CTC-16 combo - Page 7 - Videokarma.org TV - Video

DaveWM · #91 03-22-2011, 09:44 AM

prob be a while before I get to the 7, I have a few others that need some attention. Looking forward to the video of the H20 de cat.

maybe adding some yeast to the water would speed things up? I get what looks like mold or fungus in there, make some pva beer while you wait.

I have a 17 with a great testing CRT but a bad cat that I would like to try the water technique, not to mention the roundies I have that I would like to do.

DaveWM · #92 03-29-2011, 10:16 AM

listening to some LP's today I could not help but notice how much better the highs are reproduced. seems like I may have to dig into the tuner MPX output at some point and rework the de-emphasis networks. I did this to another RCA(had forgotten that until just now). The LP's sound great so I figure either something has drifted in the tuner OR maybe just todays programming has been over worked towards the bass side of things for better thumping. I used to have the local public radio station to test on since it seemed to have the least "bass" processing going on, but they dropped there music format a couple years ago. Maybe it was an attempt back in the day to have a Hi filter cut as well, to get rid of hiss. I have other vintage gear that does something like that, just not as crude as chopping it all off up high.

DaveWM · #93 05-08-2011, 05:44 PM

swapped out the CRT for the one I did the de-cat on. I used foam stick on weather strip all around the edge of the lens. Lined it up on the CRT and used some packing tape on the top and bottom to just hold it in place.

the actual replacement took about 45min start to finish, most of which was from note taking on measurements on the neck parts.

Powered it up and I got a nice bright pic, but it will of course need a purity and convergence setup. I decided had done enough, so will give to that later next week when I am in the mood for it.

the old CRT is now sitting in the nasty bong water in the kiddie pool starting the de-cat process on it.

DaveWM · #94 05-09-2011, 04:50 PM

did a 1st pass a the purity and convergence, I had to swap the blue and red static magnets around and did some minor work on the dynamic.

I am really impressed by the overall color and esp the brightness of the set.

I will button it up and snap some pics it a bit.

DaveWM · #95 05-09-2011, 09:57 PM

fighting with the purity, can't get the center red blob (yoke pulled back, blue and green screens turned all the way down). I wonder if I installed the purite magnet backwards...

DaveWM · #96 05-09-2011, 10:07 PM

checked my before photo's its on right. I can get it pretty much correct with the yoke back in place, just bugs me, this is the 1st time I could not get the blob centered with the green and blue triad blobs around it. I can get a red cloud but one side extends over pretty much to the edge. and I only get two clouds each of green and blue.around it on the the other side.

I have a couple of the dynamic pots maxed out, I wonder if the dynamic convergence is effecting the ability to set up the center red blob?

miniman82 · #97 05-09-2011, 10:27 PM

I center the dynamic pots when setting purity, then do the complete dynamic setup. It's always possible the dynamic setup is throwing off other things, just start over and follow the manual. That's what I do whenever I think I'm smarter than what's written. lol

DaveWM · #98 05-10-2011, 07:56 AM

yea I thought about doing that. Will mark the location of where they are, center them up and then start over. I guess there is not way to "center up" the right coils short of just detuning them by backing out the slugs.

I have spare convergence coil and was even thinking of just plugging in and unplugging the mounted assy. Not sure if it was a good idea to just leave the convergencs socket empty

I got bit by the yoke winding, while sliding back, I got a finger on thebell side, I guess the insulation on the windings is not quite enough to keep that from happening. ouch....

DaveWM · #99 05-12-2011, 10:20 AM

Pics with new tube

in the B&W you can see the slight purity prob in the upper right, looks a bit greenish

sampson159 · #**100** 05-12-2011, 10:56 AM

looks great!is that an rca crt?the ctc 15 and 16 produce the best picture in my opinion.purity shouldnt be an issue though.did you degauss it?deguass the rear of the set also.i had a similiar issue once.turned out to be something magnetic on the shield.dont know how it hapened but i degaussed the shield and all was well.again,the picture looks great and another roundie saved!

DaveWM · #**101** 05-12-2011, 11:04 AM

yes thats a RCA hi lite. I degaussed the Pi$$ out of it from the front but not the back.

No sheild around it, just the mount clamp. I am going to try anoher set of purity rings just to be sure. Also will try a different location, just in case I have some odd magnetic field near by.

Not even sure how I would get to the back to degausse, but I assume It would be a good idea to remove the purity rings before doing that?

marty59 · #**102** 05-12-2011, 01:25 PM

Those are some great looking screen shots. Looks like you've got that gray scale spot on too....does it stay uniform throughout the brightness range?

old_coot88 · #**103** 05-12-2011, 01:54 PM

Dave,
The purity setup procedure is as follows:
Get an all red screen (blue and green screens off), slide the yoke all the way back and center the red blob (using the purity rings). Slide the yoke forward gradually, looking for best red purity. The "sweet spot" will occur approximately 1/2 to 1/4 inch before the yoke fully seats against the CRT bell. Clamp the yoke at that position. No kidding. This is the RCA factory procedure and the way we always did it 'back in the day'. Same on the 19 and 25 inch rectangulars, but the 'sweet spot' is usually about 1/4 to 1/8 inch from the bell.
Bill(oc)

DaveWM · #**104** 05-12-2011, 02:34 PM

Bill try as I may I can't get the red blob in the middle (the procedure you described is what I did). Red screen up, yoke back, best I can do is get the red in the middle/and left side. I normally can get the red blob and have the blue and green sort of around it in 3 separate clouds. This one just does not want to behave. I try rotating the rings together as well as operating them separately, and a combo of both (rotate together and try apart).

I did not try the grey scale tracking with brightness will get back to you on that.

sampson159 · #**105** 05-12-2011, 03:05 PM

those rings usually dont go bad.try another yoke?had a 15 back 25-30 years ago that had the same issue.was a bad yoke.we played with it for a few days and changed it out.took care of the problem