Convergence and color bars - Videokarma.org TV - Video

jshorva65 · #1 08-19-2002, 01:02 PM

How's the convergence look on my Sylvania 21LC28? I'm amazed that I could achieve convergence on this set that rivals my 1990 Magnavox 25" stereo monitor set.

Steve Hoffman · #2 08-19-2002, 01:04 PM

Good job!

www.stevehoffman.tv

jshorva65 · #3 08-31-2002, 08:08 PM

I had some time to do the convergence and grayscale setup on the CTC11. I discovered while I was at it that someone had tinkered with the chroma circuits and made a minor mess of them. I'll have to clean that up, but I'll have a decent b/w picture in the meantime. The set gets a nice b/w picture for no antenna, but it's not even attempting to get color. Here's a shot of the screen reflected in a mirror (old tv repairman trick for watching the results on the screen of adjustments that are located on the back of the set) taken just after convergence setup.

jshorva65 · #4 09-19-2002, 01:53 PM

Here is the CTC11E with a color bar pattern on the screen. Still needs a 6"x9" 4-ohm woofer to complete the restoration (only the 2" tweeter works).

Steve Hoffman · #5 09-19-2002, 01:54 PM

Neat!

jshorva65 · #6 09-19-2002, 02:18 PM

Here's the same color bar pattern on the Sylvania 21LC28. My Vectorscope had a cold-solder joint on the trimmer for the 3.58 MHz oscillator, easy enough to fix. I'll need to find a spare 3RP1 CRT sometime soon. The tube is getting weak but adequate for now. The Vectorscope turned out to be a pretty good $20 eBay score.

Rob · #7 09-19-2002, 02:58 PM

John,

Which vector scope do you have? Is it the same heathkit 10-101 as I have? I have only used mine as a crosshatch/bar/dot alignment generator though the RF to the tuner on the set o far. It is very handy. I found it left behind by the trashcan at the Rochester Hamfest one year as a vendor was leaving. I wasn't doing vintage color Tv's at the time. It works perfectly. Boy am I glad now that I grabbed it!!!!

I'm looking for a copy of the user's manual for that if you might have one you can copy I'd gladly pay you.

BTW, nice avatar! Where'd you get the cool idea?

Rob

jshorva65 · #8 09-19-2002, 04:02 PM

Yes, it's a Heathkit I0-101. Unfortunately, I don't have the manual for it ... yet. Since vectorscopes in general are fairly simple instruments, I could probably get by without the manual. The 3.58 MHz trimmer is at the rear of the main PCB, the 157 kHz peaking (vertical bar sharpness) trimmer is at the front of the main PCB, I'm not sure what the trimpot on the main PCB does. That pot probably fine-tunes the 600 Hz (horiz bar) oscillator. The RF trimmer is on the front panel PCB. Since it's crystal controlled, it's very stable (unless a bad connection intermittently knocks the burst off frequency). I feed RF into the set via the antenna terminals, haven't tried hooking it up to the video yet. I connect the R/G/B gun leads to the corresponding R-Y, G-Y and B-Y points on the chassis and ground the black lead to the chassis to use the gun kill switches. A vectorscope is a great multi-purpose tool to have with these old sets.

As for the Avatar, great ideas are bound to be borrowed eventually. I like your "studio standard" bar pattern better than my simpler bar pattern.

Rob · #9 09-19-2002, 08:56 PM

John,

I have an actual TV studio color bar pattern generator that made the image on my avatar on my CTC-20 RCA new vista set. This generator even makes the pluge signal although you can't quite see it in my avatar.

What you have I think they call gated rainbow.

Rob

wiseguy · #10 09-26-2002, 09:03 AM

this must be the vectorscope you guys are talking about..

I made mine into a clock using the original 3rp1 crt.
I have a NTSC waveform and vectorscope that i use for camera repairs..but those wont work in the nice antique color sets..

terry

jshorva65 · #11 10-24-2002, 11:14 PM

Here's the CTC11 after the convergence and grayscale setup.

jshorva65 · #12 10-24-2002, 11:16 PM

Here are the color bars on the CTC11