#16
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I could be wrong, but I've had a 8TS30 and a total of 3 630TS's through the years and never heard of a belt on the fine tuning. I've also never had one where the fine tuning did not work and none had any type of belt replaced.
Last edited by decojoe67; 07-28-2018 at 06:42 PM. |
#17
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Fine Tuning
Thanks for the thoughts on this problem. Are you able to tell from my pictures whether or not it is belt driven or friction drive? Any suggestions on how to increase the friction, so it works correctly. Like I said mine just seems to spin freely having no affect. I'm not clear on how it operates and how to test it.
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#18
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Isn't the plate (green) supposed to be inside the space (red) between the two drive discs?
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#19
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That's correct. The green plate should go between the two red discs.
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#20
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Thank you Wisco Jim and Tom9589. I didn't see that before you pointed it out. I went down and popped it back in. There doesn't seem to be stopping points, so it will fall out again unless something is done. I really appreciate you taking the time to help me.
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Audiokarma |
#21
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That seems like the problem. I believe the fine tuning should have stopping point which keep the flange from coming off the wheel. Those early RCA's usually have a precise "sweet spot" that you will not need to stray far from. Once you set it, the most you'll need to adjust it is a very slight amount.
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#22
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Thanks, decojoe67. I'm at a standstill until my tubes come in, but am encouraged to hear the fine tuning is so precise once set. My picture is still too far off to notice any improvement when it's adjusted. I'd love to hear some ideas I could use to prevent the flange from falling off the wheel again. Also, I have time to work on the cabinet, which is in pretty good shape. I'd like to improve it though, and preserve the finish by spraying some Mohawk lacquer over it. I'm looking for advice on how best to do that. I don't have much experience, and don't want to mess this up. I've added new control decals.
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#23
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Quote:
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#24
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Hello again,
I can't seem to improve this television's picture using the control knobs and the phase control screw. It won't lock on horizontally or vertically, and images appear washed out. The brightness control has stopped responding. The audio is decent, but intermittent. I have to tap on the first audio IF transformer, T-111. I must have made a mistake somewhere along the line, but don't know where the best place to search first would be. I've changed many tubes hoping for an easy fix, but that made no difference. I sure would appreciate any help you could give me. Thanks, Mike |
#25
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Does the Picture control do anything? If not, I think you should trouble shoot that first. The washed out picture and lack of sync could be due to not being able to turn up the picture control.
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Audiokarma |
#26
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If you can get the brightness/contrast adjusted to normal levels and it is still rolling look at the sync separator stage.
__________________
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 |
#27
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Thanks for the quick responses. There are two mica caps that I see in the sync separator circuit. They are C145 and C147. These are 270 uF mica caps between V118 the first sync amplifier and V119, the sync separator. I didn't change those, because I thought doing so would then require me to perform a full alignment which is out of my comfort zone. Are those two possible culprits? If so, I'll get rid of them.
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#28
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Quote:
The sync separator depends on video amplitude being within a correct range. If the video level is too low or too high then even a properly operational sync separator will not provide the right output (garbage in garbage out). The sync separator has no relation to alignment. (And if you chopped off all the IF systems and injected audio and video you would still need the sync separator stage to allow H and V to sync.) If the video level into the synch sep is correct per-original design, then yes those capacitors could be a problem...As could any resistors in the circuit or the tube. General roll troubleshooting advice: in a set where all else works correctly if both H and V roll (and user controls allow you to adjust which direction it rolls) then the issue is almost always in the sync sep stage. If only one axis rolls (direction controllable) then the issue is probably in the axis rolling though could be a separator issue if the other axis has weak sync with a very small lock in range. If contrast is excessive or insufficient at normal screen brightness (assuming good CRT) and both axes roll the problem is likely to be video level. If an axis rolls, but you can only get it to roll one way that axis has problems/is operating off frequency. If only one axis rolls (other has a solid lock) then that axis or it's connection to the sync sep is at fault. This is a case where it is best to find the problem through diagnostics rather than throw parts at the wall to see if they stick.
__________________
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 Last edited by Electronic M; 08-15-2018 at 12:12 PM. |
#29
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Also do not rule out a bad connection on the tube sockets , wiggle tubes if possible to see of it makes any changes
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#30
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Quote:
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Audiokarma |
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