#46
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Is there any specific value to look for, or ask for like 3.58. I am not very familliar with crystals.
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"Face piles of trials with smiles, for it riles them to believe that you perceive the web they weave, and keep on thinking free" |
#47
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The CTC-9 I recently sold had a good crystal in it, the CTC-7 had to be replaced before it did anything, and the one in the CTC-4 still seems to be good. So it's hit and miss, I guess.
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Evolution... |
#48
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Since you are seeing traces of color, it indicates the CK circuit is being keyed 'on' by the burst signal. If the burst signal were absent, the CK would remain 'off' and you'd see no traces of color at all. (The purpose of the CK is to prevent colored hash in B&W broadcasts.) Bill(oc) Last edited by old_coot88; 04-02-2011 at 06:44 PM. |
#49
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I remember that Blue Cheer album.. I was stationed in Huntsville Alabama working on Hawk Radar at the time.. nice to see it from time to time.
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#50
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Just ask for a 3.58mhz crystal. They come in blister packs of usually two. I doubt a radio shack would have it, it has to be like a local electronics stock. They are very common, at least at the stores around here. The local store has about 5 different brands.
Last edited by ctc17; 04-02-2011 at 07:04 PM. |
Audiokarma |
#51
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Someone explained why the crystals go bad once in one of these threads. They called it 'silver migration', Where the crystal gets contaminated by the metals in the leads or something like that. A whisker type disease. Its not just tv crystals. I used to collect EF Johnson CB radios and today the whole collection is a pile of dead radios. All 20 crystals in every radio is way off frequency and their hardly worth fixing. It would cost several hundred dollar to renew each radio with a set of custom made crystals. |
#52
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To be more specific they are 3.579 mhz crystals. For a rough idea....
http://shop.ebay.com/i.html?_nkw=3.5....c0.m270.l1313 |
#53
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__________________
Just look at those channels whiz on by. - Fred Sanford |
#54
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If I thought that I could make it worth the investment, I could probably buy the inventory of tubes at a good price. The last investment I made was in NOS yokes and flys which I still have quite a few of. The popular #s like FLY 1 went pretty quick, then it died.... Last edited by Tubejunke; 04-02-2011 at 10:32 PM. |
#55
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Hey Tubejunke
Can you post a schematic of the color section? I'm betting that the problem is something other than the crystal, based on your statement that the color was strong and in sync prior to the sudden drop-out. Bill(oc) |
Audiokarma |
#56
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I don't have a way to scan a schematic, but later today I might be able to post or send you a PDF to look at. Again, from the get go the color took maybe five minutes to come in, but when it came in it was fine. I thought for sure that it was just a weak tube that was taking longer than others to achieve enough emission to do its job. Each time I powered the set it seemed to take longer and longer, till no color at all. I have a lot of studying to do for electronics tests this coming week, but I hope to at least have time to give the color killer potentiometer a good cleaning in the next day or two. I doubt that is the actual problem, but I know that it needs cleaning as it was a bit jumpy when I tweaked it the other night. Also, I need to give the underside of the chassis a better visual inspection and maybe check out some resistors. I already found the horizontal "efficiency" coil that seems to have a broken backbone (plastic), but it doesn't seem to be causing any problems. However, it might be why the horizontal hold control is off center. For now I want to focus only on color issues.
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#57
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If its that toug to find one pm me your address and ill send you one. - keep several stock because they are always bad. Sometime I forget I live in LA the land of everything instantly
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#58
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Sure sounds like like the 3.58 oscillator tube was slow warming up and finally not starting at all. Do you have a known good sub for it? Quote:
(An analogous situation would occur with a weak horiz. oscillator. A good working test for the H. oscillator is to turn the set off for ten seconds or so, and then back on. If it takes a while to lock back in, the tube is borderline weak even though it may show good on a tester.) Speaking of horiz. stuff, the 'efficiency' coil does not affect horiz. sync. But if mistuned, will cause high HOT current. It needs to be tuned for the 'dip' of minimum current. Bill(oc) |
#59
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By mentioning the 3.58 oscillator tube, do you mean the "Chroma Reference Oscillator? That is the only color related tube that I see that is called an oscillator. The rest seem to be amplifiers and demodulators. I will have to look for a sub, but I don't have a "known good". I will get back to the issue with the horizontal efficiency coil with what seems to be a broken backbone or housing. In short, I would think that it should be rigid, but I can grab the coiled end and it wobbles around separating the windings a bit.
__________________
"Face piles of trials with smiles, for it riles them to believe that you perceive the web they weave, and keep on thinking free" |
#60
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Speaking of crystals, my CTC-7 has a funny one. The manuals show the can type, but this looks like a chubby glass mini tube with a saucer inside. Perhaps a replacement. New to me, anyhow. Phil Nelson |
Audiokarma |
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