Ctc-16 - Page 4 - Videokarma.org TV - Video

DaveWM · #46 10-23-2009, 10:11 PM

ok after an hour or rockford I see how the convergence is acting up.

it seems to be out of alignment on the lower part of the screen by vertically (on vertical lines you see red green blue side by side. on the top part of the screen the vertical looks good but the colors are displaced horz (colors are separated and stacked on top of each other on horz lines).

sorry if I am not using the right terminology.

So I guess convergence can be out both directions on different parts of the screen? in my case the upper and the lower.

I am going to spend some time tomorrow with the service manual. Looks like you could need to go to school to learn this stuff, or at least apprentice for a long while.

roundscreen · #47 10-24-2009, 08:54 AM

Quote:

Originally Posted by DaveWM

ok after an hour or rockford I see how the convergence is acting up.

it seems to be out of alignment on the lower part of the screen by vertically (on vertical lines you see red green blue side by side. on the top part of the screen the vertical looks good but the colors are displaced horz (colors are separated and stacked on top of each other on horz lines).

sorry if I am not using the right terminology.

So I guess convergence can be out both directions on different parts of the screen? in my case the upper and the lower.

I am going to spend some time tomorrow with the service manual. Looks like you could need to go to school to learn this stuff, or at least apprentice for a long while.

Wow, You done good and the picture looks great.
Try cleaning all the controls on the convergence board. Check and re solder the pins and ground connections. Also you may need to replace the selenium diodes. It is not as hard as it looks. {See picture}
Ed

roundscreen · #48 10-24-2009, 09:08 AM

Quote:

Originally Posted by Charlie

Wow, Ed! That's a nice looking 16!

I had one similar a few years back, but the top of the cabinet was in pretty bad shape due to getting wet for a very long time. It was a remote set. I gave it to Rich since he was tinkering with rebuilding cabinets back then.

This was the first color roundie I saw with the swivel base so I had to buy it and rebuild it. The one side of the cabinet was facing a patio door so the finish is not so great but a good cleaning and some old English fixed it. Most of the tme I do not mess with the cabinets on the old tv's other than cleaning and polish. I would make the problem much worse if I got out the sand paper and such.

Ed

DaveWM · #49 10-24-2009, 09:18 AM

I will check it out. Are those replacement signal diodes I see for the Se?

ah I see it, on mine, do you have a 1NXXXX recommedation? I have some 1N60s germanium if you think they would be a better match that silcon signal diodes.

sampson159 · #50 10-24-2009, 11:11 AM

great looking picture.the linearity could be the resistor on the control.it goes bad all the time causing a vertical problem.if you were closer,i have 3 cabinets that i need to move out.there are in reasonable condition.i think the 15 and 16s produce the best roundie picture.those crts are really spot on.congrats on this.you couldnt have gotten a better one for a first time.

roundscreen · #51 10-24-2009, 02:54 PM

Quote:

Originally Posted by DaveWM

I will check it out. Are those replacement signal diodes I see for the Se?

ah I see it, on mine, do you have a 1NXXXX recommedation? I have some 1N60s germanium if you think they would be a better match that silcon signal diodes.

I took the diodes from a early solid state 70's xl 100 convergence board. Found out some of the ss parts in the 70's sets work quit well in the older tube type chassis so I have been on the look out for them. Last weekend I bought two xl 100 chassis for parts. I think I read that the 1n60's will work but never used them.
Ed

DaveWM · #52 10-28-2009, 10:10 PM

messed about with the convergence, got it all pretty good except for the blue horz on the bottom, I just cant get it up (pls no pun) the pot is turned all the way and it just runs out of adjustment.

Vert looks good from sides to center, and horz is fine from center up, just the blue begining about 2/3s down.

I did check the sams the replacement diode are 1N536's

could those effect the max range of adjustment?

DaveWM · #53 10-28-2009, 10:18 PM

50v .75mA silicon, so looks like any of the 1n4 family should be ok,

Phil Nelson · #54 10-28-2009, 10:53 PM

Ah, that convergence board brings back foul memories. I nearly lost my mind fussing with the board on my first CTC-11. Replaced selenium rectifer with diodes, replaced caps, replaced a couple of pots. Those controls are laughably cheap and not easy to find. Some kind soul donated one, or I'd still be cussing over bad convergence.

I spent hours playing with convergence on that set. On my second CTC-11, convergence took about six minutes, and it looks better than the first ever will. Go figure.

Phil

Charlie · #55 10-28-2009, 11:15 PM

DAve, some guys have replaced those with diodes and got great results, while others (like Phil) wanted to shoot the set after all the work that was put into it. I've only changed them on one set, and while it did indeed make a difference, it wasn't quite enough for me to be satisfied completely.

Roundie convergence isn't always easy. Some have commented that you're never going to get it perfect... just to do the best you can focusing mainly on the middle of the screen. Anything better than that is icing on the cake.

If the blue is off 2/3 of the way down the screen, I'd try changing those diodes and possibly the caps (especially if they're old tubular caps). It's certainly an easy job to change that stuff out... it's not like you have to tear the whole set apart again.

But, before you do that, just for shits & giggles, try taking that blue magnet out, spin it around 180 degrees, and re-insert it into the assembly. Then start over with all your adjustments as per the instructions and see if that makes it any better. Sometimes spinning those magnets around is all it takes.

DaveWM · #56 10-29-2009, 07:54 AM

roger that Charlie.

the only other thing is I did swap the two vert out transformer wires on pin 4 and 5 on the convergence socket. This was against the color code but the color code for the thordarson was not given (all the other replacement trannys were, and they all used the same color red for red, red blk for red blk etc...). When I installed the thordarson I 1st check the resistance of the old tranny to the wires of the replacement. They all checked for resistance for the same colors except for those two which were swapped. So I installed it with the wiring intact except those two.

I was thinking of swapping them just to see. I think the diff was .75 ohms to center vs 1.5 ohms to center which is a pretty big diff in DC resistance in a tranny.

I don't want to do too many changes at a time so I will try the magnet 1st

then the diodes, then the wire swap.

on the grid its all pretty good but the blue is about 3/8 in off on the horz line on the bottom all the way across, and that is with the pot pegged (its working just not enough range).

sampson159 · #57 10-29-2009, 09:43 AM

try sliding the convergence assembly forward on the neck.also the blue lateral.move it up or down the neck to get that blue to line up.i have had the same problem with my ctc15.moving the parts on the neck changes the geometry.can get it really close and hopefully right on.you have to experiment a little.convergence is an art!it can never be perfect,but we all painstakingly try for it.

DaveWM · #58 10-29-2009, 10:16 AM

just curious to modern TVs have all these adjustments? sorry for my ignorance I only recently got interested in TV's and have not even opened the back of a modern TV.

Charlie · #59 10-29-2009, 10:24 AM

If I'm not mistaken, modern sets go thru the menus to get to convergence. Seems that big screen sets have a menu that the user can get to and perform convergence, and from what I've seen, it's quite easy and just about anyone can do it as long as they have decent vision. I made some convergence adjustments on my neighbor's big screen a few years ago... it was rather easy. Certainly came out better than a roundie!

I believe smaller sets have a secret menu that is not available to the set's owner. If you bring the set in for repair, the repair man knows a certain sequence of buttons to push to bring up the service menu... and I would think convergence would be in there.

We've had discussions here before about the secret service menu... they were pretty interesting.

DaveWM · #60 10-29-2009, 11:33 AM

oh I get it sorta like Easter eggs...