Carrier on SSB

[Johnno]

Hi guys, I bought a CB radio (GE A3-5825B) on eBay (yeah I know), all is working, except both sidebands are giving around a 7 watt carrier.
AM is working like a champ.
Listening on another radio on AM, both sidebands sound like normal SSB signals.
Any ideas?
FWIW, video here:

 

[9C1Driver]

You can double check that your meter is working correctly, turn the mic gain down and check, or try a different mic just to be sure. If indeed this is the case your radio will need to be looked at by a tech. Sometimes with say a power mic background noise will appear as a carrier on SSB when it is really not. Turning the mic gain down will verify this. From your video it does not appear you have any background noise.

 

[Johnno]

You can double check that your meter is working correctly, turn the mic gain down and check, or try a different mic just to be sure. If indeed this is the case your radio will need to be looked at by a tech. Sometimes with say a power mic background noise will appear as a carrier on SSB when it is really not. Turning the mic gain down will verify this. From your video it does not appear you have any background noise.

Hi, thanks 9C1Driver, no power mic and no background noise. It is definitely a carrier. I was hoping someone could give me a few pointers, as CB techs are few and far between in this neck of the woods. I can't see any leaky caps on either board, could a dry solder joint cause this type of symptom?
When I key up (no modulation) and listen to another radio on SSB, I can hear a low oscillating whistling sound, like in the old outer space movies, similar to this but faster:

 

[sonoma]

the radio may have a cap leaking causing this. I love the old GE radios. ever chance I get I will buy one when it is cheap enough. not sure how old the radio is but it could be old enough to do a complete recap of the radio. any where from 20 plus years old some caps may be breaking down.

 

[Johnno]

the radio may have a cap leaking causing this. I love the old GE radios. ever chance I get I will buy one when it is cheap enough. not sure how old the radio is but it could be old enough to do a complete recap of the radio. any where from 20 plus years old some caps may be breaking down.

Hi sonoma, I love them too, I have 2 of the 4 SSB rigs they made.
It's nearly 40 years old, I downloaded the Sams Photofact for it, and that is dated 1979! You may be right about a recap, I was hoping to avoid that for the time being. I have a vacuum desoldering station coming, so it might get a workout sooner, rather than later. Although, I also have a Washington I need to recap, might practice on that first.

 

[StrangeBrew]

I have a few of those old GE's myself, they have some nice audio when tuned right.

 

[Shadetree Mechanic]

I have the same problem with a Galaxy 99v that someone made into an AM talker. I don't know if the modulation limiter has been bypassed or clipped on yours but it would be something to check.

 

[kaos513]

I have a few of those old GE's myself, they have some nice audio when t

Hi guys, I bought a CB radio (GE A3-5825B) on eBay (yeah I know), all is working, except both sidebands are giving around a 7 watt carrier.
AM is working like a champ.
Listening on another radio on AM, both sidebands sound like normal SSB signals.
Any ideas?
FWIW, video here:

uned right.

Hi guys, I bought a CB radio (GE A3-5825B) on eBay (yeah I know), all is working, except both sidebands are giving around a 7 watt carrier.
AM is working like a champ.
Listening on another radio on AM, both sidebands sound like normal SSB signals.
Any ideas?
FWIW, video here:

I had GE basestation cb radio my self years ago i had audio issues by recaping the radio fixed the audio issue.

 

[jon666]

you seed to adjust the carrier balance on ssb to 0. dont ask what vr it is i dont remember. find a schematic.

 

[sonoma]

you can go to secret cb over on cbtricks.com and look at book 9 pages 31-32 and it shows how to adjust the internals on the radio you have.
also this radio shows to be in sams cb255 book. if you could find one it will show all items on this radio

 

[sp5it]

That could be parasitic oscillation of predriver, driver or final, broken ssb filter or wrong set carrier suppression point.
Mike

 

[Klondike Mike]

When you are ready, I have this kit waiting ...

https://www.ebay.ca/itm/Electrolytic-Radial-capacitor-kit-for-GE-A3-5825B-/142577740691

 

[Johnno]

I have the same problem with a Galaxy 99v that someone made into an AM talker. I don't know if the modulation limiter has been bypassed or clipped on yours but it would be something to check.

I am still able to adjust the VR for AM mod, I guess that means it isn't clipped, maybe?

you seed to adjust the carrier balance on ssb to 0. dont ask what vr it is i dont remember. find a schematic.

I have Sams Photofact for it, this is next move, thanks

you can go to secret cb over on cbtricks.com and look at book 9 pages 31-32 and it shows how to adjust the internals on the radio you have.
also this radio shows to be in sams cb255 book. if you could find one it will show all items on this radio

I have Sams Photofact for it already, cheers.

That could be parasitic oscillation of predriver, driver or final, broken ssb filter or wrong set carrier suppression point.
Mike

A little over my head, but food for thought, thanks.

When you are ready, I have this kit waiting ...

https://www.ebay.ca/itm/Electrolytic-Radial-capacitor-kit-for-GE-A3-5825B-/142577740691

I have seen you on eBay, thanks for the reminder

 

[Robb]

My first CB radio was an AM/only GE radio that I bought for a song - new - back in the day. Had to have been some forty years ago now - woof!

You can chase your tail for a long time when fixing an old radio like this. So I'd agree that replacing all of the caps can alleviate some board problems related to caps gone afoul. At least, you will know that it is not an old cap related problem in order to find the core problem - if any - which is quite possible after forty year old caps.

Couple months back, I recapped a Uniden PC-244 radio, and after testing all of the caps after the job, only three of them were still within spec or not shorted outright. Amazingly it still worked in that condition; but with MANY different issues. All of the many problems it had (even had the same problem yours has) disappeared after the old caps were booted. That radio wasn't as old as yours is now. So you can see, it is due - even if it is going to be your daily driver or a resto job for someone else. Finding the right bad cap may be done; but next month another bad caps creates yet another hair pulling session.

A decent 20w soldering iron with the right tip, a solder sucker or soldering braid to remove the old solder joints, a felt pen for marking all of the old caps on their tops, and a cheap $5 Walmart laser pointer to locate the right solder joints on the board, will all make the job go swiftly and correctly. Do it almost all the time. It will take time; but once you get into a groove you will get there w/o too much trouble.

Oh yeah; double check your work on each cap replaced: correct solder job, correct polarity, AND correct cap chosen.

 

[Johnno]

My first CB radio was an AM/only GE radio that I bought for a song - new - back in the day. Had to have been some forty years ago now - woof!

You can chase your tail for a long time when fixing an old radio like this. So I'd agree that replacing all of the caps can alleviate some board problems related to caps gone afoul. At least, you will know that it is not an old cap related problem in order to find the core problem - if any - which is quite possible after forty year old caps.

Couple months back, I recapped a Uniden PC-244 radio, and after testing all of the caps after the job, only three of them were still within spec or not shorted outright. Amazingly it still worked in that condition; but with MANY different issues. All of the many problems it had (even had the same problem yours has) disappeared after the old caps were booted. That radio wasn't as old as your is now. So you can see, it is due - if it is going to be a daily driver or a resto job for someone else. Finding the right bad cap may be done; but next month another bad caps creates yet another hair pulling session.

A decent 20w soldering with the right tip, a solder sucker or soldering braid to remove the old solder joints, a felt pen for marking all of the old caps in the radio on their tops, and a cheap $5 Walmart laser pointer to locate the right solder joints on the board, will all make the job go swiftly and correctly. Do it almost all the time. It will take time; but once you get into a groove you will get there w/o too much trouble.

Thanks Robb. Please enlighten me on your technique using a laser pointer to locate solder joints, if you will?