Videokarma.org TV - Video - Vintage Television & Radio Forums

Videokarma.org TV - Video - Vintage Television & Radio Forums (http://www.videokarma.org/index.php)
-   Early Color Television (http://www.videokarma.org/forumdisplay.php?f=36)
-   -   Question about the Pair of CT-100's at ETM Auction (http://www.videokarma.org/showthread.php?t=270415)

Electronic M 05-08-2018 10:37 AM

Quote:

Originally Posted by WISCOJIM (Post 3199221)
I don't want to pick on Bob Dobush, I've considered him a friend for many years, and he is very valuable to Steve, the museum, and our hobby.

But we sure could use the space he uses for storage in the auction room so that there would be room for everyone to sit down and stay out of the way. We all know the room is too small, perhaps now we'll finally all realize that it's time to do something about it.

.

Back before there was a CRT rebuilding room indoors there was enough space (at least for the amount of stuff auctioned back then*) for the auction and Bob's stuff, but since that was built I have to agree with Jim that there is too much stuff that is not part of the auction crowding the auction...If the back room keeps filling in like this the number of items being auctioned is going to have to be limited, or the entire thing will need to move outdoors (perhaps under a big tent)... 2-3 more rows of TVs in that auction would have meant removing the chairs.

I've actually been thinking along the lines of Jim for a few years I just kept my trap shut because I'm not fond of rocking the boat.

*Heck I remember years where a part of the swapmeet occupied the current indoor auction space and there was still seemingly enough room.

Dave S 05-08-2018 11:44 AM

Well, I wouldn't want to piss anyone off or get flamed, but I really feel a need to defend Steve, Dave Abramson and the other volunteers.

INCOMPETENCE / MISTAKES:
I've been to every Early Television Convention since they started. It's always a whirlwind. No matter how much you prepare ahead of time the pace on Saturday is so fast, and the schedule so tight, that it often becomes impossible for well-intentioned volunteers to make sure that everything goes perfectly. Part of the problem is often that many people don't get to see what goes on "behind the curtain." I could NEVER criticize Steve, Bob Dobush, Dave A., Darryl or any of the other volunteers who put in long hours of often hard physical labor to support the Convention, without compensation or anything other than an occasional pat on the back. Dave, in particular, stepped in to serve as our auctioneer after previous volunteers weren't able to do it. I think he did a great (if perhaps not perfect) job and as with all of our other volunteers he did a heck of a lot better than "none of the above."

LEADERSHIP:
There has been a significant influx of "new leadership" over the past few years (a fully-filled formal Board of Directors, up from pretty much 'just Steve' until not too long ago.) These are people who care about the Foundation and put in time and effort (and occasionally money) to support it. New blood is always welcome, and usually in short supply. Some folks show up and the first thing out of their mouths is "how can I help?" Gotta love those people. (You know who you are!) My own philosophy is that constructive criticism is always eagerly sought and deeply appreciated. But UNconstructive criticism could mean that YOU are now in charge of whatever it is you were complaining about!

PRICES:
Regarding prices, virtually everything was a "good deal" this year if you were a buyer, or a young collector just starting out. And a "bad deal" if you were selling. In my neck of the woods, radios and TVs are selling for literally a few cents on the dollar of what longtime collectors paid for them years ago and think that they are worth. FYI a CT-100 in similar condition sold here last year for two or three hundred dollars. It's depressing, but there have been several occasions here lately where they literally have not been able to give radios and TVs away for free at auctions and estate sales. And I missed out on a couple of great buys myself because my bid was a millisecond too late. My bad.

One of my favorite quotes is "A thing is worth what you can get for it." For the record, I put a set in the auction this year for the first time ever. When the dust settled, Steve sent me a note that my net proceeds would be a dollar and sixty cents. I told him to keep it.

IMPROVEMENT:
We learn from our mistakes. The comments about the order of items in the auction are interesting, and my own observations are that is true. We are planning to do "iMag" (projecting the item being auctioned on a screen) next year, but that also adds another layer of complexity and more equipment and manpower demands on our already stretched-thin-to-the-breaking-point crew.

This year (as always :-) was "the best Early Television Convention ever." And next year probably will be too.

Chip Chester 05-08-2018 11:47 AM

Quote:

Originally Posted by WISCOJIM (Post 3199221)
I don't want to pick on Bob Dobush, I've considered him a friend for many years, and he is very valuable to Steve, the museum, and our hobby.

But we sure could use the space he uses for storage in the auction room so that there would be room for everyone to sit down and stay out of the way. We all know the room is too small, perhaps now we'll finally all realize that it's time to do something about it.

.

Four basic things would improve the warehouse situation. They cost money, and time, but probably beneficial overall:

1. Industrial style pallet racks. Abundant, but not free, on CL. As a 501c3, attracting corporate donations is possible. Locating around the perimeter would probably clear almost all the floorspace.

2. Clean pallets for organization of equipment by type, owner, long-term, item-for-auction, etc. Free is possible, but time is still needed. Not as space-efficient as existing dense-packing, but with four levels of storage where there currently is one, plus categorical organization, it's still a big plus.

3. Organization database that logs what is where (by clearly-marked pallet number), who owns it, etc. Basically free, minimal time once established.

4. Small forklift or pallet stacker/picker. Several options here. Donation possible but a longshot. Maintenance/charging expense. Insurance/training requirements possible. Abundant on CL, but have to be poised to move quickly when available.

I'm local, and regularly run across stuff like this on CL. Can advise of availability, coordinate/execute purchase and delivery, but not finance.
Not in the position to seek out donations of goods, however; but I can recognize them if I learn of them.

I do think changing up the storage system would greatly improve free space, but the ever-present danger is having that space collect more stuff. The discipline is deciding what should be collected.

The fenced-in area out back would also be prime for shipping container storage if zoning allows. Plus the museum could rent out capacity to space-challenged collectors, and possibly, as a value-add, accept shipments and store for absentee collectors. This would be for money, not for free. (Insurance would be on the collector, not ETF.)

Caveat: These are probably not new ideas. I have not brought them up to Steve or anyone. They are probably also pipe dreams and can't be implemented for a wide variety of reasons. But a man can dream, can't he?

On edit, just to keep it all in one place...

On rackmount gear, best is to store it in racks. I actually have a few I can donate for this. (They're presentable enough for display, too.) Plus, it's the kind of thing I often run across people trying to get rid of, free. But I usually need to answer quickly, so 'pre-approval' would be good.

Kamakiri 05-08-2018 01:15 PM

Quote:

Originally Posted by Chip Chester (Post 3199234)
Can advise of availability, coordinate/execute purchase and delivery, but not finance.

That's the problem.....unless some benefactors come in and dump a load of cash, that sort of thing can't happen. It's difficult enough raising funds to pave the parking lot.

Kamakiri 05-08-2018 01:23 PM

Quote:

Originally Posted by WISCOJIM (Post 3199221)
I don't want to pick on Bob Dobush, I've considered him a friend for many years, and he is very valuable to Steve, the museum, and our hobby.

But we sure could use the space he uses for storage in the auction room so that there would be room for everyone to sit down and stay out of the way. We all know the room is too small, perhaps now we'll finally all realize that it's time to do something about it.

.

Every year I usually pick through Bob's stuff and usually end up handing him a couple hundred bucks and walking away with some really nice goodies.

This year, I couldn't find more than a couple things that weren't there last year and everything was packed so tight that I couldn't get a good look at much. I probably would have hit him up on a Philco projection set that he had there, but it would've taken a good half hour to dig it out.

Kamakiri 05-08-2018 01:28 PM

Quote:

Originally Posted by benman94 (Post 3199220)
As it is, I did help unload Bob Dobush's truck when he brought in all of Jim Cozart's stuff, so I can appreciate the effort involved in moving everything. Especially the projection sets and DuMonts. I would jump at the chance to come down early next year and move stuff.

I think I moved every set in the whole museum *but* those. I think I was running around doing something with the media for the presentations when those were being offloaded.

Funny thing....when I was loading my own stuff everyone seemed to scatter. Not on purpose I'm sure. The only person who came over and offered a hand was Julian Burke. Spent quite a bit of time with him at the convention and I'm glad I did......he's a hell of a nice guy :)

benman94 05-08-2018 01:35 PM

Quote:

Originally Posted by Kamakiri (Post 3199241)
I think I moved every set in the whole museum *but* those. I think I was running around doing something with the media for the presentations when those were being offloaded.

Funny thing....when I was loading my own stuff everyone seemed to scatter. Not on purpose I'm sure. The only person who came over and offered a hand was Julian Burke. Spent quite a bit of time with him at the convention and I'm glad I did......he's a hell of a nice guy :)

Tim, those were unloaded about a month ago when Nick picked up the rebuilding equipment he had purchased. It was Bob, Nick, my father, and I that unloaded that truck.

Anyway, I regret even mentioning anything. It was just a relatively simple suggestion, with absolutely no cost to implement, that could hypothetically net more for the museum, and worst case cause no harm. I believe I've presented ample evidence to that effect.

In the future I'll keep my mouth shut.

etype2 05-08-2018 02:05 PM

Photos are up. https://www.flickr.com/photos/jsw681...57666687171147

Kamakiri 05-08-2018 02:31 PM

Quote:

Originally Posted by benman94 (Post 3199242)
Tim, those were unloaded about a month ago when Nick picked up the rebuilding equipment he had purchased. It was Bob, Nick, my father, and I that unloaded that truck.

Ahhh...I thought you meant the Dave May stuff. My bad.

Chip Chester 05-08-2018 02:54 PM

Quote:

Originally Posted by Kamakiri (Post 3199239)
That's the problem.....unless some benefactors come in and dump a load of cash, that sort of thing can't happen. It's difficult enough raising funds to pave the parking lot.

Understood. I've worked with a couple organizations with small budgets.
What could help is 'renting' space (by the pallet?) for storage of individual's goodies (that are in the scope of ETF). Granted, not everyone lives close enough for that to be worthwhile, but it may also spur more visits to the museum.

etype2 05-08-2018 03:38 PM

I learned about the ETF through my friend Jerome in 2010. I’m in the Phoenix area and getting up there in age. I get severe pains in my chest from being doubled up in the cramped airline seats, so I don’t go to the convention. I’ve watched the stream every year and have a few suggestions about the auction.

1. Get a wi-fi extender to improve the signal. They are cheap. Lots of buffering and drop outs.

2. Definitely agree that everyone should be seated once the auction starts. It seems that most folks have ample time to inspect the sets they are interested in prior to auction start. Standing up and following the auctioneer blocks the view for everybody.

3. The camera operator should be able to pan, scan and zoom without obstruction.

Reading the “behind the scenes” preparation on this thread was informative and sounds like controlled chaos. I saw the auctioneer was rushed to maintain the timeline of the Saturday schedule with so many items to be auctioned off.

I think everyone did a great job this year as always. Remember it’s all volunteer work.

I’m so sorry I can’t be there, maybe one year I will. I do what I can in my own way to help the museum and our hobby.

Electronic M 05-08-2018 04:34 PM

Good news and more towards the original topic. The green gun was FAR from dead, but WAS deep asleep and tested very weak initially. The green gun has woken up to be the strongest so far centered in the good range. Red is close to green. Blue is at the lower end of good. Edit: Blue woke up more.

This is shaping up to be a good 15GP22 CRT!:banana::banana::banana:

https://farm1.staticflickr.com/981/4...a8445441_n.jpg https://farm1.staticflickr.com/903/4...9c0e9dcc_n.jpg https://farm1.staticflickr.com/824/4...974079f3_n.jpg

fixmeplease 05-08-2018 05:38 PM

Your deal sounds even sweeter!:banana: Lets hope it stays alive.:thmbsp:

Electronic M 05-08-2018 05:45 PM

https://farm1.staticflickr.com/953/2...2a99e354_n.jpg
Here are my buys L-R T-B : Motorola mask+knobs (better ones than on my set), Silvertone roundy, Alignment sweep gen, Duo-view projector NIB, Zenith porthole, 23" Zenith table set, 21FBP22, CT-100, Dumont color monitor, and the corner of Project 'M' (which will remain secret till the time is right).

The CT-100 has sound and video, but the video is weird. Luminance if present appears negative, contrast can extinguish the raster but not affect it much otherwise, if the color is turned to minimum raster extinguishes...Based on that I think the luminance stages are not operating. Cabinet and screen pictures are from before I woke the sleeping CRT.
I built a working video injection amplifier for my 21CT55; if time allows I hope to connect it to the CT-100 tonight to better diagnose the video stages. With luck, I'll be "off to see the wizard". :D

https://farm1.staticflickr.com/943/4...125dd894_n.jpg https://farm1.staticflickr.com/945/4...ae7bde13_n.jpg https://farm1.staticflickr.com/831/4...73f1be3c_n.jpg https://farm1.staticflickr.com/972/4...c4a90b5d_n.jpg https://farm1.staticflickr.com/903/4...efd9d204_n.jpg https://farm1.staticflickr.com/971/4...02df588a_n.jpg https://farm1.staticflickr.com/947/4...ee775477_n.jpg https://farm1.staticflickr.com/952/2...7ca3bc1b_n.jpg https://farm1.staticflickr.com/976/2...594b1cff_n.jpg https://farm1.staticflickr.com/948/2...66df2a7c_n.jpg

WISCOJIM 05-08-2018 06:31 PM

Quote:

Originally Posted by Electronic M (Post 3199250)
Good news and more towards the original topic. The green gun was FAR from dead, but WAS deep asleep and tested very weak initially. The green gun has woken up to be the strongest so far centered in the good range. Red is close to green. Blue is at the lower end of good. Edit: Blue woke up more.

This is shaping up to be a good 15GP22 CRT!:banana::banana::banana:

Such luck!

Go buy Powerball tickets...

.

Phil Nelson 05-08-2018 11:16 PM

What a great score. I'm sure you'll do a thorough & careful job of restoring that CT-100.

I'm curious about that DuMont monitor, too. Perhaps you can post some photos & details when you get around to that project.

Have fun!

Phil Nelson
Phil's Old Radios
https://antiqueradio.org/index.html

dtvmcdonald 05-09-2018 07:30 AM

What we all want to see, or at least I want to see, before I start crying
in my coffee for not bidding, is a raster only, two guns cut off, that has
good purity. I have a theory that might make it possible.

NewVista 05-10-2018 03:59 PM

1 Attachment(s)
50's Admiral color ($1000) very desirable, rare.
Wonder why blonde ctc-5 went for less than blonde 12" GE B&W?
- Got excited, thought I had one, but it was a blonde Hallicrafters 12" (pic)
Good to see 50's limed oak item prices on the rise!

Kamakiri 05-10-2018 07:08 PM

The blonde 5 had an FJP conversion....I'm still kicking myself in the ass for not going on it :(

NewVista 05-11-2018 12:10 AM

1 Attachment(s)
Quote:

Originally Posted by Kamakiri (Post 3199356)
The blonde 5 had an FJP conversion.... :(

That would be a sweet TV.

I'll have to settle for adding the Hallicrafters 12 to my mid-50's blonde room, where 'time-stands-still' (pic)

old_tv_nut 05-11-2018 10:53 AM

Two questions:

Do you invite people to see your Rembrandt? :D


What is the lighted object on the wall to the left of the clock?

NewVista 05-11-2018 10:50 PM

Quote:

Originally Posted by old_tv_nut (Post 3199380)
Two questions:

Do you invite people to see your Rembrandt? :D


What is the lighted object on the wall to the left of the clock?


Wow, you spotted the Rembrandt!

Object next to clock can be identified here

Chip Chester 05-11-2018 11:13 PM

It's not really beer unless it ends with a "Z". ;)

Electronic M 05-12-2018 12:55 AM

Quote:

Originally Posted by dtvmcdonald (Post 3199281)
What we all want to see, or at least I want to see, before I start crying
in my coffee for not bidding, is a raster only, two guns cut off, that has
good purity. I have a theory that might make it possible.

Ask and ye shall eventually sort of receive...Video is still wacky which makes getting a bright plain raster tricky, and getting a pattern to attempt static convergence a downright pain in the but. It would seem the initial recap left several of those lousy chalk peaking coils, and sloppily j-hooked in many of the new caps...I'm glad it is pre-recapped, but some of the workmanship, to put it kindly, is not how I would have done it. Soon I hope to bench it and go over the video circuits. Purity and convergence pics shown below represent my first attempt on a 15GP22 based set. It is a completely different process from every CRT type that followed. Most of the time I felt like I had been dropped in Brittan and asked to drive one of their backward cars on one of their backward roads. Static convergence was off by a mile when I did the purity so if it is anything like a later set then that will affect the purity, and I'm probably going to have to go back and forth between static convergence and purity a few times before it is right (only did purity once followed by one round of convergence). Static convergence is REALLY weird on this set there is the side knob (which gave me a choice of how wrong I wanted it at first) then the static magnets are similar but different from later CRTs...Specifically, there is only blue lateral action from the magnet and the DC convergence knob on the HV cage needs to be used in conjunction (and it affects all three guns)...In summary purity and convergence are sort of decent, but not perfect.

https://farm1.staticflickr.com/954/4...95ced811_m.jpg https://farm1.staticflickr.com/967/4...e165b29c_m.jpg https://farm1.staticflickr.com/959/4...d66f3f5c_m.jpg https://farm1.staticflickr.com/967/4...e91848e7_m.jpg https://farm1.staticflickr.com/911/2...16eeba03_m.jpg

I'll probably be able to improve it more in the future.

For now, I plan to focus on the video circuits...The lumina channel will pass very weak video with the chroma off, but not nearly as much as it should, with chroma up it will get VERY bright but it seems like the color demod is not working correctly...Looking at the clock I should probably sleep and worry about it tomorrow.

NewVista 05-12-2018 09:06 AM

Experienced techs would have been skeptical of the description of this auction item as "two good guns + one no emission" doesn't add up as typical failure/aging. So definitely worth gambling on this item.

As far as vacuum goes, this is another miracle survivor of RCA's ridiculous glass-tin-glass picture tube.

Note to RCA: If Lawrence & CBS can make all-glass color tubes, so should you with your unlimited budgets.

EdKozk2 05-12-2018 09:25 AM

Hi Tom,
Great to see all three guns working on your CT-100.:yes:
Ed

old_tv_nut 05-12-2018 09:47 AM

Wow, next time I want to shake your hand to see if any of this luck rubs off! Congrats on making past the big "if" of a good tube!

benman94 05-12-2018 11:55 AM

Quote:

Originally Posted by Electronic M (Post 3199412)
Ask and ye shall eventually sort of receive...Video is still wacky which makes getting a bright plain raster tricky, and getting a pattern to attempt static convergence a downright pain in the but. It would seem the initial recap left several of those lousy chalk peaking coils, and sloppily j-hooked in many of the new caps...I'm glad it is pre-recapped, but some of the workmanship, to put it kindly, is not how I would have done it. Soon I hope to bench it and go over the video circuits. Purity and convergence pics shown below represent my first attempt on a 15GP22 based set. It is a completely different process from every CRT type that followed. Most of the time I felt like I had been dropped in Brittan and asked to drive one of their backward cars on one of their backward roads. Static convergence was off by a mile when I did the purity so if it is anything like a later set then that will affect the purity, and I'm probably going to have to go back and forth between static convergence and purity a few times before it is right (only did purity once followed by one round of convergence). Static convergence is REALLY weird on this set there is the side knob (which gave me a choice of how wrong I wanted it at first) then the static magnets are similar but different from later CRTs...Specifically, there is only blue lateral action from the magnet and the DC convergence knob on the HV cage needs to be used in conjunction (and it affects all three guns)...In summary purity and convergence are sort of decent, but not perfect.

https://farm1.staticflickr.com/954/4...95ced811_m.jpg https://farm1.staticflickr.com/967/4...e165b29c_m.jpg https://farm1.staticflickr.com/959/4...d66f3f5c_m.jpg https://farm1.staticflickr.com/967/4...e91848e7_m.jpg https://farm1.staticflickr.com/911/2...16eeba03_m.jpg

I'll probably be able to improve it more in the future.

For now, I plan to focus on the video circuits...The lumina channel will pass very weak video with the chroma off, but not nearly as much as it should, with chroma up it will get VERY bright but it seems like the color demod is not working correctly...Looking at the clock I should probably sleep and worry about it tomorrow.

Tom,

That's my old CT-100, well, kind of. The CRT in it is a different one but the chassis and cabinet are the same.

The chassis was sold to me as having been restored and my reaction to the work on the chassis was the same as yours. It was making inadequate HV when I bought it, and was frankly, a complete trainwreck. If I had known how poor the previous "restoration" was, I'd have run screaming in the opposite direction. In addition, every single IF transformer and adjustable coil in that set had been screwed with. I focused on alignment and let the caps go for the time being. I got it to the point where I could get some semblance of a signal through the IF strip and finally got frustrated, shoved the chassis back in the cabinet, and eventually sold it to John. I never did any of the recapping. Given my experience with recapping from this individual in my 630TCS, every single capacitor will need to be checked to ensure it was installed correctly. IIRC, there were also some originals tucked up in there somewhere...

I'm not sure if John did any work with it or not. I'm inclined to believe the chassis is exactly as it was left when I had it. I was able to get good strong audio and decent looking luma through it around the time I gave up on it; I watched an entire episode of the Honeymooners on it and it OK looking. Marginal, but watchable. It will need another check of the alignment. I can guarantee it is still fairly far from usable. As far as I know, the chroma sections on that set never worked post-"restoration".

Best of luck, as you'll need it.

-Ben

Electronic M 05-12-2018 01:13 PM

Thanks, everyone. Ben thank you for giving me some backstory on it. It seems the HV is around 19KV according to my backup HV meter (I still have not gotten to replacing my main meter since it broke). I built a good video injection amp for the CTC-2 family a few months ago so I plan to ignore the IF system completely until the video and chroma are working properly...Even then I probably will need to learn alignment on something else first. The look I had under the chassis was a 2min low light search for peaking coils and rough sizing up of the work on it. I'm sure the pending full exam is going to be interesting.

benman94 05-12-2018 02:58 PM

This is the second time in 12 months that I know of that a 15GP22 has been falsely accused of being a dud. This is why anything I'm interested in gets tested with my modified Beltron. Always test a tube with a tester you're comfortable with and trust, to do otherwise could be an extremely expensive mistake.

Electronic M 05-12-2018 03:23 PM

Quote:

Originally Posted by benman94 (Post 3199434)
This is the second time in 12 months that I know of that a 15GP22 has been falsely accused of being a dud. This is why anything I'm interested in gets tested with my modified Beltron. Always test a tube with a tester you're comfortable with and trust, to do otherwise could be an extremely expensive mistake.

That, in a nutshell, is why I did not bid either of the 21" sets to my limit. I brought all the equipment I needed to vet all CRTs in the sets there, and the ~1-2 hours I had before the auction got eaten by swapmeet so I never had the chance to see for myself if the claims of good and bad CRTs were accurate. I've seen enough bad tubes called good and enough good tubes pronounced dead that I don't like to take others' word on things unless I'm letting go of a small enough sum, or getting enough out of the rest of the set to not care if the CRT is good. I've had several people get but hurt over my not taking their word on CRT condition, but if I'm shelling out a C-note or more and the rest of the set is not worth far enough over the purchase price to make up for a dead CRT then I feel it is only fair to allow the buyer to check the CRT for themselves first...And I'd encourage any buyers of my sets to do so if they feel the need.

Electronic M 05-13-2018 01:14 AM

Success and failure: the tale of two coils
 
The luminance deficiency was the most obvious culprit. The original white peaking coil on the contrast control above chassis had opened...I took the longest, but the most educational approach to finding it: comparing video at various points between my CT-100 and 21CT55 on a scope...I could have saved myself a half hour by following my hunch and putting a DMM on it, but the scope was more fun. :D

That got me a monochrome picture with all the contrast and brightness I could ask for...Turning up the color got me horizontal chroma stripes. Best yet color was actually synching periodically. :banana::banana::banana:
https://farm1.staticflickr.com/981/2...3cce9d4d_m.jpg

This is the only pic I got. I had it making a great picture on a different source when it would occasionally sync. Then I tried to adjust L43 (RCA part 78891) the reactance coil to make the sync permanent. It was sticky but came loose...Unfortunately, it was not the slug that came loose but the coil form and with it the wires that connected it to the terminals. leaving me with the osc. way off sync but still working. Once I realized what happened I removed the coil and tried to free the slug. Sadly the cardboard form was too brittle, and also ~1/8" of the very long slug chipped off...I managed to grab a similar form and rewind the wire, but it will not oscillate with my repair...I'm kind of up a creek presently.

Only thing I can think of is a CT-100 parts chassis....Or there is a very slim chance that coil may have been used in a 15" Dumont color monitor carcass I acquired recently. The Dumont is missing CRT/deflection hardware, flyback, and other things, but it seems to be CT-100 based. The Dumont's HV cage (what is left of it) appears to be exactly the same as that in a CT-100 as do the purity and field neutralizer coil connectors...If I'm lucky it uses the same reactance coil too...But then again I would like to make the Dumont work again someday and hacking it up for parts does not sit well with me.

After brief success, I'm back to monochrome again.

dtvmcdonald 05-13-2018 08:37 AM

Well, I'm now crying! That price for a good 15GP22!

You'll eventually get the oscillator to oscillate again. Coils at 3.58 MHz
can be rewound, you;ll eventually succeed. There are parts chassis around.

That color bar picture looks exactly like the one I first got on my set. Good
luck getting the red and magenta balancing well with the other colors.
Beware of AGC setting and color level on the modulator.

EdKozk2 05-13-2018 05:26 PM

Hi Tom,
I was thinking of any easy way for you to fix or replace your broken L43 coil. You could use an old 4.5mc sound coil. You would have to add some more capacitance in the tank circuit. Increase the 5pf to get a center frequency of 3.58Mhz. If you have an inductance meter, maybe you can measure your broken coil if it is still intact.
Ed

old_tv_nut 05-13-2018 05:56 PM

Using a coil that resonates with a different size cap may work, but it's not the best idea because it will change the strength of the effect of the AFC circuit and therefore affect the stability of the pull-in as temperature changes, etc.

Better to get the right inductance and capacitance.

Pete Deksnis 05-13-2018 07:59 PM

Quote:

Originally Posted by Electronic M (Post 3199470)
This is the only pic I got. I had it making a great picture on a different source when it would occasionally sync. Then I tried to adjust L43 (RCA part 78891) the reactance coil to make the sync permanent. It was sticky but came loose...Unfortunately, it was not the slug that came loose but the coil form and with it the wires that connected it to the terminals. leaving me with the osc. way off sync but still working. Once I realized what happened I removed the coil and tried to free the slug. Sadly the cardboard form was too brittle, and also ~1/8" of the very long slug chipped off...I managed to grab a similar form and rewind the wire, but it will not oscillate with my repair...I'm kind of up a creek presently.

After brief success, I'm back to monochrome again.

Check L42 for continuity. An open L42 is often the cause of 'loose' chroma sync in a CTC2 chassis.

Pete

bgadow 05-13-2018 10:18 PM

FYI, RCA 78891=Meissner 17-6015. I did notice, while checking some Photofacts, that the 19CK1 uses the same part, and I suspect others do as well.

Electronic M 05-13-2018 11:43 PM

L42 was changed sometime in the previous owners' restoration(s).

L43 mesiner 17-6015 (thanks Bgadow for the cross-reference!) turns out to also be used in the Dumont monitor carcass I got at the ETF...Can't say I feel good about taking parts off of it, but others have done that enough in it's history that I'll need a parts chassis to get it working anyway...In picture form I pulled this coil from this chassis to fix the CT-100.
https://farm1.staticflickr.com/903/4...4abe2f28_n.jpg https://farm1.staticflickr.com/826/2...6a3048bb_n.jpg

Color synch held for 30 min and only wavered on a VERY saturated scene.
https://farm1.staticflickr.com/946/4...8ef98f60_n.jpg https://farm1.staticflickr.com/906/4...3c5c9d8d_n.jpg https://farm1.staticflickr.com/964/4...bf2f93de_n.jpg https://farm1.staticflickr.com/943/4...868a8351_n.jpg

Chip Chester 05-14-2018 07:28 AM

So as an aside, what is your picture source? As digital, then ATSC came onto the scene, the definition (or common practice) of 'legal' colors and black levels has changed a bit. And if you're converting from HDMI, HDR will really tax things. If you're using 'old' recordings (VHS/Beta) or a proc amp in conjunction with your modulator, or if it has one incorporated within, it may not be an issue.

Electronic M 05-14-2018 12:36 PM

I haf many sigi-nal sauces. :D
https://farm1.staticflickr.com/944/4...7926c8b6_n.jpg
That is the main rack in my room. Bottom-up there is U-matic, LaserDisc, HDDVD, Bluray, DVD-recorder/VHS, DVR/DVD-recorder, 2 S-VHS-ET decks, CED/selectavision video disc player, SuperBetaHiFi, AV switchers, PC with S-video out, ATSC box, Blonder Tounge agile modulators configured to transmit, and hidden to the side a pair of mini cable boxes and a Roku. Before the ETF I tore apart and rebuilt/reconfigured all but the agile modulators on top to fix the flying spaghetti monster that it had devolved into through 3-5 years of not really properly reconfiguring it when needed but instead hacking on to the front accommodations for the switch to digital cable, the addition of HDMI for my HD-CRT Sony, and a bunch of other stuff.

Basement rack is a Blonder Tongue, VHS, Beta, CED, Cable box and a fairly literal bunch of video game consoles (also have LD and other crap waiting to be added to it when I get around to rearranging that cluster)...

Colorbar path consists of upstairs DVD transmitted, then tuned in by the VCR in the downstairs rack and retransmitted (the upstairs rack is hard to tune in the basement so this is the easiest workaround), then tuned in again by the VCR that feeds this video injection box https://antiqueradio.org/VideoAdapte...Television.htm

The TV program path was much simpler cable RF out from cable box (it only has RF for analog output) to the tuner on basement rack and onwards like the other path.

The CT-100 shall live in the basement close to my workbench until I am satisfied enough with its performance to make it a spot in one of my upstairs display rooms.


All times are GMT -5. The time now is 11:11 AM.

Powered by vBulletin® Version 3.8.4
Copyright ©2000 - 2026, Jelsoft Enterprises Ltd.
©Copyright 2012 VideoKarma.org, All rights reserved.