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#1
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CTC 5 Super signal issues
Hi all, I'm trying to finish a CTC 5 and am having difficulties getting a good picture. When the fine tuning is set where I get a color picture, I get lots of herringbones in the picture and buzzy sound. If I adjust the fine tuning to a point where I get strong, clear sound, the picture is out of sync. If I adjust the fine tuning for good video, I can get a good, clear picture, but it's black and white and faded somewhat. I tried using a substitute tuner feeding into the IF, but it didn't seem to help. I wondering where I should look next. Any ideas?
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#2
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Sounds like IF and color alignment problems.... if you are really lucky you can fix it by replacing every resistor in the IF that is at the edge of or out of tolerance and tube swaps...but odds are it will need a proper sweep alignment... don't randomly monkey with the slugs you WILL make it worse.
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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 |
#3
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I'd also bet it's IF alignment
A couple items that are probably not a fix, but I would try really simple really quick things first: I assume the cable from the tuner to the IF is good (center conductor and ground)? Replace/swap IF tubes just in case one is causing trouble. It only takes 5 minutes to rule these out. Although they aren't likely, if they are a problem, chasing alignment will be futile. Next check resistors and other parts. Then consider doing alignment |
#4
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Adjust the 4.5 Mhz trap a little. Be sure to flag your alignment
tool so you can put it back where it was if it dont fix it. Be gentile, its old & dry in there ! 73 Zeno LFOD ! |
#5
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Thanks, guys. I'll give the easy stuff a try first. All the resistors have been replaced. I have the gear to align it, just dreading the job as you have to setup a bias supply, resistors, jumpers, etc... if I could hook this up to a test jig it wouldn't be bad, but the RCA test jigs are only compatible back to the CTC-7. I'll report back on what I find.
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Audiokarma |
#6
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The jigs should support everthhing but your convergence (which is unnecessary)...You may have to create your own deflection yoke adapter.
I was able to run a CTC-2B on my jig even though claimed support does not start till a few chassis later.
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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 |
#7
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For the 5 you have to use the original yoke from the set. If you don't the flyback will scream like a banshee.
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#8
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check for bad ground connection on IF section and cable between the tuner and IF input. Always look for the easy stuff first.
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[IMG] |
#9
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Untrue, I had 4 different CTC-5 chassis on my jig last year and none of them complained at all. I have a roundie jig, not a later square one with the silly shunts and whatnot.
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Evolution... |
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