RCA 621ts Restoration
 

One of my New Years resolutions was to post better threads of my restorations. I've used Bandersen as my inspiration. I have enjoyed so many of his threads here both as they happen and through searching archived topics. This will not be a quick project for me, I plan on taking my time with this one, posting a lot of pictures of progress, and being very deliberate. With that in mind here is my new project, The RCA 621ts.
I found the set on ETF's classified pages and have been holding on to it for a few months. Now that the Holidays are over I decided that it's time to do some work on it.
The cabinet is the walnut finish. I understand it is considered less desirable than the mahogany or blonde finish, although I've read that it was made in fewer numbers than the mahogany.
http://farm8.staticflickr.com/7009/6...dca07065fa.jpg
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The cabinet is original but not without it's flaws. It photographs better than it looks. There is some crazing on the lacquer and a couple of bad spots.
http://farm8.staticflickr.com/7029/6...3d29fd6097.jpg
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After disassembling the set I think that some of the cabinet problems are due to sun fading. You can see in the picture below that the wood that was blocked from sun is much darker than the rest of the front.
http://farm8.staticflickr.com/7164/6...6858372faf.jpg
Some other observations of the the cabinet were that some the screws holding in the safety glass seem to be non-original.
One original?
http://farm8.staticflickr.com/7160/6...eeeb288e28.jpg
Both non-orignal?
http://farm8.staticflickr.com/7004/6...e588a480f2.jpg
Also the safety glass itself is going to need to be replaced as it's flawed in between the two panes.
http://farm8.staticflickr.com/7175/6...cb27f79474.jpg

The chassis was the usual dusty but in very good condition. No signs of rust any where to be seen.
Before.
http://farm8.staticflickr.com/7015/6...e1755b53e9.jpg
http://farm8.staticflickr.com/7027/6...d7396d854c.jpg
After.
http://farm8.staticflickr.com/7165/6...9170802043.jpg
http://farm8.staticflickr.com/7023/6...4f38432e3f.jpg

The Phillips screws are the correct ones for the retainers.

Something you might want to consider doing on this set is restuffing the old capacitors to keep it looking original.

Here are a couple pictures of mine, before recapping and after, hard to tell the difference!
I even replaced a green Solar brand cap from a later repair with one that matched the others.

I make a habbit of restuffing caps on sets that I either like alot or consider signifficant historically or as an example of something.

I will be restuffing ALL capacitors as well as replacing any components that may have been added through servicing this set back to their original look.
Thanks for the info on the Phillips screws on the clips, I'll have to source two replacements for the bottom clip. Were the screws holding the back on the set also Phillips, and were they brass colored?
Also thanks for the pictures of the bottom of the chassis, they will help in recognizing anything out of place on mine.

Great looking chassis. Word to the wise: cut a piece of heavy cardboard and cable-tie it over the speaker while you're working!

For sure, for sure, for sure. Or, you can tape it on with that blue masking tape. But for sure, something will find its way into that cone.

That's a real nice set. I personally like the faded look; the walnut grain shows though bettter. I sure wouldn't refinish that cabinet, maybe touch those worn spots with a little Deft brushing lacquer.

That is about as clean a chassis as one could hope for. Glad to hear you will be restuffing it. Keep us posted!

I wish you could have told one of the previous owners that. It seems that some one at some point damaged the top of the speaker.
I was a bit short on capacitors to finish the set so I put in an order today for the replacements that I was missing. I didn't want to start work on the set and have to stop because I don't have all the capacitors. Once my caps come in I'll start restuffing and share my steps.

I'm not sure what I'll do with the cabinet. Whatever I decide on I'll not be doing the work. My wood finishing skills end at 0000 steel wool and Howards Restor-a-finish.

Sounds like this will be a nice project to follow. I look forward to it...

A couple of updates.
The cabinet is now in the hands of the best wood finishing expert in the Pittsburgh area (or so I've been told by several trusting sources). He has been finishing wood for 58 years and has a small shop where he obsesses over his work in solitude. I had hoped to have the finished reamalgamated on the set but Lou thought the finish was too far gone for that method and that the crazing would return after only a few years. I know a few people here thought that the set shouldn't be refinished based on the pictures that I posted but the set photographed much better than it looked in person. I have ordered replacement decals from Radio Daze and will be applying them myself between the sealer and lacquer phases of the cabinet refinishing. One other bonus of refinishing is that the color will be able to be brought back to original, using the areas that were under cover as a reference. One question Lou had for me about the finish that I said I would answer later was the finish, should it be gloss, semi gloss, or something else possibly? What finish would the set have had from the factory? I would like to keep the set as close to what it would have looked like brand new.
I have also dropped off the safety glass to a local glass shop to have them cut a new piece for me. I expect that to come back next week.
On to the chassis. I have not done any component restoration yet, the electrolytics have not yet arrived so I've just been doing some further cleaning and polishing of the chassis. There were some non original decals on the rear of the set next to each control knob that were tough to remove. I tried scrubbing them off but I ended up having to sand them off in the end.
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Looking at pictures of Tom Albrecht's 621 I think that the labels for the rear control knobs were ink printed directly on the back panel. If this turns out to be the case I'll have to make templates and screen print them on. Can any one post some higher res pictures of their back with the labels so that I can get a font, location, and size?
Can some one also confirm what style and color the screws are for the back of the set?

I think it should be somewhat glossy, not mirror finish but a slightly reflective surface.

I think this picture of the unfaded area is about right.

http://farm8.staticflickr.com/7164/6...6858372faf.jpg

I think the whole top cover, grille and the edges are supposed to be dark like this area.
http://farm8.staticflickr.com/7018/6...fcc26904cd.jpg

Here's a picture of mine, note the shine on the curved edges and the dark trim, it's a Mahogany set though.
http://www.vintagetvsets.com/images/621.jpg

Semi gloss then?
It's definitely a two tone color scheme with the top "hood," speaker grill, and side trim darker than the rest. I'm going to tell Lou to model the colors after the set in this picture.
http://farm5.staticflickr.com/4118/4...f86a6f57c7.jpg

I went through the pictures sent to me by 621 owners participating in my 621 database, this is the only one that looked to be Walnut to me with an original finish.
The color scheme seems to be pretty similar to my Mahogany version, maybe a little lighter.

There seems to be a lot of variation among sets, some Mahogany ones are much darker than mine, there seems to be at least two different blond versions, and Walnut seems to be pretty rare.

I think that would be about perfect, though that one looks to be refinished it's very nice.
I'm not sure if the top is supposed to be translucent like that one though, most seem to be pretty dark and opaque. Perhaps it's because it was outside in the sun?

I would aim for a darker finish on the top and trim, something similar to the knob color.
It probably has to be Toner, Paint won't look right.

Making progress with the electronic restoration now. I've got the first capacitor rebuilt. I used the tutorial posted in the tv and radio tech forum. I bent the bottom crimp up with a small flat blade screwdriver and popped the mounting ring out.
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Then I pulled the disk holding the terminals off of the rest of the can. In the process of pulling it off the paper cover on the can also came off, leaving me with four pieces.
http://farm8.staticflickr.com/7141/6...df96080763.jpg
I then aranged the new electrolytic capacitors in a way that would fit inside the old can. I soldered the leads to the old terminals paying attention to make sure the values went to the corresponding terminals as they did originally.
http://farm8.staticflickr.com/7009/6...5849f91412.jpg
The whole process was definitely time consuming and at times frustrating, but well worth the effort.
Before:
http://farm8.staticflickr.com/7154/6...a55ca3e355.jpg
After:
http://farm8.staticflickr.com/7164/6...2f31123c1b.jpg

Rebuilding the second capacitor was a bit more of a challenge than the first. Something was coating the underside of this cap, and the disk holding the terminals had become extremely brittle.
http://farm8.staticflickr.com/7025/6...a5f506144c.jpg
I was not able to remove the disk without destroying it. I am now in need of a new terminal disk with three terminals to move on with rebuilding my next capacitor. If any one is able to sell me this odd small part please send me a message.

You can buy them from AES: http://www.tubesandmore.com/scripts/...02=01_MOUNTING

Thanks for the link but that's not the piece that's broken. This part is.
http://farm8.staticflickr.com/7028/6...3dc6d0dd5b.jpg

Ah, scavenge one from another cap then.

Semi gloss is a good choice for refinishing old sets. Modern full gloss looks too gaudy to me, and not at all representative of the original finish.

I'm not stocked up much on surplus parts. I'll try my local vintage electronic shop in the area, but if he doesn't have any then I may still need the help of a member here.

Semi it is. I have to see him soon as I need to drop off the pictures of the other sets that show the color scheme.

John,
You should only need to tell your refinisher what gloss level you want. There is no need to use flat or semi-gloss finishes.

Nitrocellulose lacquer finishes need to be sanded and rubbed out when done, so you can get any gloss level you want during the polishing stage. This is how it was originally done. Semi-gloss finishes use flatteners to obscure the gloss resulting in a weaker and somewhat cloudy finish. A gloss finish can be polished to any level while a semi-gloss can never be polished to a full gloss level. Also if you don't polish a gloss lacquer finish it will look "plasticy" and terrible.

Some refinishers today will use modern CAB or catalyzed lacquers which if sprayed in a dust free environment don't really require polishing, so a semi-gloss might look better, but it will still look cloudy.

Attached is a picture of my 621 that I refinished with gloss nitrocellulose lacquer and rubbed out with 0000 steel wool.

Darryl

I wasn't even aware that there was different gloss levels to the actual lacquer. That wasn't even talked about when we discussed the refinishing. He simply wanted to know how I wanted it finished, not what kind of finish to use. He told me that he uses period correct lacquer on projects like this. I'm assuming he meant nitrocellulose but maybe I'll ask him now. I had originally told him to buff it to gloss, but I think I agree with those here who suggested semi so I'm going to tell him to go that way.
Lou was very backed up at the moment so I think that I'll have the chassis restored before I get the cabinet back from him. I did offer a little extra money to get the set done faster, if he takes me up on that offer then they might both be finished in a similar time.

Aww, man-All deze purdy Tellabishuns is makin' me GREEN w/envy...621s really WERE works of art, weren't they ?

Works of art indeed Sandy. I still like my GE 801 a bit more as far as aesthetics but the 621 is an amazing design.
I still haven't been able to find a replacement for the bottom of the electrolytic cap I broke, and not wanting to remove another multi-stage can until I finished that one, I decided to start on the paper caps. I was surprised at how much easier it was to restuff the paper caps than it was to rebuild the electolytics.
My wife got me a new soldering iron for Christmas so I used my old soldering gun to melt the old wax and cap out of the cardboard tube. Then I melted and cleaned the wax off of the outside of the tube. After I had a clean empty tube it was ready for the new cap.
http://farm8.staticflickr.com/7004/6...63fc78a4bb.jpg
Perfect fit!
After putting the new cap inside the old housing I filled the ends with hot glue and shot a coat of lacquer on the cardboard to shine it up a bit and repel dust (the idea came from Hugo Holden's amazing 621ts restoration http://www.earlytelevision.org/holden_621.html, although he used varnish).
There was one cap in the horizontal output section that had been previously replaced with a modern cap. You can see my restuffed cap just to the right of it.
http://farm8.staticflickr.com/7158/6...ee195f0400.jpg
Luckily I had saved all of the caps that I removed from the last set I recapped for just such an occasion and had a replacement value for it.
http://farm8.staticflickr.com/7174/6...2e00393c9a.jpg
I restuffed a total of six caps tonight and honed my skill of filling the ends smoothly with glue towards the end. The rest of the paper caps should be no problem. You can see the six caps all towards the top of the picture below. I'm really happy with the look of restuffing versus just cutting the old caps out and replacing them with something that just doesn't look original. Well worth the effort!
http://farm8.staticflickr.com/7154/6...9c9ac87a5f.jpg

That does have a nice appearance to it. I already use carbon composition resistors for all of my replacements, so I may try some paper restuffing on my CT-100. It has already had a bunch of its caps replaced in the past, but I kept all of the ones from the 8TS30 restoration so I could use some of those if needed.

I reciently started mixing some of the original wax in to container of hot glue to tint the glue a more original color. I then took pieces of the mix and melted them into the ends of the cap using a soldering iron. I used to take wax from other old caps and use it for restuffing, but once one has dismantled all spare junk caps for wax....cutting with hot glue seems logical (it also don't stink as much).

That was the only part I wasn't really happy with was the color of the glue at the ends. Any one ever tried a brown glue stick? A quick google search brought me this http://www.glu-stix.com/shop/page/pr...5b1ac34df.html. I have no concept of how much glue is in 5 pounds. Maybe we can do a group buy if it works.

Yes, I've been using brown and black glue sticks for a while with good results.

You can get them for a few bucks from various sellers on ebay.

I got back under the chassis tonight. I'm still taking my time and making each and every action I take as deliberate as I can. I found another capacitor that was replaced at some later time.
http://farm8.staticflickr.com/7143/6...a844816c27.jpg
You can see that there is a pretty large glob of solder on the connection point of that new cap. I've noticed shoddy work on the two obvious replacement parts in the set, both had way too much solder on the connections and you can clearly see that the repairman melted the insulation on a wire in the area when soldering a lead. You can see it on the left side of the picture below.
http://farm8.staticflickr.com/7158/6...ee195f0400.jpg
One of the advantages doing one capacitor at a time and shooting each one with lacquer is that I have lots of time to survey the set as I wait for the lacquer to dry. One thing I noticed on one of these "breaks" was that R187(according to the Riders schematic), the high voltage rectifier winding resistor, is going to need to be replaced.
http://farm8.staticflickr.com/7161/6...0b2ea95fd9.jpg
I'll file that in my noggin for later when I focus on resistors.
I still haven't been able to get out to my local antique electronic shop for a replacement multi-stage electrolytic cap to replace the one I snapped but I'm over half way finished with restuffing/replacing the paper caps. The top half of the set (as it sits on my bench) is now finished.
http://farm8.staticflickr.com/7169/6...077341140f.jpg

Almost done with the paper caps and wouldn't you know it I'm short one value :sigh:. Put the order in yesterday for the replacement. I'm hoping to have the paper caps finished by the end of the week and move on to electrolytics by the weekend.
I did run into one capacitor value that I couldn't find a direct replacement for, .0025mfd. I used one .0015mfd and one .001mfd in parallel.
http://farm8.staticflickr.com/7145/6...34b9918ac2.jpg
I used electrical tape to wrap each lead on each cap and then hot glued the two caps in place. Did any one else manage to find a direct replacement for these caps?

I thought I was the only one who restuffed caps with two in that fashion.

If the tube has a large enough diameter one can dispense with the electrical tape, and put the side of the case of one against the wire of the other.

I used either .0022 or .0027 (and .022 or 0.22 in comparable cases) for that value and did not have a problem in my RCA 8TS30.

My supplier of capacitors only has .002 which would put it right at the edge of 20% so I decided to go exact replacement value. I'm pretty sure .002 would have worked but so will .0025 :).

I finished under the chassis tonight. All of the paper and electrolytic capacitors are re-stuffed and re-installed.
http://farm8.staticflickr.com/7174/6...35be2f9314.jpg
I also replaced any bad, on the edge, and non RCA branded tubes with NOS RCA branded tubes (Four of the tubes are still not RCA branded, 1B3, 6SN7, 6BG6, and a 6H6, but I plan on finding RCA replacements for them).
http://farm8.staticflickr.com/7010/6...7f506f2156.jpg
http://farm8.staticflickr.com/7001/6...cf3086c7f8.jpg
At the end of a long day I decided to turn the bench off and wait for another day to apply power for the first time.