problem with Cobra 19xs

[mysteryman]

I have a Cobra 19xs CB Radio. At times when the Power (volume) switch is turned on nothing happens. It acts as if it is in PA mode. It is a hit-and-miss thing, turning it on and off does nothing, I turn it off and forget about it, the next time it may turn on again. It works properly more times than it doesn't. Is there any single thing causing this? Or is it possibly an accumulation of small things happening? I know that it is a low-end radio that cost me very little years ago, and can be easily replaced ... I just hate to get rid of something that can possibly easily be fixed. Thank you.

EDIT: One other thing that I forgot, at times, randomly, it acts as if I keyed the mic, it goes quiet, this may last for five seconds. Since my problem above is also a 'quiet issue', I don't know if they are related, thanks again.

 

[Robb]

1) Sounds like the power switch needs cleaning or replacement. Or simply a bad solder joint.

2) If the mic has issues, then it may well be a frayed wire inside the mic plug getting partial connection or no connection.

Good hunting . . . .

 

[mysteryman]

Thanks, ROBB, I will probably start with the mic...maybe I will remove (unplug) the mic, if I don't experience it I may have found it...or better yet, when it happens, I will jiggle the mic cord to see if that changes anything...I appreciate your response.

 

[2FB327]

Is this in a mobile? The reason I ask is that I have seen a few in trucks where you reach around and touch the power plug it will come on, the problem is in the power cord.
If you could have the covers off and when it happens check for power coming in and out of the on/off switch would be a start.

 

[mysteryman]

Yes, a rough-riding F350, however, if I recall correctly, the unit 'lights up', I will pay better attention to that next time.

 

[midnight special]

it sounds like a bad mike cord,,,,,,

 

[mysteryman]

midnight special, this evening it did it again, was silent at startup. The lights DID come on, just no sound. Disconnecting the mic at the radio did not produce sound as I thought it would, but when I grabbed the mic itself, and MAY have keyed it, the sound came on. So, still a bit of a mystery to me, but seems to be more mic-related than power switch related. I will try to observe patterns and sort details, thanks for responding to my question.

 

[Yeti Communications Ltd]

considering its age has it had a recap yet?..mics aside and dry joints the other symptom is the rx/tx rail electrolytic caps when he switches from rx to tx etc

 

[mysteryman]

It has had no service, I want to say it is a solid 30-years old...when it works, it works fine, I associate dried-out caps with garbled sound...thanks for the input, Yeti Communications

 

[loosecannon]

the radio has been shaken it's whole life?

mounted in a mobile using a bracket?

chances are that one or more of the semiconductors that is attached to the chassis has wiggled loose.

your power switch might be bad, as that is a common failure point in old radios, but your symptoms could be caused by other issues.

Unless you want to get in there and re-touch solder joints, then test the radio, then replace the volume control (you probably won't find a replacement without another 19xs to pull from), then i would say it's time to retire it. they are great for holding shelves down.

this radio is nowhere near worth the cost of repair if you don't do it yourself.
LC

 

[mysteryman]

Thanks for the response, loosecannon, I agree, makes sense that conditions over time have taken their toll.
In looking for a new radio, let's say I am looking at a Uniden PRO510XL and a Uniden PC78LTD...both within my budget and within my installation space restraints, and both meet the maximum legal output. I know that I can order with Peak and Tune, can upgrade the mic, add an external speaker. Is there any reason (other than added features) to stay away from the 'low end' unit? In other words, can I start with a lower cost, smaller size unit and spend my dollars on upgrading it? can I expect to be heard loud and clear as I hear some drivers on the road? Do these drivers have power mics? some of the calls I receive are unbelievably loud and clear, what is required to obtain that quality when I am doing the talking? [I have a single Wilson 2000 antenna, my center coil is mounted just about at my roof line (I added a pot-belly spring to get it to that point) then the 'top rod' is above that.
I thank you for any input.

 

[2FB327]

I would be willing to bet it's a cold solder joint, the more info you provide narrows it down. Does it only do it after the radio is turned on after sitting overnight outside in a cold vehicle, etc.?
Sometimes you can find the bad joint by hooking up the radio with the covers off with the solder side up and taking a PLASTIC handle and lightly touching every solder connection and you might get lucky, if you can leave it outside overnight, put it in the fridge or hit it with freeze spray even better.
As far as your other question, please get your antenna system in order, please let folks know what type of truck you have, pickups with cool looking mounts are usually the problem. You can spend a fortune on a radio, but if the antenna system isn't right it won't work well.
If your starting out buy a good magnet mount and put it on the roof, why because you will have some metal under it, some of the tool box mounts I have seen I can't believe they even work (hint: the box sits on the bed with rubber strips under it so it doesn't scratch the paint, the bed is mounted to the frame and it sits on rubber mounts. Rubber is not a conductor, and trying to get a radio to work properly in a pickup can be a real challenge (just search this site).
The other radios you hear out there that sound great are dialed in but may have an amp behind them. Buy a Cobra 29 or the 78 and you'll be happy.
Good luck with your adventure.

 

[Robb]

Thanks for the response, loosecannon, I agree, makes sense that conditions over time have taken their toll.
In looking for a new radio, let's say I am looking at a Uniden PRO510XL and a Uniden PC78LTD...both within my budget and within my installation space restraints, and both meet the maximum legal output. I know that I can order with Peak and Tune, can upgrade the mic, add an external speaker. Is there any reason (other than added features) to stay away from the 'low end' unit? In other words, can I start with a lower cost, smaller size unit and spend my dollars on upgrading it? can I expect to be heard loud and clear as I hear some drivers on the road? Do these drivers have power mics? some of the calls I receive are unbelievably loud and clear, what is required to obtain that quality when I am doing the talking? [I have a single Wilson 2000 antenna, my center coil is mounted just about at my roof line (I added a pot-belly spring to get it to that point) then the 'top rod' is above that.
I thank you for any input.

IMO - the Uniden PC78LTD is clearly the better of the two - by far. Truckers like to use noise-cancelling mics, like the Workman SS56 - a bargain at $20. Road noise will be too much for the Astatic D-104 M6; that mic is better suited for a base station radio. 'Loud and clear' is going to depend on just who peaks/mods the radio. Loosecannon will do a fine job.

 

[loosecannon]

You'll never be able to upgrade the 510xl to be as good as the PC78LTD.
don't even bother with it, just get the PC78LTD or a cobra 29LTD as they are the exact same radio on the inside.

as Robb said, no power mic if you are using it mobile. i like the Astatic 636 mic, but the others mentioned are good too.

the peak and tune will vary depending on where you get the radio from.
what you really need is an alignment, as that tunes the whole radio, and not just the modulation. you can peak the modulation yourself just as good as most places do it.
we can tell you how when you get the radio.

find a good radio for a good price, and then if you want to have it aligned, ask around here
(you can PM me if you want) and we will lead you in the direction of a competent tech.

you might save a little money by having the radio sent directly to the tech first.
LC

 

[mysteryman]

thank you for your responses, 2FB327, Robb and loosecannon...my antenna, the mentioned Wilson 2000 (I double-checked, the center coil is above my roofline) is mounted directly to the cargo box. I considered using a flat grounding braid but since I had reception without static I assumed that it was grounded correctly, I did not think that the added grounding would add to it.
So, I follow you on the Cobra 29 or Uniden 78 as being equal to each other and superior to the PRO510 as a starting point. The Workman S556 or the Astatic 636 (I assume any of the 636s) mics will be good for mobile use.
Regarding the Alignment (Alignment being superior to Peak and Tune, and the Peak and Tune depends on who does the work) and Peak and Tune, does the Alignment replace the peak and Tune or does the radio need a good Peak and Tune AND an alignment?
Thank you for your offer of guidance, loosecannon, I am gathering information at this stage as I am not going to make the purchase just yet, I don't want you to think that I moved-on without following-up.