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 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/...okeCovers.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/wh...FQSxnQodVAsAtA

maybe cut the bottom off and use that.

this looks interesting

http://www.stuff4scrapbooking.com/wh...FQSxnQodVAsAtA

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.