Make sure that you leave a note in the chassis that the capacitors were replaced and when. Your restuffing looks so original that a future repairer/ restorer will think that the capacitors are all original paper dielectric and replace them! :scratch2:

Just had a thought on how to get the seasoned look you described. Would it be possible to use some of the surface wax from a paper wrapped cap that one was intending to discard anyway from a different set and rub that on the surface of the recapped cap. I'm basically repeating what you've said but just adding that you could get the was from any old wax cap. I don't think the beeswax changes color due to heat. The darkening is due to the bits of other materials that float around under the chassis and just gets stuck in the warm wax over time. the word patina comes to mind.

The restuffed caps are now all in place under the chassis. Take a look at the before and after pictures.

BEFORE:

http://www.videokarma.org/attachment...2&d=1486626276

AFTER:

http://www.videokarma.org/attachment...3&d=1486626276

At least one change is obvious -- the big 0.047 uF grey "Bumblebee" cap in the center has been replaced with a more normal looking paper cap. I don't think the Bumblebee was original, and those molded caps are not particularly amenable to restuffing.

Other than that, each cap is pretty much right back where it started, with the same orientation.

I've never paid much attention to how the manufacturers chose which end to use for the outside foil. In this set, it is obvious that RCA didn't care at all. Caps which have one side grounded often don't have the outside foil on the grounded end, even in critical places like the first audio amp. There is a cap from the grid to ground which has the outside foil on the grid end. Just goes to show that it never mattered much, and these days they don't bother to mark it.

The set is working pretty well, except for very weak audio. I traced the problem to a broken connection within the 6AT6 first audio amp socket. If I bridge the broken connection, the audio is loud and clear. I'll have to think a bit about how to repair that with the least cosmetic damage. I have plenty of identical replacement sockets, but I'm not too keen to remove the rivets and put the new socket in with screws. Maybe I'll break the old socket out in a way that preserves the rivets, and attach the new socket with well-hidden epoxy right around the old rivets. From the top, that should be undetectable.

Tom,

I agree, it would be nice to not have to replace the socket with screws. That brings up something that I have been thinking about for quite some time. I agree that if one wishes to keep originality, those rivets would be nice to have. So, does anyone know where or who makes the old style rivets? Surely someone knows where to get them? That would make replacing a socket a lot easier.

Ha ! I'd like to see those chumps from "Restoration" take the time/painstaking care that you fellers do...Not bloody likely....

Nice work. I wonder if bumblebees can be split open, stuffed and re-glued. It would sure look good.

Did somebody mention not having a sams for the 621TS?
I found it in the Sams servicer vols 77+78

It shows that mind-bending LV power supply and cap voltages are not listed.

Can't wait to see the final picture Tom. The underchassis looks Great !

For what it's worth there were no bumblebee caps in my 621.

The next problem that needed attention was the broken pin on the socket of the 6AT6 first audio tube. Although there was nothing visibly wrong, a continuity check showed that the contact for pin 1 (control grid) was broken. With a little tug, it pulled right out, making the break very clear:

http://www.videokarma.org/attachment...4&d=1486626276

I thought I had an identical socket I could replace this one with, but checking my supplies, I did not. Even if I had had one, it was not entirely clear how I was going to get the old one out and the new one mounted without having the resort to screws to mount the new one.

I noticed that the original socket had two unused pins. By cutting a little bit of the bottom wafer away, I was able to slide out one of the unused pin contacts:

http://www.videokarma.org/attachment...5&d=1486626276

http://www.videokarma.org/attachment...6&d=1486626276

Getting the remnants of the broken contact out was much more challenging, but eventually I got it out. With a similar section of the bottom wafer cut away around pin 1 (already visible above), I was able to slide the good contact into that position:

http://www.videokarma.org/attachment...7&d=1486626285

Before trying to glue anything in place, I soldered the resistor and capacitor to the new pin, to avoid heating after gluing. Finally, after soldering, some 5 minute epoxy was added to keep the replacement pin in place permanently. This was done with a tube in the socket, so everything would be positioned properly. Final view:

http://www.videokarma.org/attachment...8&d=1486626639

With that fixed, I turned my attention to audio IF alignment. Since the 621TS is an early set that does not have intercarrier sound, alignment of the audio IF is critical. Basically every early set without intercarrier sound needs at least a little touch up of the audio IF alignment, both to get good sound quality, and to get the fine tuning to tune in both good picture and good audio at the same point.

This set was a breeze for audio IF alignment, and after just a few minutes, a perfect FM demodulator response curve could be obtained, centered exactly at 21.25 MHz. Here's the equipment I use for that -- the old HP analog sweep generator on top provides the sweep signal; the digital HP RF generator on the bottom is used for markers (it will only sweep up to 20 MHz, so it doesn't make a suitable sweep generator itself, but it will produce markers up to 40 MHz, which is fine), and the little Tek plug-in module scope in X-Y mode is used for the response display:

http://www.videokarma.org/attachment...9&d=1486626639

On this set, I don't think the video IF needs any touch up, since the picture looks good as is. Sharpness is good, and so is the low frequency response and DC restoration. So no need to mess with it.

http://www.videokarma.org/attachment...0&d=1486626639

Picture width is still a little narrow, so I will look into that further tomorrow, as well as checking all resistors for drifted ones to replace.

I'm seeing fireworks on this end too Tom, Beautiful Picture, Great Work.

Riveting is not hard to do and rivets matching the originals are available and cheap. You do need some special tools for semi-tubular rivets which can be expensive, but sometimes you can find them cheap on ebay and such. I use a local place for supplies: http://www.rivetsinstock.com/

For doing rivets in the middle of a chassis where a hand or small bench squeezer is not practical, I just use a hand tool that holds one side of the squeezer set and back the other side up with a heavy piece of steel holding the other side squeezer and tap it with a hammer. Here are some that I've done using this method:

That is exactly what I was talking about. I figured there would be some kind of supplier but didn't know what the rivets were called and where they could be obtained. Thanks for sharing the info!

Here's what a typical hand setting tool looks like:

http://www.hollanders.com/supplies/V...4-5cd139b88816

The setting tool or squeezer head must have the dimple in it for tubular rivets or they will just crush instead of rolling over as you set them.

You want to back the flat side of the rivet up with a concave tool so you don't flatten the head as you set it. Sometimes a piece of hardwood like oak can be used as it will give just enough to conform to the head without flattening it.

Darryl

Darryl,

Thanks for passing along the info on do-it-yourself riveting. I think I'll get some of those supplies for future work. Screws always look a bit second rate in restorations when everything else on the chassis is riveted.

I also hated using screws where rivets were used originally as it just doesn't look good. Once you have the tools to do rivets, you'll find lots of uses for them. Terminals on coil, brackets, etc. I've got dozens of different size and type rivets that always come in handy. You may want to get some eyelets as well (those are the ones that are hollow all the way through and rolled on both ends) as you use the same tools for these.

BTW very nice job on the restoration so far!

Darryl

Really impressive work on that 621, Tom. I did not think you could outdo the job you did on your own set, but you may be getting there now.

I had a couple of terminals breaking out of similar sockets on my CT-100, but they were not themselves broken, and I was able to carefully reposition them and use small amounts of super glue to reinstall them.

The last issue that needed attention was the lack of sufficient width in the raster. This is an unusual problem, since most sets I work on have too much overscan, and it takes some creativity to get the raster down to the correct size for the CRT mask. I think the manufacturers figured out pretty early that customers seldom complain about overscan, but will surely complain if the raster doesn't quite fill the screen. Perhaps the 621TS was engineered before manufacturers came to that conclusion.

No setting of the horizontal drive, linearity, and width controls would give me a big enough raster. Just a tiny bit too small -- not off by a mile. I checked all the components in the horizontal deflection system, and replaced some out of tolerance resistors, but there was no improvement.

What worked in the end was to change the tap on the big damper resistor in the HV cage. RCA specifically provided extra taps on this resistor for adjustment of horizontal linearity. I found that the lower resistnace tap reduced the size of the raster, and the high resistance tap increased the size of the raster. The linearity coil needs a little touch up after changing that tap, but overall, with proper adjustments, the high resistance tap gives a slightly larger raster.

This is the resistor in question:

http://www.videokarma.org/attachment...1&d=1486626639

After optimal adjustment, the overall raster linearity, both vertical and horizontal, is pretty good:

http://www.videokarma.org/attachment...2&d=1486626639

Not perfect, but pretty good for a tube TV. Many later models cannot do this well. The only ones that routinely beat this are DuMonts.

So we'll consider this set done.

Tom, Can you give us a shot with the chassis in the cabinet. I realize the CRT doesn't quite have the support on the chassis that would make that easy but it would be nice to see it complete.

Really nice work Tom!

I've been working on this stuff for 55+ years and I've never heard of that O'donnell brand of capacitor. They must've been replaced at one time in the life of this set.
The restoration really shows a great attention to detail.

Wow, that picture looks a lot better than the picture on the Zenith I'm working on looks right now! I still have a bunch of resistors left to check, though, I guess.

I tend to use a cork-screw to remove the lytic cores. I also tend to stuff the ends of my restuffed paper caps with paper towel pieces or some such so I can reuse the original wax for an original look and not run out trying to fill all that extra empty space that the paper towel fills.

I'm in awe...

Sure - here are a few shots of the set in its cabinet. The cabinet will be refinished by someone else, so for right now it is not exactly a thing of beauty to behold. Its safety glass is missing (but fortunately it is easy to get a new piece of safety glass custom cut at any decent glass shop).

All the hard-to-find stuff is there, including all chassis cages and covers, the original back, knobs, and channel selector escutcheon.

http://www.videokarma.org/attachment...3&d=1486626969

http://www.videokarma.org/attachment...4&d=1486626969

I've never seen that particular brand before either. However, they really did look original. Sometimes you can get a pretty strong indication by how the capacitor is nested amont the other components and wires, the state of the solder joints, and the lengths of the leads. I'm pretty sure that every capacitor in here was original, except for the big bumblebee-like tan/grey cap visible in the "before" photo a few pages back.

This set had capacitors from O'Donnell, Aerovox, C-D, and Good-All. Looking carefully at the caps, I was surprised to see the home town of Good-All was Ogallala, Nebraska. If you've ever been there, it's a pretty small town in the far west of Nebraska, with not much else around. Good-All was probably the most famous company to ever manufacture something there!

In 1946-47, the supply of capacitors may have been a little dicey, with the nation's industry transitioning from war production to consumer goods. Not much of anything shipped in 1946 for electronics. Perhaps this overall situation led to some no-name caps being used by a big name manufacturer.

Just a guess, though.

There's an RCA ad for the 21-CT-55 where they boast of having many different parts from many different manufactures, so it's not a stretch to imagine the same thing happened even earlier on.

http://www.earlytelevision.org/image...5_ad_small.jpg

I'm in AWESOME! too Tom


Thanks for all your hard work.

Nice job Tom as usual. I really like that style of set but most likely won't ever find one that I can afford. I am glad that you got it because you have done a wonderful job.

Thanks for all the kind comments, everyone.

I'm just a hired mercenary on this one! It belongs to someone else. Should turn out really well once the cabinet is refinished.

Immagine what that RCA AD would look like TODAY :)

A blank page. LOL

That sounds easier than the ratcheted-in lag bolt and Channellock pliers method that I have used.

The last 'lytic guts I yanked smelled faintly just like a dairy cow barn. Weird.

HAHAHAHAHA!:thmbsp: So true!

Tom, what great work you have done on that RCA :) Cheers

Actually, besides a blank page, i was thinking something modern, along the lines of an assembly line with the molding boards with parts like youd see when assembling a model car :D

SR

I received a request to bring back the original pictures to my posts in this thread. Originally they were hosted by a different site, and are now lost. So I will post all the necessary pictures here in new posts at the end (I still have the originals) and link them back to the old posts (which will all show a new edit). I hope the moderators don't mind this method of fixing the problem.

So here goes... There will be multiple posts to cover all the necessary pictures.

More pictures...

More pictures...

And a few more...

Continuing...

Still some more to go...