1962 Victor restoration

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Post by firemedic on Sun May 22, 2011 9:46 pm

Hi all, I'm brand new to the forum. Maybe you folks can help w/ a little advice on my recently acquired 1962 Victor 3VF305. I got it cuz the cabinet & speaker cloth is in great shape, and it appears well cared for. It has dual 6BQ5 single ended outputs, cathode biased. Very nice.

I installed a grounded power cord, & replaced all the paper filter caps only. The other filter caps look like sturdier construction & hard to find replacements for so I formed them up on a Variac. I'm pretty sure I need to replace the coupling cap feeding the left channel since that socket makes the tube red-plate. I also fused the B+ (HT). That said, I have a couple of issues, not having any experience w/ RF amps. I have built 4 homebrew guitar amps, that's it.

The AM & phono channels sound fine, maybe a little low volume but they're workable.
The FM does work but at VERY low volume; "FM Stereo" is lower volume, almost non-existent.
Also, I'd like to overhaul the phonograph. It seems to need a little love. It works but it has a double stylus for some reason and plays different parts of the same song at the same time. I can't use it to play a regular LP, it's the darnedest thing. Maybe somebody can clarify, maybe a good source for replacement parts would help too. I've ordered replacement tubes for the entire FM signal path hoping it's just a weak tube; I have no idea how to proceed with the record player.
It has a really cool signal strength indicator tube which still works!
Anyway, if anyone can chime in I'm all ears. I'd really like to get this thing singing again.

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Post by firemedic on Sun May 22, 2011 9:49 pm

BTW I do have the schematic, just no way of understanding it beyond the power rail & output section.

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Post by firemedic on Mon May 23, 2011 1:33 pm

OK, I fixed the issue with the stylus, quite simple actually. A new one is on the way but the old one works fine.
Replaced both coupling caps in the power output section which seems to have fixed the redplating.
I tried an old scratchy R. Orbison record to test which sounded great, then tried Frank Zappa: Guitar since I haven't heard that one in a while......
Wow. WOW. I can't describe how great it sounds.
Anyhow, the FM channel still is not working right (low volume), still waiting on the tubes.
Aaaand I seem to have poked a hole in the speaker in my zeal to get the thing cleaned up. So, 2 isuues remain: Low volume on the FM channel & I'd just like to replace the speakers; any good web sites for those?

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Post by firemedic on Tue May 24, 2011 4:01 pm

It had an open screen resistor to the FM limiter tube. After replacing that I get a pretty decent volume though I suspect it's not 100%- but it's good enough. I repaired the speaker hole with some fabric glue & I'm getting ready to button it up.
Even though I got no replies, there is a good amt. of info here that was helpful so thanks to all!

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Post by Dion on Tue May 24, 2011 5:00 pm

Firemedic: Thank you for posting. Many times responses from this group are delayed a few days; I suspect someone would have gotten around to helping you out. I did not reply simply because I'm pretty new to this and don't consider myself much of an expert. I would have said to replace all electrolytic and paper caps, and to patch the speaker with rubber cement and a scrap of paper on the back-side. Without a schematic in front of me I would hesitate to offer any advice of a more specific nature. Sounds like you did a very good job of figuring it all out though. Nice work! -Dion Morehouse
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Post by Bill Cahill on Wed May 25, 2011 2:04 am

My aplolgies, also. I am not familiar with that radio, so, without a schematic in front of me, hesitated to say anything.
Congradulations on finding the problem. It is slow here, but, we are getting a good repair section here.
Congrats on a great job!
Bill Cahill

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Post by repairtech on Thu May 26, 2011 3:51 am

Doublecheck the values of the B+ feed resistors going to the 6BA6 I.F. tubes, they should be 4.7K.
And the B+ feed to the limiter 6AU6, 27K.
Notorious for being high in value.

Also the amp B+ feeds..... 82K.




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Post by firemedic on Tue May 31, 2011 2:43 pm

Aw, I wasn't trying to make anyone feel bad, thanks for your replies.
Since I have it all buttoned up, I hesitate to take it out again when it pretty much works fine. I basically checked all the plate & screen voltages to make sure there was enough to make a tube work- & left it at that. Since it's kind of a rat's nest of wire, it's very hard for me to trace out exactly what is what. I'm sure there are some leaky coupling caps & those CC resistors are probably all way out of tolerance but, I'm happy. I'll leave it.
The only issue I really have with the FM channel is that old problem of static when I stand in certain places in the room. Which I guess I can fix by attaching an aux. antenna.
Anyway, thanks to everyone for your responses & I will check those components when I do open it up again.

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Post by repairtech on Tue May 31, 2011 9:12 pm

firemedic wrote:The only issue I really have with the FM channel is that old problem of static when I stand in certain places in the room. Which I guess I can fix by attaching an aux. antenna.

Mine had "static" too at times.
Cause? = those pesky B+ resistors!
(not enough gain to overcome weak signal)

Once the RC1205 chassis is re-capped and resistors checked/changed it played fine.

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Post by firemedic on Tue May 31, 2011 11:15 pm

All right, you have appealed to my inner tinkerer, who must be obeyed. I'll go back in.
Thanks for the advice, I'm confident that this will fix it all the way. Stand by for results...

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Post by firemedic on Wed Jun 01, 2011 5:15 pm

The 4.7ks were okay- they've drifted a little but not too bad. The 27k to the FM limiter was the one I mistakenly referred to as the 6AU6 screen resistor, I had missed that it was transformer-coupled to the plate as well. So that was already replaced. Pretty conveniently located, too, right there on top...
I got the tubes for the FM channel in today, they changed nothing. In fact the "NOS" (more like UOS) 6AU6 seems to cause lots more static. The old one is back in so I'm all set there. The station I listen to is not very powerful so that is probably contributing. The new EL84s sound just a little clearer, so my work here is done. Thanks repairtech for the advice!

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Post by repairtech on Thu Jun 02, 2011 1:46 am

As long as those 4.7K's are no more than 4.9K, fine.
One of mine drifted to 5.4K..... and that is no good.
Result is low sensitivity, weak AFC action too.

Plus new caps all around (paper ones are crap) and a good by the book alignment.... it's playing great.

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Post by firemedic on Thu Jun 02, 2011 10:51 am

Oh, one was 5.5k but I figured that was OK. I guess not.
When I get a chance I'll crack it open again but my honey-do list needs attending to first.
I already replaced the paper caps, the other ones (coupling caps, can caps) are too numerous and/or hard to find replacements for. I brought up the voltage real slow (over 24 hrs) initially in an attempt to form up whatever I didn't replace.
I have no idea how to do an alignment.

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Post by Bill Cahill on Thu Jun 02, 2011 2:17 pm

That radio needs re capping, and, electrolytic replacement, or, you are inviting more trouble.
Leaky caps can dammage tubes, circuits, etc. Electrolytics suddenly shorting, and, this has happenned, can cause alot of dammage.
Bill Cahill

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Post by repairtech on Fri Jun 03, 2011 12:18 am

firemedic wrote:Oh, one was 5.5k but I figured that was OK. I guess not.
When I get a chance I'll crack it open again but my honey-do list needs attending to first.
I already replaced the paper caps, the other ones (coupling caps, can caps) are too numerous and/or hard to find replacements for. I brought up the voltage real slow (over 24 hrs) initially in an attempt to form up whatever I didn't replace.
I have no idea how to do an alignment.

If you're going to do the job, shortcuts are not an option.
Replace those out-of-tolerance resistors, paper caps, 'lytics, and then see the change.
Most likely, if the aged sour parts didn't stress out any tubes, an alignment might not be needed.
Do NOT mess with the Matrix Balance control (Multiplex FM) on the side of the chassis!

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Post by firemedic on Sat Jun 04, 2011 11:31 pm

I'm sorry guys but after many, many, many hours of tweaking amps my philosophy has become: if it sounds really good, leave it alone. It sounds really good. Even my wife notices the difference & that's saying something.
I do appreciate the input & advice; this forum is a fantastic resource and I am truly grateful.

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Post by GaryRabbitt on Thu Jun 09, 2011 5:10 pm

Hi,
You'd be surprised at the caps that have been 'reformed' then later shorted or failed. Inside is a dried, corroded electrolyte and elements. I'll attach photos asap. Even though an amp "sounds good" on original caps, why risk the filters taking a dump, and ruining something else like a transformer?
It is false economy to keep the original almost 50 year old caps in place. I know you have 'messed' with amps for years and so far have been lucky. I hope your luck holds out. We've seen the destruction an old filter cap has done.

The analogy would be like driving on original car tires that are worn, but have not blown out yet. Don't want to replace them if they aren't blown out, right? Then if only one blows out, replace only that tire.
JMO, Good luck with your set. Smile
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Post by GaryRabbitt on Thu Jun 09, 2011 5:32 pm

OK here is only one filter cap I replaced that the owner said they reformed it, and it had no hum. They were right, the set did not hum. What did they reform? The crusty dry electro How much more life did it have? Lord knows. This was from a small table model set. If it failed, possibly nothing would happen, or it could have caused failure of other parts if it shorted. The point is, these old caps are an accident waiting to happen.

(From my post at ARF.)
1962 Victor restoration Dissect+1
Dissecting a Philco filter cap. Why would anyone leave the old ones in is beyond me. And yes, this one did "work" amazingly. But for how much longer? Cardboard tube or metal can, the insides are the same.


1962 Victor restoration Dissect+2
If it isn't broke, don't fix it. Yeah right. This filter was "working" but on the edge of failure I say. Change those caps.

1962 Victor restoration Dissect+2
If it isn't broke, don't fix it. Yeah right. This filter was "working" but on the edge of failure I say. Change those caps.

1962 Victor restoration Dissect+3
Thrillseeker cap. How long would it be before total failure?

Not worth detroying your equipment for $3 worth of parts.

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Post by Bill Cahill on Thu Jun 09, 2011 8:34 pm

And, I totally agree... Thanks for the pictures!
I have taken "reformed" electrolytic cans apart, and, seen so much acid corosion it isn't funny.
I once got a tv that he had put in reformed new old stock electrolytics in. One can after another eventually shorted out, and, started spewing it's gutts.
I was replacing each can one at a time with new ones.
Last one to blow was the first can in the circuit, and, wet was still playing. This time, the dammage was done. I put new electrolytics in, but, then, the previously overloaded power resistors in power supply blew.
Case closed, tv finnished. But, good!
I have seen ac-dc radios that had been on fire after the electrolytic shorted out.
I have also seen the dammage the paper caps can also cause.
I can't stress enough that it isn't worth taking the risk of leaving it original.
Let me tell you another true story.
A few years back a customer brought me a little Philco table radio from 1941. His complaint was the speaker rattled, and, he wanted me to install a new grill cloth.
I heard it play, yes, but, wasn't impressed with the slight hum, and, lack of reception, and, mediocre volume.
I convinced him it needed total rebuilding.
When he came back to pick it up he couldn't believe his ears. It sounded the best he ever remembered
it playing in his own life. It was his grandparents' radio, they bought it new. He first heard it in the 50's, and, it already sounded slightly muddy. He thought that was normal for old tube radios. Boy, did he find out differently!!!
Bill Cahill

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Post by Bill Cahill on Thu Jun 09, 2011 8:40 pm

In fact, let me give you one more example. I have a very nifty, rare mid 30's table radio in a wood case.
It has a power transformer driving 6 tubes.
Well, the original electrolytics were replace in the 40's, with equally cheap capacitors.
Sometime later they shorted out.
Power transformer had caught on fire.
I saw the evident dammage, and, burnt spots on transformer, and, the chassis.
It also dammaged power supply parts, and, may also have dammaged speaker field. I'm still looking for a suitable trasnsformer for the set.
Bill Cahill

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Post by firemedic on Fri Jun 10, 2011 9:20 pm

Got any good sources for a 80/40/40/20 can?
I am a true believer in replacing old caps; I did toss the old paper ones. But I'm also kind of lazy. It looked hard to replace & the Mouser site can be hard to navigate. Sorry for the trouble.
While I'm in there I'll take another crack at those supply resistors to the FM limiter. Though they're still within 20% tolerance, pretty good for 50 year old CC resistors.
And how to do an alignment?

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Post by Bill Cahill on Sat Jun 11, 2011 4:55 am

I'd stay out of alignment for now. Try Edli electronics, and, Antique Electronic Supply co.
Maybe even Allied Radio.
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Post by repairtech on Sun Jun 12, 2011 11:00 am

firemedic wrote:Got any good sources for a 80/40/40/20 can?
I am a true believer in replacing old caps; I did toss the old paper ones. But I'm also kind of lazy. It looked hard to replace & the Mouser site can be hard to navigate. Sorry for the trouble.
While I'm in there I'll take another crack at those supply resistors to the FM limiter. Though they're still within 20% tolerance, pretty good for 50 year old CC resistors.
And how to do an alignment?

That main filter 'lytic.... as well as the secondary one, I replaced with under-chassis singles.... there's plenty of room under the amp chassis for them.

As well, that 80u, right off the rectifier, is a bit high-rated.
I went with my own values = 47, 100, 47, 47, all 450v, to give the 5AS4 a break when warming up.

Increase the 6BQ5 cathode bypass caps (20u) with 47u/50v.
They can be mounted right across the wirewound cathode resistors.
Also on the amp... those 82K B+ feeds for the 6FQ7's go bad/read high.
Same goes for the 6FQ7 feeds in the preamp...... check 'em.

As for alignment.... don't mess with it if after recapping the set sounds good.
There is a strict procedure that must be followed... one goof, you'll end up frustrated.

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Post by firemedic on Sun Jun 12, 2011 3:05 pm

It's diode-rectified so I'll stick with a high value, but your point is taken, i.e. the values are not set in stone.
I haven't had a chance to open her up again, but the yard looks great!
BTW the AFC sounds terrible- all static, I believe you mentioned low limiter supply voltage as a possible cause. As well, once the FM station is pretty well set, I find myself having to go back and readjust frequently when it gets static-ey.

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Post by repairtech on Mon Jun 13, 2011 12:47 am

firemedic wrote:It's diode-rectified so I'll stick with a high value, but your point is taken, i.e. the values are not set in stone.
I haven't had a chance to open her up again, but the yard looks great!
BTW the AFC sounds terrible- all static, I believe you mentioned low limiter supply voltage as a possible cause. As well, once the FM station is pretty well set, I find myself having to go back and readjust frequently when it gets static-ey.

Ah, my version of the amp is the RS-177H chassis.
Some other versions used diodes.

Tuning: at first turn-on, tune for best closure of the eye tube with AFC "off".
Then, flip AFC on.
If it drifts into distortion/off station after 5-10 mins with AFC on, first check 6AL5 B+ resistor (27K)
(all paper/'lytics replaced?)
If that is ok, it'll maybe need alignment. (or, it might have been "screwed with")
I'd rather not get into that, particularly over the net.

I just fix 'em proper on my bench and ship 'em.
LOL

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