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  #136  
Old 12-19-2014, 07:27 PM
dieseljeep dieseljeep is offline
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Quote:
Originally Posted by DaveWM View Post
attach the ground clip before you hurt yourself.
I was thinking that myself!
Trying to remember what I did with mine. I had a Pomona brand. It seemed like most of them were. IIRC, the scale went to 40KV.
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  #137  
Old 12-19-2014, 07:38 PM
DaveWM DaveWM is offline
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some had the built in mA scale too, 0-500ma with the frankenstein neck bolts.
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  #138  
Old 12-19-2014, 08:53 PM
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Mine is the Pomona Model 2900A.. Spent all of $20 on it including shipping.. Dated 1969...


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  #139  
Old 12-20-2014, 12:41 AM
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I've got three like that, including my go to unit.
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  #140  
Old 12-20-2014, 10:44 AM
dieseljeep dieseljeep is offline
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I've got three like that, including my go to unit.
I'm trying to remember what I did with mine!
It's been years since I used it, as I quit repairing TV's for others.
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  #141  
Old 12-21-2014, 11:09 AM
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I have a Zenith high-voltage probe. It's a big sucker and measures up to 50Kv.
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  #142  
Old 12-21-2014, 12:50 PM
old_coot88 old_coot88 is offline
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Wunner how well those barber pole resistors hold their ohms value over time.
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  #143  
Old 12-22-2014, 05:23 PM
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Ok, received everything today.. Thanks to Findm-Keepm for the cap.. Very nice of you.. I'm confused which ground to disrupt to connect meter.. Sams shows 2 grounds coming from the bottom of the Horz output tube (6JS6A) but there looks to be three with the black wire.. Black wire or the bare wire right end looks to be the cathode.. But I'm not sure..




I assume this is the correct way to connect cap

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Last edited by tvcollector; 12-22-2014 at 06:04 PM.
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  #144  
Old 12-22-2014, 06:17 PM
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You've got the cap right.
This is a guess off the top of my head, but I think the middle might be the cathode. Sam's usually lists pin numbers of tubes on the schematic. The tube numbers count from the key way or missing pin clock wise or counter clock wise depending on which side of the socket you are looking at. Find a pin that you know what it is based on what it is connected to look up the number on the sam's and count. Some elements on a tube have more than one pin connection (grids and cathode usually on HO Tubes). If sam's only lists one pin when two are used googleing the tubes data sheet and looking at the pin out there will give you the whole story.
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  #145  
Old 12-22-2014, 06:27 PM
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The Sams doesn't show the pin numbers of tubes on the schematic.. Black wire is connected to pin 2.. The left bare wire is connected to pin 12.. and middle is pin 10.. If all that says anything..

Found this image of the tube on Google images.. If I'm reading correctly it would be pin 2
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Last edited by tvcollector; 12-22-2014 at 06:52 PM.
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  #146  
Old 12-22-2014, 07:34 PM
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Assuming I have the meter in the right place seeing how I'm getting readings that make sense.... It measured 170ma, as I dialed in the horizontal, the meter jumped to around 195 - 200ma.. Still the normal range.. I did go past the 215ma and powered the set off real fast and then backed off the opposite direction.. It's now in locked position with meter reading around 195ma. Now I hear a slight pop noise of static electricity every few seconds around the fly area.. The picture is black and white, as i suspected seeing how the scrambled out of horz pic looked, and also real blurry...

Update: I turned down all the drives to about mid way and the picture is much better in focus.. alot of green and blue off images and alot of noise in the picture.. I tested one of the tuner tubes and it's also a questionable tube.. Horizontal and vertical seems to be fine.. HV pop noise went away.. Vertical has good range and locks in the middle.. Color and tint do nothing, though slight crackle in the speaker when adjusting..

Seeing how I'm still new to all this.. I have no idea where to go next.. I suspect this will need a recap.. The electrolytic cans don't get hot, but barely warm after a while..
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Last edited by tvcollector; 12-22-2014 at 09:42 PM.
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  #147  
Old 12-22-2014, 09:52 PM
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Turn the color up and adjust the fine tuning from being swamped out with noise at one end to being swamped at the other. Often times you will not get color with the fine tuning just a bit off of the right spot.

If it keeps regularly popping then, with the set off discharge the CRT, and clean the inside of the HV cage especially around and in the HV rect socket and insulator and the top lead of the fly, and HV rect filament winding.

It is safe to let it run up to 230mA for short periods during adjustments, but don't let it sit that way for over 15 minutes.
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  #148  
Old 12-22-2014, 10:15 PM
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Oops you're right.. Fine tuning brought color back.. Plus I hooked the cable up to a coax adapter and the picture went from crappy looking to beautiful.. The tint needs to be adjusted.. Tint all the way up makes the face tones better.. The popping went away.. I've got some videos I'll be posting in a few.. To do convergence and set up with test patterns.. What does anyone recommend?
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  #149  
Old 12-22-2014, 11:42 PM
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Use a crosshatch pattern to adjust the static (center) convergence using the adjusters on the convergence clover (yoke). *After that put a full red raster on the set either from a pattern generator or by turning down the other screens, slide the deflection yoke back until the screen looks tie-dye, center the red blob with the purity rings, then slide the deflection yoke forward until the screen is all pure red.
After that touch up static convergence, and proceed to the dynamic convergence following the sam's procedure. It is a complex process so you may need to repeat it 2-3 times to get it optimal. If after a few tries you conclude that don't have enough control range try moving the clover around...When you have a good feel for the controls you may be able to know when/how to tweak the clover by instinct. Convergence can rarely be gotten perfect, once you have it good up to 1-3" from the edge of the screen declare victory...If you can do better give your self a cookie and a pat on the back.

* You may need to degauss the face of the CRT first. You can make a degaussing coil easily by taking one out of a newer junk CRT and fitting a power cord on to it.
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  #150  
Old 12-22-2014, 11:52 PM
old_coot88 old_coot88 is offline
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..It is safe to let it run up to 230mA for short periods during adjustments,...
Sorry, no way. If he's running a 6JS6, it'll be close to red plating at that current. Keep it below 210 if at all possible.
A 6KD6 it will handle higher current safely.
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