RCA CTC-16XL Suggestions/Tips - Page 3 - Videokarma.org TV - Video

old_coot88 · #31 04-09-2019, 09:51 AM

Quote:

Originally Posted by zeno

And they are timed by a horz pulse to grab & amp the 8 burst
signals on the back porch.

73 Zeno

LFOD !

..And then the osc. free-runs during the whole scan period (one scan line) before the next synchronizing "burst".

Yamamaya42 · #32 04-09-2019, 09:54 AM

If you still don't get full height, you may have to look at ALL resistors in there...
r98,99 ,100,101, (102,103,104, OK ) 106,107,108...
The only unknown factor is the VDR @ r105, Still not sure how they are ment to act, or test them. ,

I have been putting off checking all the resistors in my set for a while, as I wanted it to sit in an dry climate controlled environment for at least a month or more before I started, I brought it inside early Feb.

Rocket · #33 04-09-2019, 10:18 AM

Glad the shield isn't super critical, still going to find one to replace it.
This evening going to go back to checking out more components and see what I find.
Don't know why but it's a lot of fun working on these old sets! It is totally amazing we were able to make color work back then and doing it all on fly without microchips and computers! Amazing so cool

Yamamaya42 · #34 04-09-2019, 10:24 AM

Quote:

Originally Posted by Rocket

Glad the shield isn't super critical, still going to find one to replace it.
This evening going to go back to checking out more components and see what I find.
Don't know why but it's a lot of fun working on these old sets! It is totally amazing we were able to make color work back then and doing it all on fly without microchips and computers! Amazing so cool

“microchips and computers” Funny you mention that. :p
It's what I have spent the bulk of my life working on ( debug ) since I got out of electronics classes. :p

Rocket · #35 04-09-2019, 09:32 PM

Quote:

Originally Posted by Yamamaya42

“microchips and computers” Funny you mention that. :p
It's what I have spent the bulk of my life working on ( debug ) since I got out of electronics classes. :p

Thats awesome!! and here we are working on these vintage sets *lol*

Rocket · #36 04-09-2019, 09:36 PM

Quote:

Originally Posted by old_coot88

The vert. oscillator plate load resistor frequently goes 'waay out of spec from being hammered by high level spike. This applies across all makes and models, both BW and color. Worth bookmarking.

Did some checking and it was out of spec, it was not really really bad but it was higher than it should be. Also found one on the horizontal section as well.

Yamamaya42 · #37 04-09-2019, 11:19 PM

now that is odd, does yours have an RF shield over the IF board, like shown in the sams on page 17, Chassis top view? mine does not have it, or did not when i got it...

Rocket · #38 04-10-2019, 05:43 AM

Quote:

Originally Posted by Yamamaya42

now that is odd, does yours have an RF shield over the IF board, like shown in the sams on page 17, Chassis top view? mine does not have it, or did not when i got it...

Indeed mine does, I went and took a picture for you to compare. I wonder if there are other things we could be missing. I also wonder how hard it could be to come by one of these shields... though could maybe make one out of thin sheet metal.

Yamamaya42 · #39 04-10-2019, 07:19 AM

Which means, most likely that someone was messing with the IF before I got it, &I need someone to make a template from a same model 16xl when they have time,

Electronic M · #40 04-10-2019, 06:15 PM

Quote:

Originally Posted by Yamamaya42

Which means, most likely that someone was messing with the IF before I got it, &I need someone to make a template from a same model 16xl when they have time,

If you pull the tubes and cut out for the protruding transformer can you could probably make a usable template out of paper from your own set.

Rocket · #41 04-10-2019, 06:43 PM

Quote:

Originally Posted by Yamamaya42

Which means, most likely that someone was messing with the IF before I got it, &I need someone to make a template from a same model 16xl when they have time,

Yeah, its a shame that they didn't bother to put the shield back. Also I will be glad to try to work up a template for you from mine ; )

Rocket · #42 04-10-2019, 07:01 PM

Got a question about properly doing the HV setup. I will be ready to put the chassis in for a test run in the next few days and I want to get this set correctly as one of the first things on my list. I have been reading up on the Sams instructions. Its my first time doing a HV setup so I don't want to botch it and get everything connected up correctly.

I drew up a little thing and attached it.

Please correct me if I am wrong, I pull the top of the horizontal output tube and have my meter in series with that lead as well as a capacitor in series with my meter. Then adjust to get below 210ma while maintaining 24kv on the picture tube anode at normal brightness setting.

Yamamaya42 · #43 04-10-2019, 07:16 PM

Quote:

Originally Posted by Rocket

Got a question about properly doing the HV setup. I will be ready to put the chassis in for a test run in the next few days and I want to get this set correctly as one of the first things on my list. I have been reading up on the Sams instructions. Its my first time doing a HV setup so I don't want to botch it and get everything connected up correctly.

I drew up a little thing and attached it.

Please correct me if I am wrong, I pull the top of the horizontal output tube and have my meter in series with that lead as well as a capacitor in series with my meter. Then adjust to get below 210ma while maintaining 24kv on the picture tube anode at normal brightness setting.

the Horz current setting is on the CATHODE , not the plate
you will have to interrupt its path to ground. (pin 3)

this may help explain
https://www.boxcarcabin.com/rcacathode.htm

Rocket · #44 04-10-2019, 07:33 PM

Quote:

Originally Posted by Yamamaya42

the Horz current setting is on the CATHODE , not the plate
you will have to interrupt its path to ground. (pin 3)

this may help explain
https://www.boxcarcabin.com/rcacathode.htm

Thanks Yamamaya42! That helps a lot : D

Electronic M · #45 04-10-2019, 09:13 PM

Quote:

Originally Posted by Yamamaya42

the Horz current setting is on the CATHODE , not the plate
you will have to interrupt its path to ground. (pin 3)

this may help explain
https://www.boxcarcabin.com/rcacathode.htm

A useful tip when you disconnect the cathode lug of the socket run a wire from it to the top side of the chassis and add a fuse holder above chassis. Ground one side of the fuse holder, and connect your cathode wire to the other. When you're using the TV as a TV install a 250mA fuse to protect the flyback...If you ever need to check the cathode current all you have to do is pull the fuse and clip your meter to the terminals of the empty fuse holder.

Adding that fuse/holder above chassis both gives your flyback added protection and and gives you a convienent cathode current test point.