB is old technology, it is still very much in use and many jeep clubs still require CB on their runs despite the trend to replace CB with GMRS. (Cal4Wheel still requires CB on many of its sponsored runs.) In addition, in Northern California and large portions of the PNW, logging trucks use CB and one will often see a paper plate or sign nailed to a tree with the CB channel in use on that logging road.

Its all about options in time of need. I run CB, GMRS, and ham radio in my jeep and in my Sprinter. I also carry a Starlink Mini for WiFi, Internet and telephone anyplace in the world I may happen to be.

In late 2025, we were able to reach a taxi driver in a nearby town in Baja California via CB, who in turn alerted the bomberos and Cruz Roja of the accident we had just witnessed. GMRS and ham yielded no local response in that situation other than from within our own group. 'Obsolete" CB saved a man's life that day.

 

[suicideking]

Although CB is old technology, it is still very much in use and many jeep clubs still require CB on their runs despite the trend to replace CB with GMRS. (Cal4Wheel still requires CB on many of its sponsored runs.) In addition, in Northern California and large portions of the PNW, logging trucks use CB and one will often see a paper plate or sign nailed to a tree with the CB channel in use on that logging road.

Its all about options in time of need. I run CB, GMRS, and ham radio in my jeep and in my Sprinter. I also carry a Starlink Mini for WiFi, Internet and telephone anyplace in the world I may happen to be.

In late 2025, we were able to reach a taxi driver in a nearby town in Baja California via CB, who in turn alerted the bomberos and Cruz Roja of the accident we had just witnessed. GMRS and ham yielded no local response in that situation other than from within our own group. 'Obsolete" CB saved a man's life that day.

Sure, it still works. If someone has a usual group they wheel with, and all have CB, nothing wrong with that. Probably have no interference from other groups in the area, which used to be a problem on busy trails.

Though if someone is like me and only wants necessary electrical items connected in their Jeep and are asking what single solution they should get, GMRS is definitely the answer. I wheel with a few different groups and have only used GMRS in the last 2+ years. If someone said they were on CB, I would be shocked (and wouldn't be able to talk to them lol).

I have a mobile GMRS connected in my Jeep as my main radio (Radioddity DB40). I do keep a Baofeng UV-5R with me just in case someone wants to use ham frequencies. I am also a scofflaw and have GMRS channels programmed.

I keep an eye of vehicles on the street and freeway. I do see many trucks (privately owned pickups) that still have CB antenna.

As far as Jeep orgs requiring CB? I would say they just haven't updated their website. I find it hard to believe that you would show up for a run and they would send you home because you don't have a CB. I would have some choice words for them.

 

[KennethS]

Years ago on a run a Jeep at the meeting site could not receive. I had my SWR meter so we tuned his antenna and that resolved the issue.

 

[OilSpot74]

Years ago on a run a Jeep at the meeting site could not receive. I had my SWR meter so we tuned his antenna and that resolved the issue.

Much better to have a cheap radio and a good tunable antenna than a good radio and a cheap untunable antenna if you are going to use CB.

 

[tm dean]

The cobra 29 had a known problem with the receive. I repaired one by going on the internet and googling cobra 29 receive problems. There was a complete section on it. Usually a short wire and a solder gun can have your receive back shortly. Unless it has already done then, no dice. Where the red wire on the board is soldered looks real close....footnote the cobras have used the same circiuit board since the early 80's. Cobra is aware of the problem but have no interest in the 29, repair issue. My understanding from reading earlier is its a 29 clone. Truck drivers buy them and have them peaked at maybe 6 watts, but their power supply will not hold out. The man that peaks your radio knows you have a short life radio, and will be back in for galaxy final transistors. I have no idea of how many clones the 29 has.