Yeah, I’ve made a habit of doing that or completely removing components to test them

Alright, well finally managed to get a HV up and running as well as isolate a short. I was able to get a decent picture as well, though it has a slight horizontal jitter. Any thoughts? What's the best way to isolate the source?

Besides the few size adjustments, not too bad.
Attachment 198235

I have 6 of these Motorola sets and 2 of them are ts4j chassis and it don't matter early or late, there are Micas in the horizontal and verticle change them you may be surprised at the result as I was with my sets as all my sets but 2 I had to change the Micas in both horiz and vert , they were bad. I had jitters from both sides of deflection as well as verticle would not lock to the horizontal not being right. OH and also look into resistors around the verticle and horizontal circuits they will probably be out of tolerance .

The test pattern looks good.:thmbsp: Glad to see you stuck with it on the TS-4J. You may want to try swapping tubes for the horizontal oscillator and afc tube. Maybe corroded sockets and ground connections, rivets. Try the easy solutions first.
Ed

Tried swapping tubes and cleaning a little bit to no avail. I don't have many mica caps, so I'll have to order them. Hopefully that should work.

Thanks all,
Zach

You will see in the schematic the values of the Micas, IIRC there a couple of 100mmf and I think one 250mmf but check the schematic. What did you use for the hv defection caps.

I used .0047 and .001 film caps at 6kv (From JustRadios)



Well, got the new caps and replaced most of the components in both the vertical and horizontal sections. There's still a significant jitter, and the picture quality appears to be getting worse the longer I troubleshoot. Any ideas?

Hi,
What kind of jitter are you seeing, vertical or horizontal? Many of the tv's and radio equipment I repair have flaky potentiometers. They can be a source of erratic operation. A little electrical contact spray helps sometimes.
Ed

I've had Tin whisker issues in pots in TS-4 Motos before. Also the Mica caps in the sweep can be problematic.

I changed the value of the resistor on the wiper of the vertical lock form 3.3m to 4.7m and was able to get a lock on the vertical. However, by replacing other components, the image now looks like this and this.
Attachment 198278
Attachment 198279

I think it's something in the video sections affecting the sync signal before it gets stripped?

I've replaced most of the components in the vertical and horizontal sections, though that's made the video worse than what it was before.

There is also a mica under the 12sn7, horizontal sweep, don't know if you changed that one but if you didn't be careful when changing make sure it's the right value and don't make a mistake putting the legs back in the correct position otherwise the horiz won't run and it will burn up the horiz hold pot. At one point I had changed the resistor to get vert to lock only to realize that I missed a mica in the verticle section and once changed I put back the right resistor and it was fine. Look in the schematic at the vert and horiz section and write down all the caps that are marked MMF those are the ones to change. The one under the horiz tube looks like a dogbone. Although some look like dog bones and others look like a domino.

Just for the heck of it run the set and turn the horiz hold pot all the way to one end then start back to get the best pic because you can get a pic but will have distortion if turned to much in the opposite position, it's happened to me .

Ive recapped my VT71 and it has a case of slight horizontal and vertical jitters. then again, every tv where i use the dvd plaver has the same jitter issue. i wish i had ann over the air signal to use. maybe it the video source causing the jitters

did you try one of those 75-300 ohm transformers where it has the threads on one end and the 2 wires on the other, that's what I use and it's perfect.

Well, I had replaced all of the caps in the sweep circuits. Later today I'll try injecting a composite signal and seeing where that gets me.

~Zach

It may be possible that the alignment is out just a little, if you check the schematic you can very slightly move the channel 3 adjustment on top of the chassis, but do make sure you have a good signal to start with.

Well, tried injecting a signal, couldn't get it to go through the way I wanted. I've combed over the horizontal, vertical, and sync and cannot seem to locate the problem. Is it possible that it's emanating from earlier in the circuit in one of the video sections? The picture appears darkened and has the horizontal jitter. The frame is not centered all of the way, with a little black bar at the bottom.

More pics.. You said the pic is on the dark side and Alittle jittery, have you checked the contrast/ agc adjustment on the front right. There may be 2 caps off that pot, maybe check them.

May want to scope the sync separator...if it is letting video or noise through that could be freaking out the sweep.

It could be, the when the contrast is all of the way up, the picture goes out of control. I'll replace the three that are there. EDIT: I was able to successfully get the picture back to normal by replacing the three capacitors around the contrast control. However, the slight shudder is still there along with the uncontrollableness created by turning the contrast or brightness to full.

Not entirely sure what to look for, however, here's the output of the plate on the sync. Hopefully that helps.

Attachment 198290


I've also purchased a TV analyst for troubleshooting, seems like a useful tool. WOn't be here for another week

Did you check resistors around each IF tube because my sets had several bad resistors around that area. Especially if you think it may be a signal problem.

Yeah, I'd already replaced a few that were double their resistance. Is there a specific way to figure out what section this is emanating from? I've noticed that the power supply has a decent ripple in it, how much is acceptable for a power supply like this?

That waveform looks pretty messy and weak...See if sams has a waveform and compare. If your sync pulses are messy you will trigger retrace mid line and other troublesome things like that.

http://www.earlytelevision.org/pdf/m..._rider_tv1.pdf

ETF has the riders which has the waveforms in it on page 30. It's interesting to see that there's a 60hz signal on the sync output, that might explain the jittering. How much of a waveform should I realistically be getting on the power supply? I would have thought that the filter caps being as big as they are would have taken care of it.

There should be 60Hz in the synch output. Vertical sweep IS 60Hz* and it needs 60Hz sync pulses.

*Granted color changed it to 59.9Hz, but rounding is a thing.

There is a resistor at v1 it's a 1k with b+ at the one end, just from my troubles with my sets double check that resistors value because I have had that resistor bad and even burned up.

Checked that, however I just realised that some of the caps that I installed in the horizontal are 500v mica caps when it calls for 2kv caps. That might explain a little of that. The two caps are C71 and C72 680pf and 900pf respectively. Do those need to be mica caps or can i use ceramic discs?

No don't use ceramic, and as for the voltage yes the cap may show 2k volts but the 500 volt works fine since all the Micas even the ones in the sweep section are 500 volts that I put in my sets and my sets work great with them. I don't think 2 k Micas are available anymore. To answer your question yes Micas belong in that section, the schematic shows mmf , that would be the Micas.

Do you have the high voltage cover in place? It can cause issues if it's not installed.

Yes, it's in place, I messed with it and the picture got worse so I think it's making a good connection to chassis.

Does the distortion of the picture slowly move vertically with respect to the picture? If it does, the source is likely 60hz power related, which is not quite in sync with the vertical frame rate.

jr

There is a high voltage filter capacitor to chassis ground which is a .001 6kv , was that one changed. It may or may not effect the quality of the picture but you never know. Can you at all figure out weather or not it's verticle or horizontal, it would help things a lot at this point. Just a crap shoot but there is a mica that is usually mounted under the terminal strip where the .01 caps are for the verticle and if it's under there it is well hidden and that one should be changed as I had lots of problems and found that one hiding under there and that cured the headache I had with one set I have. Just trying to toss things out there.

I'm thinking it's more some sort of external signal. For now I've put it back in the cabinet and I'll recheck it. One question though. Since this is a transformerless set, I assume the chassis is hot during operation right? and would justify a polarized power cord?

It wouldn't matter...

Oh, ok, nevermind then, I wasn't sure because I had measured line voltage from chassis to wall ground. Any reason for that?

Some of the crazy things they did back in the day would be illegal today, lol. Or UL wouldn't pass them as safe.

The chassis is floating. Neither side of the AC line connects directly to it. One side does via a 470K resistor in parallel with a 0.05 uF cap if memory serves. I believe that is to provide a return path for RF.

Yes it is the RF return path but even though there is a.05 and 470k resistor, depending on what you may touch and the chassis there would be shock though, it has happened to me, not shocking, lol lol. I myself did measure line voltage from chassis to other areas of the set.

Does this screenshot of the manual help? I had the same problem with my set and discovered that I replaced the cap that parallels the primary side of that transformer with a higher value and it filtered out the horizontal sync pulse to almost nothing.