View Full Version : RCA 8PCS41 from CL update


Eric H
03-23-2013, 06:09 PM
Well if I wasn't crazy already this should push me over the edge. :yes:

I found this locally while browsing Craigslist last night, it was obviously rough but I wasn't quite expecting this. I took my CRT tester with me because there was no way I was bringing this home if the CRT was bad, it turned out to be a GE replacement, it started off in the high red zone but after 10 seconds at 8 volts it shot up to high green and stayed there at 6.3 so I figure it has some life left in it, what the screen and mirror looks like is anyone's guess but I expect some screen burn, that won't hurt anything though.

The main chassis is amazingly clean and rust free, it's well protected inside the cabinet, the only somewhat rusty dirty chassis is the main power supply, this was a Mouse House for quite some time and it got peed on.
The inside of the HV cage was stuffed full of grass, obviously their home but it looks rust free for the most part an nothing looks chewed on so I think it'll be OK too.

The cabinet...well it's a horrible mess, the good points are that nothing seems warped, it's complete except for the back, and the doors all open and close as they should and the panels look flat, the bad is that there's a lot of loose joints and bad Veneer, the front can probably be saved but everything else needs redone including some of the substrate material. The screen looks okay and it lifts and closes fairly smoothly.


http://vintagetvsets.com/images/8pcs41/8pcsfrontclosed.jpg
http://vintagetvsets.com/images/8pcs41/8pcsback.jpg
http://vintagetvsets.com/images/8pcs41/8pcsinsideempty.jpg
http://vintagetvsets.com/images/8pcs41/8pcsleftlegs.jpg
http://vintagetvsets.com/images/8pcs41/8pcstopleft.jpg
http://vintagetvsets.com/images/8pcs41/8pcsrightside.jpg
http://vintagetvsets.com/images/8pcs41/8pcspowersuppies.jpg
http://vintagetvsets.com/images/8pcs41/8pcshvcage.jpg
http://vintagetvsets.com/images/8pcs41/8pcsscreen.jpg

cbenham
03-23-2013, 07:01 PM
This will be a challenge on all fronts, but I hope you make it light up and play again.
Once you get everything working you'll be surprised at the picture it makes. A 25 inch diagonal picture was unheard of in 1949. Direct view sets that size didn't appear until 4 or 5 years later. From across the room it is bright and has good detail. Best luck!

Steve K
03-23-2013, 07:13 PM
Eric:

Every TV collector needs at least one projection set in their collection! You will probably need to have the mirror resilvered and if you do I can give you the name of the place that did mine. Let me know if you would like a photocopy of the owners manual.

Steve

hi_volt
03-23-2013, 07:30 PM
That's going to be a nice set when you get it restored. It has 4 separate chassis, and lots and lots of electrolytics and wax caps. The 5TP4 runs at about 24KV. The HV section has a tube tripler, which is kind of unique. Treat the canvas cloth shroud very carefully, as they become quite brittle and fall apart easily. I've got two RCA projection sets myself, and I had to have a reproduction shroud custom tailored for my second set, as my original literally fell apart in my hands. Look forward to seeing your restoration thread.

Eric H
03-23-2013, 09:14 PM
Eric:

Every TV collector needs at least one projection set in their collection! You will probably need to have the mirror resilvered and if you do I can give you the name of the place that did mine. Let me know if you would like a photocopy of the owners manual.

Steve

Hi Steve, I already have a Philco 48-2500 that I haven't finished yet but I like the screen on the RCA better.
I would love a copy of the manual, I'll P.M. you with my address. Thank you.

I took the cabinet to my back patio and sprayed a 50% mixture of Clorox in the cabinet and rinsed it out, it still has some globs of "stuff" stuck to the bottom but at least I feel a little better about the sanitation issues.

The chassis's don't bother me so much, I can just take my time and do one at a time but the cabinet is daunting, I always seem to get held up on the cabinet because I don't like doing them and don't really have the tools to do much serious work.

The cloth shroud on this one is in good shape, it doesn't seem to be at all rotted or brittle.

Does anyone know how the HV Umbilical unhooks from the HV cage? It seems to slide out a little and stop, do I have to unscrew something from the underside to remove it? It's difficult moving the HV cage and the CRT barrel around together.

bandersen
03-23-2013, 09:40 PM
Wow! Nice find :thmbsp: That's going to be quite a project. Good luck :yes:

hi_volt
03-23-2013, 10:35 PM
The HV umbilical doesn't separate from the HV cage without unsoldering it from the third HV rectifier, and you can't get to it with the HV cage still installed in the cabinet. You need to separate the umbilical from the CRT/optics barrel instead. Unplug the CRT socket and the deflection yoke socket, remove the plastic cover at the top of the optics barrel, remove the yoke, unplug the second anode lead from the CRT and then remove the CRT. Be careful you don't lose the anode spring clip. The entire metal bracket that holds the CRT is connected to the HV and the spring clip connects them electrically. Once you have the anode lead removed, you can remove the HV umbilical by unscrewing the fitting at the side of the optics barrel and pulling the umbilical out. It took me a while to figure all this out on my first projection set.

http://www.videokarma.org/showthread.php?t=256597

http://www.videokarma.org/showthread.php?t=252908

John Folsom
03-24-2013, 10:05 AM
When removing the HV cable from the optics barrel, make note of which side of the plastic lens is "up". If reinstalled upside down, you will not be able to focus the image on the screen.

Eric H
03-27-2013, 09:08 PM
A bit of good news with this set!

I took the CRT out so I could transport the parts to work to clean them up, the face of the CRT has ZERO screen burn so I'm guessing it's a very low hour tube.
Also, even though it's branded General Electric, the EIA code is 274 so it was made by RCA.

The mirror is nearly perfect! It had a little dead grass sitting on it but it didn't affect it at all. It's stamped with the serial number and it was made by Bendix Aviation.

Sandy G
03-27-2013, 09:40 PM
Wish you lived closer-We have a Furniture Restorer in this town that could make that cabinet at least as good as new...I've eused him a BUNCH of times, & he's NEVER failed to make something "Knock Yer Socks Off"...

tvdude1
03-27-2013, 10:05 PM
Hi John is there a difference in the clear lens?

cwmoser
03-28-2013, 06:04 AM
That projection TV cabinet has a classical look and will make a great looking TV.
I like the square cabinet pulls on yours over the other design that looks like bedroom furniture.

Hope you continue this restoration thread.
I too have a Philco 48-2500 and have dreamed of finding an RCA projection TV like yours.

Carl

Eric H
03-29-2013, 02:44 AM
I did some clean up on the various chassis today, they all came out remarkably nice, especially the HV cage which was full of dried grass where the Mice had made a home. There is almost no rust at all in that and just a bit on the power supply chassis.

I used purple cleaner and a brush and rinsed them with hot water, even the Flyback got a bath but I was careful not to let water get in the bottoms of the power transformers or on the paper Capacitor covers. I also didn't allow water to get in the big Focus pot in the HV cage.

I baked them in the Oven tonight at 185 degrees for about an hour to dry, they won't be powered up for who knows how long so they'll be good and dry when they are.

I also cleaned the projector barrel.

cwmoser
03-29-2013, 06:16 AM
I've washed off chassis's before to - even with a garden hose.
If you are careful like you described should be ok.
Its nice to have a clean chassis to work on.

Carl

cwmoser
03-29-2013, 06:21 AM
Here is an RCA 8PSC41 one like yours on Ebay:
http://www.ebay.com/itm/VINTAGE-RCA-VICTOR-PROJECTION-TV-MODEL-8PSC41-COMPLETE-NOT-TESTED-/171015439110?pt=LH_DefaultDomain_0&hash=item27d1508306

Man. the wood grain in those cabinets are gorgeous.
Yours will look like that too once you get the dirt and grime off it.
Folks in the Radio Forum talk about the "treatment" - a simple way to
bring out the beauty in wood without refinishing. Just clean the cabinet
and the use the smooth NON-PUMICE non-gritty GoJo hand cleaner.
Then follow with Johnsons Wax.

Carl

hi_volt
03-29-2013, 07:51 AM
Wow...nice clean up job. I would not have recognized the chassis. That's going to be a sweet set when you get it done.

Eric H
04-06-2013, 08:48 PM
I decided to take the cabinet further apart and inspect it closer, it's truly a nightmare.

I realized this is probably going to have to be knocked apart down to the last board, repair or replace whatever is falling apart or destroyed and reassembled.
This is beyond what I am capable of or have the tools for but luckily my best friend and his Dad are both expert cabinet makers, I talked to the Dad last night about doing the repairs on this and he said he'd take a look at it.

I figure I can do a lot of the taking apart and he can fabricate new parts as needed and glue up the stuff that's complicated, like the feet that are all busted up, i can do the Veneer and refinish it if need be.
It'll probably cost me a fair bit but it's not going to get done any other way.

If you want to see the HD photos of the cabinet in all it's lack of glory, I posted them here:
http://vintagetvsets.com/images/8pcs41/

Luckily the upper mirror is in good shape, it's got a film on it but I think it'll clean off, it's not corroded at all, also the screen is is great shape.

I discovered while washing it that the screen isn't just a simple piece of frosted Plastic, it's actually a Fresnel Lens! There's a circular pattern of grooves on the back side of it, the side you view has the texture of brushed Stainless Steel, I will need to be VERY careful with this since it's irreplaceable with anything but the OEM part.

Eric H
04-06-2013, 08:52 PM
I decided to take the cabinet further apart and inspect it closer, it's truly a nightmare.

I realized this is probably going to have to be knocked apart down to the last board, repair or replace whatever is falling apart or destroyed and reassembled.
This is beyond what I am capable of or have the tools for but luckily my best friend and his Dad are both expert cabinet makers, I talked to the Dad last night about doing the repairs on this and he said he'd take a look at it.

I figure I can do a lot of the taking apart and he can fabricate new parts as needed and glue up the stuff that's complicated, like the feet that are all busted up, i can do the Veneer and refinish it if need be.
It'll probably cost me a fair bit but it's not going to get done any other way.

If you want to see the HD photos of the cabinet in all it's lack of glory, I posted them here:
http://vintagetvsets.com/images/8pcs41/

Luckily the upper mirror is in good shape, it's got a film on it but I think it'll clean off, it's not corroded at all, also the screen is is great shape.

I discovered while washing it that the screen isn't just a simple piece of frosted Plastic, it's actually a Fresnel Lens! There's a circular pattern of grooves on the back side of it, the side you view has the texture of brushed Stainless Steel, I will need to be VERY careful with this since it's irreplaceable with anything but the OEM part.

On the chassis side of things I have replaced all the paper caps in the audio chassis and removed the filter can for restuffing. The can has a couple of odd sized sections of 70 mfd, I've never seen 70 mfd before, 40 & 80 yes but 70 seems weird, I reckon 80 is close enough.

Eric H
04-07-2013, 01:56 AM
Just got done on Mouser ordering 22 Electrolytics for this and three 1000v film caps that I don't stock.

Eric H
04-12-2013, 01:04 AM
I started working on the cabinet, I figured the only way to do it was to start at the bottom (literally) and work my way up.
To that end I dismantled the cabinet, first by removing the base from the upper part, later I will rebuild the sides and then move on to the top. Taking it apart was fairly simple since all the glue joints are pretty well shot.

First task was to rebuild the feet, they were solid but had some cracks from having been wet. The front feet are made in two pieces and one of them had come apart so I had to re-glue it.

I took the base completely apart, removed all the dowel pins, sanded everything clean, filled in any damaged spots, filled in the cracks and chips on the feet and sanded them smooth.

I also took the lower shelf apart because the plywood is coming apart at the edges.
I glued it together and it has a 200 lb tool box sitting on it right now to press it flat while it sets up, if i can't make it look satisfactory (or get rid of the Mouse smell) then I'll have a new piece of Plywood cut for it and glue the original edge parts on it.

I plan on toning the base with a dark toner to hide the crack repairs in the feet.
The sides of the cabinet will likely need replaced, or at least stripped bare, glued and re-veneered. Luckily the pop up lid where the screen is is in good shape, just a strip and stain should fix it right up. I'll also be replacing every wood screw in the cabinet with new ones, they are all pretty rusty.

The Capacitors should be here tomorrow so I can start on the chassis soon.

http://vintagetvsets.com/images/8pcs41/base-1.jpg
http://vintagetvsets.com/images/8pcs41/floor-1.jpg
http://vintagetvsets.com/images/8pcs41/floor-2.jpg
http://vintagetvsets.com/images/8pcs41/floor-3.jpg
http://vintagetvsets.com/images/8pcs41/foot-1.jpg
http://vintagetvsets.com/images/8pcs41/foot-2.jpg
http://vintagetvsets.com/images/8pcs41/foot-3.jpg
http://vintagetvsets.com/images/8pcs41/foot-4.jpg

cwmoser
04-12-2013, 08:25 AM
I decided to take the cabinet further apart and inspect it closer, it's truly a nightmare.
...
It'll probably cost me a fair bit but it's not going to get done any other way.
...
Luckily the upper mirror is in good shape, it's got a film on it but I think it'll clean off, it's not corroded at all, also the screen is is great shape.

I discovered while washing it that the screen isn't just a simple piece of frosted Plastic, it's actually a Fresnel Lens! There's a circular pattern of grooves on the back side of it, the side you view has the texture of brushed Stainless Steel, I will need to be VERY careful with this since it's irreplaceable with anything but the OEM part.

Eric, I can tell its a labor of love.
One nice thing about your efforts and expense is that it should turn
out to be a beautiful set. The Mahagony wood patterns in those
RCA sets are very eye appealing.

BTW, you mentioned the Fresnel Lens Screen - can you tell me more about it
as compared to the screen in the Philco 48-2500. Your restoration has
piqued my interest and would love to find one this year at the ETF convention.

Carl

Eric H
04-12-2013, 11:20 AM
BTW, you mentioned the Fresnel Lens Screen - can you tell me more about it
as compared to the screen in the Philco 48-2500.
Carl

Hi Carl, The main difference between the Philco and the RCA is the Philco is a front projector and the RCA is a rear projector.


The RCA screen is a flat sheet of translucent Plastic with a series of fine concentric rings molded into it to amplify the light.
Wiki has an article about how Fresnel (https://en.wikipedia.org/wiki/Fresnel_lens) lenses work.

The Philco uses a sheet of Stainless Steel mounted so it's forced into a slight parabolic shape.
It has fine vertical grooves cut into it and is coated with a Lacquer type coating that contains microscopic glass beads to reflect and disperse the light hitting it.

zenithfan1
04-12-2013, 11:32 AM
Hey Eric, make sure you use Titebond wood glue. It's the best, as you will soon see what I had to do to my recently shipped and broken CTC7. I did a strength test with a similar piece of wood like on my set and broke it, glued it together crudely and I had to hit it with a hammer until it fell apart. It never did break where it was originally. Amazing stuff, that glue is:) Good luck on this one, it'll be a ton of work but it will pay off. I can't wait to see it all done. Personally, I love cabinet repair. Lucky for my shipper too. I'da taken his head off if I didn't know woodworking:D

Bill Cahill
04-13-2013, 05:56 AM
Hi, Eric.
One thing I've found out about finnishes, especially on RCA equipment.
While RCA certainly did do some cases in brown mahoganny, they never did a mix, and, match. I see yours was originally red mahoganny.
RCA put a deep red on first to darken the color, and, give it the red look. Then, they put a brown stain over that to soften it up a bit.
Not such a cherry mahoganny look that way, more of a soft, dark red.
That poor thing looks scary to me. I sure hope that hv section comes back. I think that's thw worst I've ever seen.
Good luck on this set. Wish I had a projection set of my own.
Bill Cahill

miniman82
04-13-2013, 08:21 AM
I think that's thw worst I've ever seen.



Not me.... Bob's Halli was much worse.

http://antiquetvguy.com/Web%20Pages/The%20Restorations/1955%20Hallicrafters%2021CK801M/1955-Hallicrafters-21CK801M.html


I've had my own problems with cabinets. The CTC-7 with photo finish I rehabbed is something I would not want to do again, but the result speaks for itself. I think from now on I will pass on sets with shabby cabinets, recapping and alignments are more my style anyhow.

Bill Cahill
04-13-2013, 12:10 PM
Wow! What a project that Hallicrafters was!!
Excellent job!
Give me more hope on my RCA 8TR29. It was less than half as bad, and, I still am having agc problems with it, even though the set now plays.
If anyone is interested, find my link at bottom of post to my forums, go to antique televisions, and look at al the pages of my set so far under RCA Vitor tv. A new dog in the family. It plays!
I think you will succeed. You always do, and, your knowledge is far above mine.
Bill Cahill

holmesuser01
04-13-2013, 04:19 PM
I remember reading thru all of the National Radio Institute TV service instruction books when I was young in the 1960's. There were lots of views of the RCA projection sets like yours. I marveled at them, but never saw one in real life.

I'm really glad you got your set. So far, your progress has been GREAT!! I look forward to your updates!

Bruce

Eric H
04-19-2013, 07:00 PM
I got the base section put back together, I was able to glue the plywood back together so I didn't have to make a new one.

It's nice and solid now, there are some small gaps at the joints but that's unavoidable due to some shrinkage, they aren't bad and won't be noticeable unless someone gets on their hands and knees and inspects it with a magnifying glass. The base will also be toned a darker color to hide the crack repairs.

I came to the realization that perfection isn't going to happen with this cabinet so I'll just have to settle for solid and presentable.

I tried fitting the cabinet top to the bottom and realized I forgot to rebuild the intermediate section that joins the two, that should be easy, it's just three strips of hardwood, that will make a nice color break point between the base and the rest of the cabinet.

I've also started recapping the chassis, done with the Audio, working on the HV section now, got three of the cans done but I will have to make new paper covers since I had to destroy the old ones to get them apart.

I also need to replace a few bits of rubber covered wire here and there, I think the 22ga solid core 600 volt wire that AES sells should look about right?


I am fortunate to have my faithful friend Otto working quality control, or perhaps he just smells a Mouse.

Bill Cahill
04-19-2013, 11:44 PM
Nice work.. I see no major shrinkage. Looks good, under the circumstances.
Bill Cahill

Eric H
04-28-2013, 01:52 AM
I've completed recapping on the Horizontal/High Voltage section, the entire horizontal sweep section is inside the big cage.
Four multi section electrolytics, all with lots of connections to them made it quite a chore, there are four more cans on the i.f. chassis as well but for now this is enough to test for high voltage, really high voltage, more than a 21" Color Roundie!

Both of the 6BG6's in this set were weak, I found a couple good ones and replaced them, the metal 6AC7 Horiz AFC looked totally fried and checked dead as a doornail, though I could feel the heater getting warm, found a good used one to replace that.

First I had to hook all the chassis together, plus a resistor pack, the switch and the interlock switch.

First attempt on the Variac, two of the 5U4's on the PS aren't lighting up, wiggled them around a bit and they came on (note to self, clean the sockets).

Second attempt, getting a couple thousand volts at the Anode but two of the three 1B3's I picked at random from my stash are lighting up purple, replaced them with three, brand new, Russian made 1B3's from the case of 50 I bought a decade ago.

Third attempt, success, though I can hear something arcing down in the cage, I'm getting 28k (or darn close) at the second Anode! :yes: (note to self, don't slip and touch the Second Anode :no:)

On the Cabinet front, I got the base reassembled and glued the connecting section back to the main cabinet, I haven't joined the main cabinet to the base yet because I want to stain and tone the base first.

This was in much worse shape than I first thought, lots of delamination on the sides, the veneer on the top will need replaced, the veneer on the sides may be repairable or I will replace it all whichever is easiest, the fortunate thing is all the book matched crotch-wood on the front is in good condition, a few cracks here and there but they won't show.

I reflowed the Lacquer on the control panel, it still has some issues so I will attempt to improve it some more. Basically I just poured Lacquer Thinner all over it, brushed it around and and let it soak, it clarified it greatly but there is some grit and bubbles in it so a second try is needed.

There is supposed to be a Mohawk dealer near me so I need to take a drive over there and see what Toners they have, it would be much easier in person that trying to figure out what color I need over the Internet.

cbenham
05-01-2013, 02:01 AM
Your efforts and work in all areas of the restoration of this set are great.
I hope you enjoy watching some "Old TV Programs" on it when you finish.
Watching this thread is both interesting and educational.
Thanks for all your documentation and pictures.:thmbsp:

cwmoser
05-01-2013, 05:53 AM
Keep on posting what you are doing and pictures.
I like to see what makes these old TVs work again.

Carl

snelson903
05-01-2013, 06:11 AM
its turning out vary nice ,i think it's great to take something that everyone [frends / family ] thinks is beyond repair and why did you bring that home for ,and restore it to better than new condition .

Eric H
05-01-2013, 11:09 PM
Thanks guys, I was thinking no one was reading these posts.

Anyways, here's a few more pictures.

The Shroud for the optics is in rough shape, it wouldn't be all that bad except it looks like the Mice ate a big hole in it, other than that it could be fixed with some iron on patches.

I have a nifty 1953 Swiss made Elna Sewing machine (bought it cheap because it looked so totally cool) and I think I might be able to figure out how to use it well enough to make a new shroud, it's not that complicated really, probably should be Fire Retardant material considering the potential for arcing and what not.
I washed the old one today at work in a bucket of hot water and Purple Cleaner, the water turned to blackish muck, possibly some of it was the black dye but most of it was years of smoke and dirt.

I took out the upper mirror so I could work on the pop up lid, the mirror is in pretty good shape but looked a little hazy. I hosed it off in the Tub and rubbed it gently with a soft cloth to remove the film, it came out better but it still has some haze, I think it'll work OK though. It's a surface coated mirror of course so a common back coated mirror won't work correctly.

I have been experimenting with Stain to see what color it should be.

Originality is out the window with this set, it's so far removed from factory now I just want it to look good, even if it's not exactly the right color.
The Base is such a mish-mosh of Glue and Filler that it won't take stain evenly, it's going to have to be toned somewhat dark to hide the flaws, the rest of the cabinet is either in good shape or will have new Veneer so it should be OK to stain and Lacquer.

I have some new Poplar Crossbanding material on the way, this goes between the Plywood and the Veneer to provide a smooth surface for it to stick to.
The two top edges and front on either side of the screen are the worst, I'm just going to replace the crossbanding and veneer there, the sides I will attempt to repair the Veneer, worst case I rip it all off and replace it too.

The other option was to build a new cabinet out of Cardboard boxes and Duct Tape. :D

bandersen
05-01-2013, 11:19 PM
Sure, we're reading them :yes:
One option for the base might be to use pigment based (opaque) rather than dye based (transparent) toners. That way you don't have to go dark and the flaws will be hidden. So will all the grain but I'm guessing that doesn't matter at this point.

Mohawk calls them 'Tone Finish Toners' and you've got quite a palette to choose from: http://www.mohawk-finishing.com/catalog_browse.asp?ictNbr=170
Perhaps 'Medium Red /Shading Mahogany' ?

Phil Nelson
05-01-2013, 11:26 PM
The base wood probably doesn't have interesting grain in the first place, so pigmented toner should be no problem.

nifty 1953 Swiss made Elna Sewing machineThat machine rules. You're leaving it to me in your will, right? :)

http://antiqueradio.org/art/temp/BozoApproved.jpg

Phil Nelson

Eric H
05-02-2013, 12:55 AM
I found a Mohawk Distributor about 30 miles from me so I went this past weekend and bought a few cans of Toner in different shades.

I tried a light dusting of Deep Red Mahogany on this section of the front and it looks pretty nice, the stuff is really dark though so when I say "light dusting" it was really just that, any more and it would be too dark to see the pattern, perhaps just right for the base though.

The last picture is from an eBay auction and shows what it should look like, it gives a nice color reference, or at least as nice as possible given the variables in photography, it seems to match up OK with the undamaged parts of my set at least.

The bottom doors (one door, one dummy door actually) seem to be a darker color than the top sections, that could just be the different way the grain reflects the light though.

cwmoser
05-02-2013, 05:30 AM
Its already looking great. The grain patterns in the wood work is
something you just don't see in any furniture today.

Carl

earlyfilm
05-02-2013, 07:12 AM
The bottom doors (one door, one dummy door actually) seem to be a darker color than the top sections, that could just be the different way the grain reflects the light though.

Eric,

I definitely have been following this thread and watching for the differences between your 1948 built set and my 1949 built one.

The bottom platform in your set with the 9 holes drilled around the light barrel hole for mounting, definitely proves that my 1949 was not done after it left the factory as it only has three holes. The 1949 8PCS41 is electrically identical to the 9PC41 and apparently always included the remote that was optional in the 9PC41. The remote was not available on the 1948 model.


The grain on the top imitation drawers runs one direction, while the grain on the bottom door and dummy door runs the opposite, so it is expected that light plays differently on these.

The only picture of my 1949 8PCS41 in the sunshine is in the fifth post in the thread at

http://www.videokarma.org/showthread.php?t=254448

In this picture the angle of the sun makes the bottom seem brighter.

My wife took the picture just as the set was about to jump in the back of my car to follow me home.

By the way, the backside of many of the dummy doors have a surface that does not show and can be used as a testing surface for stain matching.

James

Eric H
05-02-2013, 11:04 AM
Something easy to do in between cabinet repairs.

Polishing up the Door Pulls, solid Brass of course, no plastic or fake Chrome here. :D

ChuckA
05-02-2013, 11:57 AM
Thanks guys, I was thinking no one was reading these posts.
It's a surface coated mirror of course so a common back coated mirror won't work correctly.


Actually Eric you can use a back silvered mirror for the top mirror. You just have to use the thinnest glass mirror you can find, 1/8" will work fine. Use a backing board to make it the same thickness as the original.

It won't be perfect, but it will give you more brightness than the old one.

Chuck

John Folsom
05-02-2013, 12:23 PM
Or... you can buy front surface mirrors online, either cut to fit or have your local glass shop cut it for you. You should have the spherical mirror resilvered for best results. This company does good work at reasonable prices:
Spectrum Coatings:
1165 Ring St. Deltona, FL 32725
Phone: (386) 626-9782
Contact Person: Paul Zacharias
paul@spectrum-coatings.com

cwmoser
05-02-2013, 02:28 PM
Hey John, didn't you restore a Philco 48-2500 projection TV?
How much of an improvement did a resilvered spherical mirror
make over your old mirror? I ask this because the spherical
mirror in my 48-2500 is not perfect but it looks pretty good.
Mine does though have some places in it that you can see straight
through though.

Carl

John Folsom
05-02-2013, 06:56 PM
My mirror in my 48-2500 was in very poor condition, so having it resurfaced made all the difference. However, dummy that I can be, I attempted to clean the curved mirror in the lid. Disaster! The top coat on that mirror is a multi-coat lacquer coat filled with micro-spheres which act to provide optical gain.

But I have restored several RCA projection sets from the late 1940s, and if you want to achieve optimum optical resolution, resilvering the spherical mirror and replacing the flat front surface mirror is the way to go. These sets can provide quite acceptable bright (though very directional) images when operating at peak performance. Of course, of "close is good enough", then the mirrors you have may be tood enough.

Eric H
05-02-2013, 06:58 PM
The Spherical mirror in my set is in very good condition, surprising considering the rest of it.

cwmoser
05-03-2013, 06:12 AM
The Spherical mirror in my set is in very good condition, surprising considering the rest of it.


I'm curious as to what an RCA Spherical Mirror looks like.
Do you have any photos?

Carl

Eric H
05-03-2013, 02:01 PM
I'm curious as to what an RCA Spherical Mirror looks like.
Do you have any photos?

Carl

I don't have a photo at the moment but it pretty much looks just like the one in the Philco, I think it's a bit larger due to the larger CRT.

Eric H
05-08-2013, 11:00 PM
Finished recapping the i.f. chassis tonight so I decided to give it a full power up, everything's connected except the Audio Amplifier, that is a separate unit and I don't think it needs to be in place for the set to work.

I put the CRT in a plastic container, must be High Dielectric since it didn't arc through. :yes:

First try I got a line on the screen followed after a couple seconds by a shutdown, probably the protection circuit kicking in to prevent a phosphor burn from lack of sweep.
I did a little poking around and didn't see anything obvious, then it occurred to me to check the 5U4's in the power supply (there are three of them!), sure enough one of them was stone cold.
I had been having some trouble with them lighting up before because of bad or dirty sockets, I wiggled it a little and it came on so I gave it the juice again, now I have a full raster!

The focus looks terrible and I have no control of the brightness, it's the same no matter what control I turn, I do get some flashing when I turn the tuner (one channel in particular with the Agile Modulator broadcasting) so I think it's passing a signal all the way to the CRT, I just can't see it because it's washed out, can't hear it either because no amp hooked up. :scratch2:

Anyhow I've had enough X-Rays for tonight, at least it powers up now so I just have to figure out the rest of the issues and finish the cabinet.

Einar72
05-08-2013, 11:12 PM
I talked to an old-timer TV tech in Tacoma about these RCA-type sets about 20 years ago. He said his hair fell out after working on one!

Eric H
05-08-2013, 11:35 PM
I talked to an old-timer TV tech in Tacoma about these RCA-type sets about 20 years ago. He said his hair fell out after working on one!

LOL, he probably pulled his hair out after working on one of these.
I intend to put the CRT in the barrel before I do any more serious work on it, I just had it on for a couple minutes to see if it would run. I put the lid on the HV cage at least and kept my distance from the CRT.

Bill Cahill
05-09-2013, 01:14 AM
These sets have no protection circuits to shut them down.
I suspect that tube socket is shot.RCA used some very cheap sockets.
You could have an hk short in pix. tube. Check your voltages from video amp to brightness control, and, with socket removed, voltages on cathode, and, first grid pins. See if brightness control varies the B+at that pin.
You should see variation.
If the picture tube is bad, the good news is they are fairly common.
Bill Cahill
5TP4

cwmoser
05-09-2013, 06:13 AM
LOL, he probably pulled his hair out after working on one of these.
I intend to put the CRT in the barrel before I do any more serious work on it, I just had it on for a couple minutes to see if it would run. I put the lid on the HV cage at least and kept my distance from the CRT.

I'm curious because I have a Philco 48-2500, but where are the
X-rays emitted? From the face of the CRT or all around?

Carl

earlyfilm
05-09-2013, 11:35 AM
Anyhow I've had enough X-Rays for tonight, at least it powers up now so I just have to figure out the rest of the issues and finish the cabinet.

Whoa there Eric! There are three ways to avoid radiating yourself.

1) Measure the distance from the top of the light barrel to the center of the mirror and then to the center of the screen in the cabinet. Mount the CRT in the light barrel on a table approximately that distance from your ceiling. If you are sitting very close to the light barrel, I'd suggest adding scrap sheet metal between you had the barrel. Don't forget to ground both the scrap metal and the barrel.

2) Mount the CRT in the light barrel and jury rig a mirror at a right angle to reflect the image off the wall. or operate the light barrel on its side and project directly on the wall. Determine distance by experimentation. Don't forget to put a metal shield on the mirror side of the barrel when operating this way.

3) Disable the voltage trippler. Remove the 2nd and 3rd 8016's and feed the HV directly from the plate cap of the second now-removed 8016, to a standard high voltage 50-53 degree 5 inch test CRT. You will probably have to shim the yoke. The test tube is close enough to the sweep angle of the 5TP4 to not cause a problem, and any X-ray generation will be minimal at this much much lower HV.

James

Eric H
05-09-2013, 04:43 PM
Whoa there Eric! There are three ways to avoid radiating yourself.

3) Disable the voltage trippler. Remove the 2nd and 3rd 8016's and feed the HV directly from the plate cap of the second now-removed 8016, to a standard high voltage 50-53 degree 5 inch test CRT. You will probably have to shim the yoke. The test tube is close enough to the sweep angle of the 5TP4 to not cause a problem, and any X-ray generation will be minimal at this much much lower HV.

James

This option sounds the best for longer term testing and diagnosis, safer for me and the 5TP4.

I would think it should be fairly safe inside the barrel, it's thick Aluminum and the face of the CRT points downward against a thick, Aluminized mirror.

When I was testing my Philco 48-2500 I pointed the CRT away from me and viewed it in a mirror, later I installed it in the barrel, in any case I avoid being around it as much as possible.

I'm assuming most of the X-rays would be coming out the face of the CRT, the glass is very thin on the face of the 5TP4 and the TP-400 and possibly not Leaded.

Does anyone have any hard facts on the amount of X-rays produced by the 5TP4 operating at 28kv? Guessing the third HV rectifier tube will also be putting out some rays at that voltage?

This set uses three 1B3's by the way, not 8016's, maybe a different version?

Eric H
05-09-2013, 04:53 PM
These sets have no protection circuits to shut them down.

If the picture tube is bad, the good news is they are fairly common.
Bill Cahill
5TP4

Bill, the CRT tested good, no shorts, probably something in the circuit.

I thought it had protection because it would operate for a few seconds with a narrow line and then shut down, it did this several times, possibly it just didn't have enough B+ to keep running?

John Folsom
05-09-2013, 07:11 PM
The 8016 is just the developmental number for the 1B3. Same thing.

At <= 30KV, the X-Rays produced are relatively soft, and the glass of the mirror and the metal of the barrel are effective in stopping them. And if you keep the covers on the HV cage, likewise. But caution is advised. And distance is a good protector.

Einar72
05-09-2013, 10:34 PM
I bought three WWII-dated JAN 8016's on ePay some years back. Anyone know what piece of gear they went in?

Eric H
05-09-2013, 10:36 PM
I removed the second 1B3 and hooked a jumper to the output of the first, then I installed a 5AXP4 test CRT, turns out it works very well this way.

I still have no control over the brightness but the "Picture" (Contrast) control does work, possibly the Brightness Pot is bad.
The Sync is all over the place but I was able to get it to hold still long enough to snap the picture below.

Unfortunately as the set gets hot the picture fades out, also I noticed the image is negative, not sure if the 5AXP4 has it's Grid and Cathode wired differently than the 5TP4 or if it's a problem with the chassis.

I haven't tested any of the tubes in the i.f./Vertical sweep chassis but I did swap out most of the relevant ones with no improvement, there are probably some drifted resistors somewhere.

Eric H
05-10-2013, 01:44 AM
I wanted to take a look at the brightness issue before I went to bed so I studied the schematic (http://www.earlytelevision.org/pdf/RCA-8PCS41-9PC41-648-741-Sams-90-9.pdf) from the brightness control to the CRT and I found a cap I overlooked.

I didn't pay much attention to it because it was the Domino style and I was probably thinking it was a Mica, however the schematic showed it to be a .05@600 and most likely just a common paper cap, why they used this one odd style I don't know, maybe it was supposed to be better quality.

It's cap# 58 on the Sams (http://www.earlytelevision.org/pdf/RCA-8PCS41-9PC41-648-741-Sams-90-9.pdf), between the 6V6 Video Output and the 6AL5 DC Restoration tube, from there it goes to the Grid of the CRT.
As soon as I turned it on I could tell it was better, not only does the video and brightness work now but the sync is fixed too.

I tried it with the 5TP4 also but still with only 10kv on the Anode, the tube works but I can't get any focus with so little HV.

earlyfilm
05-10-2013, 05:14 AM
I didn't pay much attention to it because it was the Domino style and I was probably thinking it was a Mica, however the schematic showed it to be a .05@600 and most likely just a common paper cap, why they used this one odd style I don't know, maybe it was supposed to be better quality.

It's cap# 58 on the Sams, between the 6V6 Video Output and the 6AL5 DC Restoration tube, from there it goes to the Grid of the CRT.


Sams capacitors C58 (which goes between the plate of the video output and the grid of the CRT) & C59 (which goes between screen grid of the video output and the cathode of the DC restorer) are called C168 & C171 by RCA and RCA sez:

RCA part # 72996 Capacitor-Moulded paper, .05 mfd., 600 volts (C168, C171)

(Yep! They must have been conservative 'cause they used the old spelling of "molded" )

These RCA projection sets were notorious for blooming issues with high voltage regulation, and I've heard of stories of service men intentionally disabling the DC restoration to lessen focus shift and blooming as the HV drifted when the sets got older. It seems like cutting off your nose to spite your face, but it did allow a failing CRT to remain in service a little longer. Once people started watching TV in more brightly lighted rooms, the DC restorer went the way of the dodo bird as designers no longer saw any benefit.

I suspect the HV issues had more to do with the design of the early 8016's than with DC restoration.

The RCA 630 had a similar circuit, except the 630 used a 6K6 instead of a 6V6 for video output, and it used a normal tubular .05 mfd 600 volt for these two caps.

cwmoser
05-10-2013, 06:17 AM
What does "blooming" look like?
I've heard this term but never really knew what it means.

Thanks

Carl

jmetal88
05-10-2013, 09:01 AM
What does "blooming" look like?
I've heard this term but never really knew what it means.

Thanks

Carl

If it's being used the way I use it, it's when the picture gets larger due to increased brightness.

old_coot88
05-10-2013, 10:13 AM
'Blooming' occurs when the high voltage drops signifigantly. Static attraction from the front of the CRT decreases, allowing sweep angle to increase or "bloom". The raster progressively dims and goes out of focus as it blooms.

The most common cause is a weak HV rectifier. Or excessive CRT beam current can lug the HV supply down (eg., from the brightness control being turned too high).

jmetal88
05-10-2013, 10:19 AM
'Blooming' occurs when the high voltage drops signifigantly. Static attraction from the front of the CRT decreases, allowing sweep angle to increase or "bloom". The raster progressively dims and goes out of focus as it blooms.

The most common cause is a weak HV rectifier. Or excessive CRT beam current can lug the HV supply down (eg., from the brightness control being turned too high).

I feel like I'm getting off-topic (sorry), but thanks for that explanation. That might actually help me with the blooming on my set. The 1K3 rectifier was dead when I got the set, so I replaced it with a 1B3 I had lying around, thinking it would be 'close enough'. If it's outputting on the weak side, that might explain the weird blooming pattern I've been seeing lately.

earlyfilm
05-10-2013, 12:23 PM
This set uses three 1B3's by the way, not 8016's, maybe a different version?

My 1949 made 8PCS41 cabinet sticker calls for the 8016.

Between it and the other 1949 9PC41 I had one 8016 (probable replacment) and two RCA branded 1B3/8016. The rest were replacment 1B3.

The 8016 is just the developmental number for the 1B3. Same thing.

Usually interchangable, but:

8016 = PIV 10,000 max, Ip = 7,6 max ma, average 2 max ma (1942 data)
1B3/8016 = PIV 30,00 max, Ip = 17 max ma, average 2 max ma (1949 data)
1G3/1B3 = PIV 33,000 max, Ip = 35 max ma, average 1.1 max ma (1965 data)

As the tubes improved the PIV increased, the short-flow current increased, but the average-flow current decreased. I would not put a 1G3 in an RCA projection set.

James

Eric H
05-18-2013, 12:13 AM
Did some resistor checking tonight and replace a few high ohm resistors that had drifted out of tolerance. Not badly out but like a 2.2m that measured 2.8m, 1.0m drifted to 1.4m, it seems to have improved the sync and vertical lock, they were all in those sections.

The Contrast control was having no effect except a slight increase in Contrast all the way at one end, I opened up the Pot and found this: http://vintagetvsets.com/images/8pcs41/contrast-pot.jpg

It's a 1000 Ohm Pot and it's stacked with the Brightness control, according to the schematic it's not the same as used in the 630, I had hoped it might be since I have some spare parts for one of those.

Hopefully I can find a good Carbon in something else and transplant it to this control.

cbenham
05-23-2013, 01:56 PM
'Blooming' occurs when the high voltage drops signifigantly. Static attraction from the front of the CRT decreases, allowing sweep angle to increase or "bloom". The raster progressively dims and goes out of focus as it blooms.

The most common cause is a weak HV rectifier. Or excessive CRT beam current can lug the HV supply down (eg., from the brightness control being turned too high).

Here's 4 pages from the RCA HB-3 Tube Manual showing the specs. for the 5TP4 CRT.
The limiting factor for this tube is that it can only dissipate 5.4 watts. This is determined by multiplying the Ultor operating voltage ~~27,000 volts by the beam current ~~200 microamps.

If this value is exceeded for a long time the heat developed can crack the faceplate. This results in what RCA laughingly calls a "catastrophic failure" of the CRT.

You can measure the beam current by connecting a 1000 ohm resistor in series with the cathode lead to ground and measuring the DC voltage across it. 200 microamps [0.2MA] would show a voltage of 0.2 volts.

It is always gratifying to see these projection sets restored because they represent an important step in the development of television.
Your restoration is specially interesting because you have done so much work
and very well to make this set look and operate like new again. Congratulations.

Eric H
05-26-2013, 07:58 PM
I have spent hours over a period of days trying to figure out why the Audio Amp in this set wasn't working, it was dead silent except for a very faint bit of static if you touched a screwdriver to the plate of the output tube.

I poured over the schematic, checking wiring, checking resistors, checking voltages, convinced I'd wired something wrong, I tried jumping the field coil in the speaker and using a PM speaker, I tried different sources and not a peep, voltages all looked good enough that it should be working but it wasn't!.

I had subbed the 6J5 where the signal comes in but I didn't test the 6F6 output tubes because no way could they be dead enough for it to be completely silent.
They had a nice getter and looked fine, anyway it's a push pull amp so if one is bad it'll still work on the other, and no way could they both be dead enough to kill the whole thing, could they?:dammit::yes:

Both 6F6 output tubes were completely dead, heaters lit, no shorts, no apparent gas, just absolutely no emissions at all. I couldn't find any 6F6 tubes handy so I stuck the first somewhat similar audio tube I could find in the amp, a 6L6 and viola, it worked fine on one tube. I dug up a couple 6V6's and plugged them in and the Amp is alive, of course now the TV chassis is somewhat dead waiting on a contrast control but one thing at a time.

Einar72
05-26-2013, 09:49 PM
I've had 3 or 4 of those amps, and I've never seen one where the green power resistors didn't look like they'd run hot. I finally got another 8PCS41 last year, and it came with a newer pair of 6K6's in it. Got a fair amount of audio while the plates were glowing! I'm assuming the owner who had it serviced used it this way for years.

Eric H
05-26-2013, 11:00 PM
One of the big green resistors was open, I don't think it was originally since they were all running hot to start with so maybe I blew it open while tinkering. I subbed it temporarily with a 2.5k @ 5 watts.

I'll have to look for some 6F6's, not sure I have any.
Will the 6V6 sub it on a permanent basis or do I need 6F6's? I tried a 6L6 also and it worked.
I'd like to get some in an ST bottle like it shows in the Sams picture.

Boobtubeman
05-27-2013, 12:58 AM
Didnt hurt my 37 Delco subbin the f6 with a v6....

SR

kvflyer
05-27-2013, 07:40 AM
I believe that a 6V6 is a good substitute for a 6F6. The heater current of the 6V6 is .45 amps vs 6F6 which is .7 amps. So, you can use two 6V6s until you get a pair of 6F6s or keep the 6V6 in there.

Einar72
05-27-2013, 09:18 PM
They have the same 315 volt maximum plate supply voltage, but the 6V6 grid bias at maximum rating is only -13, while the 6F6 is -22, so there's less danger of it running too hot when biased for a 6F6. Values are similarly safe for push-pull configuration...

Einar72
05-27-2013, 09:39 PM
BTW, is there -21 volts on the Grid #1's?

Eric H
05-27-2013, 10:00 PM
BTW, is there -21 volts on the Grid #1's?

Yes, all the voltages on the 6F6 sockets were in the ballpark.

Einar72
05-27-2013, 10:30 PM
Good! I was looking on the ETF copy of the schematic, and it looks like some of the green resistors aren't powered directly, but go into the interconnect plug, but I haven't traced it out yet. Very confusing, since I've never seen both radio and TV audio connected to the lone amplifier simultaneously!

Eric H
05-28-2013, 12:38 AM
This set doesn't have a radio, and the Amp can run independent of the TV chassis & power supply, it does need the speaker due to the field coil and what appears to be a choke or some type of hum bucking coil built into it. The Sams isn't real clear on that part.
The three green resistors seem to be strung is series on this chassis, using unused socket pins to mount them.
The main power and lid switch switch are connected to the Audio chassis, there is a power socket to plug the power supply chassis in to. The HV cage also has an interlock with the power supply chassis but it's lust a loop at the HV cage, the PS won't fire up unless the HV cage and cord are in place.

I didn't think the Sams had an underside photo of the Audio chassis but I just now found it.

Lots of different cords on this one, it is a bit confusing. I've been running it by using separate cords for everything.

Eric H
05-05-2016, 10:15 PM
I've been working up an interest in finishing this project, or at least getting it all back together.
Getting it back to it's original factory state is out of the question, my goal is just to make it solid and presentable, to that end I've been working on fixing up the cabinet so I can get the chassis off my bench where it's been sitting the last couple years.

I sprayed the interior with some "Camoflauge" paint, this is to hide the water and Mouse stains and make it look a little nicer, yeah I could ahve used black or something darker but i wanted it to look less dingy.
I gave the outside a rubdown with some cherry stain to make it look better, I'll probably use toner on the hardwood trim to cover up it's many defects, the rest will get stained and lacquered eventually.
It's missing about a three inch wide strip of veneer from the left side, I'll patch it up and not worry too much about a perfect blend.

I've got it basically put back together, most of the hinges and screws and such, I had to use longer screws in most places to get a good bite in the dry wood.

Maybe soon I'll reinstall the guts and see what it'll do.

Electronic M
05-05-2016, 10:49 PM
It looks fairly good. I've seen some pre-war RCAs with gray interior paint, so it is not horribly unoriginal looking with that cammo paint.

Bill Cahill
05-06-2016, 08:29 AM
I also call it livable. But, you really need to rebuild it electrically. These sets get a lot of shorted electrolytics, and, shorted paper caps.
I think it's worth saving.

Eric H
05-07-2016, 08:00 PM
Took it out to the garage and spritzed some cherry toner on it today, I wanted to do that before I put the guts back in because after that it's an immovable object.

It's far from perfect, or even nice, it's actually pretty bad in person, but a lot better than the mouse infested, water damaged mess it was when I hauled it home. It's a 20 footer, i.e. it looks okay from 20 feet away. :D

After it dried I brought it in and put all the "stuff" back inside, Main, HV, Audio and PS chassis plus the barrel and CRT, there's still a lot of little bits that aren't on yet like the lid switch, mirror, screen, a few things that I don't even remember where they go...

It's far from working too, the Audio chassis recap needs to be finished up and all the AC cords that go between the chassis's need to be replaced and hooked up, it'll be fun figuring that out.
There are some cloth wires that are rotten and need to be replaced too but those can wait.

My main goal was to get all the parts off my bench so I don't have to work on my kitchen counter.