CB voltage spike??

[topgun1986]

Happy Thanksgiving to all!

OK...
CB burping for now has stopped.

Audio works fine now, as well. Apparently, you have to have the mic inserted in order for the speaker to work properly. Oops.

But now the green "RX" LED is stuck on. Squelch does not seem to have any effect on it. When I key up mic, red "TX" LED comes on just fine, but as soon as I let off the mic, the green "RX" led comes back on. I do have a SWR meter and small antenna hooked up to the radio, and meter swings appropriately when I key up. Anyone have any ideas/clues of possible problem?

Also, I have found something odd on the circuit board. A wax looking substance has melted over some various resistors. There does appear to be a burn mark on top of the silver, flask looking device, where the wax substance probably came from. Anyone have any ideas/clues what this is?

[topgun1986]

Here is the wax substance.

[k3cfc]

Originally Posted by topgun1986

Happy Thanksgiving to all!

OK...
CB burping for now has stopped.

Audio works fine now, as well. Apparently, you have to have the mic inserted in order for the speaker to work properly. Oops.

But now the green "RX" LED is stuck on. Squelch does not seem to have any effect on it. When I key up mic, red "TX" LED comes on just fine, but as soon as I let off the mic, the green "RX" led comes back on. I do have a SWR meter and small antenna hooked up to the radio, and meter swings appropriately when I key up. Anyone have any ideas/clues of possible problem?

Also, I have found something odd on the circuit board. A wax looking substance has melted over some various resistors. There does appear to be a burn mark on top of the silver, flask looking device, where the wax substance probably came from. Anyone have any ideas/clues what this is?

The green light is supposed to be in receive it shows you are receiving not transmitting.as for the wax it is put there to keep moisture from getting on these parts and also there bent in a certain way because i think what you are looking at is an oscillator so just don't touch it.

[topgun1986]

So with the CB on, and not receiving a signal from another CBer, the green "RX" LED should be on regardless? I ask because I honestly cannot remember if it stayed on like that before, when I had it in my jeep temporarily.

Thanks for the info on the wax. I will leave it alone.

[k3cfc]

When the radio is just on the green light should be on. it need not be receiving a signal from anywhere. some radios wont let the red light come on if the radio has a defective transmitter. if you google the name and model number of the radio you should be able to find an operating manual for it.

Happy thanksgiving to you and your family.


K3CFC

[kb2vxa]

To paraphrase Rod Stewart, every picture tells a story don't it? Sorry Charles, (K3CFC) you came close but no cigar. That waxy substance is rosin flux (the solderer used too much) that flowed down onto the circuit board when the ground connection between the crystal case and IF can next to it was made. Yes, that's a metal cased crystal with a plastic band on it. IF cans and other variable magnetic components usually are sealed with wax to keep vibration from turning the slugs. It's also a "security measure", since it must be removed for any adjustments to be made it's an indicator whether or not a "golden screwdriver" has been in there voiding the warranty.

That's an oops alright, today's rigs need the mic connected to work. Way back when it was a relay and when it was first eliminated it was called electronic switching which is TR switching is accomplished by multiple contacts on the PTT switch. Yeah the green light, likely you didn't notice it in the mobile but it was working all along.

Interestingly you "fixed" the problem while poking around inside the radio, probably jiggled a loose connection without realizing it. It may be permanent but don't be surprised if it returns, then it will drive you batty trying to find the exact cause. Having been a serviceman I know how frustrating an intermittent fault can be, it either never shows up on the bench or when you catch a glimpse out of the corner of your eye and turn to look it disappears. There are several methods that work to varying degrees, poking, tugging, freeze spray, praying over it, or a full scale exorcism. Avoid the use of holy water however, that smoke you see isn't an evil spirit.

If at first you don't succeed use a bigger hammer. If all else fails dynamite always works.

[k3cfc]

Originally Posted by kb2vxa

To paraphrase Rod Stewart, every picture tells a story don't it? Sorry Charles, (K3CFC) you came close but no cigar. That waxy substance is rosin flux (the solderer used too much) that flowed down onto the circuit board when the ground connection between the crystal case and IF can next to it was made. Yes, that's a metal cased crystal with a plastic band on it. IF cans and other variable magnetic components usually are sealed with wax to keep vibration from turning the slugs. It's also a "security measure", since it must be removed for any adjustments to be made it's an indicator whether or not a "golden screwdriver" has been in there voiding the warranty.

That's an oops alright, today's rigs need the mic connected to work. Way back when it was a relay and when it was first eliminated it was called electronic switching which is TR switching is accomplished by multiple contacts on the PTT switch. Yeah the green light, likely you didn't notice it in the mobile but it was working all along.

Interestingly you "fixed" the problem while poking around inside the radio, probably jiggled a loose connection without realizing it. It may be permanent but don't be surprised if it returns, then it will drive you batty trying to find the exact cause. Having been a serviceman I know how frustrating an intermittent fault can be, it either never shows up on the bench or when you catch a glimpse out of the corner of your eye and turn to look it disappears. There are several methods that work to varying degrees, poking, tugging, freeze spray, praying over it, or a full scale exorcism. Avoid the use of holy water however, that smoke you see isn't an evil spirit.

If at first you don't succeed use a bigger hammer. If all else fails dynamite always works.

Well Warren MR.License Class: Technician. if this was true how is it all of these radios have the same wax in the same place??? K.I.S.S. now on to some blocking.

[mmckenna]

I think what Warren was saying is that the stain on the crystal is from the flux when they soldered the ground to the top. The waxy substance is just that, wax used to hold the coils in place and keep tuned items from becoming de-tuned due to vibration.

I've also repaired a lot of stuff over the years and have seen the same stuff.

[k3cfc]

Originally Posted by mmckenna

I think what Warren was saying is that the stain on the crystal is from the flux when they soldered the ground to the top. The waxy substance is just that, wax used to hold the coils in place and keep tuned items from becoming de-tuned due to vibration.

I've also repaired a lot of stuff over the years and have seen the same stuff.

Yes you are right about the wax 100% but i have read the post twice and i fail to see the word stain. i was Lafayette radio 's repair man for many years. you have a great day.

[kb2vxa]

Here we go again with someone passing judgement based solely on an Amateur Radio class, being totally clueless as to the individual's knowledge or experience. Another who pays no attention to posts in which it has been mentioned many times. There is a name for it and we all know what it is.

Funny how the word "stain" does not appear, it doesn't describe either substance.
"I think what Warren was saying is that the stain on the crystal is from the flux when they soldered the ground to the top."
No I wasn't, the brown stuff isn't a stain, it's flux residue. Now tell him that, looks like having been trumped he put me on his ignore list and went off in a huff. You can also answer his question, all those radios have wax in the same places because it's industry standard practice.

[mmckenna]

Alright guys, settle down...

[mancow]

The wax is not flux. It's there in quite a few of them as a sealant or some sort of anti microphoning physical buffer.

[RUSTY_SHACKAFORD]

I had a Cobra CB with WX and had the same "Burping" problem. The WX board was bad and had it removed.

[JayMojave]

Hello Top Gun 1986:

Yes many many radio enthusists have hit problems head on. Don't let it get you down, think of it as building a radio type charactor. My first CB Radio was a old tube type radio that didn't transmit, the 12 volt car battery eat a hole in the carpet, that powered it. Another story.....

The Corba 25 is not the best radio out there, the Corba 29 has a great NB (Noise Blanker) and is a better radio in my opion. I agree you might want a tech to look over the radio, or send it back to the manufacture for repair.

I like the CB audio ext speaker connected to the aux input of the radio, thats a good call. I am hard of hearing, snotty, hard to deal with, and just a paint at times so the aux input I will install today in my Ford F-250 4x4 Truck with the worlds loudest PA system in it. Might even run the CB audio to that?
The PA system is used for advising weiving drivers to get off their cell phones.

My ham radio at home feeds a pair of computer speakers on LH and RH sides of the radio table, and then is feed to a DSP Speaker just over head on the upper shelf. It surly helps me hear it all.

Good luck

Jay in the Mojave

[RUSTY_SHACKAFORD]

Emergency Weather Alert
Alerts you if threatening weather is nearby with an alert tone even when CB is turned off.

I had a Cobra CB with WX and had the same "Burping" problem. The WX board was bad and had it removed.