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#301
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#302
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This is very frustrating not finding anything wrong except the ohms of the oscillator coil wrong or not right colors yet it’s got lock. Did resistance check on v-20-25-24 all are very good. There was a voltage difference between 24&25 going to check again.
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#303
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I’m going to put this project on hold I decided one way or the other I need to rule out the oscillator coil I have a supplier that may have this coil and a 15pf mica and the 27k resistor that makes up the whole coil and maybe he will have listed in the miller coil book if there were any production changes pertaining to this coil.
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#304
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To repeat:
If you complete the AFC procuedure and have lock there is no more to be done in this section. Please send some close-ups of the color bars with the tint control at both ends and centered and it may be possible to come up with some diagnosis. You have proven repeatedly that the oscillator is not a problem any more. |
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#305
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Last edited by timmy; 08-13-2023 at 05:35 PM. |
| Audiokarma |
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#306
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I thought you found a way to send pics to yamamaya42 so he could post them. I am sending you a private message to see if you can send them to me. |
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#307
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Ok, so I got the video that you guys posted, thanks! I can see the blue, red, & green colors bars moving through the picture "barber pole" style. This is the burst color not locked, or in sync with the local 3.58mhz color osc. I have labeled "A" in my screen shot off your video.... I don't understand the vertical bars in the picture..."B" Are they produced by the defect with this tv? Will your signal source make the same bars on a different tv? If they only show up on this tv..... What happens when you turn down the color... All the way off to B&W....? Do they go away? If those bars only appear on this tv, then I'm wondering if there is possibly something wrong in the burst gate.... Does your color bar generator put some separator between each color...? Anyway, maybe it's a good idea to take a breather from this project for a few days as you said.... To anyone who did not see the video, the blue, Green, & red bars remain at that 30 degree angle, but raise upward through the picture continuously. The vertical bars labeled "B" remain stationary, and are partially effected by the colors passing by - as if they are behind the vertical bars.... Night.... .
__________________
Yes you can call me "Squirrel boy" Last edited by Username1; 08-13-2023 at 09:34 PM. |
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#308
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What are the status of things when taken?
__________________
=^-^= 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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#309
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So I hear the the grid resistors in the demods are super, super critical I don’t know what would be considered to high befor there is a color problem. It almost seems like only one demod is working. If there is no sign of any blue then I would think maybe a problem in v24 I did resistance check and found that pin 7 1.145k should be 1000k pin 7 399 should be 390 ohms.
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#310
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The reading of 399 ohms which I will assume was on pin 8, ( you listed pin 7 twice ), is of very little concern, for its common to all Y amps, and comes from R205, and is in tol.
What should be of concern is if the resistance readings for pins 7 on V25/V24 are noticeably different, if they are, then BOTH the 68 ohms resistors should be replaced with a closely matched pair.
__________________
=^-^= 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 |
| Audiokarma |
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#311
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#312
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Timmy and I have been chasing his problem via email.
He once got good resistance readings on A17, but no more. Now reading multiple k ohms. Hard to believe that all three windings have opened up, but that appears to be the case. This would kill the blue demodulator. He has a new A17 on order and meanwhile I have asked him to triple check the readings on A17. If this fixes the missing colors, then we can proceed on finding the problem with the tint control. |
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#313
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Quote:
__________________
=^-^= 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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#314
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as for Tint, if L32 is bad, there is a replacement,
https://www.vivatubes.com/nos-nib-vi...id-8-2-uh-rfc/ as listed in SAMS.
__________________
=^-^= 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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#315
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Definitely in the The Twilight Zone with the development, if what he is reading is correct.
The only thing I can picture happening is, A17 was acting up from the start, and the cause of the old crystal to not work, or, something went VERY wrong when it was adjusted for maximum reading, like the entire coil turned, and tore wires perhaps? Timmy's last voltage check of pin 6 V23 (PLATE) was at 189v, should be 220v, a tad low, from a 275v source, via a 8.2k resistor and through the 5.2 ohm coil, I would suspect if the coil was open when this was taken, it would be much lower than 189v? :O
__________________
=^-^= 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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