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A couple of questions for those with "experience"...

guitar_199

guitar_199

Sr. Member
Mar 8, 2011
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Deer Park, TX
I am hoping some of you might respond with a little practical advice to help further my learning and expectations!

1) Have any of you ever seen a radio that had been neglected for a long period of time and you put it on the bench...and it is WAY out of alignment? What kind of component issue causes it to go out of alignment? Assuming it once worked OK and now it doesn't.... something changed! I am going to suppose electrolytics could be high on the list..... but what else?

2) is there anything you need to know when you get ready to attack the various coils/transformers in an attempt to align? I know about the use of "proper alignment tools" and not to use hard steel screwdrivers... so I am going to go ahead and count THAT as number 1!!!!! Other than that though..... do the cores tend to be tight or resist turning when the radio is older? (worthy of note, I took a very close look at all of my tuning slugs yesterday... and I do not see wax on a ONE of them! Does that surprise anybody?)

3) Have any of you ever seen a case where, immediately after a successful recap....... things the didn't work do? Or things that didn't work well... work better?

Thanks in advance. These are just some thoughts occupying my mind as I roll closer to the alignment on this Console V.

Bob
 
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guitar_199 said:
I am hoping some of you might respond with a little practical advice to help further my learning and expectations!

1) Have any of you ever seen a radio that had been neglected for a long period of time and you put it on the bench...and it is WAY out of alignment? What kind of component issue causes it to go out of alignment? Assuming it once worked OK and now it doesn't.... something changed! I am going to suppose electrolytics could be high on the list..... but what else?

2) is there anything you need to know when you get ready to attack the various coils/transformers in an attempt to align? I know about the use of "proper alignment tools" and not to use hard steel screwdrivers... so I am going to go ahead and count THAT as number 1!!!!! Other than that though..... do the cores tend to be tight or resist turning when the radio is older? (worthy of note, I took a very close look at all of my tuning slugs yesterday... and I do not see wax on a ONE of them! Does that surprise anybody?)

3) Have any of you ever seen a case where, immediately after a successful recap....... things the didn't work do? Or things that didn't work well... work better?

Thanks in advance. These are just some thoughts occupying my mind as I roll closer to the alignment on this Console V.

Bob
Click to expand...
Hi Bob,
I am a real amateur as well but I have done about 20 radios that have been re-capped and aligned. I will say this regarding your questions:

1) I have not seen a radio that was way out of alignment that had not been messed with. They are generally close but do need to be aligned. The other part of that equation is that I rarely get a radio that has not been messed with. It is amazing how most older radios seem to have had someone in them. I have mainly worked on late 70's and early 80's radios. I have done a few early 90's Galaxy bases but they are not my preference.

2) I will say that the correct alignment tools are a MUST!!!! Most coils I have adjusted move fine but there are a few (mainly in Cybernet boards) that have been hard to move but I have found that you may need to try to spin them down a little and then up a little to get the best motion out of them.

3) I have had 2 radios that after a re-cap they did not work right. They were both Cybernet mobiles with the same board (Lafayette Telsat 120 and a GE mobile). I found that the marking on the board was incorrect and I put a cap in backwards. The Telsat worked fine after replacing and the GE still does not.

Here is my final AHHH HAAA moment. I was aligning the receive using a vacuum tube multi-meter and was not getting the best results. Not awful but not great. What I found/learned was that the meter was reflecting the noise as much as the 1kHZ tone and I was missing the peak that way. I ended up buying a sinad meter (Sinnader model 3) and I have been able to do a better job that way. Someone on here may have some suggestions on how to do a receiver alignment without a communications test set and we can all do better.

I am beginning a Cobra 1000 this week. We shall see how it goes...

All the best!!!
 
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I’ve seen one Cobra 138XLR that was way off due to age, mostly dried out caps way past tolerance. Recapped the radio, was fairly close, alignment and it’s the best radio I’ve ever used for SSB.

Far as alignments go, the job turns out no better than your equipment, so I agree the right equipment is a must. That also means equipment that’s close to calibration (did I really say that?) because if it’s out bad, your alignment will be out also.

Experience. Nothing beats experience.
 
I will say that in 30 years of dealing with radios I have never really come across a radio that required a recap...yet. I've owned just about every radio twice or more and like Pork Chop said they usually are slightly off but with just some minor adjustments I can get them back on frequency. Even some of the oldest ones have been totally ok. Maybe it's the area I live in, but I always read these threads of people recapping radios and always wondered why I haven't run into radios where I had to do that :)
 
I’ve not seen a bunch that needed it but I have seen a few, some that were out farther than the 10% tolerance on the caps. Maybe it is area dependent? Maybe it’s how the radio was taken care of previously throughout its life?
 
This radio has been mine since around 1982 and once upon a time worked fine. But I took it out of service around 1985ish... and never messed with it again until recently. I know that I never once put a diddle-stick to it.

I am getting ready to order the tools, by number, from GC Electronics. They have every one I need and it is about $16.50.... not bad.

As I recap, I am doing one cap at a time, and as I pull the cap, I check the polarity of the cap as it comes out with the markings on the board. So far they have been spot on correct.... but I am not letting my guard down!!!!

As it happens, I have the first model Sinaddr which does not have an AC voltmeter. But I thank you for the caution as I can look for that effect and work around it.

Thanks a bunch for your reply!

Bob


Lkaskel said:
Hi Bob,
I am a real amateur as well but I have done about 20 radios that have been re-capped and aligned. I will say this regarding your questions:

1) I have not seen a radio that was way out of alignment that had not been messed with. They are generally close but do need to be aligned. The other part of that equation is that I rarely get a radio that has not been messed with. It is amazing how most older radios seem to have had someone in them. I have mainly worked on late 70's and early 80's radios. I have done a few early 90's Galaxy bases but they are not my preference.

2) I will say that the correct alignment tools are a MUST!!!! Most coils I have adjusted move fine but there are a few (mainly in Cybernet boards) that have been hard to move but I have found that you may need to try to spin them down a little and then up a little to get the best motion out of them.

3) I have had 2 radios that after a re-cap they did not work right. They were both Cybernet mobiles with the same board (Lafayette Telsat 120 and a GE mobile). I found that the marking on the board was incorrect and I put a cap in backwards. The Telsat worked fine after replacing and the GE still does not.

Here is my final AHHH HAAA moment. I was aligning the receive using a vacuum tube multi-meter and was not getting the best results. Not awful but not great. What I found/learned was that the meter was reflecting the noise as much as the 1kHZ tone and I was missing the peak that way. I ended up buying a sinad meter (Sinnader model 3) and I have been able to do a better job that way. Someone on here may have some suggestions on how to do a receiver alignment without a communications test set and we can all do better.

I am beginning a Cobra 1000 this week. We shall see how it goes...

All the best!!!
Click to expand...
 
I'm going to do the best that I can here. Have a decent scope, spectrum analyzer, VTVM, Freq Counter, RF Generator is a good brand. Calibration....well....at this point that is probably my weakest point and I understand that. At some point I need to learn to calibrate the freq counter using the 10 MHz WWV. It may sound weird but I ahve seen the procedure for it.

Believing that everything has a "first time" .... experience is exactly what I hope to gain here!

Thank you!!!
Bob

TheRealPorkchop said:
I’ve seen one Cobra 138XLR that was way off due to age, mostly dried out caps way past tolerance. Recapped the radio, was fairly close, alignment and it’s the best radio I’ve ever used for SSB.

Far as alignments go, the job turns out no better than your equipment, so I agree the right equipment is a must. That also means equipment that’s close to calibration (did I really say that?) because if it’s out bad, your alignment will be out also.

Experience. Nothing beats experience.
Click to expand...
 
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Well I meant experience from screwing up and learning your own equipment, didn’t mean it in a harsh manner or negatively towards you.

Your equipment is probably close enough, for CB anyway. Like a good friend says, it’s CB not bloody rocket science, we’re not trying to pinpoint terrorist here.

It’s a hobby and you should have fun with it and enjoy learning what you may not already know. So like Bobby Boucher’s momma said “go have fun with your friends playing the fools ball”.
 
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I'm sure we have all heard it before.......but it never goes out of style!!!!!

"Good judgement comes from experience!
Experience comes from bad judgement!"



TheRealPorkchop said:
Well I meant experience from screwing up and learning your own equipment, didn’t mean it in a harsh manner or negatively towards you.

Your equipment is probably close enough, for CB anyway. Like a good friend says, it’s CB not bloody rocket science, we’re not trying to pinpoint terrorist here.

It’s a hobby and you should have fun with it and enjoy learning what you may not already know. So like Bobby Boucher’s momma said “go have fun with your friends playing the fools ball”.
Click to expand...
 
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Stupid trick for polarity on caps. Before you start pulling them, use a Sharpie to mark the part of the caps that are oriented towards front of the radio. If you forget which way the cap you just pulled was in, check for the mark.

Also, when you're swapping out one cap at a time it serves as a visual marker of your progress.
 
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The life of an electrolytic cap has more than one influence.

Initial quality. SBE CB radios seem to have been built with the lowest-quality electrolytics of the day. Once you find more than a handful of failed electrolytics in one radio it's best to admit that more of them will continue to fail down the road. Replacing them all will avoid playing "electronic whack-a-mole" as the rest of them quit one, two or three at a time.

Heat exposure. The first electrolytics to break down in a typical Cobra 2000GTL are in the clock/counter module. No coincidence that it's hotter inside the metal shield box than in the rest of the radio. Mileage matters. A 40 year-old radio that's truly NIB probably won't have any bad caps in it. Yet.

Circuit stress. A capacitor may run hot because of heat from its surroundings. A filter capacitor will also generate its own internal heat from either leakage current or from ripple current. A power-supply filter cap is constantly discharging and recharging. All conductors have resistance. The conductors inside the cap will always turn some of the energy being pumped in and out into heat. Best way to test an electrolytic is an "ESR", or equivalent series resistance tester. A high resistance reading means that cap is not long for this world.

Long-term storage after a period of service. Over and over we would see the same story. A 40-channel base radio would be used heavily for 10 years or so. Gets replaced by an "upgrade". Usually a 'black radio' of one kind or another. The black radio breaks after a few years and the old 40-channel gets pulled off the shelf as the spare base radio. It works for less than a week before (choose one)
>No receive audio, S-meter still kicks.
>No transmit audio on AM, no transmit on sideband.
>No transmit at all, AM or SSB.
>Squeal on AM transmit audio.
>Wattage dropped in half, and sideband sounds terrible.

Seems that being awakened from a long nap after years of everyday service causes caps to break down.

The one common thread will be the physical structure. The internal chemistry that makes an electrolytic cap work uses liquids that will evaporate. Those liquids are soaked into a layer of brown paper, not sloshing around. They used to call this construction a "dry" electrolytic capacitor. A rubber plug, usually on the positive side of the cap is what holds it in. Rubber doesn't last forever. Sooner or later it will harden and shrink. When that happens the seal with the metal housing will be broken, and it dries out.

Sooner or later.

73
 
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. . . . very limited experience here - compared to the real vets.
But - xtals are another part that can go foul. Also diodes can leak and transistors can go low gain. Never seen disk caps go yet. Never seen a coil or choke go open yet either. But that is my limited experience talking here - too.

As far as seeing radios that were bad just because of caps? Oh; yes! The radio I am using now is a Uniden PC 244. Nearly every single cap in it was dried out so badly that they barely read any capacitance at all, or were shorted, Or ESR was really high, or just went open. A SS 360FM was also really just as bad. The list goes on.

If I come across a cool old radio, like a Grant XL or 148 GTL, it has proved never to be a waste of time recapping them. Some great old radios like those and others (usually Unidens IMO) really are worth the time, parts, and effort. They have monetary value as well as just being a better built and engineered radio. I steer away from buying a lot of the newer radios because of dubious build quality.

But hey . . .what do I know?
 
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Good thoughts there to ponder for a while.

nomadradio said:
The life of an electrolytic cap has more than one influence.

Initial quality. SBE CB radios seem to have been built with the lowest-quality electrolytics of the day. Once you find more than a handful of failed electrolytics in one radio it's best to admit that more of them will continue to fail down the road. Replacing them all will avoid playing "electronic whack-a-mole" as the rest of them quit one, two or three at a time.

Heat exposure. The first electrolytics to break down in a typical Cobra 2000GTL are in the clock/counter module. No coincidence that it's hotter inside the metal shield box than in the rest of the radio. Mileage matters. A 40 year-old radio that's truly NIB probably won't have any bad caps in it. Yet.

Circuit stress. A capacitor may run hot because of heat from its surroundings. A filter capacitor will also generate its own internal heat from either leakage current or from ripple current. A power-supply filter cap is constantly discharging and recharging. All conductors have resistance. The conductors inside the cap will always turn some of the energy being pumped in and out into heat. Best way to test an electrolytic is an "ESR", or equivalent series resistance tester. A high resistance reading means that cap is not long for this world.

Long-term storage after a period of service. Over and over we would see the same story. A 40-channel base radio would be used heavily for 10 years or so. Gets replaced by an "upgrade". Usually a 'black radio' of one kind or another. The black radio breaks after a few years and the old 40-channel gets pulled off the shelf as the spare base radio. It works for less than a week before (choose one)
>No receive audio, S-meter still kicks.
>No transmit audio on AM, no transmit on sideband.
>No transmit at all, AM or SSB.
>Squeal on AM transmit audio.
>Wattage dropped in half, and sideband sounds terrible.

Seems that being awakened from a long nap after years of everyday service causes caps to break down.

The one common thread will be the physical structure. The internal chemistry that makes an electrolytic cap work uses liquids that will evaporate. Those liquids are soaked into a layer of brown paper, not sloshing around. They used to call this construction a "dry" electrolytic capacitor. A rubber plug, usually on the positive side of the cap is what holds it in. Rubber doesn't last forever. Sooner or later it will harden and shrink. When that happens the seal with the metal housing will be broken, and it dries out.

Sooner or later.

73
Click to expand...
 
There are Electrolytic blues, Grey and the in-betweens...

There is also the efforts the DISC caps provide.

When you mention the "Why did this do that?" when all you did was take it out and put it away for another day, then "Life" happens and suddenly you're spinning a dial trying to find traffic reports while you're stuck in traffic trying to get to your next new job...

These moments are also why I love the discrete-based designs, it's kind of a job security.

There were times of the "Glue blues" as well as the Flux-Sux's moments where the corrosive effects of neglected flushes and too much adhesives - make your day into a week a frustration waiting on new parts to show up or scramble thru town looking for a parts store that "just might have one left"

Had my share of "Wow - when did this show up?" as the radio now squeals - that's the time you realize the older parts and variables, are "indented" into their respective spots they were last turned to and now, you have to find a way to recover their linearity.

I haven't even talked about the switches yet...
 
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