Any linear pro's?

[543_Dallas]

you mean the whole amp?
ya replacing it is coming.

That works but I thought you wanted to fix this one. If it has a bad pill I'd junk it. The thing isn't worth the price of 2 1446 transistors.

 

[Robb]

Sounds to me as though you need to invest in a decent DVM if you are going to do this work at all in the first place. Like a UNI-T UT61E; it is the same meter that I use. Cost you $45 on Amazon. Although not the best; far from being the worst. Check those components . . .
Amazon product ASIN B007THZMWI

 

[357]

I got a meter and a cap checker.
I bought another class ab messenger amp.

This palomar, I put a 620 and a 560 as per the schematic, SWR went down to 1.5 and only getting warm now.
Problem solved.
Cost me $10 for the caps though at the local TV shop.

 

[357]

So for future reference, I ditched the 1000PF on the output and put a 620 and a 560 as per the photos.
I also yanked this orange pos out of the output path.

 

[Robb]

So for future reference, I ditched the 1000PF on the output and put a 620 and a 560 as per the photos.
I also yanked this orange pos out of the output path.

I think that your 1000pf cap was bad to begin with. But remember, that is a tuned circuit you have just altered. Better to have replaced it with a variable cap and adjust it to specs to get a closer impedance match.

The 010 cap is no doubt a RF bypass cap.
What was the other, smaller cap you took out?
Where were their numbers on the schematic?

 

[loosecannon]

Gad that man is a moron!

i'm not usually so harsh with my critiques of Tim, but watching this video just pisses me off!
He actually charged someone money to look at their amp, and it is SOOOO obvious (as if i didn't already know) that he knows NOTHING about amplifiers.

first, he has no idea what that lo-med-hi switch does. any person that is charging people money to "fix" their amp should know how to check whether or not the switch indicates the input level or the output level. there are many different amps, and some are one way and some are the other.
the amp he's working on sets the input level, so if your radio puts out a 6 watt deadkey you set it to "high" and the gain is swamped. LO doesn't mean low power out, it means low input with max gain.
MORON!!!

and then he goes on to bullshit his customer into thinking that there just isnt anything to be done about the input tuning, and advises him to just "run it" that way.
MORON!!!

and the relay rattling?
could be a few different causes, but he just assumes it's because of the lack of SSB delay.
MORON!!!
as if there is no one out there who runs an amp with no SSB delay where the relay doesn't buzz.

I just can't figure why people think he's a real tech.
It used to be that Tim would scour the internet forums and that's how he learned all his "tricks" for modding the old unidens and cobras.
He has since become such a pariah to the CB tech community that no one will even talk to him anymore.
He now has to sneak around the forums with an alias and doesn't DARE post anything for fear that he will end up with a situation like the one that happened over at mauldroppers forum. (a great read! LOL)

So he has no network to keep up on new developments, he has no advisers to learn from, and he has no fellow techs to bounce ideas off of and learn from.
Tim is the most isolated "tech" in the country, and is just making shit up by this point.

hey, if you want a radio re-capped and you just can't stand the thought of not paying an extra 50-75 dollars in order to watch a video of him slamming your radio around, then by all means, send him your radio.
As i've said before, he's gotten good at soldering over the years, but he obviously has no desire to actually learn how this stuff works.
why should he? people keep giving him their money.

Ok, rant over.
Seriously, if you want to watch him freak out and then backtrack, check out the "snake butthurt" thread over at MD.
Too funny.
LC

 

[loosecannon]

oh, and 357, it sounds like RF might be causing that heating, which might mean that you have a bad bypass cap.
check the disc caps that go to ground.
LC

 

[357]

oh, and 357, it sounds like RF might be causing that heating, which might mean that you have a bad bypass cap.
check the disc caps that go to ground.
LC

thanks its all fixed now.
I'm not sure if the 1000pf was factory but according to this and this (exact same layout) its supposed to be 560, 620 and that cleaned it right up.

As for Tim...lol, I was cringing hearing that relay buzz, not very healthy those relays are wimpy to begin with.
The SSB delay, mine had that exact same buzz and it was a broken trace on the delay cap, which was a garbage acom or acorn pile of turd I replaced with a fresh 470uf and that worked perfect after fixing the trace best I could.

I hate class C and this "palomar" is class C.

I got a messenger 250 coming thats AB1 and has a low pass, much better.

ps: yes I re-flowed the caps a bit better after the photo.

 

[357]

Just remember on your schematics, the last cap to the antenna is 90% the weakest link.
That orange 0.01 cap is a joke.

 

[357]

Anybody guess the radio that green one come out of?

 

[Robb]

Gad that man is a moron!

i'm not usually so harsh with my critiques of Tim, but watching this video just pisses me off!
He actually charged someone money to look at their amp, and it is SOOOO obvious (as if i didn't already know) that he knows NOTHING about amplifiers.

first, he has no idea what that lo-med-hi switch does. any person that is charging people money to "fix" their amp should know how to check whether or not the switch indicates the input level or the output level. there are many different amps, and some are one way and some are the other.
the amp he's working on sets the input level, so if your radio puts out a 6 watt deadkey you set it to "high" and the gain is swamped. LO doesn't mean low power out, it means low input with max gain.
MORON!!!

and then he goes on to bullshit his customer into thinking that there just isnt anything to be done about the input tuning, and advises him to just "run it" that way.
MORON!!!

and the relay rattling?
could be a few different causes, but he just assumes it's because of the lack of SSB delay.
MORON!!!
as if there is no one out there who runs an amp with no SSB delay where the relay doesn't buzz.

I just can't figure why people think he's a real tech.
It used to be that Tim would scour the internet forums and that's how he learned all his "tricks" for modding the old unidens and cobras.
He has since become such a pariah to the CB tech community that no one will even talk to him anymore.
He now has to sneak around the forums with an alias and doesn't DARE post anything for fear that he will end up with a situation like the one that happened over at mauldroppers forum. (a great read! LOL)

So he has no network to keep up on new developments, he has no advisers to learn from, and he has no fellow techs to bounce ideas off of and learn from.
Tim is the most isolated "tech" in the country, and is just making shit up by this point.

hey, if you want a radio re-capped and you just can't stand the thought of not paying an extra 50-75 dollars in order to watch a video of him slamming your radio around, then by all means, send him your radio.
As i've said before, he's gotten good at soldering over the years, but he obviously has no desire to actually learn how this stuff works.
why should he? people keep giving him their money.

Ok, rant over.
Seriously, if you want to watch him freak out and then backtrack, check out the "snake butthurt" thread over at MD.
Too funny.
LC

Hey LC:

Didya catch that bit about the SWR calibrate on that video? He tuned it way to the right of that little triangle on the meter for 'CAL' and then said that is the way that it is supposed to be done.
Wha?!?

Ya think he could have helped out that guy by just putting on a $.50 electrolytic on the relay so that it wouldn't buzz while on SSB? Customer got no help there . . .

Yikes!
Bet he will pull that video off of Youtube . . .

Think it is amazing that people still lap his stuff up.

 

[RoadRanger]

I just watched that video.
I can't believe his ears aren't bleeding from that sound, I know mine were just about.
I deaf guy could tell you something is wrong.

 

[357]

at least I could see the amp I'm working on, lol.

 

[543_Dallas]

Glad you fixed it. The people that designed it used those values for a good reason.

The repair looks pretty good. The only thing I will say is when you replace caps keep the lead lengths as short as you possibly can. Just a tip, what you did looks fine.

As for the class C thing. There is a thread on this forum where someone biased a class C rm Italy amplifier. It's very simple and very informative. I used this for my first bias circuit. Add an adjustable regulator and a diode for thermal tracking and you'll have an above average CB amplifier.

If you try that have it connected to the power supply so that you can monitor current and pull the plug FAST if it breaks into oscillation and won't unkey. I would have smoked the pills in the first amp I biased if I didn't get it disconnected fast enough. I didn't even have to key that thing. I'd flip the on switch and off it would go.

 

[Robb]

Glad you fixed it. The people that designed it used those values for a good reason.

The repair looks pretty good. The only thing I will say is when you replace caps keep the lead lengths as short as you possibly can. Just a tip, what you did looks fine.

As for the class C thing. There is a thread on this forum where someone biased a class C rm Italy amplifier. It's very simple and very informative. I used this for my first bias circuit. Add an adjustable regulator and a diode for thermal tracking and you'll have an above average CB amplifier.

If you try that have it connected to the power supply so that you can monitor current and pull the plug FAST if it breaks into oscillation and won't unkey. I would have smoked the pills in the first amp I biased if I didn't get it disconnected fast enough. I didn't even have to key that thing. I'd flip the on switch and off it would go.

Already posted that link on the previous page; I think this what you are talking about?

http://www.worldwidedx.com/threads/quick-and-dirty-class-ab-mod-for-kl300p.93982/

I'd put that bypass cap back in too . . .