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#196
03-27-2020, 10:17 PM
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this is just not making any sense...
IF the flyback was damaged/ had a shorted turn, would I not also get weak Horz sweep at the yolk as well as poor HV? BUT... https://imgur.com/YanCyvE they are perfect... https://imgur.com/30SwwKS Cathode of Damper https://imgur.com/QAX2DQS input to horz yolk coils , pin 4 of damper, 100x probe this is getting very strange  if there was a FBT problem, should i not see it in the sweep output?
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=^-^= Yasashii yoru ni hitori utau uta. Asu wa kimi to utaou. Yume no tsubasa ni notte. いとおしい人のために 
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#197
03-28-2020, 04:48 AM
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I'm a recent joiner to this forum, and only recently been bitten with the vintage TV obsession, but aren't 630s like the most common postwar TV ever made? Must be tons of used parts available, perhaps from someone here. BTW, on another thread, I was chided (gently!) about not doing a full recap on an old Andrea TV before doing any other work on it. My rationale was that if it had a bad yoke, HV transformer, or CRT (metal cone), it would be a waste of time on a rare bird like the Andrea. Once I verified the hard parts were good, I scheduled it for a full recap. But I don't think you have a dead end here with a 630 clone. Best of luck. John
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#198
03-28-2020, 10:31 AM
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Yes, I would expect sweep issues if the was a short in the windings. Does adjusting the drive control do anything ? Also don't assuming anything until you can try a different 6BG6.
It's not the most common post-war set, but a lot were made. Total TV production in 1946 was only something like 180,000. Replacement flyback should not be too hard to find though. I believe a Thordarson FLY-1 is what you'd want. It was used in many other brands and models too. Last edited by bandersen; 03-28-2020 at 10:36 AM.
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#199
03-28-2020, 11:02 AM
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flyback removed...
https://imgur.com/VQodl6R https://imgur.com/qw1tylZ There are cracks in the " doughnut" but not too bad, right now I think there is nothing to loose in covering the windings with corona dope. at this point I tend NOT TO believe what the meter is telling me, as when I had this apart, I took the chance to check the 2 resistors under the HV rect base, the 3.3 ohm to the heater is OK, but the 1m going to the CRT anode lead checked wide open, VERY BAD, even with it like that, I was getting 5kv at the CRT. So... I have a new 6BG6G coming, gonna try and dope the FBT as best as I can, replace the 1m, put it all back and see what happens.
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#200
03-28-2020, 01:50 PM
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#201
03-28-2020, 06:17 PM
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1 meg resistor replaced.
flyback put back in. https://imgur.com/NV9COl1 taken with no CRT hooked up. YES, adjusting the drive control has slight effect on HV, by about 1.5 volt. At this point, I'm not sure if I believe what the DVM told me or not, as the HV is now normal. and the sweep looked OK,I did look briefly for a "Fly 1 " but did not get any hits, if it is really bad I'd have to look harder, but I'm not sure where  EDIT-- just hooked up a CRT and the HV went up to 11kv. i am really doubting the FBT is bad now...
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=^-^= Yasashii yoru ni hitori utau uta. Asu wa kimi to utaou. Yume no tsubasa ni notte. いとおしい人のために Last edited by Yamamaya42; 03-28-2020 at 06:33 PM.
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#202
03-28-2020, 08:50 PM
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#203
03-29-2020, 12:02 AM
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The IF is obviously going to need work. :/
https://imgur.com/jT1W485 https://imgur.com/VIv1zqV yes, I now know I have the yoke on backwards :O https://imgur.com/nFmlP4w https://imgur.com/oGGx7gd but this is through the tuner
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=^-^= Yasashii yoru ni hitori utau uta. Asu wa kimi to utaou. Yume no tsubasa ni notte. いとおしい人のために
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#204
03-29-2020, 10:00 AM
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For starters don't go randomly tweaking all the IF's. I'm reviewing the alignment instructions from Sams. Do you have an rf signal generator that you can trust the frequency settings? And a high impedance DC voltmeter(I prefer a scope) to monitor the AGC voltage?
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#205
03-29-2020, 10:32 AM
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Following Sams, you basically want to adjust only A4 and A6 on the coil you replaced per directions below. If you don't have a reliable rf signal source I suggest substituting a test pattern on a DVD through a rf modulator into the tuner. Assuming everything else was close, I think you could get away with visually aligning A4, A6 for best picture. Since it's a replaced IF you don't have much to loose by only adjusting those two coils. If you do that make sure you have the tuner adjusted for best picture. Since the sound is split from the picture at the tuner, don't worry about best sound for the time being.
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#206
03-29-2020, 10:41 AM
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I do not have a generator right now, but am looking at... https://www.ebay.com/itm/Signal-Gene...ry!78665!US!-1
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=^-^= Yasashii yoru ni hitori utau uta. Asu wa kimi to utaou. Yume no tsubasa ni notte. いとおしい人のために
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#207
03-29-2020, 11:05 AM
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Yes most modern DVM's are high enough impedance, but for myself it's much easier to watch an analog needle or scope trace moving than numbers flying by. Some DVM's even have a analog graph.
Your call if you want to wait until you have appropriate alignment equipment. My gut feeling is you could get your first IF stage visually better, understanding that you keep track of your starting points and you don't mess with any other coils. Generally it's not advised to adjust anything without having the correct alignment tools, although over the years we've been proven wrong when complete newbies pull off almost miraculous visual alignments. If you be patient I'm sure someone wiser than I will provide alternate suggestions.  Oh, forgot to ask, did you ever get your sound working?
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#208
03-29-2020, 11:23 AM
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https://imgur.com/ej7sfiL https://imgur.com/gbsSKCO https://imgur.com/1oDkIJe how it looks with yolk NOT backwards.. the problem is with trying to do the 1st IF visual is, there is on adjustment that you can get to from top and the other only from the bottom... but in order to hook up the CRT safely I need to lay the chassis down, cutting off access to the adjustments on the bottom... https://imgur.com/lsyrjzp I have no easy way to have the chassis on the side and have the CRT supported, mainly cause of the short leads to the yolk
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=^-^= Yasashii yoru ni hitori utau uta. Asu wa kimi to utaou. Yume no tsubasa ni notte. いとおしい人のために
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#209
03-29-2020, 11:48 AM
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From those pictures it's difficult for me to tell just how bad the video really is. Any chance you have a test pattern DVD?
I understand the struggle of getting to both the top and bottom adjustments. I've been known to roll the whole shebang onto it's side, but only if there's a band holding the CRT secure. Just for fun here's a couple pictures of me having used my HP8662A synthesized sweeper to align an Admiral 20Z1 chassis. The 8662 has 5 programmable markers and they are being intensity modulated using the Y axis input to the Tek scope. I know it's crazy overkill, but sometimes you need to do absurd things just because you can.    
Last edited by Kevin Kuehn; 03-29-2020 at 12:22 PM.
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#210
03-29-2020, 12:51 PM
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building something to hold this little CRT with the chassis sideways is not impossible, just not very easy, no mounting points on it :/ I could try gluing something to it.. who knows.
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