If someone has a junk CTC19 or a CTC24, the color circuits are the same.

All bets are off. No time frame now, so don't rush. You don't need to rush your self on the 16 or the 20. I'll wait. I don't want to have to sit and worry that fly is going to melt inside it's cage and or burst in to flames if I don't shut it off after under an hour of use. OR the Fly is just going to go KERPOOF after a couple uses and leave all your hard work moot with a dead set. Unfortunately, I'm not able to, or willing to fork over another possible $250 for a "good" flyback plus your labor on that set if that flyback ends up killing it self. That set's future is hanging on it's flyback.

Take. Your. Time. As much as you need.

Feel free to drill and open the cage anyway you need to look inside and see what the fly is doing or aid in cooling it. I'm willing to bet money on that arcing issue, either internally or externally, silently. It's burning the tire in the same exact spot that the videos on youtube. It seems like a simple thing, it's just a bunch of windings inside there, and look at how his was arcing and melting it self, but still worked and keeps working after. Mine is working decently except getting hot with no real explanation and melting the tire in the exact area he mentions in his two videos. I think it's arcing inside the tire and melting it.

Like I said, if you think my fly is sick and I think it's arcing, peel it's tire off and look inside, then seal it back up with RTV. The stuff is only like 4 bucks for a large enough tube to cover the whole flyback. I use Grey all the time, I just used it last week to replace valve cover gaskets on my Ranger.

Looks like it was arcing on the back of the tire.
http://i1095.photobucket.com/albums/...psihv5aclu.jpg http://i1095.photobucket.com/albums/...psclgzu2ey.jpg

I wanted to duplicate the arcing behavior so I ran it 20 minutes, and forgot the mirror inside....When the symptoms came back they were fresh ones from the mirror falling between the 11'oclock outer edge of the fly and the cage. Mirror silvering is conductive so all it had to do was melt the plastic edges of the mirror.... After removing the mirror it wanted to arc from the mirror contact point on the tire so I ripped enough off the tire to help, and put a piece of plastic (seen in the last tireless shots) in there to block the spot in the cage it wanted to arc to.
http://i1095.photobucket.com/albums/...psoxp8l7pk.jpg

I then ran it for almost 2 and a half hours watching it closely, and periodically putting my ear next to the cage to listen for bad noises in hopes the blackened back top of the tire would arc to prove my theory that it was the cause of yesterday's 1 hour arcing.....Nothing happened in those 2+ hours! It worked fine. The tire was warm at the end and some external wax was on the edge of melting/slightly melty, but the only reason I had to shut it off was because I was summoned by the folks for a menial task.

I pulled off the back charred section, and came to the conclusion the tire was so loose it might as well be removed entirely. I'll get some silicone tomorrow and give it a new coat.

http://i1095.photobucket.com/albums/...pssfdmdksb.jpg http://i1095.photobucket.com/albums/...pszbifvg27.jpg http://i1095.photobucket.com/albums/...pswclhvw71.jpg http://i1095.photobucket.com/albums/...psx1h6q8dt.jpg

Here is what I got out of the 20 last night, but forgot to post. :tongue:
http://i1095.photobucket.com/albums/...pslurjmgtz.jpg

Thanks for allowing me time to get it right. I have been pushing to get it done since there is other stuff (my stuff, and others') I want to work on, and honestly I can see why you were/are not a big fan of this set....I'm sort of tired of pouring my energy into it only to find the next thing or get lack luster non-proportional improvements.

It's darn fascinating working on these chassis and seeing what they are all about compared to others I've seen/worked on, but now my curiosity is sated and from this experience I can say I don't think I'll ever actively seek out another CTC-16 or 20....These sets remind me why I'm (mostly) a Zenith man.

Looks like my theory and hours of watching Shango's videos paid off.

Remember to peel off that beige silicone stuff that he removed in the second video to make sure there is no carbon tracking on the fly it self behind that gross stuff.

Go to the car parts store and get the Permatex UltraGrey. Automotive RTV lacks the acids, as Shango mentioned in the videos, and it can withstand very high voltage, is completely non-conductive. And it can stand up to very high temperatures.

Yeah. Now you see why I passed it on to you for repair. I bought it thinking it was working well and would be simple to keep going. In reality it was very sick and in very bad shape internally and it needed a lot more work then I knew how to give it...

I'm super excited to see it working again and look forward to seeing it in person once it's complete.

I'm glad to see the CTC20 has life. If you can fix or source those coils, I bet it'll come back to life. It's a fairly nice set honestly, I wish it had better care when it was being stored so it would have survived better. Makes me feel even better that it works, you'll get the cash you asked for. You got a Roundy that works with a good CRT and a lot of potential, and a couple other bonuses I am tossing in for all the time you put in to this thing for me that I think you'll like =)

This may be interesting to you, Tom.

http://www.videokarma.org/showthread.php?t=254649

I found the original thread from Colin when he found the CTC20 back in 2012. It looks like the TV worked pretty well. I would try and bring it back to life if I were you. If you can't fix those snapped off coils, I would try and source them.

If down the road you decide to sell the CTC20, I'll be first in line to get it back. I actually find it to be extremely attractive. I'd make the space to have it with the CTC16 =)

Kellogs frosted fly
 

I got the old silicone off and recoated the fly for the CTC-16 on Saturday. It went well, and aside from the rubber tire being charred/bubbled there were no scorch marks or carbon tracks to be found (the old silicon and fly paper were fine).
http://i1095.photobucket.com/albums/...ps0qt22sf6.jpg http://i1095.photobucket.com/albums/...psrdlqupoy.jpg http://i1095.photobucket.com/albums/...psfytwlplj.jpg http://i1095.photobucket.com/albums/...pspwofhwxc.jpg http://i1095.photobucket.com/albums/...psdnfeojma.jpg
http://i1095.photobucket.com/albums/...pso9swbuzc.jpg http://i1095.photobucket.com/albums/...ps4a2w4bt7.jpg http://i1095.photobucket.com/albums/...pstdxliusp.jpg http://i1095.photobucket.com/albums/...pssgsptye4.jpg http://i1095.photobucket.com/albums/...psnyuan3gv.jpg

I decided not to smooth it since a rough surface has more surface area, and thus should cool better.

I gave it about 1.5-2 hours run time with the silicone still soft (which cured it nicely), and it ran like a champ the whole time.

Then I got sidetracked till last night upgrading my laptop to Windows 10 (long story).

I gave it another hour and 40 minutes on. No, arcing, no wax ooze, but the fly does get rather warm...I want to try and find some time to put 3-6 continuous hours on it to see how it holds up. When I can I'll get some heat sink compound for the fly to chassis (may also squirt some between the windings and core). I'll also try to add some vent holes and a fan to it, but I gotta figure out where and which fan (the best side to put a decent sized fan is against the side of the cabinet, and not usable).


I worked on the 20 today. I resoldered the busted coax to the color level control, and resoldered the snapped off chroma transformers.....It came on, a moment later I hear a snap and the vertical fills out.:thmbsp: Then I proceed to adjust what I believe is the chroma osc. transformer and start to get color barber-poling.....Then another snap, raster is lost, and smoke from the area of the chroma osc. transformer. I swap the two leads I guessed the connection points to, and try to reassemble it, but the bottom has melted/warped to the point where I'm not sure that transformer is worth fixing anymore....The vertical relapsed to not filling the screen too. That CTC-20 is a real mess.

I think I'll work on something else for an hour or two to get a break from RCA color work.

Heat doesn't cure RTV, only exposure to air and time. Room Temperature Vulcanizing. Heat may open air passages (tunnels) within the RTV, which is why the DoD bans heat application to RTV products. If you are trying to seal up something, why heat it and create tiny tunnels?

Now epoxy, yes - heat that stuff! It shortens the cure time, and makes bubbles trapped within to pop, making for a better cure. But RTV, no.

I think with the CTC20 it's going to come down to sourcing good replacements for those two transformers... I wish better care had been taken when it was stored disassembled. I like the style, I may wanna buy the set back, so I'd be interested in helping seek the parts.

I'd almost be interested in coming up there and learning from you while you work a little. Learn the basics I'm missing from you, that stumped me so endlessly with the CTC16. How to read and test resistors, check voltages properly, test capacitors.

As for cooling the CTC16's flyback, I was thinking of putting a small, low voltage brushless computer fan on the bottom of the right side of the flybox (Facing it with the back of the set off), blowing in on the transformer, with a vent hole on the top left side to blow the heat out. It would only take a low voltage wall-wart to power a computer fan, which could easily be wired to the TV's cord and switch, so when the set is switched on, the fan powers on. Brushless computer fans are very quiet and move plenty of air. I have several plus several power supplies laying around that'd drive it perfectly.

I'm going out of state in a few days and I'll be gone until December 10th. so while I am gone, feel free to watch and enjoy my CTC16 all you like. Besides the warm flyback, I would certainly call it done.

Windows 10 sucks so far. If you want Windows 7 I have an unlocked installer that I can give you that updates it self and is fully featured. I'm giving you a pretty high end business grade dell laptop as a bonus for all the work you did on the CTC16. it'll have Windows 7 Professional installed on it and I'll include a DVD of the reinstall stuff for you.

Having worked in the Automotive Industry for the last 11 years, and having sold parts for the last 3 years, I feel I can step in.

You're right, heating it will create bubbles, but UltraGrey, UltraBlack, and the more modern RTV's set up with in an hour of being applied, and cure fully with in 24 hours. It can be placed in to service with in an hour.

Also, we're talking about a hot engine block, not a paper & wax flyback transformer in a vintage television. The flyback doesn't get nearly as hot as an engine. It's heat did nothing to aid in making bubbles, or curing it any faster then it would cure anyway.

I requested he used UltraGrey because of that reason, and because I have had amazing personal success sealing up leaky Flybacks with it before. I keep a small tube in my toolbox. Sony Fly's are notorious for splitting in the center of their hard plastic "tire" and leaking out high voltage and arcing. I just slather a little UltraGrey on, let it cure, and the voltage leaks are gone.

Just my two cents. You are 100% right, it will have that issue on a smoking hot engine, but a warm flyback won't effect it in the same manner.

And I've used RTV many times for corona prevention before - but conductive tracking does occur, and only at high voltages - where the RTV was heat cured and paths for corona were created.

I've serviced TVs since the 70s, dealt with corona and arcing in 55KV AWG-9 radar transmitter power supplies, 16KV Conrac monitor power supplies, and solved many problems with RTV. But in my humble 30+ years in electronics, I've seen RTV'd flys fail just as often as the originals, and mostly due to the carbon tracks - their death certainly created by heat or disturbed curing. RTV has such a strong dielectric strength that 1/20" will seal against corona in a 50KV system, but one tiny (electron wide) hole is all it takes to fail. Patience and curing at room temperatures, with no disturbance for the allotted time is all that is needed for success.

Now with ATS (Activation Temperature Sensitive) silicone (similar to RTV) products, the crap won't cure without heat, and at a prescribed temperature. I've use it as well - aerospace stuff - we can't afford it - but take some good old RTV3145, the good grey stuff, simply apply and let it cure, no heat. No reason to bake out bubbles that leave a tunnel behind as they head for the surface, setting up a corona/burn path....

Remember, we're trying to save flybacks, not guarantee a kill....

But i digress, it's not my flyback.

I have my fingers cross that Tom did it well and no tracking happened.

You like the CTC16 chassis. Do their flybacks normally run a tad on the warm to almost hot side?

Warm to the touch. I use the back of my finger to test. I can hold my finger there for as long as I want, not hot.... Too hot, and you've got any of the problems I mentioned in the other thread.

Only RCA flys that ran hot were in some of the 19" tube portables - the pulse regulator sets, as we called them. The load vs size got them hot, but I can't recall one ever failing. We used one as a loaner and the only problems were usually related to the 5GH8s. Too unreliable to sell, so we kept 'em for loaner sets.

I like all RCA color sets, up to the CTC175, and any with a MST/MSC module....

The CTC16 was RCAs largest-selling tube sets, with the exception of the CTC38 (another flyback eater, 119834), IIRC. The 16 was extended in the CTC16X, so those numbers were thrown in too.
Somewhere in Google books is a book about Japanese dumping, and the EIA production numbers for domestic sets from 1964 to 1970, by brand, is listed. RCA creamed the competition in the mid-60s, but Zenith and others caught them by 1970, through initial quality and features. We sold and serviced RCA until 81, then it was just servicing. Mass merchandisers were selling sets cheaper than we could get them from RCA, but we didn't buy entire railroad carloads at a time either....

Back to the flybacks - read the service clinic articles in Radio Electronics and Electronics World magazines - authors such as Jack Darr, Art Margolis, Carl Babcoke, and Homer Davidson - these guys were servicers that got to write about it, and dogged many a chassis to find the unlikely culprit. But Darr and others also wrote about prevention of problems (callback avoidance) and how to get a set healthy for the long haul. Not too many specifics, but enough generalities to get a sense of what to check....all of their stuff is over on AmericanRadioHistory - the search engine is wonky, so try different combinations to find what you are looking for. Oh, and the January Issue of Radio Electronics in the 60s generally was their "Color TV" issue, with more articles on Color TV than the rest of the year's issues....

Here's just one service clinic, this one dealing with Boost voltage, but in the artilcle, Jack Darr gives up some info on HOT current and why it may be high:

http://www.americanradiohistory.com/...-Page-0070.pdf

Boost cap leaky or shorted, or a shorted winding in yoke - both can cause HOT current to increase, and cook the fly.

Here, the biggest killer of flybacks and yokes was heat and humidity, something our region has plenty of during the summer, when the TV was used as a babysitter for the kids. "The kids said it went fuzzy, then white, and then it smoked. They said they didn't touch it...." Dead give away, either a bad fly, or a focus rectifier stick gave up the ghost.

Findem Keepim: I did give it around 15-25 min to dry before reassembling the cage and running it. I've never needed to use a caulk or corona dope to fix an arcing/corona problem before (previous issues I've dealt with were solved by cleaning dirt off insulators and or replacing bad HV wire). I only ran it that way because in the youtube videos by Shango66 that Arcanine pointed me to for reference Shango66 seemed to do the same thing: remove old material, caulk and turn it back on with the caulk wet....I'll remember to give it more dry time next time I need to do this. Wish I'd known before I did it....

The issue with fly warmth is that the cathode current is on the low end of the range. I don't think it's exceeding the back of the hand contact rule, but it still bugs me how warm it gets.

If you want to buy the 20 back from me later I'd be open to that. If you want to come over and work on stuff with me some time I'm cool with that.

It did not look like there is a enough clearance between the side of the cabinet and the side of the HV box for a fan, but I can recheck. A separate PS is not really necessary. It's fairly easy to rectify the set's heater line, add a filter cap so the fan sees clean enough DC, and a small user fan switch in a discreet place.

The laptop sounds awesome! :thmbsp: I have my own windows 7 install disc that I've used with several machines. The 10 installation was a free upgrade from 7 on my school machine, and most of the time spent was preparing the Win 7 OS for a drive image backup (closing/saving the mountain of open stuff that being on for a few weeks-months straight accumulates, moving files to external drive to shrink the size of the backup image, defragmentation, run anti-virus, etc.). With the drive image backup I can go back to Win 7 anytime, or throw the image on another drive and go between them by drive swapping.
I like Win 10 so far. The back end is better programmed and it runs better/faster on my laptop than 7 did. There are a couple of things about the look of the taskbar I dislike, but I'll fix or get over them. I also hate the change in mouse commands for photo viewer (makes reading Manga a PITA), but there should be ways around that.

BTW: I got that little Admiral going last night. It was the ion trap that was extinguishing raster. It has a funky intermittent in the tuner (I believe) that kills all reception, but it can be persuaded to work. I recapped the IF board since that was easy with the back off. It is rather dim yet so I plan to test the CRT.
http://i1095.photobucket.com/albums/...psvljxhr1w.jpg

Quote: "The HV rect tube is a RCA 3A3C the chart calls for a 3A3A....I seem to recall once reading that some variants of that tube caused arcing in the CTC-16, but I can't recall it exactly or find it....Could that be the cause?"

There seems to be some variance in the height of the tube(s) and the "C" versions may be somewhat shorter, causing issues with the tube contacting the top of the flyback. There should be enough slack/adjustability in the top cover as it sets in place but good to verify.

Any updates on this? My DM's not making it though?

I'm starting to miss it~

It is basically as I left it in the last post (started other projects and left it as is). I tried to unbolt the fly to put heat-sink compound between it and the chassis for better cooling, but the bolts holding the fly are stubborn, and after trying every safe hand tool I have and penetrating oil with no results....I decided I rather not do it than start trying things that might risk damaging the flyback. I probably should look for a high line voltage tap on the primary of the power transformer and if there is one connect it...I did not install the cooling fan (but I'll give you some fans, parts and advise if you want)...I should also try to make a line bucking transformer for you...

I sent you a PM.

The line voltage tap is easy to spot. It's on a terminal strip under the chassis, right under the power xfmr area. Look for a terminal with only one wire and nothing else going to it.

I have looked into cooling fans. The only set I have one on is a CTC-5 due to the rarity of the FLY. One thing to remember about vintage TV's do NOT leave them on unattended, even for just a few minutes. They are WAY past any expected use date and the flys were an issue even back when new. The concern I have over forced air cooling is IF the fly still manages to overheat, you will have a blow touch on your hands. The flys tend to be in a confined steel box I presume on reason was safety, as in fire containment. Adding the fan pumping oxygen to a burning lump of tar will really stoke the flames.

5 flybacks are super easy to find, I have one here you want it? It's the 4's and 21-CT-55's that are near impossible to replace, in fact I'd take the fly out of my Wingate and replace it with one from a 4 if I had one to spare. A Wingate with stiff HV would be a super nice set to watch, too bad they made 'em wrong from the jump.