Picked this up today, details later...

oh thats a nice one ,it would look better at my house though:thmbsp:

SUPER!!. Oops, I mean DeLUXE!!! happy for you! :yes: :banana:

Awesome score! Nice job.

oh thats a nice one ,it would look better at my house though:thmbsp:

No, Dammitt, I think it'd look better at MINE !! (grin)

Wow. Diamond in the dust. :thmbsp:

A very nice find. I like the cabinet.

This must be CTC-5 week.

Trade ya for my Maple finished Wingate? Nice set!

Where did you get that,being in Florida?

its going to be a while before I get to it, still in the back of my truck. I want to finish up on that GE roundie before I get into another set. Maybe in a couple weeks before I can get any more details on it. Between this one and the 2 other 5's I have (both are pretty ruff and I have not touched them so don't know much about them), I am pretty sure I will be able to get it going. My next oldest nice set is a CTC-9 with a good 21CYP22 so it would be nice to have something older. I like the sets with the doors on the front, nice protection for the CRT's.

:banana::banana:Hey I had a ctc5 I sold earlier this year sometimes you have to let it go for something more important I did get a ctc 16 but the crt is broke hope I can find another crt for this set:tears::tears:

Great score! That Wingate is very nice looking, where did you find it? My Wingate is on the NEVER sell list, they are just so pretty, it's the best 5 you can get IMHO:D I hope your 21AXP22 is good. It took me about 3 years to find a good one for mine but it was worth it to keep it un-modified.

Awesome find!! I like that style cabinet! :yes:

Where did you get that,being in Florida?

I wonder if it migrated south with a retiring couple who may have bought it new. Wouldn't it be a gas to find it was purchased on Radio Row?

http://www.nyc-architecture.com/GON/GON031.htm

Dave,

Welcome to the Wingate club. Seems a lot of this model were sold and are turning up. It was RCA's most expensive CTC-5 model. I have the Maple finish but have also owned a Wingate in the French Walnut finish. Very nice find.

-Steve D.

No, Dammitt, I think it'd look better at MINE !! (grin)

no it wouldnt, i have a place special picked out for it.:D

no it wouldnt, i have a place special picked out for it.:D

But I'z gots more rooms to puts it in so I's can finds the perfect spot.:D

I think it would look great displayed next to my CTC5 Chandler :banana:

Would look even better next to my Stanwyck. :)

:wtf: :worthless:

Well, I think it WOULDN'T have a hard time finding a new home if he ever decides he don't want it no more...(grin)

:thmbsp::wtf: :worthless:

ok this one is next...

went ahead and pulled the chassis. do not see anything burned up, the PT has continuity, no B+ rail is NOT shorted, but one fuse was open (one of the two mounted on the top of the chassis.

tube sockets and pins show rust, hope the humidity will come out of the flyback. I have it inside now so hoping the AC will begin to dry it all out. Its going to be a while before I work on it but at least I have something t look at while hand heals up.

I still don't get how the CRT removes, it looks like there are 4 bolts on "fingers" that engage the plastic cover. I will re read the service manual when I get that far. The yoke plastic is disintegrating, but I think I have seen folks post on a fix for that.

Beautiful set. Hope it works out to be a great playing one

I am tempted to pull the B+ fuse and see how the PT checks out...

oh man you brought this post back up again ,i had forgoten all about it . now we got to start over again of who's house it would look the best in.

its going to need a bit of work, besides the busted CRT (guns looked perfect), no back, its also got some rot on the bottom of the feet maybe 3/4 inch. I am thinking either cutting off and grafting on some new back feet (the front is ok), or trying some of that epoxy fillers. Also missing the door pulls (I have the top but not the main door pulls). I was pretty pissed when I say the busted CRT but that's the way it goes sometimes....

did not have my metered variac handy I decided to throw caution to the wind and plugged it in. filaments came right up, B+ at the 5U4 cathode (fuse out) was 412vdc so so far so good. there are a bunch of paper caps so it would be pointless to go any further with out replacing those. I will check the filter caps, they are mostly single or two sections which is nice. I will take them out of the circuit and see how they check out for leakage, reforming them with the cap tester as I go.

No, Dammitt, I think it'd look better at MINE !! (grin)

your mistaken, it would lok beter at MINE! MINE! MINE!:D

pulled the chassis cover off the bottom of the chroma section (this one has that done point to point not PCB) yikes a bunch more wax paper caps. I can see this is going to take a while. One of my other unrestored 5's had a PCB for the chroma section. interesting that they are both considered 5's this is not a minor difference (at least in construction, maybe the circuits are the same).

there is a lot of wax film on on the PCB from the caps that must have oozed wax which then flowed all over the PCB. Normally I don't bother to clean them but these are so bad (wax film with dust captured) that I cant read anything. So I spent a little bit of time to clean up the boards.

well the 1st power filter cap was badly shorted, so I don't think I am going to waste any time on this. All the cans are very easy to get at with the bone saw so they will all get zipped off and caps installed from the top. using this process leaves all the orig lead dress undisturbed and is very very quick. 4 cans would prob take me no more than an hour to do if I get it all setup ahead of time (have all the caps on hand).

well I only have enough of the correct caps to do 2 cans, so I will be going over it and making up a list of caps for the whole set for order, then I can sit around and stare at it while recouping on the hand....

I should prob order enough to do all 3 of the CTC-5 chassis just to cut down on the shipping cost. would be nice to have 3 working chassis.

in my desperation to do something went ahead and cut the cans off and drilled the bottoms with my pin drill. Installed the caps in two of the cans.

while putzing with it I noticed what looked like a mod in the contrast circuit, a 68ohm resistor/cap tacked in between point "T" of the video board to the contrast, also the contrast pot has a 50uf cap and 1k resistor (like a cathode bypass setup). It would seem this is some kind of mod to the video amp tube cathode bypass.

I did that mod to my 5 and made a huge difference. Before the mod, when the contrast was turned up, the HV would drop out and the picture would dim and blur. Link:http://i184.photobucket.com/albums/x293/bgadow/ContrastMod.jpg

I see this chassis still has its HV box cover. Very nice! It seems that nine out of ten CTC-5s have no cover.

that is the circuit, thanks for the link :thmbsp:

I must be lucky, mine has all its covers.

been no progress due to hand surgery, but I did manage a little bit of work just before.

1st pic if two of the completed can caps.
2nd pic is just some of the cleaned up PCB's so I can see what I am doing
3rd pic has the bone saw used to cut off the cans right at the shoulder and the pin vise used to drill the holes from the bottom side up. Drilling from the bottom lets me get the idea spot for the hole. One hole right by the pos terminal and then the other hole right by the soldered twist lug. Doing caps like this lets me use the cheaper radial lead caps and leaves the lead dress undisturbed. You just need to clean well so the solder will flow.

I'm diggin those 82@450 lytics... they are pretty skinny compared to the ones i usually get... so it looks like they fit nicely in the cans. Where did you get them?

thoughs are pretty cool looking ,make good fit in a restuffed can.

Those are the new ones that Mouser has, yes the fit very well, are 105c IIRC they are 12mm wide, you can get a 4 cap can done no problem.

The main thing is how fast you can do a can , those 2 can caps take 10min tops from start to finish, figure about 5min tops per cap. Its much faster than my old way of removing the old cap, and prob as fast as doing under the chassis installation if you take into account good wiring practices (like term strips, no flying lead stuff). I would say its faster than if you had the correct twist lock can since you do not have to unsolder anything.

did the remaining two filter cans, very easy method again. going to lay off it for a while now, then will get on the paper caps. There are quite a few that are point to point (the chorma section is NOT on a pcb) On those I am prob just going to go pig tail method. The tube sockets are not the best quality and I don't want to goof them up trying to unsolder. The others on the bottom have some coils involved so again pig tail. I know some purest think this is sloppy work, but I think its less invasive, and since I have no way of determining the operating status, I dont want to create a problem.

On those I am prob just going to go pig tail method. The tube sockets are not the best quality and I don't want to goof them up trying to unsolder. The others on the bottom have some coils involved so again pig tail. I know some purest think this is sloppy work, but I think its less invasive, and since I have no way of determining the operating status, I dont want to create a problem.

I do this, for this reason, all the time. Just have the pigtiled lead follow the same pattern of lead dress as the old part had. That is, keeping the splice a straight path and not creating a bent pattern.

TV repairmen of the day would do this, they didn't want to spend extra time on a job, and also didn't want to risk breaking something.

ok all the wax caps under the chassis are now done, just a few on the pcb that mounts on the back and then on to the rest of the PCB. I replaced the 2 .47's in the flyback cage, dusted it gently, it "looks" ok for whatever that is worth.

By doing all the Point to Point stuff 1st it the hard part, the PCB caps are a cinch.

I do as you said, keep the part in the same location and keep the lead dress as original as possible. Had no breakage of parts in the recapping.

At this rate I would hope I can get the balance of it done before next weekend.

I typically do the pigtail method as well. If I had a CT100 or a 16CK1, I would take the extra time to completely desolder the original part. I don't feel like I do a very good job desoldering... especially when many parts are soldered to one point... so the pigtail just seems more practical for me on common sets. On occasion, I will unsolder the original part if there's plenty of room to work and little chance of me screwing something up.

progress

I typically always pig tail to coils, and will take the time to remove if its to a term strip as long as it does not have a bunch of other stuff on it. I also generally always pig tail to mini tube sockets. I large tube socket has an easy to get at term with out a bunch of stuff I will generally try to not pig tail, but if its at all hard to get at I will pig tail. I comes down to ease and fragile.

To keep is simple I just ordered a bunch of 1.6kv and 1kv for .047 and .01's. there were a lot of them, and the larger HV caps fit better to the orig part locations.

I found this somewhat helpful. I got the orig doc from ETF, the cut and pasted into excel. the cap numbers are cross ref to the schematic. I print it out and used a marker to clearly ID the caps on the board layout. Just a double check to make sure I don't goof anything.

two more caps to go on the audio board, then the video board. Sure looks a lot nicer with those shiny new caps :yes:

I am going to need to find some new coax, one of the lead is rotten out to a pot.

all done. the two paper caps on the video pcb were a PITA to get at, the solder pads were under the delay line, but I got them done. So all recapped now. I left the few orange and brown drops alone for now.

Next up I will sweep the resistors looking for any way out of whack, then will test all the tubes for shorts and emissions. After that I think I will be good to go for a power up. Will check the B+ rail for shorts 1st if thats ok I will do a full power start, no need to variac it since I have all new filter caps and 5U4 rectifiers anyway.

oh forgot the dumb coax, will have to get that worked out 1st before I do the power up.

all pcb done

fixed the volume control coax lead. So its all good to go. Now I just have to pull the chassis out of the donor set (leave the CRT in it for now) and slide this one in for a test run. Prob be in the next couple of days. (oh after checking the tubes duh...)

Sounds good. We'll be 'a watching...

the few caps I did not change were the domino types, there was at least one large value 1000pf on the horz board. I figured I would leave them be until I test it and see if there is an issue. This thing sure has a LOT of paper caps.

A quick pass did not turn up any faulty resistors. I did have an open fuse the .75amp on the top. I did not have the correct fuse type, so I rigged up a in line fuse holder that uses the blown fuse as a plug, and lets me use the more common stye. Just a temp fix until I get the correct fuse type. There is a B+ fuse, a HOT cathode fuse, and I am not sure what this one is for its a bit confusing on the schematic, seems like its tied into the yoke/vert out/damper circuit.

so whats the deal with the yoke plastic?, I seem to recall this being a problem and there being some easy fixes using common plastic parts. Mine is turning into a white mess.

one shorted 6EA8 AGC and sync amp, Schematic shows a 6U8 a quick check shows that as a sub
weak 6LF8 1st video and noise inverter, schematic shows a 6AW8 a quick check shows that as a sub
getting tired still need to check the chroma and video amp, the rest look ok.

Yeah that yoke plastic sucks, doesn't it?! I've got a few sets that have that issue... or simply a lack of plastic to hold it all together in there. I notice that Motorolas of that time period seem to always have this issue (as well as Motorola knobs).

Bob has section covering this on his site at http://antiquetvguy.com/Web%20Pages/My%20Methods/Replica%20Yoke%20Covers/ReplicaYokeCovers.html

all tubes checked on the chassis, did not check the tuner tubes, and did not replace any paper caps on the tuner (I think there is one). So hopefully I will be able to do that tomorrow, then maybe Sat I can give it a try :yes:

I replaced the one 6EA8 with the slight short and a 6LF8 that was shorted a bit harder.

got raster, then pic and audio, but the pic looks like its got an agc issue or a sync sep issue, (vert and horz sync are soft). HV is right around 20kv but that is thru a 100ft cord AND a isolation trans that can barely handle 3amps, so I am hoping at full line voltage it will be up a bit. I did not see if the HV adj did anything. the tuner has a paper cap so maybe that is an issue, I presume its an AGC filter cap. I will start by replacing that. I did not fiddle with the AGC pot so of course that could be it as well. If neither of those work out I will try a composite video feed. I need to back and review the AGC setup.

Its coming along...

hmmm I seem to recall cleaning the pots up front, so I bet I just need to reset the noise/agc, but too tired to fool with it any more, so back on it tomorrow.

AGC pot has no effect what so ever. So I think I will start with a simple AGC bias and see if that clears it up. If so I will dig into the AGC circuit. I just hope its not a feed back pulse from the fly back that is missing.

Even though the bias did not seem to work I still think its got to be in the AGC circuit, just cause the agc pot did nothing. But will get the scope out and look around. will start at the plate of the AGC tube looking for the keying pulse. Will also look to see what the signal to the sync sep looks like going in and coming out. I suppose the smart thing would be to try new tubes there 1st.

Hi Dave:

Where did you get the skinny electrolytic caps you used to replace the former FP cans? I've never seen high volt electrolytic caps like that before. :scratch2:

Its a new cap that mouser carries. They work great for inside can stuff.

I have been thinking about it, I am betting its something to do with the noise inverter. The agc does something just not much, and if the H sync is off, the AGC is of course not going to work right since the keying pulse will not match up with the sync tips.

put a new 6U8 in place of the 6EA8 that was there, (sync sep) fixed the sync and now the AGC works as it should. Only thing left is to setup the purity (screen colors are all over the place with HUGE convergence issues), but its coming along.

I did not even touch the convergence magnets so that should help some, but I still need to fix the yoke plastic AND move the CRT to the new cabinet.

oh so there are no PM for static, instead there is DC pots, thats something new to me. I can see how this should be easy to setup with evey thing out front.

oh so there are no PM for static, instead there is DC pots, thats something new to me. I can see how this should be easy to setup with evey thing out front.

Good luck on the pots - all three were burned open on mine, and 2 of 3 someone gave me from a donor chassis were also. These are special 100 ohms tapped at 25/75, esentially unobtainium. It was a poor design since this is at the low end of what carbon comp pots can do resistance wise.

The problem is that the tap is used to set up a zero-current point so you can go plus or minus. The only way I could get it to work with an untapped pot was to use two pots with a toggle switch to select if you wanted zero to plus or zero to minus. It seems like it would be easier to use the convergence coils from a later set with the permanent magnets, but I think they are wired differently for dynamic convergence too, so won't just drop in.

contrast was a bit low, I had a new video out tube already, so a new 1st video amp and now the contrast is very good, can go from little to too much now.

I was trying to set up the purity so tried sliding the yoke back, and killing the green and red grids with 100k resistor to ground, when I powered it up, no HV. Popped a 3/4 fuse. My guess is I must have shorted out the yoke somehow. I monkeyed around with it some more and tried a new fuse, and got it back. I adj the purity and slid the yoke forward, got a nice full red screen. I am not sure what happened on the yoke but I will not mess with it again until after I have moved the CRT and fixed the plastic. I have a spare yoke so will experiment with it on making up the plastic piece. that way I can keep working on the set while getting the spare yoke ready to go. The center convergence is pretty good now, but the dynamic is still way off.

I have not yet tried adjusting the eff coil for lowest current. IIRC the service manual has you checking the voltage drop across the cathode fuse. I think I will just use my fuse adapter and plug that in with the current meter in place of the fuse to dip the cathode current.

I have a donor chassis as well, so hopefully I can get it right. but since the center is looking good I may be ok.

Convergence is a real pain in the ass on those sets. Be prepared to spend an entire evening doing it. it will never be perfect. Just get it as good as you can and leave it. Those DC pots will need to work to get the convergence right or your efforts will be futile. Don't turn the coils all the way in otherwise you may never get them to come back out without removing the chassis. Been there, done that.

I have a donor chassis as well, so hopefully I can get it right. but since the center is looking good I may be ok.

Don't mean to be a party pooper, but the dynamic convergence circuits in this chassis are AC coupled - so when you move the edges up, you move the center down, etc. Some point about halfway to the edge stands more or less still. It's an interative PITA to get both static and dynamic. Start by doing dynamic to get lines to be parallel, then do static, and repeat.

Doing convergence on the production line for those sets must have been a nightmare. One thing manufacturers hate is having to fiddle with product, they prefer it if they can just stuff circuit boards and have it work with no adjustments. SAW filters in TV IF strips was very nice, no alignment needed.

here is a pic where I am now

Looks decent. Much better than mine but mine needs a full alignment and is a Super.

its a CTC-5N, I am using a super cabinet which had the good CRT in it.

I am also at the extreme end of the vert hold to lock. I did not replace all the caps, there were some orange drops in there in the feed back circuit, I left them. I will try a new tube JIC its getting gassy or weak, but if that does not do it I will recap those old caps and check the resistors in the vert hold circuit and the pot as well.

oh and what is the function of the metal disc on the back of the yoke plastic anyway?

went back and re reads Bobs article, magnetic shield, I presume from the yoke to the convergence area.

CTC-5N is a deluxe, much better set. Not sure about the metal disk. Mine has been converted to a all glass CYP CRT with the conversion kit. Has the newer yoke cover.

I tried 3 different 6CG7's all the same, vert hold at the extreme end of the range, so I will pull the chassis and check out the resistors and replace those old caps (I did not even check to see if they were the right value, I have often found the wrong values used for replacements.

I was just about ready to pull the chassis and I see this monster a$$ lizrd sitting on the flyback cover, Geez if I had been pulling that chassis and that monster jumped on me I would have prob dropped the damn thing. I tried to knock him out but not sure if he went to the floor or just deeper into the set.

Now don't get me wrong I really like them as they eat bugs, but this thing was HUGE. I know the wife would freak out if it came in the house.

I was just about ready to pull the chassis and I see this monster a$$ lizrd sitting on the flyback cover, Geez if I had been pulling that chassis and that monster jumped on me I would have prob dropped the damn thing. I tried to knock him out but not sure if he went to the floor or just deeper into the set.

Now don't get me wrong I really like them as they eat bugs, but this thing was HUGE. I know the wife would freak out if it came in the house.

I have that to look forward to. I am moving to NE FL and I see them on the screens in the morning having bugs for breakfast. Cute little guys.

Now, back to that repair!

well a .01 was replaced by a .0033, but I think its just part of the integrater, C506, so I don't think it would effect the timing of the osc, but I am not sure about that. I will put the correct cap in anyway. I confirmed the .01 by checking another chassis and indeed it was a .01.

Next up I will need to check the 6.8meg 5% resistor that goes to the vert hold pot, and then finally the 820k from the screen of the vert out to the pot, seems to form a voltage divider from the 300v to ground thru the vert hold pot. will also look at the 39k resistor in the feed back circuit and a couple others there as well.

One of the caps in the feed back loop on the vert board a .0039 had the fuzzy eye syndrome, the others tested ok, but the are all replaced and with 1.6 to 2 kv caps now. there was a 1.2 meg resistor that had been replaced, again on the grid circuit of the vert osc. I checked the schematic AND the other CTC-5 and both had a 1 meg there so I went a head and replaced it as well. The 6.8meg in series with the vert hold pot is over 8meg and its a 5%. I need to check my stash of resistors. I also need to check the pot while that resistor is out of the circuit.

ah that's better all fresh caps and a couple resistors. Too late to go install it, just hope I did not goof anything up. If this fixex the v hold setting I will pull the yoke and start in on that plastic piece.

Vertical hold is very much centered now. Don't know which part (or parts) was the culprit, but its good now. So I think I will stop futzing with the chassis and move on to the yoke. that is going to be a week end project for sure as I need to get some plastic (will try the local surplus store "skyjunk") for that. Over all this set has been a push over.

got the yoke off, I assume the plastic cover is just a friction fit on the plastic of the yoke. I am tempted to look around the garage and see if I can find a plastic lid that fits.

Have you seen Bob's article about making yoke covers?

http://antiquetvguy.com/Web%20Pages/My%20Methods/Replica%20Yoke%20Covers/ReplicaYokeCovers.html

More discussion here, including the Home Depot paint can cover solution:

http://videokarma.org/showthread.php?t=254453

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

yes I saw the article from Bob, but I think I will make a trip to home depot tomorrow. I did find some plastic in the shop, but its pretty thick stuff (1/8) so its a bit of a bear to work with.

this looks interesting

http://www.stuff4scrapbooking.com/white-lid-7-h-x-6-5-dia-large-plastic-paint-can-wtlpc-17171.html?CAWELAID=1018319051&cagpspn=pla&gclid=CN65qrmx-rICFQSxnQodVAsAtA

maybe cut the bottom off and use that.

this looks interesting

http://www.stuff4scrapbooking.com/white-lid-7-h-x-6-5-dia-large-plastic-paint-can-wtlpc-17171.html?CAWELAID=1018319051&cagpspn=pla&gclid=CN65qrmx-rICFQSxnQodVAsAtA

maybe cut the bottom off and use that.

or one of these lids

http://www.usplastic.com/catalog/item.aspx?itemid=26147

I finally put a meter on the HOT cathode fuse, yikes 12v, per the setup instructions it should be 7.5v so clearly my HOT is pulling too much current. I will see if adj the eff coil helps.

If you want to add a horizontal drive control, I added one to my Wingate. It can help with setting up the horizontal section, and I even went one step further with a HV pot.

what did you end up with on cathode current. I am getting 205ma with my simpson 260 at 117vac

hmmm I see the cathode fuse is thru an 82 ohm resistor AND all the DC convergence pots. I can see how drift there would account for my 12v reading. I would have rather the the schematic give a current reading. I did dip the current with the eff coil, but very little improvement (it was pretty close to the dip already. I suppose I should check the HO tube control grid, there is no PP given but it does say -40v. It looks like it taps into the horz osc tube for some grid bias, with a voltage divider that also feeds the video out (assume H blanking for the Y signal). If I dont get the -40v I will take a look at those resistors a 1 meg and a 470k.

home depot snap on lids, 79c each.

It does indeed fit perfect, snaps right on with enough force to keep it in place but not so much as to stress anything. I just held the metal shield in place left the brass rivits in place, used an exacto blade to open up small holes where the rivits could then be pressed thru (the hole was small enough so I had to "work" the flattened part thru. after that I used the exacto to open up a center hole using the now installed shield center hole as a guide. 5 min tops.

is there some trick to adj the static convergence coils that are buried back in the chassis? Seems like a major PITA to get a micro screwdriver on them and the idea of going back and forth is a nightmare.

I am going to see if I can build a custom tool that allows you to slide over the screw holding the screw driver in place. Maybe just a bit of brass tubing slipped over the screwdriver would do the trick...

well that worked well enough, I had some stiff plastic tubing that makes a nice guide for the precision screw driver. I just need to make up two more (have to find a couple more precision drivers) and will leave them in place. the static looks good but the edges are way out of whack the V G/R is way off on both the right and left side, but seem more so on the right (facing screen). Anyway will proceed with the convergence before swapping the CRT into the good cabinet. I am wondering if I should attempt to swap the entire bezel with the CRT attached, as opposed to pulling all the stuff off and having to re do all the setup (assuming I can get it good on the current set).

They do make a tool for that. You will need to get it from a local electronics supply store(if there is any anymore).

I was not seeing much action when fiddling with the various coils. I wanted to confirm that the H pulse was getting there, I scoped U1 and see about 65v horz pulse so that part is good. I will get my tools together and see whats up. I wonder if its possible some of those 22 ohm resistors across the coils have opened up? they are big, looks like 2watt and 10%, can not test them in circuit, if I have no luck with the cross hatch and following the directions I will have to go there.

a ha!

while checking the convergence coils out (all good) at the male convergence pins, I next check started to check the female pin on the chassis, 1st up was the ground... hmm no ground to chassis, pull the chassis back a bit, got the flashlight out, whats this the ground buss is clipped! no ground for the convergence coils, well gee no wonder they did not seem to be working (at least the dynamic) Not sure why that would have been clipped, I know I would not of done it since it was just a ground to a connector that would have been unplugged so no need to clip it out. Taking a break know but hope to report back soon...

Sometimes it's a simple cure. Glad you found it.

hopefully that will make it work, while I had the chassis out I replaced the old .0039/68ohm fix done some time ago. figured I may as well replace that cap as well. I checked to see if the 330pf had been changed to the 390pf per the fix but that was not done. I assume its some kind of improvement on video response, but as I did not happen to have a 390pf on hand I left it alone.

oh and the 22pf C66 on the article is still there (plate to cathode), so it looks like they only did the cathode bypass change from the cathode to the contrast pot and electrolytic.

At 1st it seemed a LOT worse, poor color (weak) lousy convergence even in static, then I decided to check the purity, cut off G and B put on a blank channel, big green blob in the middle, wow was it jacked up. I did a quick purity correction got it better and then back to the channel. color back strong, and convergence seems a lot better, but I am getting tired so time to quit.

just keeps getting better, but now I think I am getting a weak RF tube, starting to get some snow. Anyway while adj the focus why not just grab the focus pot shaft plastic piece rather than fooling with a screw driver......zapppp.... ok not such a bright idea :nono::yes::D will not be doing that again.

convergence is tricky, the static adj are very touchy right around the correct spot, I am guessing a dirty pot but maybe wear. I am able to get it but its tough.

geez I am getting tired of this thing, really makes you appreciate the improvements by the time they got to a 9 or 10. I dont know if its the CRT, my convergence, the low CRT anode voltage, my signal, the tuner, it just does not make a very nice pic. It like its all chroma, I am going to have to go back and look at the video board again, make sure there are no open coils etc.... Seem worse now than just a few days ago. and I can't get it to track worth beans, the green highlights always come up too much when the contrast or brightness is turned up. This set has the PM blue lateral, so it has a R background pot. I tried setting it for 90v bias from the K to G1 per the service manual as a starting point. I am tired of fooling with it I think I will stay away from any more 5's...

I don't know if this is an issue, but I will check that 82 ohm HOT cathode resistor that is in P with the DC convergence pot. Maybe if its off it will shift the "sweet spot" for center convergence to a less touchy area.

whew... got the CRT swapped, wow that was a lot of effort, but its in and looks great. will be much nicer working on it with the better cabinet (the old one was nasty, big time). I removed all the hardware from it and will put it out in the trash. I was tempted to swap the bezel but it was a different color (green on the donor, brown in the wingate). Now I just need to find a good back for it.

had this set on the back burner for a while. Needed to clean up and get organized. I have an idea, I have an extra CTC-5 chassis. I am thinking of recapping it, see where I am on it. IF I can get it going, I would like to see about making up a fly from more recent fly by adding my own windings for the secondary windings including the convergence windings. I have some flys that have a lot of extra taps, fly 331 IIRC for an admiral. Would be an interesting project. I would like to scope the working fly (assuming it works) then I could try and match up the donor fly. Its a long shot but if it worked it could help boost the HV up from the low HV from the stock 5, not to mention improve reliability.

I am pretty sure I could just convert to a later model like a 15 for HV with the use of a modern convergence cluster and board, and a new vert out, but I would rather try to at least see if I could make one that is closer to the orig.

That would be an interesting project. I have a CTC-5 Special chassis that I "rescued" from a field, but the CRT and associated neck components had been destroyed. The chassis is complete, though, and it will be worth evaluating with the thought of restoration. I only borrowed one resistor from it for my 5N chassis. I'd really like to have working examples of both types of chassis to go with my 4 and 7.
Good luck, and I look forward to know how you progress. :yes:
Kevin

it will be a while just musing it over. It just seems a shame to have some really nice thordarson flys and not be able to use them. they are monsters compared to the stock flys in the 5.

the more I look it over the more I think just using a reg convergence board with static PM would be the way to go. Maybe even able to use the stock vert out trans. The trick would be to make the conversion easy to reverse for the purest collectors out there. Oh well be a while I just boxed up one of my CTC-5 chassis. Still have one more to work on that is a complete set. Its the blonde special (early 5 with the PCB chroma).

I found a couple of the 100 ohm tapped pots for the DC convergence, that should make the convergence a bit less jumpy. I will pull the chassis and install them when they get here. Then a full convergence setup, and a flyback cooling fan, using what I learned from the CTC-12 flyback cooling experiment.

finally got off my rear and replaced the RG static convergence pots. They were really fouled up, once I got them out of the circuit, one side was open and both had drifted a lot. there are some more pots in there, but I would rather not have to replace them as they are on a mount that is inside the chassis, with the dynamic coils mounted to the same. It would be a major pita. Since the chassis is so easy to pull I am just going to see how it works now.

I decided to open up the old pot, there was a break between the tap and one side, the pot wiper would complete the circuit when placed directly over the break, its hard to see but must be a crack.

Exactly the failure mode of the pots in mine. I think a poor design, too much current and pushing the technology to the limit to make a pot of only 100 ohms with a 25 ohm tap.

yep both pots opened in the 25 ohm section. Hopefully the new pots will hold up, I know I will not be putting the kind of hours on them they used to see when this tv was in regular service.

Got my fingers crossed for you - maybe they suffered from high contact resistance after getting dirty, so the new ones will last for a while?

I noticed one of the speaker plug in mounted to the fiber board on the speaker had come loose, so I pulled the speaker and fixed that. while I had it out I checked the 8mfd cap that is the crossover to the tweets. It checked at about 1 ohm on my simpson 260, both ways, so I dug around and found a sprauge atom 10uf 50v NP. I piggy backed it to the existing cap, clipped on lead so the old would be out of the circuit. the ne cap would quickly go to 700k ohms on the 260. I figure it prob will make no difference, but as long as I had it out I wanted to fix it. I also noted one of the two tweets has a lead broken where it mounts so I will have to pull it and see if I can fix. if not I have a few spares.

been slow to move on this, but I did replace the cap on the crossover and did fix the speaker fiberboard, and put it all back in. I have the chassis on the bench just need to get off my duff and put it back in the set and do a setup.

I am missing the two top pulls for the doors, a close up pic of them may help me find something that will be correct, those who have this set pls post a pic of the top pulls.

Curious: I had exactly the same failure on the red static convergence pot on my CTC5. There was a crack about a half way along the low resistance element end.

I do not think the pot suffered from electrical stress. I think the problem was with manufacturing and shrinkage of the carbon element over time. The break always seems to occur between the two rivets on the lower resistive portion to the tap simply because there are physically close together.

This evening I tried my fix: I went to "Canadian Tire" and picked up a rear window defroster repair kit. The kit includes conductive paint. I cleaned the pot element where the break occurred and painted a narrow band right over the crack.

After the paint dried, I reassembled the pot and it seemed to work fine. I checked the resistance of the previously broken section and it now measured 35 ohms, which is slightly low but about right. I then reinstalled the pot in the set and the static convergence adjustment now works okay.

Overall, I like the static adjustment on the front panel. But the pots are a pain. The design isn't bad: even though the static convergence voltage is derived from horizontal output plate current, any variations in current are mostly compensated for so that the convergence does not vary. It's just those bad pots. I would be just as happy to substitute the convergence clover leaf assembly with one which has permanent magnet adjustment, but that would be non-original.

I suspect the repaired pot should last a while until I can think of a better solution.

I made an interesting discovery today. I was troubled by the low grid bias on the horizontal output tube. This pointed to a slight reduction of horizontal drive.

I examined the circuit of the 6CG7 synchroguide horizontal oscillator. Comparing with the CTC7 and CTC9, the plate voltage of the oscillator was a bit lower.

To increase the drive, I thought I could raise the plate voltage a little. I discovered that R604 and R603 form a voltage divider. Further, I discovered my set had an 82K 1watt resistor for R603 where the schematic showed 100k. I tried substituting a higher resistance which raised the drive a bit. The offshoot is that the unregulated HV has gone up (good) and the grid bias on the horizontal output is now correct (very good).

Then after this, I read in the "Series 700 Setup-Service Manual" (available on at the ETF website), where, on the page 71 pictorial of the horizontal oscillator circuit board, there was a little note to the side of figure 132. It reads "Note: R603 may be reduced in value if less drive to horz. sweep output is desired".

So whadaya know?

Nice catch I will check that before I take the chassis off the bench :thmbsp:

glad to hear about the pot fix, i was wondering about how that conductive paint may work. I saved the bad pot after taking it apart, think I will try it as well.

reviewing the schematics I can see the ctc-5 has the 82k and the ctc-5N has the 100k for R603. I have a ctc-5N and it has the 82k, hmmmm.

the ctc-7 has a different setup, with a pot for drive adj, and a cap in series with the 100k/pot.

Question for Pentode, did you check the cathode current before and after the switch from 82k to 100k?

I had no evidence of a drive bar on my set so I may try changing the resistor if for no other reason to see if I can get that cathode current down. I still have to try it with with the new convergence pots so I can get a good reading in the cathode voltage of the horz out tube. It was high before, but I think that was just due to the increased resistance of the old pots. IIRC the called for cathode voltage is 7.5 v and I was at 12v. So will base line it with the new pots, get a revised cathode voltage, then experiment with the R603.

I did check the current (200ma) but the RCA schematic did not specify what it should be, just gave the cathode voltage. I suspect 200ma was about right but would like it to be a low as possible. I did adj the eff coil for the dip.

Don't bother worrying about it. The horizontal trans in my Wingate runs cool as a cucumber after hours of play time, and that's after I added pots for drive and HV to try and boost HV output. Most I ever saw out of it was around 22kv, I suspect the transformer itself and the way it's wound are holding back any more output potential. I think mine was around 200ma as well, but like I said it's not like it gets hot anyway.

Don't bother worrying about it. The horizontal trans in my Wingate runs cool as a cucumber after hours of play time, and that's after I added pots for drive and HV to try and boost HV output. Most I ever saw out of it was around 22kv, I suspect the transformer itself and the way it's wound are holding back any more output potential. I think mine was around 200ma as well, but like I said it's not like it gets hot anyway.
Nick! Did you move all those sets out east with you.

Question for Pentode, did you check the cathode current before and after the switch from 82k to 100k?

I ended up selecting 110k. This yielded -40 volts on the Horizontal Output grid as per the schematic. The cathode current measured 210mA.


I did check the current (200ma) but the RCA schematic did not specify what it should be, just gave the cathode voltage. I suspect 200ma was about right but would like it to be a low as possible. I did adj the eff coil for the dip.

With 7.5 volts on the cathode, and the cathode resistance to ground at 23.5 ohms (the 82ohm in parallel with the static convergence 100ohm pots), this equals 320mA.

I now measure 5.0 volts for the 210mA. I increased the drive well below the appearance of the drive line. The HO tube runs a bit cooler and I have better regulated HV.

Nick! Did you move all those sets out east with you.

I only had room for the CT-100, 21-CT-55 and CTC-4. The rest are at my folks' house awaiting a chance for me to rescue them.

i check those two resistors in the plate circuit R603 and R604.

R603 is coded as an 82k which was on on the CTC-5 but shown as a 100k on the N chassis. I checked it out of the circuit and it had drifted up to about 94k so I left it alone.

the R604 which is coded as a 39k tested at 60k. Its 10% banded so I went ahead and replaced it with a 39k (tested at 41k) from my stash of old carbon comp resistors.

there was also a 1000pf cap that was from the junction of those two resistors to ground, If it leaked it would really mess things up, so I pulled it out and tested it. It tested perfect with no leakage so I put it back in. It was one of the red dominos, but I don't like to replace parts that check out perfect.

The only other caps in on the H board that were not replaced were a couple 82 pfs that were in the AFC circuit. As I was having no issues with sync I left them alone.

I really need to reinstall the chassis and see where I am just need to make some room in the shop as I don't want to work on it out in the garage.

i check those two resistors in the plate circuit R603 and R604.

R603 is coded as an 82k which was on on the CTC-5 but shown as a 100k on the N chassis. I checked it out of the circuit and it had drifted up to about 94k so I left it alone.

the R604 which is coded as a 39k tested at 60k. Its 10% banded so I went ahead and replaced it with a 39k (tested at 41k) from my stash of old carbon comp resistors.


With R604 now in tolerance, you should see more drive and the bias on the horizontal output higher. Please let us know the result.

will do.

I noticed in the RCA service manuals the CTC-5N had the 100k listed with 120k and 150k alternates. My plan is to try it as is (with the new 39k) and then try a 120k for the R603 (vs the 94k reading 82k resistor that is in there now.

all this time I have been saying I have the N chassis, I just double checked, its a AA chassis.

will do.

I noticed in the RCA service manuals the CTC-5N had the 100k listed with 120k and 150k alternates. My plan is to try it as is (with the new 39k) and then try a 120k for the R603 (vs the 94k reading 82k resistor that is in there now.

all this time I have been saying I have the N chassis, I just double checked, its a AA chassis.

I did find raising the resistance slightly improved the HV supply slightly. But the increased drive may have slightly stretched the left side of the raster.

I think the problem is the back flyback HV supply design with limited beam current in this set. It would be nice to be told whether or not the CTC5 picture is as dim as other color sets of the same vintage.

CTC-4 is definitely brighter, but it also has a stiff 25kv anode supply. The later sets all had better horizontal sections as well, not as good as a 4 or 21-CT-55, but the 5 is the only odd one out of the whole early color RCA line with respect to HV generation. I still would like to one day sub a different anode supply into a 5, to see if more HV would make it perform as well as the others.

I think a few minor modifications to the sweep circuitry may be all that is required. I do not like the static convergence DC supply coming from the horizontal output cathode. Tying the cathode to ground and providing a separate DC supply might help. I expect there are other issues with the design as well.

I agree that the CTC5 seems the odd one out.

I think a few minor modifications to the sweep circuitry may be all that is required.

Like what? I already tried more drive, and removing the regulator tube completely. If I had to guess, it comes down to the flyback and how it's wound. If that's not it, there are still a few things to try. My 5N uses 5U4 vacuum tube rectifiers, swapping to solid state diodes to boost the B+ may help. I think the early CTC-7's were the last ones to use vacuum tubes for LV rectifiers, the rest had silicon. Might also try a solid state HV rectifier for more efficiency, but I hear they can cause issues like lines in the image on screen/video noise.

I do not like the static convergence DC supply coming from the horizontal output cathode.

Not sure where else the convergence voltage could come from, you need it from the horizontal for the waveforms. Maybe a tap from the flyback would be a better choice, then the cathode could be more normal with just a resistor.

Not sure where else the convergence voltage could come from, you need it from the horizontal for the waveforms. Maybe a tap from the flyback would be a better choice, then the cathode could be more normal with just a resistor.

If you look at the CTC5 circuit diagram for the horizontal output tube, you will see that the cathode is heavily AC bypassed to ground. There is no signal on the Horizontal Output cathode. The voltage drop on the Horizontal output tube cathode resistances (100 ohm pots and the 82 ohm resistor) is purely DC for static convergence only.

I am suggesting tying the cathode to ground. This will in effect copy the later chassis' CTC7 onwards. I am curious if it is not the reactances in the cathode circuit which reduces the flyback pulse amplitude and makes the HV supply soggy?

As for the DC supply for the static convergence, I was was thinking of constructing a separate regulated DC supply. The DC would be derived from the filament supply. A suggested diagram is attached.

Certainly, simply ignoring the static convergence and simply grounding the Horizontal Output Tube cathode right at the socket would test the HV supply and I will be game to try it when next I pull the chassis.

Huh, I thought they pulled waveforms from there as well. It's been a while since I've been inside my Wingate, and I don't have it near me to play with it since I moved or I'd try it myself. Seems to me it would change the operating point of the output tube by a little bit, but probably not much. It would have the effect of driving the stage harder, since lowering the cathode voltage to ground would turn it 'on' more. But since the same thing can be achieved by the drive pot mod I already did (which accomplished nothing), I suspect the result will not be more HV output. Curiously though, I noticed that the 5 is not as prone to getting drive lines as the other chassis are. All these things are what leads me to believe that the transformer itself it what they changed, since it all leads back to that one part of the circuit.

I would expect the HO tube bias measured with respect to ground to rise by 5 or 6 volts when the cathode is grounded by virtue that the bias is derived by grid rectification. Hence the total bias is dependent upon the drive amplitude.

My thought is the added reactance to the cathode circuit (5ufd cap and wiring) may hinder the ability for th HO tube to be turned off at the end of forward scan. This would reduce the pulse height and inrease the effective series impedance of the HV supply. This is only my thought and I'd next like to explore.

getting there, I brought it in the shop, put the chassis back in and started setting it up (I had swapped in a replacement CRT, so I knew it would require a full setup)

In the process of adj the yoke for level I got bit pretty good. seems the outside of the CRT cover is not grounded very well. Perhaps thats just the way it is with these 21AXP22. I will confirm that all my grounding straps are in place on the CRT cover hold down AND the connection the the chassis is good. From what I can see the only connection to the chassis is a pressure connection from tabs on the front of the CRT mount that press into the chassis on the front.

I had a heck of a green neck shadow that I could not seem to correct without upsetting the purity. I never got the purity perfect anyway, I could get the red blob right in the cener with nice blue and green blobs around it, but when I moved the yoke forward I could not get a pure red screen, the bottom was the problem. I have not yet futz with the screen magnets nor tried degaussing (My 1st 21AXP22 set) so I will have to figure out how to adj the perimeter magnets so they are retracted and give it a proper degausse. This set is def a bit trickier than the later roundies I have worked on.

I need to get a handle on this hot yoke first. I did not try and measure it but the metal plate is def sparking up when grounded.

shoving the chassis up tight against the front of the set seems to have solved the grounding issue of the yoke, need to look into that a bit better. Maybe scuff up the chassis and the springs that make the contact and make sure all is clean. I am a little bit surprised there is not ground strap directly to the chassis.

I was not able to get the bezel out of the way, I can get the top out (the 3 spring clips that hold it in) and the side are not retained but the bottom is not budging. I looked at an old bezel that was loose and I see two holes that I assume fit over pegs on the bottom but can not say for sure.

Wingate owners please comment on how to remove.

while fussing with it I decided to check the voltage at the horz out fuse, was around 12v IIRC, now its more like 7.5 right on the money per the schematic

:yes:

during the intial setup I checked the blue screen purity (after getting the red as good as I could) the green was good but the blue was TERRIBLE.. I tried turning up the drive which helped but it was not just weak but more blue/green.

during a prelime setup of the center convergence I noticed the blue was way out, so I tweeked the blue lateraly, bingo blue not only converged but overall was much brighter. seems the blue lateral must have been causing the really bad purity also.

all this is just me messing about, I know I need to do a proper setup using the instructions which are a lot more complicated than what I have seen in other later roundies with later convergence boards.

I was not able to get the bezel out of the way, I can get the top out (the 3 spring clips that hold it in) and the side are not retained but the bottom is not budging. I looked at an old bezel that was loose and I see two holes that I assume fit over pegs on the bottom but can not say for sure.

Wingate owners please comment on how to remove.

Dave,

Remove the pencil box knobs. Remove the pencil box. This wll reveal, at the top of the opening, two spring loaded metal inserts that hold the bottom of the bezel in place. Take a small flat blade screwdriver and place into the insert and push down. You can do one at a time. This will release the insert from the bezel. Reverse the process when replacing the bezel.

-Steve D.

ah thanks Steve, One of them was missing the little metal clip, but I am pretty sure I can just pull it with some needle nose, the other one moved easy.

well the one missing the little clip is really in there tight, maybe that is why the clip is missing....

I don't want to damage the wood by a half ass approach with the needle nose so I will have to see if I can machine a tool to fit under the head of the pin and allow me to pull down. Dang so close.

got it with some hemostats, bezel out, glass out, magnets fully CCW so tomorrow I can do a degauss, thanks again to Steve for the hints. I hit the little mech with some lube so it should go easier next time.

My thought is the added reactance to the cathode circuit (5ufd cap and wiring) may hinder the ability for th HO tube to be turned off at the end of forward scan. This would reduce the pulse height and inrease the effective series impedance of the HV supply. This is only my thought and I'd next like to explore.

I tried simply grounding the cathode. The was little difference. Perhaps a minor improvement but this was not the crux of the problem.

The CTC5 chassis seems to have HV issues. As Nick pointed out, it may have to do with the B supply. I noticed that as the brightness is advanced to blooming, the vertical scan increases (as would be expected with drooping HV) but the horizontal scan decreases. This suggests the horizontal sweep is has problems.

However, the HO Tube cathode current is low after I minimized it with the adjustment of the efficiency coil. I read elsewhere the that on another chassis the instructions called for a minimum adjustment and then the core was adjusted further into the coil to raise the HO Tube current to the correct value.

Any thoughts on this?

I will have to check the cathode current again. I did not check the line voltage, but the fly is getting pretty hot, and I do not seem to have any HV blooming (but I do have the video out contrast mod in). My concern is the heat in the fly HV tire. what currents are you seeing? are you checking the AC in and setting at 117v?

I bought several HO tubes to compare with.

My opinion at this point is that the flyback is wound in such a way that it is somehow current limited. In other words once you get to a certain point, perhaps the core begins to saturate. Can't do anything about that, because messing with the core (or its gaps) changes the magnetic properties of the entire transformer in possibly undesireable ways. Lets remember the whole transformer is a precision engineered part, especially with regard to frequency. Mess up one thing in any of the windings, and it goes haywire.

Or maybe the primary simply has too much resistance, since the amount of current supplied is influenced by the resistance of the primary. More primary resistance means less current when HO tube conducts, which means a weaker magnetic field and corresponding flyback pulse when the stage suddenly cuts off. Obvisouly, there is nothing short of rewinding the flyback that can cure it if that's the problem either. Folsom is the only one I know of that's tried (re?)winding one, and the results were less than satisfactory.

The secondary might not have enough turns in it, but that seems unlikely since it does in fact produce the required voltage at low brightness. That tells me the problem has more to do with the supply side of things, since the problem doesn't manifest till more demand is placed on it. It's not that there's a lack of HV per se, 21-22kv would be just fine for a 21" CRT. The problem is lack of adequite current delivery, which is why HV sags when brightness approaches normal viewing intensity- the beam current required by the picture tube outstrips the flybacks ability to produce it, so the picture blooms and lacks brightness. The situation is analagous to power grid sagging during the hot summer months, when everyone is running their AC units. Too much demand, and line voltage sags. The fact that the horizontal scan decreases in width is another clue, pointing to a lack in magnetic flux to power the scan coils. Again, I can only think of too much primary resistance being the cause.

If I'm right, about the only thing that's likely to make things better is an increase in B+ voltage. Since you can't get a load with less resistance, you can always try driving a larger waveform into it in an attempt to extract more power on the other side. This would likely require vast changes to the LV power supply, including a switch to solid state rectifiers and juggling the dropping resistors to all circuits besides horizontal scanning. Careful attention needs to be paid to cathode current in this case, since a small change in input voltage can push current way overboard in a hurry.

A good test would be to put the set on a variac, with the brightness set so that the picture just starts to bloom. At this point, you should be able to read a slight drop in HV. Try increasing the AC input voltage to say 125 from 117, and see if HV tries to come up at all. If it does, there may be something to investigate.

I will have to check the cathode current again. I did not check the line voltage, but the fly is getting pretty hot, and I do not seem to have any HV blooming (but I do have the video out contrast mod in). My concern is the heat in the fly HV tire. what currents are you seeing? are you checking the AC in and setting at 117v?

I bought several HO tubes to compare with.

I was measuring about 210mA with the efficiency coil adjusted to minimize current. I believe the current should be a bit higher than this. The schematic inicates there should be 7 volts on the cathode with respect to ground. I measure 5.5 volts.

My thought is that adjusting the efficiency coil for slightly higher current will result in and increase to the unregulated HV. However, as Nick points out, the problem may relate to a limitation of the HV transformer.

I found the 6BK4 regulator is not really regulating the HV. This appears because the HV unregulated (with the 6BK4 cap off) is only about 23kV. When increasing the brightness hence the beam current in the CRT, the HV sags below 23kV.

Here is what I'd like to test: if the focus voltage does not track with the HV eg the focus voltage remain constant with the HV dropping, this means it is an unregulated HV supply issue. That is, the HV transformer is okay but the pulse to the HV rectifier is not of sufficient amplitude. If however the focus voltage also sags with the HV, then the HV transformer is likely at fault, as Nick suggests.

As for raising the B supply with a variac on the 117vac side, if the HV regulates better, that would suggest the former and not the latter.

Do you agree?

I was at 195ma, tweeked it just a bit to get to 190ma (simpson 260 VOM), solid 21kv with no noticeable flux on the HV meter (simpson 248 hv probe).

I am going to try some tube swaps just to see the effect with the current setup.


I don't have my good VTVM handy to get a control grid voltage reading on the HO tube, but will use my DMM and see what I get. Then will replace the 82k with a 120k in that voltage divider on the osc plate just to see if that will effect the drive/bias at that control grid (and perhaps further reduce the current thru the HOT). As long as I get good regulated HV I will see how low I can go.

I suspect some of the variations we are seeing is maybe do to the calibration of the test equipment?

matix balance pot (deluxe chassis) I get that is seems like a way to balance the gain of the X and Y demodulator tubes, but I could not find anything on how to set this up.

wow, new tube, gets me to 180ma and still good 21kv

yes pics coming soon :)

I found the 6BK4 regulator is not really regulating the HV. This appears because the HV unregulated (with the 6BK4 cap off) is only about 23kV.

The 6BK4 regulator does not work by regulating the voltage. It works by regulating the total current load on the high voltage. It measures this current at the bottom of the flyback. That is, when the CRT draws less current (dark picture), the 6BK4 draws more current from the high voltage anode lead, keeping the load constant. Therefore, the load (and the voltage) should be constant, until the picture is so bright that the 6BK4 has reduced to zero current. If the CRT draw is raised higher, then the draw on the high voltage output does increase and the voltage drops.

So: if operation is proper, the high voltage should remain constant as brightness is increased up to a certain point, and then the voltage should start to droop as you try to get more beam current. If the voltage is drooping gradually as you increase brightness from black, the regulator is not drawing compensating current like it is supposed to.

hmmm while getting set the pic starts slowly bloom check the current 230ma and climbing, yikes, tried another NOS tube (elmenco branded) and back to 180ma, going to have to watch this.

matix balance pot (deluxe chassis) I get that is seems like a way to balance the gain of the X and Y demodulator tubes, but I could not find anything on how to set this up.

This appears to set the relative gain of X and Z. The effect should be most visible on saturated colors, like color bars. This will affect all the color bars in some way. For example, one direction should make magenta more reddish and the other direction should make magenta more bluish.

I found the 6BK4 regulator is not really regulating the HV. This appears because the HV unregulated (with the 6BK4 cap off) is only about 23kV. When increasing the brightness hence the beam current in the CRT, the HV sags below 23kV.


As Wayne pointed out, I think you're misunderstanding how the 6BK4 does what it does. It doesn't tell the flyback to 'make' more power, which is what I understand when I read your post, it's only there to provide a constant load on the flyback. The flyback always operates wide open, only thing that can drag it down is the CRT or the 6BK4. When beam current at the CRT is low (dark images), the 6BK4 picks up the slack so to speak. When beam current at the CRT is high (bright images), the 6BK4 will be cut off. In this way the load is always constant on the anode, but if you ask me it's a pretty crude and wasteful way to do things.

Here is what I'd like to test: if the focus voltage does not track with the HV eg the focus voltage remain constant with the HV dropping, this means it is an unregulated HV supply issue.

Regulation isn't the issue here, since the 6BK4 only absorbs 'excess' HV when the CRT doesn't need it. The issue is lack of sufficient headroom in the HV supply to begin with, which explains why the chassis works the same wether the regulator tube is installed or not. It made little to no difference to the images on screen for me, there's just not enough HV to make a difference. Other sets will overshoot by a lot without the regulator, my CTC-9 for example would hit nearly 32kv unregulated. In that situation there would be a difference in images on screen, but not the anemic CTC-5.


Do the variac test, see what happens.

I disconnected my shunt and the HV shot up to 25kv with a MUCH brighter screen, still holding at 180ma... So I will mess with the HV setup and regulation tomorrow.

I just realized there is no HV pot, so I will start with some tube swapping on the 6BK4

I disconnected my shunt and the HV shot up to 25kv with a MUCH brighter screen, still holding at 180ma... So I will mess with the HV setup and regulation tomorrow.

I just realized there is no HV pot, so I will start with some tube swapping on the 6BK4


really? You must have the one chassis the was built right then, none I have ever seen made more than about 22kv. You can copy the circuit from any of the later sets to add the HV adjust pot, then you should see some improvement in brightness. Set it so the chassis puts out around 23kv with a blank raster, see if that does the trick.

Tube swapping the 6BK4 won't help, you need to change the tube bias with the HV pot.

yea I was kinda shocked by all I have seen with other reports, that's is why I had not even bothered to try disconnecting the shunt tube cap before as I just assumed it would not make any difference.

I hate the idea of drilling a hole in the chassis to add a pot, so if a tube swap does not work I will try upsetting the voltage divider of the two 1.8 meg resistors that are used to establish the bias with a fixed resistor bridged on the lower half of the divider. Will start with a 10 meg just to see. A better way would be to just replace one of the resistors with a 1.5 meg fixed and then a 500k pot is series as done on the 7's.

The schematic shows a 100meg cap in the cathode to grid, 100meg? yikes, anyway if that has gone low it would foul things up to. I did replace the .0033 cap that is there as I have read that leaky caps there have been responsible for regulation problems due to bias issues on that tube.

After talking it over, I think I will just check to make sure that all the existing values are correct and not try to up the HV more than the design calls for.

My concern is HV breaking down the insulation and arcing over in the HV tire.

I would rather have a dimmer CRT than no HV at all with a fly that is so hard to come by. I did try a new shunt, same HV 20kv. the old one was completely dark, which I presume is from Xray bombardment of the glass.

I've been following this thread, I'm about to tackle my Wingate chassis in a few weeks (finally! :sigh:). After studying a lot of early color set designs, I found it really weird that the schematic has 19.5Kv going to the anode while all others are 21-25Kv. I guess RCA was experimenting with different methods and I'm glad this one was only done on the CTC5. I agree with you, Dave. I think when I get into my chassis, I'll just make sure everything is as it should be and live with it. The only thing I'm thinking about doing is that contrast mod just to see what happens. It seems that the mod works better on some sets than it does on others.

Well the good thing about my set anyway is the HV is rock solid (with 5kv of head room it should be). I did not try it without the mod, but with it there is no sign of blooming at all.

Make sure you check the plate load resistor on the horz osc borad, its the 39k.

After talking it over, I think I will just check to make sure that all the existing values are correct and not try to up the HV more than the design calls for. My concern is HV breaking down the insulation and arcing over in the HV tire.


Won't happen, starting with the 5 there was a little bit of potting and a rubber insulator around the HV winding. Previous designs (CTC-4/21-CT-55) only had some wax dribbled around the bare windings, and they operated at higher voltage than the 5 does. CT-100 was different as well, it has some sort of plastic around the winding instead of wax.

It already makes 20kv, another 3-4 isn't going to hurt it. You don't have to drill a hole in the chassis either, you can use the pot temporarily to figure out what value you need. When you know, replace the pot with a fixed resistor and be done with it. The benefits are worth the potential risk, IMO. If I could get 23kv out of my set, I definitely would do it. Also, chassis for the 5 seem to be popping up lately. So if a flyback did blow, chances are you could find another one. It wouldn't be as hard as trying to locate one for a CTC-4, those are made of unobtanium.

while futzing with it I noticed the green was a bit weak, after screwing with drive controls, I finally decided to check tubes. Normally if they test a bit low on my mercury tube tester I don't sweat it, and one of them was a bit low. swapped in and color looks a lot better. per my tester SHB 3000, was about 1500, new tube was 2000 for what ever that is worth.

another odd thing was when I tried to use my vector scope the pattern was a mess on color bars. found out that if i disconnected the grid leads (so the vectorscope was not ready the chroma) the color bars on the screen look good, with in connected it was a disaster. I have never had a problem with the vector scope loading down the signal like that before.

oh the tubes where the 12BH7 difference amp tubes.

I disconnected my shunt and the HV shot up to 25kv with a MUCH brighter screen, still holding at 180ma... So I will mess with the HV setup and regulation tomorrow.


Perhaps its blasphemy to suggest, but would using a separate HV supply to provide the desired regulated 25KV be a solution? Would this also reduce the load on the flyback and lower its temperature?

Dave

As Wayne pointed out, I think you're misunderstanding how the 6BK4 does what it does.

Sorry guys. I think I my post was misinterpreted. I guess I wasn't clear.

Since the 6BK4 is a "shunt" regulator, I realize it shunts current to maintain a constant load current, hence supply voltage. Also to regulate, the 6BK4 does not sense current, it senses voltage. The boost B+ voltage is sensed which should be directly proportional to the HV.

What I was suggesting is that if unregulated HV voltage is at or below the point the 6BK4 begins to conduct, the 6BK4 will not shunt any current, hence will not regulate the voltage.

I measured about 23kV with the 6BK4 cap disconnected. (The cap removed effectively removes all HV regulation). When the cap is connected, the voltage remains about the same. This means the 6BK4 is not conducting, probably because the unregulated HV is too low.

The question I have is if the focus voltage remain constant at the point the HV begins to drop (HV out of regulation), this means the problem is the unregulated voltage at the output of the HV rectifier is too low. This in turn implies that the HV pulse arriving at the HV rectifier is of insufficient amplitude. Further, because the focus voltage remains the same (constant CRT load), the HV transformer core is not being over saturated with the HV supply current demand. In other words, the transformer is okay.

On the other hand, if the focus voltage drops with the HV, the transformer core is perhaps becoming over saturated and I would suspect a fault with the transformer.

It is interesting to note that the schematic suggests the HO Tube cathode voltage is 7.5 VDC. This means the cathode current should be 7.5/24 = 312mA. I do not think the current should be appreciably lower than this because I believe the flyback pulse would be reduced which in turn reduces the HV.

while checking some other stuff, mainly I wanted to see if the two 5600 ohm resistors in the chroma matrix used to drive the green were ok (they were I noticed the 5600 ohm resistor in the grid circuit of the green diff amp was about 50% out so I replace it. while check other stuff I found R702 (6800) was reading over 100k. The odd thing was it was not wired as in the schematic. In the schematic it show it across C and D of the chroma take off transformer T701. In mine its connected from pin 7 of V701a to D with no direct wire from pin 7 to D as shown (which is why it was easy to check in circuit).

I replaced it as well. Turn the set on and there is too much green in the highlights now, so a minor tweek and all good again.

for fun I tried putting a 22meg in P with the ground side of the voltage divider on the shunt, increased about 1kv to 21.5. The overall bias with this setup is about 12v but of course it would change with brightness settings. the schematic shows a 15v (375/390) so its all pretty good.

adding the 22meg in p is within the tolerance level of the resistor so I will just leave it at that.

I don't know what happened but the HV started going up to over 25kv and I could see the shunt was not glowing green suddenly. I tried wiggling the tube and even a new tube, still not regulating. finally I pulled the chassis and check the filaments for voltage, all the resistors, put it all back in the cabinet and now its working again, I have no idea what was going on with that.

I am going to try changing the voltage divider resistor to 120k vs 83k (as done in later production runs) just to see if there is any effect on the cathode current in HO tube (the voltage divider resistor is on the horz osc board).

the 82k measured at 94k I went with a 120k. No drive bars, horz lin looks good,
21kv (with a 22meg on the ground side of the shunt) and the cathode is less that 180, about 178, which is about as low as I have seen on ANY of my color sets. there is a 'tiny' hint of a drive line that I can see on a blank raster, so I may go back to the 100k but will leave it be for now, and will check the fly temps as well.

The color looks good, but I still need to go over the purity and convergence again.

duh after looking a bit closer I think I am at 22.5kv the divisions are not 1kv I should have looked closer.

some progress pics

couple more OOT resistors, a common cathode resistor on the 2nd bandpass amp and blanking amp 270 reading 750, and I doubt it will make any difference but will replace anyway.

normally when I am replacing parts on old wafer style tube sockets, I just clip the lead and pig tail, this is to prevent breaking a tube socket pin connector and ruining my day.

In this case it was just the 270 ohm resistor and I could see it was not really wrapped around the hole, so I got out the solder wick and safely removed the resistor. Replaced the resistor all looked good, the only other connection to the tube socket was the wire that went to the blanker tube socket, but I did not disturb that.

I always confirm my work so if its a pig tail I make sure I have good continuity across the pig tail connection (if the wire is not clean its easy to have a good looking connection but no actual contact INSIDE the pig tail.

in this case I did not have to worry about that as I could see I had good flow and had filled the hole in the tab with solder. I did check to make sure the wire that goes to the blanker tube cathode was still good and surprise, it was open. a closer look and I could see the wire had broken right at the pin that I had just soldered to. it was partially corroded and I guess the minor movement done in the install of the resistor must have broken it.

I had to fish the wire out and strip it to get a good clean piece, lucky there was enough slack (just). solder wick out the connection again and redo thru the hole and wrap, solder back. Needless to say I was very careful as the socket tabs break easy.

when done I confirmed that I had continuity back from the pin thru the wire to the other tube socket, AND the 270 ohm resistor was still 270 and connected.

Watch out for those very fragile hookup wires used, in this case I think it was 26 gauge solid so not much to break it.

after fighting poor greens I decided to try the vectorscope again. this time I clipped on the other side of the grid coupling caps for RGB on the CRT. Much better, did not effect the CRT display at all.

While there were color bars, the blue and reds were fine but the magenta was weak as was the green.

looking at the scope you could see the fingers but they were much more of an elipse that an a circle.

My interpretation of this is the phase of the CW from the osc was not correct to one of the demodulators, and the transformer that changes the phase needed to be adjusted. Since green is derived from the X and Y demodulators, then a defect there would really mess up green.

What I like about the vectorscope is the instant visual response (not just that its changing but that its changing in the right direction.

as it turned out about 1/4 turn of that phase adj transformer was able to open up the elipse and give a nice circle pattern, when I looked up at the CRT it now had a very nice color pattern.

This is the second time the vectorscope came to the rescue for me, I highly recommend one. Besides they also have nice dot and cross hatch settings.

funny thing is how good you can get flesh tones even with green so useless, I guess its just the flesh tone does not need much green unless your looking as Spock.

color looks great, but it was a bit weaker than before (which makes sense as the elipse was larger than the circle) a tweek of the ACC (which controls the chroma band pass amp gain based on burst amplitude) fixed that.

I still plan to make a custom top for the fly cage, it will have a plenum with a built in filter to help keep the fly temps low. Even with the low current thru the fly (about 175ma) it gets hotter than I like after extended viewing (hit about 165f after about 1 hr).

... Also to regulate, the 6BK4 does not sense current, it senses voltage. The boost B+ voltage is sensed which should be directly proportional to the HV.


You are correct - don't know what I was looking at before.

I also found the vectorscope useful for touching up the matrix balance pot on the back of the chassis as well. this pot varies the cathode bias resistance of demodulator tubes. the effect on the vector scope is to squash down the circle pattern to get it as round as possible. I found that by adjusting the top core of the CW driver trans and the matix pot at the same time was the best way to setup the matrix.

I assume with the vectorscope you are using a gated rainbow pattern producing a "flower petal" vector display.

If the drives required for the red and blue guns were equal to make white, then the pattern would need to be elliptical, with the B-Y gain = 2.03/1.14 = 1.78 times the R-Y gain. (These are the ratios dividing the B-Y and R-Y axes before the chroma is modulated.) However, the red phosphor in the early tubes is weaker by about the same ratio, so equal (approximately) is correct (that is, the pattern is circular).

By a fluke of changing both the green and red phosphors in later tubes, the red gun requires less drive to make white; so there was a fix to reduce the red luminance drive; and at the same time, the yellower green sulfide phosphor means that the extra R-Y drive is still needed, to approximately compensate by making the difference between reddish and greenish colors greater. So, the matrix adjustment does not have to change, and can stay with a circular pattern when a new CRT (e.g., 21FBP22) is substituted.

Yes I am using the gated rainbow pattern. The petals are roughly circular now, but not very pretty (somewhat misshapen pointy, sickle shaped), so I am sure more work could be done, but I am not sure if its a fault of the demodultor or the chroma signal coming from the video detector or maybe just the design. I plan do do an IF and Chroma sweep alingment later with a BK 415.

It may be fun to play with some of the chroma tubes just to see the effect.

I was a little bit surprised at how small an adjustment was required to from practically no green (green would look either blue or brown depending on tint setting) to perfect green, the adjustment was about a 1/4 turn and it is very narrow. I have had quite a few sets that had brownish greens, so next time before I touch anything I am just going right to the vectorscope and the gated rainbow to see whats happening. But you mention that in some cases a round petal design is not optimum. Most of the CRTs I work on are the 21fjp22 or 23vadp22 types. I have a both grey face and green face types of the roundies.

Yes I am using the gated rainbow pattern. The petals are roughly circular now, but not very pretty (somewhat misshapen pointy, sickle shaped), so I am sure more work could be done, but I am not sure if its a fault of the demodultor or the chroma signal coming from the video detector or maybe just the design. I plan do do an IF and Chroma sweep alingment later with a BK 415.

It may be fun to play with some of the chroma tubes just to see the effect.

it's hard to say exactly what shape the petals should have. Remember that the signal that's being gated is changing phase across the width of each bar, so even if phase response of the chroma is perfect, the trace will go outward from the center and back to the center while changing phase at a rate determined by both the varying phase and the final demodulated chroma bandwidth. Sickle shape is an indication of some phase distortion (rising waveform is different from falling), but this can be affected by fine tuning, adjustment of the sound trap(s), etc. and can be very hard to get perfect. On the other hand, if it's very bad, it will show up as edge discoloration on strongly colored objects.

If you really want to look for distortions, you need regular color bars, which have the same phase across the whole bar. Then you can make out things like the green-magenta transition not going directly across the gray center point, or other transitions not going straight between bars.

I was a little bit surprised at how small an adjustment was required to from practically no green (green would look either blue or brown depending on tint setting) to perfect green, the adjustment was about a 1/4 turn and it is very narrow. I have had quite a few sets that had brownish greens, so next time before I touch anything I am just going right to the vectorscope and the gated rainbow to see whats happening. But you mention that in some cases a round petal design is not optimum. Most of the CRTs I work on are the 21fjp22 or 23vadp22 types. I have a both grey face and green face types of the roundies.

The circular case has been closer to correct than the case of greater B-Y for all tubes, since there never was a tube combining rare-earth red and NTSC green. The early tubes (weak red with NTSC green), and the later tubes (sulfide red or rare earth red with sulfide green), both require something closer to a circular petal pattern.

You are lucky you aren't looking at a Motorola with the single tube chroma section - that got G-Y off the cathode, where it was weaker than nominal and matrixed from the wrong proportions of R-Y and B-Y, resulting in that "brown or blue" syndrome you observed.

I next tried a reg NTSC color bar pattern, pretty good, but very noticeable ringing was observed, it was tunable but as crystalization was approached it got pretty bad. Turned out to be the 1st IF (stared with the 3rd and worked back subbing as I went). I am glad I have a good supply of tubes to sub.

It just keeps getting better in small increments.

I do get a little bit of color bleed that shows up more on the NTSC as there is no gating but most of my old color tube sets do this to some degree.

There are quite a few check points for setting up the chroma, but I am running out of gas and don't feel too inclined to mess with it much more.

the ring is still there, slight but still there (its a ring not a ghost as you can see multiple diminishing rings. Its tunable so I am pretty sure its in the IF. It looks like this set relies on pressure grounding of the pcb's (not the solder stakes like later RCA color chassis). Any one with some tips on what I may look for as far as IF ringing (of if there is another area that could cause ringing? its in both the luma and chroma. I don't think it would be delay line issue since it is tunable.

the ring is still there, slight but still there (its a ring not a ghost as you can see multiple diminishing rings. Its tunable so I am pretty sure its in the IF.
For the heck of it, try subbing the 3rd IF again (i know you subbed it before and the main culprit was the 1st IF). I've had a number of cases of ringing being caused by the 3rd IF tube.

I will try a few more OC and report back later.

did not get to more tube swapping but did notice some odd voltage on the video amp (6aw8). the screen was way high, like 210 vs 180 and the plate was low 110 vs 150. I checked the voltage divider on that tube and found the 15k was 11k and the 56k to ground was 65k. Not a lot but in those direction it would add up to too much screen voltage. I went ahead and replace those two ( had some old school 2watt carbon comps on hand) and check it again, much better screen at 178 and plate at 138. Seemed to help the video out, brighter and the contrast control is not as sensitive anymore, but still has a good range.

this all stemmed from what I thought was a bit dim of a pic, I started with checking out the video out, then moved to the video amp. Interesting effect of the change was before the fix I thought I had a slight tracking issue, as increased the contrast, the green highlights seemed to worsen (was checking by watching a B&W program. I just assumed it was a CRT issue. After correcting the video amp tube (and the contrast seems to work "better") I don't notice the green highlights happening. I spent a LOT of time trying to setup the the CRT drive pots to get rid of problem before. Perhaps it just not as much drive at the CRT cathodes, but it def is better.



Its fun to check things out, make a few changes check again, to slowly see improvements. I think it may add to overall trouble shooting, by being able to see direct cause effect. Not perfect, and certainly no substitute for good trouble shooting technique, but fun non the less.

more intresting tidbits, looking over the schematic, I can see the brightness control gets it neg voltage for low brightness from the horz out grid (filtered thru a .22 cap and 470j resistor. I am pretty sure I increased this neg voltage from the -40 to something less (more neg) when I was changing the plate load resistor in the horz osc in a attempt to increase drive to the horz out. Later CTC get this neg voltage from the grid of the blanker tube. I think I will check the later CTC-7 and see if it makes any changes for the great neg voltage at the horz out tube shown on that schematic (and if there is any changes in the circuit that taps this to supply the brightness control with its neg voltage).

tried a few more 3rd if tubes, found one that got rid of the rings. I think any more improvement will have to come from a full alignment.

while checking on brightness level I checked the cathode and grid voltages at the CRT. I don't have my VTVM handy, but the green grid was maxed out at 240v while the schematic has it a 255, the cathode voltages were much closer.
I don't know if the load of the DMM is more than a VTVM, but I may just check that 1 meg resistor that feeds the B+ to bias the grid thru the background pots. I would think that I should be able to hit the 255 at something less than max setting, as opposed to the max of 240v. the other drive controls seem to have no problem getting the the correct bias setting. While I am able to get good gray scale, its at a reduced brightness. Later I plan to install my CRT test socket so I can see where the G2 voltages are (they are not easy to get at like the cathode and G1). I am pretty sure I should get a brighter pic, the CRT test fine, and the HV is solid at 22.5 kv, I know the early CRTs were not as bright as later but I would at least like to see how it looks when the voltages are closer to what is in the schematic.

chasing low brightness down the CRT bias voltages turned up some interesting notes. The blue background when maxed out would only bring up the G1 to 240v the schematic calls for 255v and it makes a big difference here. So I started by checking the resistance of the 1 meg resistors that couple the pot adjusted boost voltage to the G1s. I checked the blue G1 1 meg out the circuit and it tested at 6 megs. Replaced that one. The other two G1s had no problem getting two the specified voltage so I will leave them be for now (can't test in circuit and I don't want to replace something that is working, even if it has drifted as the pots can make up the difference).

While I was at it I check the 10k resistor that provides the boost to the pots, it was 16k. I have noticed that when it comes to voltage dividers you need to be pretty close to the correct values to have the correct ratios to divide the voltage by. Since I was low on G1 voltage and a drifted high resistor would make that worse I went ahead and replaced it as well.

turned it on and wow, solid blue screen, I was able to turn the background control to about the 1/2 way, and now since I was not limited to brighness (and greyscale to the weakest color blue) I was able to increase the overall brightness to what is pretty much normal for all my color sets.

I am getting a bit tired so will leave the checking of the screen voltages to later, but one of those (or both) resistors was really a problem (the 10k that was 16k or the 1 meg that was 6 meg).

Still no blooming at all, I don't know why you guys with 5's are having such low HV voltage and regulation issues, this one seems rock solid. All I did was make sure I had good HV tubes and I did change out the 83k to 120k plate load resistor on the horz board, but that was just to get the fly current as low as possilbe with out a drive bar (there is just a hint of one in there now, 100k would prob be perfect). Iam getting a solid 22kv with plenty of head room.



My recommendation to folks having low brightness, remember to check voltages at the CRT.

I don't know if mine has the mods done to it or not, and I'm 950 miles away from being able to find out any time soon. But as I said, yours must be the exception rather than the rule. Every single one I've run into so far has been really weak, even with pots for HV and drive mine fails miserably to sustain 22kv at anything close to a normal viewing brightness level. Count your lucky stars.

I am currently hundreds of miles away as well from working on my set. But I have exactly the same problems with my CTC5 as Nick. The shunt regulator is hardly passing any current because my set is only generating about 22kV with the shunt removed.

I am curious if in the murky past someone hasn't replaced the Horizontal Output Transformer in your set. Are there any traces of resoldering?

turned it on and wow, solid blue screen....

Don't ya just love it when you finally find a culprit and changing it brings such a happy surprise! :yes:

the fly looks very orig, I can see no evidence of replacement, I am basing this on how it looks compared to two other CTC-5 chassis that I have (and have not done anything with so don't know how they will perform) it has a kinkda grey/green moldy looking tire. Just for the grins I am going to check the B+ under load and see what I am getting. Could not see any difference in solder of the Fly connections either.

Don't ya just love it when you finally find a culprit and changing it brings such a happy surprise! :yes:

yep always good when a change results in positive results. :thmbsp:

123vac at the plug, under load, 403vdc at the fuse.

No wonder you're making more HV, you're putting in too much power at the AC side. Turn down the power to 117 VAC, then tell me how much HV you end up making... You'll be struggling just like the rest of us. That also explains why your fly is getting warm, I can run mine for hours on end and it's not even thinking of heating up.

This is why I'm in favor of modifying the chassis for more HV, instead of simply cranking up the power at the plug. There has got to be a way to make these things better, without risking the horizontal output transformer.

117 I get 22.5 with the shunt pulled right about 21.5 (my meter is not that fine, but its about 1/2 of a 2.5kv increment) this is with the brightness as below.

will leave it on for a while and see hot hot the fly gets.

after about 1 hr I was still at about 160 at the hottest spot, I think I will stay with plan A and put in the forced air cooling and not sweat the line voltage so much. It did not seem to reduce the heat that much.

just leaning a fan on the back edge of the cage and the yoke, roughly aiming it towards the fly is keeping the temps much lower, I doubt I will hit 125 even with this poor temp arrangement. Yea, a fan is def in order.

No wonder you're making more HV, you're putting in too much power at the AC side. Turn down the power to 117 VAC, then tell me how much HV you end up making... You'll be struggling just like the rest of us.

You have only 117 volts coming from your outlets? I thought everyone nowadays had 120+ at a wall plug.

'turn down', i.e. use a variac.

mini man, have you tried comparing heat in the fly using different line voltages? in some sets I know this translates into heat, but it does not seem to effect all my sets the same (I this one for example runs hot at 123 and 117 and it does not seem like the 123 is a LOT hotter than the 117, both get too hot after about 45 min to 60min of run time.

I measure them at various spots on the fly with a LED targeted hand held heat sensor.

I use a Variac while working on a set, but once it's finished, that baby gets plugged in the wall. They might have drawn up those schematics using 117 volts, but those sets were designed to work in the real world... where someone's line voltage was likely anything but 117.

Risk your flybacks at your own peril, I can only tell you that for me they have always run much cooler when the AC input voltage was set where the schematic shows- 117 AC. If you don't like the variac because it gets hot, buy an RCA isotap transformer. It has a switch instead, so you can set it and forget it.

Main reason high input voltage is bad is because it causes horizontal output cathode current to rise objectionably high, test and see for yourself. The more voltage goes into the set, the higher it will go. That's why flybacks run hotter why you plug it directly into the wall. More current=more heat, and if you're like me you don't like replacing flybacks from a preventable situation.

well its too hot at 117 or what ever is at the wall so I am going with the fan, with that it will prob not get over 90f (with it right on top of the fly).

I think I will tap the DC off the HOT cathode fuse, just use a couple alligator clips one to the chassis one to the top of the fuse (just need to be sure I don't tap the B+ fuse :D )

made up a cardboard top, cut the hole for the fan right over the fly. The cathode supply voltage at the fuse was not enough to run the fan, so I am back to a 9v battery for now. I only cut an opening on the top for the fan, there are cooling holes on the side but I will prob open up a hole for the air to escape, but for now I am running some temp test.

I will next make up the fan supple from the 6.3v supply, seem like where the tuner connection would be a good place to tap into it.

Check your pile of cast-off wall warts: likely there'll be one that will run the fan. I have several in my collection that will do so and not complain.

I've been following this thread with great interest, as I have a CTC-5N in the works, but have yet to continue (the chassis is re-capped, and has been powered up using load resistors without any trouble:D), and the info here will be invaluable. I'm particularly interested in what is being used to remotely measure the fly temperature, and where to obtain such a device. My CTC-4 fly seems to run hotter than I would like at 117 volts, and maybe I should use a small fan for that one.
Thanks for all the info!
Kevin

Check your pile of cast-off wall warts: likely there'll be one that will run the fan. I have several in my collection that will do so and not complain.

good idea, I recall having one that let you select the VDC from like 6v to 12v, I could just run the wires out the back, plug both the TV and the Wallywart into a remote switch (uses a small hand held RF transmitter to turn on) to turn them both on. Side benefit, saves on the stress on the of off switch on the volume control.

this is what I have been using to check temps

http://shop.advanceautoparts.com/webapp/wcs/stores/servlet/product_x_22980004-P_x_x?cm_mmc=ACQ-_-Google-_-enhancedRM-_-22980004&ci_src=17588969&ci_sku=22980004&ci_gpa=pla&ci_kw={keyword}&gclid=CMaZzdrurLUCFQ-ynQodBGQAIA#utm_source=acq&utm_medium=google&utm_campaign=enhancedrm&utm_content=22980004

AKA raytek minitemp

Thanks! I'll order one.
Kevin

they are a very handy tool, the LED spot makes it easy to aim.

I just tried another mount, this time I used the same cardboard top, enlarged the opening so I can move the fan around a little. the fan sits on top of a 1" thick piece of soft foam rubber (not real rubber but the kind used in packing stuff). I cut a round opening to fit the fan, but left the foam an oversize square. this lets me move the opening round on top of the cardboard, plus it spaces the fan another inch away from the damping effect of the flyback energy. the foam damps out the sound and does not pass the vibrations (little as they are) from the fan to cardboard. Bottom line is you can barely hear the fan running at all, I actually have to turn the volume down and listen closely to hear it run. Its all gerry rigged up but seems to be working great, Now I just have to find that wally wart and it will be good to go :thmbsp:

12v wallywart, works great, more VDC so I think I can now work on a air filter to put on top of the fan, keep the dust level down...

pics including the rigged fly cage top

one more the obligatory Dorthy close up...

Are you planning to replace the cardboard and foam with metal? I'd be leery about putting anything flammable in my set.

oh yes that is just temp to work out the design. prob make it from copper as its easy to work and solder together.

one more the obligatory Dorthy close up...

Man, check out those ruby-red lips..... that's friggin awesome, Dave! :thmbsp: Did you already do an alignment?

Nope to the alignment, I only touched up the chroma matrix using a vectorscope. before that the greens were either brown or blue. It only took a minor tweak but it made all the difference in the world.

I do plan to put the BK 415 on it soon to see if I can get the pic a bit sharper.

I have another CTC-5 that uses the super chassis, has a different chroma chassis that I will also be working on. It also has a 21AXP22 so it should be interesting to see them side by side.

here is a link to the completed Wingate.


http://www.youtube.com/watch?v=FlJ0mmAFU-8

http://www.youtube.com/watch?v=awBdl94wvbk


I just found the correct pull knobs for the missing lowers, and thanks to Steve, I have an idea about the escutcheon need. I am going to see if I can find an oversized escutcheon (brass with squar hole) the file to the correct shape as its a very simple shape so I am pretty sure I can get it very close.

here is a link to the completed Wingate.

I just found the correct pull knobs for the missing lowers, and thanks to Steve, I have an idea about the escutcheon need. I am going to see if I can find an oversized escutcheon (brass with squar hole) the file to the correct shape as its a very simple shape so I am pretty sure I can get it very close.

Dave,

You should post the photo of the lower Wingate door pulls I sent you. Someone out there may have a complete set from a junked Wingate. Who knows?

-Steve D.

Thanks Steve,

here is what I am looking for. The pulls rings I have found on ebay, but the small backplate is missing from my set

funny thing about that video of the wizard of oz, on my other sets I have the same issue with the tint range, you have to advance it much more toward green to get normal pictures. With other video sources the tint range is much more normal. I don't recall having issues with other DVDs so I assume its not the player but rather the DVD itself. odd....

Here you go. Available on ebay.

http://compare.ebay.com/like/220725189034?var=lv&ltyp=AllFixedPriceItemTypes&var=sbar

http://www.ebay.com/itm/200298858825?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649

this is what I found, maybe that key you linked is two part and I could use the backplate.

On Bob's link I asked them if its two pieces, and if so to get a pic of just the back plate. The pull part I found looks to be identical to the orig. I may just fab up the back plate based on Steve's pic as it does not seem to have any ornate decoration.

funny thing about that video of the wizard of oz, on my other sets I have the same issue with the tint range, you have to advance it much more toward green to get normal pictures. With other video sources the tint range is much more normal. I don't recall having issues with other DVDs so I assume its not the player but rather the DVD itself. odd....
A while back, there was a discussion with comparison pictures of various Wizard Of Oz disc versions, and their hues varied quite a bit. If you don't have the newest version that was released a couple of years ago, it might look better than older ones. It certainly looks fantastic on Blu-ray.

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