How to get tube type RCA to look as good as Zenith Chromacolor 2?

[sampson159]

many of these rca sets had a crt with a thick safety glass.that crt always looked soft.it could be strong as hell,but just looked worn.get a good sylvania or zenith crt.that will turn that set on like fire.we did many swaps in the day and that will cure the rca soft look.good luck and regardless,that is a great set!

[ctc17]

Last night I made a video of my 35 displaying a graphics program I use at the nightclub I work at.
This may give you an idea what the set should look like. This set has the factory crt and smoked glass.

Notice how some of the scenes shift the crt bias and the background changes color. keep an eye on the bottom inch....this really pushes the set up to the limit.

Check it out http://www.youtube.com/watch?v=ExqyNrgjyfw

[freakaftr8]

That's wild! I wonder what the grid voltage on the three guns look like when you are playing this.

[Chad Hauris]

Thanks, that video looks real good.

I tested the CRT in my set with an RCA CRT tester and it tests good on all guns. It is a new RCA Hi-lite replacement from 1976 and is a 23VALP22.

I have been trying to improve the purity on it but I found that the clamp which holds the plastic yoke housing to the CRT is busted and the blue lateral/purity magnet unit is crumbling from heat exposure. I went down to the spare parts bin and found 3 blue lateral units but all the mounting clamps were broken on those too.

I'll try and see if I can find a better blue lateral unit from another set and try and use a hose clamp which has been degaussed to hold the plastic yoke on (I know I did that when I was a kid on an RCA CTC-31)

[ctc17]

A good friend was a sound mixer for 30 years, he retired in the late 80s. He was telling me about all the standard limitations they used when filming in NTSC. There was a maximum contrast ratio, no one on set was allowed to ware pure black or white, etc. He worked on many popular tv shows and movies. It was just the way they did things. Thats why old programming looks washed and the colors are all pastels.

Now none of that applies so modern programming pushes these sets into an area they were never designed. Well maybe designed to when every adjustment is perfect and the parts are factory fresh. The old programming was designed for the average viewer who has every adjustment off by 25% and had to place a house call to do a basic setup.

The graphics generator makes the chassis buzz and they tubes squeal on some of the scenes. Its really pretty cool, I should video it with the sound turned down.

[Chad Hauris]

I found a coil going to the video output tube was really corroded so I will get one from a junk chassis and see if this helps. It is in the grid circuit so its likely the problem.

I did try injecting video into the 1st video stage grid and it was pretty weak still with poor sync so this told me the problem is likely in the video stages and not IF/tuner.

[Chad Hauris]

I really was able to improve the picture by replacing the coil going to the video output tube plus replacing the 1st video and AGC/sync tubes. I salvaged all the parts from a CTC-17 chassis that someone gave to our repair shop when they converted a CTC-17 cabinet into some other use.

Here is a video of the performance:
http://www.youtube.com/watch?v=_-x1pTz8M_Y

[radiotvnut]

Glad you got it going. That set looks to have a very good picture!

[ctc17]

Looks good! Im going to attempt a chroma alignment on mine now. Align the chroma bandpass, or at least try.


Sylvania, Vertical, Caps. The orange drops go bad.
Here are my notes on my tube sylvanias take what you can from it.

Sylvania 22 inch color console CE36-K Sams 1072-2. Tin Whisker shorted AGC pot, blew open short with b+, open 1.5 meg Red screen pot replaced with fixed resistors. Verticle hold issue, changed c38 and c41 .0033uf caps in the feedback circuit. Vert hold was all the way counterclockwise and would fall out of correctability as set warmed up. Whisker shorted vert linearity pot. Still has a minor vert linearity issue at top. Horizontal output Cathode current 200ma, sams lists 280ma. Traces on boards very fragile and some came off on caps I replaced. Cabinet and CRT are in great condition. Great color picture, maybe the best I have seen on a color tube set. Problem is vert is running to slow. I have the vert hold control all they way closed (grid at -5volts not -10) the picture will lock when the set is cold. After on for 45 minutes it drifts to a point where it starts skipping. If I decrease the size it will lock and stay.