Not Quite Sure What To Call This

[old_coot88]

Originally Posted by vts1134

...I wouldn't describe this as full width ribbon lines in the picture. The trailing white only happens to the right if the brightness control is set to a normal level. It's like some one takes the right hand edge of a white object and pulls it out horizontally to the right.

Oh, so the lines on the left appear only at max brightness but not at normal level. Right?

For the heck of it, double check the value of R138 (grid leak resistor of 1st video tube V115). The print is really smudged but it looks like 475K.

And double check R140 (plate load resistor, 3.3K)

Pin 2 (suppressor grid, G3) is grounded. Check to be sure the tube's pin actually makes contact thru the socket to ground.

Wiggle V115 and V116 in their sockets and see if there's any change in the wackadoodle lines.

Did you try subbing V115 and V116?

[Zenith6S321]

Originally Posted by vts1134

Can any one tell me what this problem is called, and what the possible causes of this problem might be?]

I have also been restoring my 630TS and after the replacement of all the paper caps, all the electrolytics, and all resistors out of tolerance by more than 7% I recall seeing a similar (if not the same) image while using my little 5AXP4 test CRT. Unfortunately I did not take any pictures of that problem. Since then I have spent several days struggling with the video, audio, and tuner alignment. This is my first attempt at aligning a tuner, so I could be completely wrong. Most of my struggle was with the tuner alignment which ended up being solved by carefully selecting the 6J6 tube that worked best (alignment sweep response pattern wise) in each of the three tuner 6J6 positions. It went from only getting a weak picture and no sound of channel 3 on tuner channel 4 to getting a good picture and good sound of channel 3 on tuner channel 3 and channel 4 on tuner channel 4. I found that I had to perform the video and audio alignment again after the tuner alignment to get the video and sound right. The final video alignment was able to flatten the response curve, but not as good as the alignment figure in the procedure. Here is an picture after the final tuner and IF alignment. Its not well focused yet but I do not seen any smearing now. I still need to go over the horiz/vert linearity and size adjustments once the chassis is back in the cabinet.

[Geist]

Hi All;
I like what your screen says -- Your TV or its cables are NOT HD -- ..
That says it all..
THANK YOU Marty

[old_coot88]

Originally Posted by Zenith6S321

?...The final video alignment was able to flatten the response curve, but not as good as the alignment figure in the procedure. Here is an picture after the final tuner and IF alignment.

Fine detail in the pic doesn't get much better than that. "Proof is in the puddin'" as the old saying goes. I would call it a day on the IF alignment.

[Zenith6S321]

Thanks, I'm happy with the way the alignment turned out as the sound is as good as the picture, unlike my 721TS. I will have to take another shot at its alignment, before I forget the details .

Dave

[Zenith6S321]

Originally Posted by Geist

Hi All;
I like what your screen says -- Your TV or its cables are NOT HD -- ..
That says it all..
THANK YOU Marty

Yeah, I grabbed the remote to try to find some text like vts1134 used to show the problem. When I saw the DirecTV's low-res warning text I thought it was kinda cool. May not be HD but I really like this set (now that it works ).

Dave

[Phil Nelson]

Originally Posted by Phil Nelson

There was a recent thread in another forum by a guy who had similar horizontal lines (on a different television) that looked like overdriven video. I think they disappeared when he removed (or changed?) a modification he had installed to minimize retrace lines.

Here's that other thread I was thinking about:

http://www.videokarma.org/showthread.php?t=257163

His symptom was different -- full-width horizontal lines with some vertical folding -- and you don't have a retrace mod to un-install, but the discussion may be mildly interesting.

If you haven't already done so, may as well follow up on old_coot88's most recent suggestions.

Phil Nelson

[earlyfilm]

Originally Posted by vts1134

The usual cause of video streaking, in your 630, in order of probability is:

1) Gassy tube in video, DC restorer or CRT.

2) Plate to grid coupling cap is leaky in video or CRT circuits. In a 630 there are four .05 caps doing the coupling.

3) Grid or cathode resistor in video or CRT circuit has gone high.

4) Circuit in general around the DC restorer, especially the one meg ohm resistor from cathode to plate.

5) The internal resistance and capacitance of the B&K has overloaded or detuned the tube at the injection point.

6) The B&K itself has the problem.

James.

[vts1134]

Sorry for the delay guys. I have been crazy distracted with another set that I recently acquired. I'll post details on that gem soon.
I got back under the 630 for a bit this evening. I checked the resistors in the video circuit. Three resistors seemed a bit high to me. R138, the grid leak resistor on the first video amplifier is supposed to be 470K and it reads 570K. R148 (grid leak on the CRT?) is supposed to read 100K and it reads 125K. Those two are still fairly close but the worst offender is R147 which is supposed to read 3300 and it reads 4800. I will replace as necessary and report back.
I have not tried subbing V115 and V116 as I do not have replacements. Also my B&K is not causing the problem as I am using a modulated DVD player for these shots. The B&K was my first suspect so I wanted to eliminate that possibility.

[earlyfilm]

Originally Posted by vts1134

I have not tried subbing V115 and V116 as I do not have replacements.

Your audio is working fine, correct?

Once you have changed out the high resistors, borrow the V106 and V109 from the audio for testing the video.

Jas.

[vts1134]

Originally Posted by earlyfilm

Your audio is working fine, correct?

Once you have changed out the high resistors, borrow the V106 and V109 from the audio for testing the video.

Jas.

The audio is completely out of alignment. I can got some FM radio broadcasts on some stations so the audio amplification stages do work, but the entire section is not functioning as it should yet. I am planning on moving to audio when I finish with the problems in the video section.

[vts1134]

I got back under the chassis tonight and got R147 down to 3300 ohms. I can't quite tell if it made the problem less noticeable. I reported earlier that the controls on the set didn't affect the problem, but I did figure out that the higher I set my picture control the less noticeable the symptoms becomes. When the picture control turned all the way up the symptom is much reduced, although definitely still there. The overall picture also lacks good contrast which could point to that area. I've started to do some resistor checking in the picture IF section, but nothing is standing out yet. I feel like the picture control just isn't adjusting the signal like it should. As Phil stated before:

Originally Posted by Phil Nelson

At one end of that control's range you'll get almost no signal, and at the other end you'll get wackadoodle picture & sound.
http://antiqueradio.org/index.html

My picture control at one end is 0 signal and the other end seems like it should "go further".

[Alastair E]

Looks to me to be something with the IF or the detector...

How is the vision IF Alignment? Detector OK?

[vts1134]

Originally Posted by vts1134

I don't know if it is apropos to this problem but the contrast control on this set seems more like an on/off switch. There is only three different settings- no video- weak contrast- good contrast. Other sets that I have are more of a gradual even ramping of the contrast level from no video to over driven.

I'm turning back to this thought. I've scoped the video output of the set and it confirms this description. At one end of my picture control setting I have no video, as I turn up the control I get a gradual increase in signal but at about 1/3 of the way up the signal stops increasing. When I meter the impedance at the control itself I get the results you see in the video below. I am adjusting the picture control at the same rate for the entire time the video is being shot.

http://www.youtube.com/watch?v=jmCvh9sm0Wg

Would this point to a malfunctioning picture control pot?

[old_tv_nut]

It's possible this is intended - an "audio" or approximately logarithmic taper. I don't see any obvious jumping that would indicate a bad pot.

Is this the original pot? If not, it may have been replaced with the wrong one.

If you can measure the voltage range at the wiper, you might try disconnecting it and substituting a power supply that lets you adjust the voltage over a somewhat larger range, just to see if there is more gain range available.