#601
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And you've tried moving the purity rings around to where the red blotch is in the middle? On some sets I notice if it's slightly off centered the red fills in much better...
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Looking for an all tube or hybrid color TV set from the late 1960s, early 1970s that's in a steal cabinet.. |
#602
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I've tried that too no luck. I haven't tried putting it slightly off center though. Should I try the edge purity or just off center the red splotch a bit in the regular purity?
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Admiral C322C2 Regent (Restoring) RCA CTC-7 Pensbury (Restored) RCA CTC-5 Westcott (Restored) CRA CTC--4 Director 21 (Restoring) |
#603
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I don't know what edge purity is.. Just off center the red slightly in different positions, and keep trying..
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Looking for an all tube or hybrid color TV set from the late 1960s, early 1970s that's in a steal cabinet.. |
#604
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Here's the standard purity procedure..
First do the degaussing as discussed earlier. Turn the G and B screens fully off. Turn the R screen up. Slide the yoke back as far as it'll go without disturbing the other neck components. There'll be a red splotch. Use the purity rings to exactly enter the red splotch. Slide the yoke forward until the red splotch fills the screen and best R purity is achieved. The yoke's 'sweet spot' for best purity will be about 1/4" to 3/8" short of being fully seated against the CRT bell. Tweak the purity rings again slightly if needed. (if the set lacks auto-degaussing, first be sure the set is in the same location and compass heading it'll be used in.) |
#605
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Just trying to follow, so the signal source was causing an out of focus picture that would resolve after a few minutes? Never heard of that.
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Audiokarma |
#606
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Well it went away after I hooked up the BT modulator and adjust the video and audio modulation down. So either it magically fixed itself in those few minutes when I was hooking the modulator up or fixing the over modulation stopped the lack of focus and the buzzing.
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Admiral C322C2 Regent (Restoring) RCA CTC-7 Pensbury (Restored) RCA CTC-5 Westcott (Restored) CRA CTC--4 Director 21 (Restoring) |
#607
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1) I don't believe fixing overmodulation will fix focus. Apparently you have been using the word focus to describe something else, or it has to do with too much drive pulling down the high voltage, or something else I can't tell from your description.
2) Does this set have hairpin shaped wire gizmos on the CRT mount? These are edge purity adjustments - turn them this way or that until your blotch is compensated. |
#608
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BAD video frequency response can look like bad focus.
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Tom C. Zenith: The quality stays in EVEN after the name falls off! What I want. --> http://www.videokarma.org/showpost.p...62&postcount=4 |
#609
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Yes that is what it was
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Admiral C322C2 Regent (Restoring) RCA CTC-7 Pensbury (Restored) RCA CTC-5 Westcott (Restored) CRA CTC--4 Director 21 (Restoring) |
#610
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as is smearing yes, but I still don't understand why it would self resolve after running for a few minutes.
And if it was a freq response issue, is it with the TV or the Modulator? If its fine with the BT then that would clear the TV as the issue. So it would have to be with the orig modulator. The OP should try the orig prob modulator on another set and see if the "focus" issue self resolves or is not a problem. These kind of problems are very hard to understand and diagnose. Perhap a video of the problem (both the initial lack of "focus" and the subsequent resolution) would be helpful when asking the group for help. |
Audiokarma |
#611
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Perhaps it was tricking the AGC into an operating point where the normal signal was over/under driving the IF.
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Tom C. Zenith: The quality stays in EVEN after the name falls off! What I want. --> http://www.videokarma.org/showpost.p...62&postcount=4 |
#612
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I cant see it being agc, most of the AGC rca stuff I have run into is either it works or its set incorrectly. incorrectly would be a under contrast pic that I would not describe as out of focus but more like lack of contrast. Over load it and you get a dark pic or loss of sync, but again more like too much contrast.
The only defect I recall in AGC was on a zenith with an open cap in the circuit, it would manifest as overly critical range (complete wash out of pic to complete loss of sync in about 1/8 of a turn of the pot. Maybe the OP can duplicate the prob with the old modulator and this time get some video of it. Its nice to see different problems and solutions, may come in handy in the future is someone runs into a like problem. I am still wondering exactly what it looks like, focus mean something very specific to me and I just cant get there with signal source. I wonder if the OP ever tried adjusting the focus control to see if there was an optimum setting somewhere if going either way it would get worse. That would tend to indicate the focus voltage control is working and getting the correct voltage. Then if it went out of focus would touching up the control bring it back. Again to establish focus voltage as the issue. If it was smear from IF response then the focus adjustment should still work just getting the most in focus smear, with out of focus smear on either side of the adjustment optimum setting. |
#613
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Here is the set after I fixed the edge purity problem. I think I finished it once and for all except the screen is a bit tilted. Here is a video of the set. Does anything need to be done still? https://www.youtube.com/watch?v=mwJ5...ature=youtu.be
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Admiral C322C2 Regent (Restoring) RCA CTC-7 Pensbury (Restored) RCA CTC-5 Westcott (Restored) CRA CTC--4 Director 21 (Restoring) |
#614
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looks good, just enjoy it.
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#615
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Alright finally done! Thank you all here so much! A big thanks to you Dave for sticking with me this whole time. Would have been a nightmare without you and all the great folks here at videokarma. I will post any problems I encounter with the set here. Hopefully no problems will surface for years to come. Full steam ahead on the Admiral restoration now!
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Admiral C322C2 Regent (Restoring) RCA CTC-7 Pensbury (Restored) RCA CTC-5 Westcott (Restored) CRA CTC--4 Director 21 (Restoring) |
Audiokarma |
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