Videokarma.org

Go Back   Videokarma.org TV - Video - Vintage Television & Radio Forums > Early Color Television

We appreciate your help

in keeping this site going.
Reply
 
Thread Tools Display Modes
  #1  
Old 05-31-2017, 02:22 PM
Electronic M's Avatar
Electronic M Electronic M is online now
M is for Memory
 
Join Date: Jan 2011
Location: Pewaukee/Delafield Wi
Posts: 10,187
Thumbs up Brought a 21CT55 back from the ETF!

I've been wanting a major league early color set since my teen years reading about the CT-100 and the early days of color, and I finally scored one. The one from this thread.
http://videokarma.org/showthread.php?t=268880

There is quite a lot behind the scenes that goes into the purchase of a set that cost the better part of one my cars...I'd like to thank Larry W.(El Predicta) for selling it to me, Crist Rigott for transporting it well on the long trip from Texas to Ohio, and our founder Tim P. (Kamakiri) for passing on it, which allowed me the chance to buy it, as well as for the sound guidance given.

It survived both trips well. I requested that it be transported face down with the chassis and pencil box removed (and it rode that way on both legs of it's journey). The cabinet, chassis, CRT, and small parts box all survived the journey unscathed.

It now rests in my basement waiting it's eventual turn on the work bench. I'm planning to go slowly and methodically on this set once I start. I want to take the time to read up on these, and have all the right parts and prep. Aside from an orange drop the under chassis looks virginal, and I'm very tempted to do a restuff of the capacitors on this set.



As you can see the chassis and cabinet serial numbers match, but the lid and cabinet 4 digit numbers do not, which I assume means at some point someone 'borrowed' a new top panel for it off of a different set.

I hope to get better pictures of it taken/posted soon.

And in closing: Whoopie, I finally have one of the 'holy grail' color sets!
__________________
Tom C.

What I want. --> http://www.videokarma.org/showpost.p...62&postcount=4

Reading between the scan lines since the mid 2000's.
Reply With Quote
  #2  
Old 06-01-2017, 01:54 AM
SpaceAge's Avatar
SpaceAge SpaceAge is offline
VideoKarma Member
 
Join Date: Jul 2016
Location: Denver CO
Posts: 256
Awesome! I'm looking forward to reading about your progress.
Reply With Quote
  #3  
Old 06-01-2017, 01:13 PM
IsthmusTV's Avatar
IsthmusTV IsthmusTV is offline
VideoKarma Member
 
Join Date: Nov 2010
Location: Madison, WI
Posts: 325
Very cool, Tom. Congratulations!

I'm looking forward to following the restoration.

-Clark
Reply With Quote
  #4  
Old 06-01-2017, 01:47 PM
Phil Nelson's Avatar
Phil Nelson Phil Nelson is offline
VideoKarma Member
 
Join Date: Jan 2006
Posts: 3,957
Quote:
Originally Posted by Electronic M View Post
I'm planning to go slowly and methodically on this set once I start. I want to take the time to read up on these, and have all the right parts and prep.
That's a good approach. Take your time and enjoy the process. There are not a lot of these out there, so make the most of this opportunity.

Phil Nelson
Phil's Old Radios
http://antiqueradio.org/index.html
Reply With Quote
  #5  
Old 06-02-2017, 02:05 PM
Steve D.'s Avatar
Steve D. Steve D. is offline
VideoKarma Member
 
Join Date: Sep 2002
Location: Hollywood Hills, Ca.
Posts: 1,754
Quote: "As you can see the chassis and cabinet serial numbers match, but the lid and cabinet 4 digit numbers do not, which I assume means at some point someone 'borrowed' a new top panel for it off of a different set."

Tom,

Different cabinet tops and cabinet #'s were common. As on the assembly line the tops & cabinets weren't always in sync. Also, sets that didn't pass the final inspection were pulled from the line and repaired. This also separated tops from cabinets and what ever top was handy was used prior to final packing and shipping. This also occurred on the CT-100 line durning its assembly.

-Steve D.
__________________
Please visit my CT-100, CTC-5, vintage color tv site:
http://www.wtv-zone.com/Stevetek/
Reply With Quote
Audiokarma
  #6  
Old 06-02-2017, 04:39 PM
etype2's Avatar
etype2 etype2 is offline
VideoKarma Member
 
Join Date: Mar 2010
Location: Valley of the Sun, formerly Silicon Valley, formerly Packer Land.
Posts: 864
Congratulations on acquiring this rare television. Pull out the wood piece that covers the front user controls. There should be a serial number stamped on the back.
__________________
Personal website dedicated to Vintage Television https://visions4netjournal.com
Reply With Quote
  #7  
Old 06-02-2017, 05:33 PM
kvflyer kvflyer is offline
VideoKarma Member
 
Join Date: Nov 2006
Location: Fernandina Beach, FL
Posts: 836
A little late to the party (been out of town) but congratulations!
Reply With Quote
  #8  
Old 06-11-2017, 09:38 PM
KentTeffeteller's Avatar
KentTeffeteller KentTeffeteller is offline
Gimpus Stereophilus!
 
Join Date: Feb 2006
Location: Athens, TN
Posts: 589
Congratulations!!!! A major achievement in early Color TV, and a great set to own. And in great hands as a VK Moderator. Enjoy and be proud!
Reply With Quote
  #9  
Old 01-17-2018, 11:36 AM
Electronic M's Avatar
Electronic M Electronic M is online now
M is for Memory
 
Join Date: Jan 2011
Location: Pewaukee/Delafield Wi
Posts: 10,187
So....A lot of stuff has happened since I last posted...



Back on new years eve, I decided: "dagnabbit I'm at least going to start the resto this year!".
I took shots of the chassis organized my parts and got ready to rebuild some caps.
Before pictures:


I knew I'd have to find paper shells to stuff to sub for the bumblebees and white ceramic tubulars, but what eventually really frazzled me was the realization all the 'paper caps' were Dumont Duramold Bakelitized tubulars....Essentially bumblebees with a paper jacket molded on. I had some samples from other sets that I attacked with various methods (heat and dremmel), and after a few tries, I concluded there is no practical means of separating the guts and the paper sleeve without ruining the sleave. After nearly giving up on restuffing (part of me wishes I had since restuffing that many caps is a LOT of work) I came to the conclusion "heck if I was going to find alternate caps to restuff for ~6-10 of them, why not just do it for all of them?", and off I went. (hoarder alert! )I've got a bankers box worth of can lytics, paper caps, vintage molded plugs, and other interesting defective parts I've saved since the beginning of my resto work. From that box, I was able to pull re-stuffable paper caps to restuff in place of the originals. Since I found Sprague and Aerovox in the set I tried to stick as much as I could to those as the new shells. I gutted MANY paper shells, saving the wax and altering a few label numbers as needed, selected shells slightly smaller than original where possible to open up chassis space, and placed modern caps of the correct value in the shells filling some of the extra internal space with paper towel scraps (to conserve wax) than sealing the ends with the saved wax.
There were 3 orange drops from vintage repair work that I decided to leave alone. And in the HV cage I basically decided to not restuff anything (I figure smaller caps are harder to arc to)...Except the .22uF cap since I had one restuffed cap laying around.
Every restuffed cap has a red band on it, to denote the restuff.
The original paper caps are labeled with the Sam's ID number in the 'bad parts' bag.
I decided to mimic Christ Riggot's cap rebuilding technique on the multi-section lytics making a central wire bundle for the cap pack and substituting a piece oa aluminum from spare cans for his PVC section. The 4 cans under the seleniums I did my way: drill one hole per lead of the replacement cap through the wafer near the terminals and wire them up....Also since 2 had cardboard tubes I simply pulled the cardboard off, beheaded the can, put the new cap in and placed the cardboard tube over the topless can...I then decided to copy that on the metal cans by stealing the cardboard off other spare caps I had...It is easier and you barely see those caps anyway.
The result:


I need to order more parts...All the tubular lytics 50V and under on the underside of the main chassis are still untouched, the 4uF 350V cap on the RED video amp board consists of 2 10uF 150V parts in series tacked in since I mistakenly ordered 2 3.9uF 450V caps instead of the 3 I needed, and the ballast resistor is dead (I kludged together a sub with series-parallel parts but it is not worthy of the final work).

All the white peaking coils were predictably wide open and got replaced...With 2 exceptions: The one under the IF shield was fine, and one of the demod-matrix coupling coils was a brown replacement probably from the 60's (shows how lousy those coils were that techs were changing them back then).

Powering it up on saturday got me a raster, sound and 10KV of HV...After some head scratching I finally pulled the 6BK4 completely out (it's top is so close the HV rect cathode that disconnecting the 6BK4 top cap had no effect!). The grid of the 6BK4 was too positive, and tacking in some parallel resistance with the 4.7M got grid voltage back in a range where the HV pot works decently. With the reg out it can do about 28KV. With the reg in I had it set at 25KV. Based on the grid voltage that was producing that regulation VS the listed voltage on the schematic I probably need to replace the HV reg tube and do more work on the circuit. The 6BK4 is one of the oldest I've seen. It sort of looks like they soldered the plate together and then it redplated or something.
__________________
Tom C.

What I want. --> http://www.videokarma.org/showpost.p...62&postcount=4

Reading between the scan lines since the mid 2000's.

Last edited by Electronic M; 01-17-2018 at 02:51 PM. Reason: add pictures and split the post to add more pictures/info
Reply With Quote
  #10  
Old 01-17-2018, 12:01 PM
old_tv_nut's Avatar
old_tv_nut old_tv_nut is offline
See yourself on Color TV!
 
Join Date: Jul 2004
Location: Rancho Sahuarita
Posts: 4,794
Beautiful! Keep at it!
__________________
www.bretl.com
Old TV literature, New York World's Fair, and other miscellany
Reply With Quote
Audiokarma
  #11  
Old 01-17-2018, 12:38 PM
BigDavesTV's Avatar
BigDavesTV BigDavesTV is offline
BigDavesTV
 
Join Date: Jan 2013
Location: Farmington Hills, MI
Posts: 482
Looking great, Tom, congratulations! So much more going on there, as compared to my CTC-7, which is the oldest color set I own, and the oldest color set I have ever worked on! Good to see results, even on the test crt, this should be a really nice performer, before long!
__________________
[B]"Bee care-eh-full to don't broke thee pic-sher tee-yube!" :-)
Reply With Quote
  #12  
Old 01-17-2018, 02:44 PM
WISCOJIM WISCOJIM is offline
VideoKarma Member
 
Join Date: Sep 2005
Location: Grand Chute, Wisconsin
Posts: 2,014
Quote:
Originally Posted by Electronic M View Post
All the white peaking coils were predictably wide open and got replaced...With 2 exceptions: The one under the IF shield was fine, and one of the demod-matrix coupling coils was a brown replacement probably from the 60's (shows how lousy those coils were that techs were changing them back then).
Tom, what parts did you replace the old peaking coils with?

.
Attached Images
File Type: jpg Weyauwega clump.jpg (64.0 KB, 5 views)

Last edited by WISCOJIM; 04-12-2018 at 03:03 PM.
Reply With Quote
  #13  
Old 01-17-2018, 03:11 PM
Electronic M's Avatar
Electronic M Electronic M is online now
M is for Memory
 
Join Date: Jan 2011
Location: Pewaukee/Delafield Wi
Posts: 10,187
Thanks guys!

Splitting text past the 16 pic limit above.


I wanted to do the horizontal setup. but I could not really get video through the set with my ch13 basement modulator...I was able to get what looked like weak fuzzy sync bars and it looked like the horizontal was off freq. And I could get video waveforms on the bench, but no video with the chassis in the cabinet. I began to realize I was chasing my tail: I could not scope the Horizontal section and completely adjust it (can't adjust it is your not sure it is on frequency) in the cabinet or drive the set with my other bench equipment, but with the deflection disabled on the bench the AGC was probably being affected and there was no CRT to confirm injected or received video was being handled appropriately.

I then grabbed a test jig given to me by Dieseljeep and began trying to figure out how to connect it...There was no listing for the CTC-2B in 2 of the manuals I skimmed, and the adapters I have are mostly solid state era with some tube rectangular mixed in....Combing through I found an adapter that I recognized is for the yoke of a Zenith 15Y6C15 (a set in my collection) I was able with the Zenith schematic to decipher the adapter wiring color code and make a new yoke adapter for the CTC-2B (I can post up the pinout if anyone is curious). From there the HV and CRT connections were straightforward, and dynamic convergence I outright skipped connecting.

H out cathode current was down a lot VS its value with the correct yoke, and if the HV was connected to the jig there were some concerning noises, but for 30 sec raster duration powerups, this was sufficient. I began testing tubes and injecting video with the B&K analyst...I quickly found that the lumina chain was dead before the 2nd video amp. Then I found the contrast pot was open and the carbon track at the ends was gone. I also solved the mystery of there being 2 contrast pots on the shaft, but the front pot only using 1 lug. comparing the Sam's I was working off of to the RCA service clinic I found my set's contrast circuit is an in-between design. The rear pot on the shaft (delay line output) is wired according to the RCA manual, but the front pot (secondary chroma gain) is omitted, but used as a terminal strip/tie point like in the Sam's. I found a usable pot, but unfortunately, I had to remove both pots since the Allen key set screws on the shaft coupler between pots is frozen. I've got a new pot cobbled in, but will probably need to revisit this. Here are pics of the original and my sloppy repair.


I did some more playing around with the B&K analyst injecting video and RF, and at one point noticed there were nice color bars from the analyst....I was SO focused on troubleshooting the IF's refusal to pass decent lumina that I turned off the distracting color on the analyst without thinking about what I was seeing....About 30 minutes later during a restroom break, it finally hit me: "holey crap the color circuits are working, aren't they!?".....
The color circuits seem to be working and in or somewhat close to proper adjustment.


After checking that, I remembered something useful: Phil has an article about building a video amp for composite video injection for the CTC-2 on his site...I whipped one up last night and now have a good way to feed it video. I built it with a twist. I added a switch to go between IF and external video so if I can fix the RF/IF issue I can pick my input method.


With that I can finally tune the horizontal stage up and KNOW that it is in sync...Which is the plan going forward.
I also intend to check the tuner on a different channel for good measure.

I took over 100 pictures of it and don't feel like posting them 16 (VK's pictures per post limit) at a time so here is a link to the rest: https://www.flickr.com/photos/137849...57690691153411 Lots of chassis pictures, and some more screenshots there.


A missed points from the cap rebuild discussion: on the tubular lytics I tried a new technique. I normally slice an end completely off, but found only slicing most of the way through leaves a nice hinge that keeps more structure in the rebuilt cap.


Someone had added piggyback fuse replacements. That seems normal till you notice they used higher amp fuses and the larger B+ fuse had a MacGuyver style replacement...When the Piggyback spare blew, they simply stuck some aluminum foil in parallel! Only way they could have made it derpier is if they had used a foil gum wrapper instead of straight foil.

Last edited by Electronic M; 01-28-2018 at 12:51 AM.
Reply With Quote
  #14  
Old 01-17-2018, 03:14 PM
Electronic M's Avatar
Electronic M Electronic M is online now
M is for Memory
 
Join Date: Jan 2011
Location: Pewaukee/Delafield Wi
Posts: 10,187
Quote:
Originally Posted by WISCOJIM View Post
Tom, what parts did you replace the old peaking coils with?

.
See link.
http://www.videokarma.org/showpost.p...22&postcount=9
Digikey still stocks them.
__________________
Tom C.

What I want. --> http://www.videokarma.org/showpost.p...62&postcount=4

Reading between the scan lines since the mid 2000's.
Reply With Quote
  #15  
Old 01-17-2018, 07:55 PM
WISCOJIM WISCOJIM is offline
VideoKarma Member
 
Join Date: Sep 2005
Location: Grand Chute, Wisconsin
Posts: 2,014
Quote:
Originally Posted by Electronic M View Post
See link.
http://www.videokarma.org/showpost.p...22&postcount=9
Digikey still stocks them.
Thank you, and thanks also for expanding my vocabulary. I never heard of derp, derpy, derpier before. Not sure if I'll ever remember to use them.

.
Reply With Quote
Audiokarma
Reply


Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -5. The time now is 12:08 PM.



Powered by vBulletin® Version 3.8.4
Copyright ©2000 - 2018, Jelsoft Enterprises Ltd.
ęCopyright 2012 VideoKarma.org, All rights reserved.