Ts18 verticle problem
 

Ok this ts18 I recapped and upon trying for the first time the hold pot was maxed to keep from rolling then after Alittle while the roll started and now has got so bad that the pic can hardly be seen, just massive lines and jumping. So I changed all Micas in the vert and horiz no change. So I already went over resistors in the beginning and changed 2 resistors and there are no more resistors out of tolerance still no change. Checked the vert size and hold pot resistance is good . I'm sure I'm missing something here if anyone has an idea what's going on with this please I'm all eyes. The crt is bright so the hv is ok and also subbed tubes in the vert and horiz nothing works. What I did do is I was able to get the roll to stop and almost a full screen by placing a .01 cap from ground to pin 4 of the 6sl7 at the 100k resistor which is good also. So I don't know maybe a ground leak to something in the vert but where. The horiz is perfect. The lines look like retrace lines without the mod. I'm lost here. Is it possible for a resistor to check good out of circuit but in the circuit change drastic value.

Did you replace the high voltage caps with tubulars? When I did my TS-18 chassis I used ceramic discs and they did not work well in the vertical. I would check every resistor and cap in the vertical oscillator and output circuits. Also check for wiring errors. Despite being careful, it does happen. These chassis perform well when restored.

Well I am using ceramic disc for now and I know they work since upon getting done recapping it had a great pic and clear. I already checked all resistors more then once and replaced a few but that's it. I have several others like this, 2 ts18 s and ts4ds and they work great but this one is giving me a run for sure.its like something failed shortly after running it but can't find it. I have a cap checker and the discs I'm using for now are fine.

There are 2 10meg resistors that I changed at the 6sl7 and put in 2 1meg resistors mistakenly , and some how I have verticle hold close to maxed on one end but the vert size is almost maxed to fill the most of the screen. So I'm wondering if because I'm using ceramic disc caps instead of tubular could this be messing up the verticle and size because there is not enough capacity. And the wrong resistors I put in maybe they accidentally made the wrong caps work. Because these sets are known to work with disc caps mine seems to be the exception to other sets like this one.

Put the right resistors in, check and if it is still not right loose the ceramic caps, then check back.

I had the right resistors in as they were at 10.55 meg so I mistook the colors on the resistors and changed them but I put in 1 meg so putting them back won't solve it. I'm just not sure if these caps alone would do this, although I have one tubular on one side of the verticle and ceramic on the other side. The horiz has both exact same ceramics in but that's fine so maybe the mix between the tubular and disc maybe throwing it off. I didn't order the right caps yet figuring I could use these to get the set running.

Horizontal runs at a much higher frequency so you can usually get by with ceramics. Ceramic will definitely give you problems in the vertical unless you use a much larger value then specified.

Tom used 0.01 uF caps with good results.

You can read all about it here: http://www.videokarma.org/showthread.php?t=260749

The 0.01 would be the same as .01 ?

Yes

well I need some direction here with this ts18 verticle problem . After changing all Micas in the vert section and horiz and recapped all else the weird thing I have going on here is not only can I not find any bad resistors anywhere and the b+ and b++ is right on the money but there is lines jumping all over and really can't see any pic but if I take a .01 cap and parallel it to the .004 at the 6sl7 I have vert hold and almost a full screen except for some linearity loss and a great picture. One end of the .004 is ground .

Have you changed the 2 resistors in the vertical back to the correct value (10meg) ?

jr

Yes put the 2 10 meg resistors back. I don't have a hv probe it stopped working so could it be low hv but yet still have a bright screen.

That .004 cap has to be exactly .004 mfd. Try another .004 cap

Well don't have another, the one I have is new but is there another that may be close enough to rule anything else out.

Here is what I have you can see a picture in there but there's to much roll that cannot be adjusted. I even adjusted the hv ring thinking maybe low hv but no change. Sorry the iPad flipped the image.

Have you checked the value of the vertical controls? I had a open vertical centering on a TS-18 that drove me nuts! It had sweep, just bizarre. I had another one with 1/2 the value on vertical centering control. I had to add resistors on each end. Once I did, it worked great.

Both the vert hold and the size are good, ohms wise and the vert centering works correctly. This set is bizarre since I cannot find anything wrong.

Do you still have the mis-matched capacitors in the vertical output?
Are you absolutely positive the vertical circuits are wired correctly?

Do you have a spare vertical oscillator transformer?

jr

I still have the different caps in place but they both test what they should in NF 4.50NF and I went over the SAMs and more then double check everything. Which is the vert oscillator trans T? I may have one from another set. I don't think there is a vert oscillator trans in the ts18.

You are correct... no VOT in the set... sorry !

jr

Is one of the caps in the vertical ceramic ? It's capacitance will change when high voltage is applied causing problems. That's why you should use film or a ceramic cap much larger than what is called for. Swap the two caps around and see if the problem changes.

I thought about switching them around. I did put several red film caps in series and parallel to make .005 but that didn't do anything to help. I have the one white tubular on one side and 2 ceramic 2kv caps on the other side and are equal to the NF of the other but if the capacitance changes with hv then I guess it won't work.

2kV??? those caps should be at least 6kV!

jr

I know 6 kv but I'll post a pic of the screen the way it is and another pic with a .01 cap paralleled with the .004 . This is baffling since it has a bright screen and a decent pic with these caps, which is only one side of the verticle has the ceramic.

Ok here's the pics with the ca and without. And I tried another .004 I made up of film caps, 2 to match the pf. Ok the next post has the other pic.

And the other.

Timmy,
Where did you ground the .004 cap, chassis or B- buss. It should be the B- buss.
Ed

It's grounded to a factory tie strip that's tied to the 6sl7 that's where the .004 is grounded. Nothing was changed was all original where the cap was is where the new one went. The weird thing is upon turning it on for the first time it had a pic that rolled but the hold pot had to be maxed at one end to stop the roll then it went down hill fast to what I have now and it was good with those caps I have in there now . It's on b- not the steel chassis.

Ok there is no more ceramics in the verticle and still after putting together several 2 kv metalized caps in series to make 6kv and the proper NF for this application no change. Is it possible that the 2 ceramics in the horizontal could be causing this even though the horiz works perfect. The ceramics in the horiz are .002 10 kv. My mistake the caps in the horiz are .002 not .001 so I don't think that would make much difference.

You need the correct 6kV tubular caps in the vertical circuit to have correct linearity. The mix and match does not work well here.

V11 pin 5 measured from pin4 of v10 measures 232vdc but the SAMs says 70vdc and I cannot get an accurate voltage reading on pins 2 and 5 of the 6sl7 with a digital vom. And v13 pin 2 shows 20k or 520 ohms but it measures 2.2 k this set is going to drive me to drink, omg lol.. Any help out there? I'm also using a glass ballast and tried a ballast made up of resistors.

I belive that the 20k, 520ohms indicates a range of readings possible, depending on the setting of the horizontal size control... 2.2k is within that range.

As far as the high voltage on the plates of the vertical output tube is concerned, my guess is that your under voltage rated caps may be leaking CRT deflection high voltage back to the output tube (6SL7).

Until you replace the mis-matched under-voltage caps that you have in the vertical output circuit, all bets are off. :thumbsdn:

jr

I have one correct tubular in there and the other is met film in series made up to 6 kv. With these caps I have in there now I thought it would work for now since I didn't order the rest of the caps.

What is the value and voltage rating of each of the caps in series?

jr

The caps are 5.6 NF at 2 kv each. I have them in series to make up just about the equivalent of a .0047 6kv. My Dvom measures caps this is how I was able to do this, measure the asc cap I have and this is how I got the result using the others.

You would have to have 3 in series to make a 6 kV rating... 3 5.6 nF in series would only be about 1.8 nF. Do the math, something is wrong in your configuration.

jr

At the risk of sounding like a jerk, this is what you need. It's what I use and all I can say is that they just work.

http://www.justradios.com/ASCcapacitors.html

In a previous post there is a pic of the set working with a really good picture but this will only happen when I parallel a .01 cap or even a 1 meg resistor with the .004 cap at the 6sl7 without that the other pic shown in the previous post is what I got so if these caps are not working then how would I get such a good pic otherwise. I know I need the right caps and I intend to get them but now I feel something else is going on here because when I put the new caps in and if I have the same problem then I'm back to square one looking for it. When I have the cap or resistor paralleled the vert hold works fine but I'm Alittle short on linearity so it seems as if there is another small problem that I'm not finding. I tried another .004 cap and made no difference. Resistance checks at the 6sl7 are right on but on v13 pin 2 SAMs shows it should be 20k to 520 ohms seems like a big swing but I'm getting only 2.2 k .

And if the incorrect caps ARE causing your problem, and you decide to wait to change them until you've fixed the problem you will only end up chasing your tail forever....
You've already said every other component is good, the most logical move is to start with replacing the two that ain't. If your problem persists then we'll be a LOT more happy to help you trouble shoot it.
Besides how much time have you spent on it, and how much more might you waste on a probable cap issue? That time is probably several times more valuable than the caps.

:smoke:Ok, all the hv caps are new and still don't have verticle this set is beginning to remind me of the silvertone. Any ideas what may be going on here. It's like it's rolling so much the screen just collapsed. There are 2 caps at the 6sl7, a 100 mmf and a 250 mmf I subbed those as well even tried another .004 cap at the 6sl7 also checked both vert size and hold pots both good 5 meg . There are no resistors that are bad I went over them clipping one leg to be sure. The 6.8 Meg's at the 6sl7 are up Alittle 7.5 meg which my other sets were up around there as well. All the 2.2 meg resistors are good except one I changed. Tried other tubes no change. The b+ and b++ voltages are right on. All Micas in the verticle and horiz I changed one at a time to see if there was any difference from mica to mica still no change. So now I guess I'm looking for one of the pros here to tell me what I may or may not have done. When I first fired the set up for the first time it had vert hold but the pot was maxed to keep it from rolling I then turned it off for some reason or other came back to it and had this crazy verticle problem.