View Full Version : Beautiful - RCA Victor 621TS
M3-SRT8 03-18-2014, 06:32 PM This just in...
A 621TS in Walnut. Serial Number C 003539. Complete, except for the brass channel dial.
With an NOS GL-4592 aluminized crt. Sealed in the box.:smoke:
M3-SRT8 03-18-2014, 06:41 PM Found the brass dial.:smoke:
Nice - thought you had one already.
M3-SRT8 03-18-2014, 06:46 PM Appears unrestored. All RCA tubes. Haven't tested the CRT yet.
M3-SRT8 03-18-2014, 06:47 PM Nice - thought you had one already.
I did. Couldn't pass this one up.:smoke:
Tom Albrecht 03-18-2014, 06:58 PM Very nice cabinet condition! Can't say much good about your camera, however! :)
M3-SRT8 03-18-2014, 07:31 PM Very nice cabinet condition! Can't say much good about your camera, however! :)
I know. It's my cellphone.
The pictures don't do it justice.
Took a peek inside. The RCA tubes have codes on them like: 6-30, 6-24, 6-29, etc.
Are they original 1946 tubes?:smoke:
Eric H 03-18-2014, 07:33 PM I know. It's my cellphone.
The RCA tubes have codes on them like: 6-30, 6-24, 6-29, etc.
Are they original 1946 tubes?:smoke:
Yes, mid 1946 date codes.
Username1 03-18-2014, 07:52 PM Looks like you died and went to heaven.....
I might just get into a set like that more than a CT-100......
M3-SRT8 03-18-2014, 08:03 PM I will do my very best restoration on this chassis. Restuff all caps so it appears "ex-factory."
I'm tempted to pull all the factory tubes and record their original locations. Perhaps put them aside and swap in new tubes.
So, based on the tube's date codes, we can assume a third quarter 1946 assembly date?:smoke:
Username1 03-18-2014, 08:09 PM So you think that is a low hour set, or NOS never really used....?
M3-SRT8 03-18-2014, 08:31 PM The chassis is covered in dust. No rodent activity.
I'm going to pull the chassis and document it thoroughly. :smoke:
M3-SRT8 03-18-2014, 08:49 PM It appears completely original.
The Tuner tubes are dated 3-43. The earliest 1946 tubes are dated 6-17. The 5U4 is missing.
The cad plated chassis is well preserved under all that dust.
All caps and resistors appear ex-factory. :smoke:
M3-SRT8 03-18-2014, 08:53 PM Using a soft brush, I swept aside a small section of dust from the top of the chassis. You can see thr cad plating is very nice.:smoke:
M3-SRT8 03-18-2014, 08:59 PM The 7DP4 appears origional to the set.
The black socket is marked MADE IN USA 043.
This is fun...
:smoke:
M3-SRT8 03-18-2014, 09:09 PM So you think that is a low hour set, or NOS never really used....?
Looks low hour. And the latest tube date code is 6-30
Where is the date code on the CRT?
Should be on the base somewhere. I'd have to look at mine. This is a nice one. Bet you paid 4 figures. If not - what a deal.
M3-SRT8 03-19-2014, 11:17 AM Not.:smoke:
vts1134 03-19-2014, 11:27 AM It appears completely original.
The Tuner tubes are dated 3-43. The earliest 1946 tubes are dated 6-17. The 5U4 is missing.
The cad plated chassis is well preserved under all that dust.
All caps and resistors appear ex-factory. :smoke:
Ever give a second thought about keeping it in its completely original condition? Relatively speaking "restored" "working" 621ts' are a dime a dozen, but examples as original as the one you currently have are probably quite rare, and getting rarer every day.
ChuckA 03-19-2014, 01:08 PM It appears completely original.
The Tuner tubes are dated 3-43. The earliest 1946 tubes are dated 6-17. The 5U4 is missing.
:smoke:
RCA changed to a year-week code in 1946 so 6-17 is 17th week of 1946, if there is a dash it's an OEM tube, no dash it's a replacement tube.
Before that the code was a letter (Year) number (Month pair) combination, U=1937, F=1946; 1=Jan/Feb, 6=Nov/Dec, so 3-43 isn't an RCA date code.
In 1956 they changed again to the RMA-EIA code format YY-WW.
Chuck
M3-SRT8 03-19-2014, 04:37 PM The latest tubes are 6SN7s, all dated 6-30, with a dash. All the tubes have dashes.
I haven't ventured inside the HV cage yet.
Soooo...6-30 is Mid-August. The sound discriminator is a 6AT6. An early production 621TS. Say, September 1946?:smoke:
M3-SRT8 03-21-2014, 09:08 PM Taking inventory and testing components. Cleaning and checking as I go.
All the ww resistors in the HV Cage and the bleeder resistors are fine. I checked the flyback for resistance and it is fine.
All the tubes test very good to excellent. Since all but four tubes are as the tv left the factory, I find that remarkable.
The only tubes, in fact, the only components that are not ex-factory are the 6BG6-G, 5V4-G, 5U4-G, and one of the 6SN7s.:smoke:
M3-SRT8 03-22-2014, 11:15 PM Checked all the transformers for resistance, and they're all fine.
Did a partial recap. Restuffed and replaced 17 out of 27 tubulars. They are the new looking caps at the right of the picture. I replaced them exactly as before, duplicating the factory positions.
On a lark, I plugged it into the variac and brought the a.c. up slowly. At 100 volts I tested the second anode and it read 7kV.
That's good enough for tonight. :smoke:
Sandy G 03-23-2014, 08:59 AM You're doing the Right Thing... A set THAT good deserves a chance to "Live" again.... It will likely "Wow !" as many, if not MORE people now & in the future as it did in 1946...
kvflyer 03-23-2014, 09:53 AM ...
Did a partial recap. Restuffed and replaced 17 out of 27 tubulars. They are the new looking caps at the right of the picture. I replaced them exactly as before, duplicating the factory positions.
...
Looks good as usual! What do you use to seal the ends of the capacitors after you "stuff" them. I have not been happy with what I have found so far. A good sealing wax may be the ticket but I have only found a kinda hot glue and I am not satisfied with the color.
Thanks for sharing and good luck today!
M3-SRT8 03-23-2014, 04:12 PM So far, this is boiling down to a glorified recap. Strip away all the fancy re stuffing of cardboard capacitors, quick resistance checks, and this is a pretty simple restoration.
I'm using clear hot glue and dark amber colored beeswax on the caps.
Only a few more tubulars to go, under the video IF sections.
It appears the ion trap magnet assembly was replaced, with a stock RCA unit. Lead number 2 was disconnected. I don't know why it was left hanging...
I briefly power up the unit every three or four cabs replaced. Last test at 110 volts yielded a full 8 kilovolts at the second anode connection. Looks pretty healthy.
The original electrolytics are still on the chassis. I'm saving them for last. I'm only powering up the chassis briefly, so as to not endanger anything.:smoke:
ChrisW6ATV 03-23-2014, 04:52 PM Very nice acquisition, Lee. Since this is a walnut version, are the center trim pieces and left and right stripes lighter in color than the knobs? That seems to be the one way I can tell a walnut set from a mahogany one.
TVTim 03-23-2014, 05:04 PM Great find. Even 70 year old dust!
Can't wait to see photos of it up and running.
M3-SRT8 03-23-2014, 09:45 PM Very nice acquisition, Lee. Since this is a walnut version, are the center trim pieces and left and right stripes lighter in color than the knobs? That seems to be the one way I can tell a walnut set from a mahogany one.
They are about the same tone.:smoke:
M3-SRT8 03-24-2014, 10:55 AM Oops. My error. The sound discriminator is a 6AT6. Original tube.:smoke:
M3-SRT8 03-24-2014, 10:30 PM She's up and running. Has audio has a raster but looks like the horizontal frequency is off. I can't find the hor.frequency control like in my 630TS.
Anybody know...?:smoke:
M3-SRT8 03-24-2014, 10:35 PM Here's a pic of it running. :smoke:
Eric H 03-25-2014, 12:17 AM Not positive but I think this is the Horiz Osc coil.
M3-SRT8 03-25-2014, 07:27 AM That's L113, the horizontal linearity control. I saw that.:smoke:
M3-SRT8 03-25-2014, 08:26 AM I think the problem is not horizontal synch or oscillation. It might be in the tuner.
I don't get a blank white raster on the screen. There's lots of dark in it, with or without a signal going through it.:smoke:
ChrisW6ATV 03-25-2014, 05:54 PM They are about the same tone.:smoke:
OK, so I cannot use that as a way to tell either. Well, maybe mine IS walnut, then. Every time I try to compare it to other sets I have or look at it in different light or a different angle, I see something that makes me not sure one way or the other. Thanks.
Eric H 03-25-2014, 07:18 PM The picture you posted looks like the Horiz Oscillator is running way off frequency but maybe it's just lines of interference?
Does the Horiz Hold control on the front have any affect?
It's been so long since I worked on a 621/721 I can't remember if they have an adjustable frequency coil or not, I would think they would have to.
Looking at the Riders on the ETF I can see a Horiz Osc Transformer but it doesn't appear to be adjustable.
M3-SRT8 03-26-2014, 11:42 AM Yup. I see the same thing. No adjustment.
I checked the 470 pf mica under the 6SN7-GT V-108, and it measures fine. Don't have a leak tester though. A 470k resistor measured 617k so I replaced it - nothing.
It may not be a horizontal oscillator or discharge issue.
Perhaps it's in the tuner. But I get real clear audio via the test DVD.
I'll keep at it.:smoke:
decojoe67 03-30-2014, 06:12 AM Your 621TS is one of the nicest I've seen. Still the best vintage TV in my opinion. My only complaint with it, as well as my 630TS, is the annoying audio buzz they all seem to have. The audio also requires a very specific "sweet-spot" of the controls or it goes out completely.
M3-SRT8 03-30-2014, 05:45 PM Yup. A fine television.
I'm still making my way thru it. Just replaced all the 2W resistors in the HV section. They were all toast.
The Focus control is dirty, or catching on something, as it reads too high. Before I started cleaning it, it was reading only 1.87 Meg's. Now, it reads over 7 Meg's. Strange. I have it soaking in a cleaning solution, with the cover removed, at present. I may have to replace it.
Many thanks to kbmuri, who is, as usual, invaluable in endevours like these.:smoke:
M3-SRT8 04-10-2014, 09:35 AM From the D.P. Gumby restoration dept:
Whilst checking voltages in the 5V4-G, I fried my Velleman VM890 DMM. This, of course, is not recommended.
A new Fluke 87-V is en-route. Happy Birthday, to Me.:smoke:
Eric H 04-10-2014, 10:29 AM From the D.P. Gumby restoration dept:
Whilst checking voltages in the 5V4-G, I fried my Velleman VM890 DMM. This, of course, is not recommended.
Bummer, this is why I'm now using a $20 Harbor Freight meter, don't care if it gets fried.
M3-SRT8 04-10-2014, 11:54 AM Bummer, this is why I'm now using a $20 Harbor Freight meter, don't care if it gets fried.
Oh, yeah. I have some of those Harbor Freight cheapies.
They are the electronic equivalent of Soviet Straff (Punishment) Battalion soldiers being thrown into the fray.
Zhukov to Rossokovski: "How many matches did you light today?":smoke:
M3-SRT8 04-29-2014, 04:43 PM Back on the 621. While checking around V105, 1st & 2nd Video Amp, I think I caught a recap boo boo.
Stand by. I think I'm close...:smoke:
DavGoodlin 04-29-2014, 10:19 PM Oh, yeah. I have some of those Harbor Freight cheapies.
They are the electronic equivalent of Soviet Straff (Punishment) Battalion soldiers being thrown into the fray.
Zhukov to Rossokovski: "How many matches did you light today?":smoke:
Ha :D
M3-SRT8 04-30-2014, 08:10 PM Tapped into V104 video and V117 (6AT6) 1st Audio.
Got a fair raster, with horizontal tic lines. Picture detail and depth is not good. Barely any audio. Sounds like just the preamp is audible.:smoke:
kvflyer 05-01-2014, 10:50 AM :thmbsp:
Nice job...
M3-SRT8 05-01-2014, 10:05 PM Tapped into the wrong audio junction point. Tapped into the correct point and was rewarded with audio. Good gain, but I have a buzzy, distorted 4 x 6 cone.
After prodding the voice coil by pushing on the center cap, I believe the coil is not blown or rubbing in the gap. Found that part of the cone is detached from the center cap.
After masking off the spider with a trimmed piece of paper (see photo) I applied glue (Titebond) to the torn area and applied light pressure to the speaker cap with a rolled up ball of paper towel and a piece of masking tape. I'll let it dry in place overnight.
Fingers crossed. :smoke:
GKinTN 05-02-2014, 02:04 AM Great sets! I have a very clean 621TS with all original tubes, and only one changed part ever (a power resistor) and it still plays very well. That said, I'd like to see your technique for restuffing the caps and getting the tubulars to look original with the colored wax and hot glue.
M3-SRT8 05-02-2014, 06:38 AM Great sets! I have a very clean 621TS with all original tubes, and only one changed part ever (a power resistor) and it still plays very well. That said, I'd like to see your technique for restuffing the caps and getting the tubulars to look original with the colored wax and hot glue.
Thanks. My technique is similar to what others do. I just fill the ends of the tube with hot glue. Then I dip in hot beeswax to give it the proper amber color.
Alas, I tried the speaker this morning and it is indeed blown. Bah!:smoke:
kvflyer 05-02-2014, 09:09 AM I hope that I am not distracting this thread but have a question about the color of the bees wax that you guys are using. I found the stuff at Hobby Lobby and it is great for dipping the capacitors. But it is rather light in color. Did you by chance put some darker coloring in the wax? Possibly using a crayon?
"Just askining..." Thanks for the sidebar...
M3-SRT8 05-02-2014, 09:58 AM In retrospect, putting in a brown crayon would have been better. It would have aged the caps a bit. The way mine look are too perfect.:smoke:
M3-SRT8 05-02-2014, 10:00 AM 721TS donor chassis to the rescue. It shares many parts with the 621, including loudspeakers.:smoke:
M3-SRT8 05-02-2014, 10:02 AM Great sets! I have a very clean 621TS with all original tubes, and only one changed part ever (a power resistor) and it still plays very well. That said, I'd like to see your technique for restuffing the caps and getting the tubulars to look original with the colored wax and hot glue.
BTW, what is your serial number and date codes on your tubes?:smoke:
M3-SRT8 05-03-2014, 08:35 PM I've been running the 621 a few hours each nite on a test pattern, and I've noticed the resolution has pickup up nicely. Looks to be climbing past 3.75 mhz, and the horizontal tics are gone.
I measured the 2nd anode, and the voltage is 9kv. Is that too high for the crt?
I'm guessing the CRT and the flyback are burning in. Any guesses out there as to why the picture quality is improving? :smoke:
Eric H 05-03-2014, 09:25 PM Could be tubes waking up after being dormant for 50 years, resistors drying out and so forth.
I pulled my set out a few weeks ago and ran it and it looked better than it did a couple years ago when I last fired it up. My CRT is a little slow but it came right up this time and was razor sharp.
I made a short video of it:
http://youtu.be/DkBcYmZVUkk
These sets have a much better picture than any of the 7JP4 based sets I've seen.
M3-SRT8 05-03-2014, 10:26 PM Yeah. That's what I figure. Shaking out the cobwebs.
Since most of the tubes are original, and haven't been lit up in over 50 years, I guess they're entitled to stretch out a little.
I'm going to keep running it, a little longer each day, and see if the picture quality continues to improve.:smoke:
M3-SRT8 05-04-2014, 07:33 AM This is wierd. I just fired up the 621 and the picture just compressed horizontally with a audible little "ffft" sound.
I wonder what let loose?:smoke:
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