RCA CTC38 tube question - Videokarma.org TV - Video

damen · #1 09-23-2009, 01:02 AM

I have a Rca CTC38 works very well I decided to buy all new old stock tubes for it on Ebay but found that the new 6LQ6 makes it have a slight white shadow right down the center of the screen from top to bottom and you can here a high pitch sound. I put back in the original 6mj6 it came with and it works perfect again I know the set calls for a 6LQ6 so should I send this tube back or is there an adjustment that should be made on the set for the diferent tube? Any of you guys who worked these back in the day have an opinion?

freakaftr8 · #2 09-23-2009, 09:45 AM

You mgbt have a shorts 6LQ6 causing that. Test it if you can. Also make sure the socket is ok and pins are making contact. Nice looking set too! Those 38's are nice. I used to have one when I was a kid. I miss it.

andy · #3 09-23-2009, 10:21 AM

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wa2ise · #4 09-23-2009, 03:37 PM

to test linearity, put a football game on, and look at the lines on the field when they show up diagonal across the screen. If you see a kink in the middle of the screen, then that would demonstrate the deflection nonlinearity you suspect.

bgadow · #5 09-23-2009, 09:36 PM

The horiz effiency should be adjusted anytime that tube is changed, adjusted so that the current is acceptable. I suspect few people ever really do it. That could be the problem. The -38 is notorious for eating flybacks and high current will quicken that.

If you ever need tubes in the future, post a want ad on here. Guys like me are drowning in TV tubes! (but, alas, no spare 6LQ6's)

ctc17 · #6 09-23-2009, 09:48 PM

Quote:

Originally Posted by bgadow

The horiz effiency should be adjusted anytime that tube is changed, adjusted so that the current is acceptable. I suspect few people ever really do it. That could be the problem. The -38 is notorious for eating flybacks and high current will quicken that.

They always seem to be off. All my rca sets have been off by around 50ma. Its worth the time to check.

Chad Hauris · #7 09-23-2009, 10:05 PM

Also be careful of the core in the effieciency coil, one time I tried to adjust it and it was frozen up and the whole coil broke off of the board!

damen · #8 09-24-2009, 07:49 PM

Thanks so much for all the help on this guys. I am working on it now to see if I can get it fine tuned where it should be.