Answered a Craigslist ad and picked up this little gem:

http://i119.photobucket.com/albums/o121/mrx3750/RCA.jpg

It seems to be in good shape for being 30 years old. The CRT looks good for its age.

I don't want to keep this TV. I don't have any room for a console TV. However, I thought I'd post about it in case someone wants it before I junk it.

I like those drawers :thmbsp:

far as I can tell, they're fake.

if you part it out i sure need the high voltage tripler out of it. steve

I wouldn't know how to remove that without damaging/destroying it.

I'd like a fellow AKer to take the whole TV off my hands. I don't want to see it go to waste. It's not every day I find a working 30 year old Colortrak console.

I'd keep it in place of a more modern set. These last forever and usually look good. Nice find.

EDIT: What chassis set is this? I was referring above to the CTC-89 chassis. The ctc-92 sets seem to have more issues.

It's a CTC 92A chassis. (Forum's acting up today...)

EDIT: It has a lot of controls on the CRT neck board... Delta gun tube?

It also has a damn good picture... I definitely don't want to part it out. I want it to go to a good home.

Then again, I may keep it... dunno... It being a big console TV doesn't help its case, neither is the fact that it defaults to channel 2 if you turn it off then turn it back on.

I'm torn on this one.

It's a CTC 92A chassis. (Forum's acting up today...)

EDIT: It has a lot of controls on the CRT neck board... Delta gun tube?

It also has a damn good picture... I definitely don't want to part it out. I want it to go to a good home.

Then again, I may keep it... dunno... It being a big console TV doesn't help its case, neither is the fact that it defaults to channel 2 if you turn it off then turn it back on.

I'm torn on this one.

Yes, that set uses a delta gun tube and that board you see around the CRT neck with all the controls is the convergence board. As you can see, there is much more to the convergence circuitry on a delta gun tube than on an inline tube.

You are lucky to have such a good picture on that set. I wonder if the CRT is original. Many of those later delta gun RCA tubes didn't hold up. I've seen many that were weak and/or shorted.

Dunno. The inside of the TV is VERY clean. Low hour set maybe?

EDIT: Nah, couldn't be a low hour set. The "On/off" lettering is worn, meaning this TV's been turned on and off a LOT!)

Those were very good sets. The very last modular chassis before they went to the troublesome CTC-99/101 with the ever-failing flyback. The only weak spot on those last delta gun sets was the tube itself. I replaced plenty of them when the sets were only 3 or 4 years old. So yours probably is either very low hours, or the tube was replaced with a better one.

Charles

Hm, 30 years old, On/off knob worn from use, CRT is still bright with good black levels... Maybe the tube was replaced. I could get a number off it if that would clear up the mystery. I know it's 25xxxxxxxxx something or other.

well the tube does look awful new in the pics. too sharp of a pic to be that old. it was probably replaced in the 80s some time.

The CRT is a 25VEHP22.

...

It may be a good TV, but I think cabinets like that are responsible for putting people of consoles forever.

I don't mind the cabinet. To me it's just dated. I don't particularly see it as ugly, and I like that I can lift it by myself, unlike a few consoles out there.

I think this set might need a recap. Light text on a dark background is a bit distorted. Hell, the caps are 30 years old. I can't fault them, unlike some of the modern day lytics that fail in a year or two.

Some people are a bit careless with fingernails when using knobs and that could cause a low hours set's letters to become scraped off early. If it's the original CRT it may have a serial number sticker on it or glue where one was. Looks like a great find! A freind of mine says he can make such letters on his computer to put on things that were silk-screened originally.


Dunno. The inside of the TV is VERY clean. Low hour set maybe?

EDIT: Nah, couldn't be a low hour set. The "On/off" lettering is worn, meaning this TV's been turned on and off a LOT!)

I don't mind the worn lettering.

I have an issue that I pretty much created myself. I was trying to adjust the screen positioning, and not finding a horizontal or vertical position control, I decided to play with those controls on the CRT neck board. Well, I think you can guess that I messed up the convergence.

Oh, I can fix it, I still have my test pattern DVD, and I can probably make the convergence better then it initally was (one corner was a bit off before), but how in the hell do I adjust the screen positioning? I want to move the picture an inch or so down and to the right, so it's centered better.

...

That sucks.

I can move the red and green over, but the blue only wants to move up and down.

That sucks.

I can move the red and green over, but the blue only wants to move up and down.


The Blue Lateral (left-to-right) is another magnet on the neck; usually on the same assembly as the 2 purity rings. It's the CLOSEST one to the socket, but don't confuse it with the 2 purity rings. It could be a thumb wheel, or an axle-looking magnet, or other designs. But you'll see something nearest the socket.

Charles

Ehh, I ain't going to mess with that. It'll be a big enough PITA to fix the convergence without having to fiddle with the rings.

It's OK to mess with the blue lateral; it won't affect the purity or other convergence. But be sure you're on the blue lateral magnet, and not mistakingly on the purity rings. If you post a photo of the neck, I can point out your blue lateral and verify that the stuff is all installed correctly. I'll be on the computer for at least 20 minutes, and I'll check the thread again before I get off.

Charles

First off, the entire neck is covered in some kind of shield that I have no idea how to remove.

Second off, I might accidently mess up the purity, and I don't want to even RISK doing that. That'd probably cause me to rip my hair out.

The convergence grid is still entirely on the screen, so the centering isn't really *that* bad. It's just that I'm picky, and there's a lot of knobs to adjust...

...

Heh, want a real challenge? Try getting perfect convergence on a Delta gun CRT... Even converging the red and green perfectly is proving to be impossible for me.

And to think, this all started cos I was being picky about one corner of the screen...

I've managed to improve the centering, but convergence, not tonight. Taking a break as I'm too hot and too frustrated to continue.

Convergence is something you have to get good at over time. It's a practiced skill, no matter how good you are with that type of thing. When I was servicing projection sets at a rate of 3 or 4 per day, I got to the point where I could do a complete setup after installing one or all new tubes, in about 20 minutes. Other excellent techs who didn't happen to do convergence on a regular basis, might take a week of evenings or call for help. By now, I'm probably rustier than anybody since I only work on 1 or 2 TVs a year nowadays.

Your best bet is to get together with somebody who is in practice, and learn hands-on. There is a good procedural in the RCA Color TV Pict-O-Guide, which is good for most all delta gun tubes.

Charles

Part of it is I'm picky. I can get the convergence to within 1-2 pixels, but it's not good enough for me. Also, the places where the convergence is off have no controls for them! Like there's a bottom R/G/whatever, but no top R/G control. So I figure I can align it at the top and use the bottom controls to bring it together, but then it throws something else off.

I need to get some of those plastic diddle sticks.

Yes, you need to get some of those plastic diddlesticks. Do not use a metal tool on such controls. The metal tool will throw the inductance of the coil off and make adjustment difficult to impossible.

.
..

Putting this on hold until I can get some proper diddlesticks.

RCA, in the early 80's, was using, in production, a kind of magnetic tape that was formed in a ring around the CRT neck. In the factory, they would adjust various magnetic fields thru this tape ring, to do convergence. Once the factory worker felt that this convergence was good, on this particular CRT, the production machine making the convergence fields would "record" these magnetic fields into this magnetic tape, like a tape recorder does to imprint the desired magnetic fields onto tape.

Field repairs would require that the TV repairman throw away this piece of tape, and install a thing that had several adjustable magnetic rings, and adjust them to get convergence. repairs like replacing the yoke, or the CRT.

Don't know if RCA was using the above magnetic tape scheme in 1978.

RCA, in the early 80's, was using, in production, a kind of magnetic tape that was formed in a ring around the CRT neck. In the factory, they would adjust various magnetic fields thru this tape ring, to do convergence. Once the factory worker felt that this convergence was good, on this particular CRT, the production machine making the convergence fields would "record" these magnetic fields into this magnetic tape, like a tape recorder does to imprint the desired magnetic fields onto tape.

Field repairs would require that the TV repairman throw away this piece of tape, and install a thing that had several adjustable magnetic rings, and adjust them to get convergence. repairs like replacing the yoke, or the CRT.

Don't know if RCA was using the above magnetic tape scheme in 1978.

I've seen it used on most RCA sets that used an in-line CRT from the late '70's until recently. It would have been nice if a delta gun CRT could have been converged that way.

I've never had the need to remove the tape on these CRT's. By the late '80's, RCA CRT's featured bonded yokes which means the whole CRT, yoke, and convergence magnet is changed as a unit. Sure beats having to set the purity and convergence. The downside is that if the yoke fails; you have to change the CRT unless you can figure out how to un-bond the original yoke. Fortunately, I've never seen a bad yoke on the bonded RCA tubes.

...

RCA, in the early 80's, was using, in production, a kind of magnetic tape that was formed in a ring around the CRT neck. In the factory, they would adjust various magnetic fields thru this tape ring, to do convergence. Once the factory worker felt that this convergence was good, on this particular CRT, the production machine making the convergence fields would "record" these magnetic fields into this magnetic tape, like a tape recorder does to imprint the desired magnetic fields onto tape.

Field repairs would require that the TV repairman throw away this piece of tape, and install a thing that had several adjustable magnetic rings, and adjust them to get convergence. repairs like replacing the yoke, or the CRT.

Don't know if RCA was using the above magnetic tape scheme in 1978.

i lucked up once or twice and resused the magenitic tape on the replacement tubes with great results. sold rca for over 25 years and replaced very few tubes they were fine crt,s steve

Okay, I've discovered some things about the complex convergence setup on this TV:

The 3 color gun positioning controls also affect purity. Assuming that all 3 must be adjusted for best purity, I have done that.

There are two sets of ring magnets on the back of the CRT: The set closest to the back seems to control the screen centering. The other set seems to help control the blue convergence.

the rings are for purity.it must be set first.use a red only screen for this adjustment.the 3 controls on the crt neck are for center convergance only.the smaller controls are for top.bottom,left side,right side.etc.steps are as follows-
1.-red screen -purity
2.gray scale-service line,adjust rgb to a white line,even luminance.
3.center convergance-red and green,blue vertical and horizontal(dial on purity assembly)
4.top -small controls-marked-red,green,blue
5. bottom-same
6.left side-same
7.right side-same

once purity is set and center is aligned,it should be close enough for viewing.no reason why a delta gun cant be near perfect with some tweaking.dont drive yourself insane trying get it perfect-not going to happen.it can be very close and deliver a fine picture.
use an alignment tool(diddle stick) for the sides.i have an xl100 from 1974 and it came out very well. good luck!

Um, no... I swear the rings around the neck of the CRT do as I just described. One of them moves the entire raster and the other seems to mess with blue, as red and green aren't affected.

if this is a delta gun-then,yes,the rings are for purity. 2 rings nearest the yoke will be for best red purity.adjustment will move the picture off center.the other set will be your blue lateral (horizontal).use red screen(turn blue and green controls off) and move the first rings for best purity. if red screen is not attained,then you have to degauss or reposition yoke. adjust screen to white line in service position.then use the 3 controls on the neck of crt to converge center. this should give you good purity and center. adjust smaller controls as needed and they are marked as to what they control.i worked as a young man in a repair shop and my main job was to repair tuners and set up convergence.i have worked on that colortrak series before.i owned more than a few of those great sets.use procedure as i posted before.sometimes those old pots get screwy with age and those will really throw your alignment off.the procedure to set up a delta gun didn t changed much in the 25-35 years in production.crt number is a delta gun 25 inch full viewing.should be a great performer for you.

Well, Misfortune has struck again.

Most of the controls on the TV are plastic knobs that I can turn by hand. However, a few adjustments are coils that I've been using a small allen wrench to turn (turn it, remove wrench, reinsert wrench and turn somemore, remove it, and repeat.) Anyway, I BROKE one of the coil slugs and it's stuck in there!

I'm going to try removing it with a screw that has some glue on the end. My hope is that the glue bonds and I can just twist it out. if not, then I'll have to replace the entire coil, but where do I find a 30 year old coil?!

i did the same th ing to my roundie. thats why it still sits unused collecting dust.

what roundie do you have? i have lots of rca coils.you are welcome if you need something.
mrx37-a broken slug is no big deal.set everything else and maybe you are good enough without the hassle.you can desolder coil and take it out fro the bottom side,resolder into circuit and reinstall another slug. i have broken millions of those things.not a big deal. it cant be that far off unless you broke the coil.good luck

Where it's at right now makes the red and green impossible to converge on one side of the screen. I'm going to try removing the slug and replacing it, assuming I have a similar sized slug.

Failing that, I'll need to find a 30 year old coil...

EDIT: My glue trick worked! Got the old slug out, and am hunting around for a new one!

Okay, here's my substitute for the broken slug, tell me if it's a great or a stupid idea:

I found a steel bolt that is of the same diameter and threading as the slug. I put it in and it seems to work fine.

I also found a diddle stick that actually fits the other coils too!

I found a steel bolt that is of the same diameter and threading as the slug. I put it in and it seems to work fine.



If it seems to work, why not. :banana: It may be a bit lossy, but if the set appears to converge fine, then I'd leave it, unless you have a huge piece of it sticking out, flapping around enough that you think it might bust the coil off the board.

Most any ferrite core with the right threads will probably work. Old IF transformer coils and such stolen from something in your "junk box" (we all accumulate a fair amount of scrap electronics we keep around just for reasons like this).

what Roundie Do You Have? I Have Lots Of Rca Coils.you Are Welcome If You Need Something.
Mrx37-a Broken Slug Is No Big Deal.set Everything Else And Maybe You Are Good Enough Without The Hassle.you Can Desolder Coil And Take It Out Fro The Bottom Side,resolder Into Circuit And Reinstall Another Slug. I Have Broken Millions Of Those Things.not A Big Deal. It Cant Be That Far Off Unless You Broke The Coil.good Luck


24nc31

Most any ferrite core with the right threads will probably work. Old IF transformer coils and such stolen from something in your "junk box" (we all accumulate a fair amount of scrap electronics we keep around just for reasons like this).

Yeah, but all the ferrite cores I have are either too big or too small. The bolt sticks out a tad, but not very much.

Okay, here's my substitute for the broken slug, tell me if it's a great or a stupid idea:

I found a steel bolt that is of the same diameter and threading as the slug. I put it in and it seems to work fine.

I also found a diddle stick that actually fits the other coils too!

be careful, unlike the original ferrite core, the steel bolt, being highly conductive, is subject to parasitic induction currents and may overheat and damage the coil

Don't ask me how i learned this...

be careful, unlike the original ferrite core, the steel bolt, being highly conductive, is subject to parasitic induction currents and may overheat and damage the coil

Don't ask me how i learned this...

Ai yai yai...

I think I'll just hold off until I get another ferrite core.