My CTC-16XL Project. - Page 24 - Videokarma.org TV - Video

Electronic M · #1 08-12-2019, 09:33 AM

I'd make the shield before worrying about the alignment... You would be surprised some of the wacky problems removing a shield from a working set can cause.

It ain't terribly hard to make that shield out of sheet metal with hand tools. Photo copy the template, cut out the template and trace around it on to a small piece of sheet metal (most home stores have 1sqft pieces of sheet metal) and tape the template down to the metal clamp the metal down to a piece of wood you don't mind drilling into and drill through the hole marks in the template. On the square can holes drill the biggest round hole through the center as fits in the border and file out the corners to get square or if you have a rotary dremmel use the cutting wheel to cut the can holes instead of the drill. Once the holes are done cut the outer edge you marked earlier out with tin snips. File and or sand and Sharp edges off pound any warps or dents flat with a hammer and install.

If possible use a soft metal like aluminum or copper... I've made stuff like that out of sheet steel and it can be a bit of a pain to work with. Also wear thick canvas work gloves so you don't cut your hand like I did yesterday.

Yamamaya42 · #2 08-20-2019, 01:45 PM

Replacement IF shield came and went on ALMOST, w/o a problem.

https://imgur.com/hjMsDmV
https://imgur.com/RrRS7IP

it's that slight difference between the CTC-16 & CTC-16XL again.
XL has a different video output, so the hole for it is slightly offset, so it had to be made to fit .

but it IS on there now!

Yamamaya42 · #3 08-21-2019, 10:28 AM

As you can see, it's mostly all covered now, except for a small area next to V4, over R22 (sound reject), which i don't think will matter much, or perhaps I could shape a small piece of HVAC Foil Tape over that bit and put kapton over it.

Yamamaya42 · #4 08-25-2019, 02:52 AM

https://imgur.com/HGb3e1Y
chassis installed, set in final location , ready for final convergence.

Yamamaya42 · #5 08-26-2019, 10:19 PM

back installed. (for now,)

Will prob have to work on the convergence PCB at some point, could not get it as neat as I wanted, not that they are ever perfect, but , there was some unevenness with red /green horz at the top where bot was perfect and could not get it to even out.

will leave it for now.

https://imgur.com/3hZnlmW
https://imgur.com/2IRpnlp

the sucker puts out a lot of heat!

but not where is should not!

https://imgur.com/ia7K5mV
https://imgur.com/OXaBvHJ
a pic of the stubby legs i got to fit under my screen & the cooling fans.

Yamamaya42 · #6 08-27-2019, 07:40 AM

Convergence problem in detail.

As mentioned in previously, set has been moved to it's final location and spent over an hour trying to make fine adjustments.
Noticed there was a slight convergence problem, this is only seen at the top with red/green, bottom, left & right were able to line up w/o issue.
R-G vert lines (top) are least affected, and almost lined up completely, but the pot for it (r27) had to be turned to the extreme point of travel to get as close as I could get it.
R-G horz lines (top) are worst affected, as they appear to be distorted, IE, red below green on one part and red above green on others, no amount of adjustment would clear it up, at one part at the top, R-G would be off, so I got it as close as I could for now, and will try and fix when I do the IF alignment.

I seem to remember seeing somewhere that the diode pack on the convergence PCB (x6) is a possible trouble spot, and / or the the orange drops.
Has anyone seen something like this, R-G issues only at the top?

Electronic M · #7 08-27-2019, 09:02 AM

The diode pack is multi section and has its fingers in every part of the dynamic convergence pie...also most of those were selenium diodes which are not the most stable rectifier technology...

What I do when I repair a convergence board is change the caps and diode pack, and check resistors...if that don't fix it there can be 2 problems (the set I most recently did this on had both) 1 the convergence yoke happens to work better somewhere under .5" fore or aft of its intended resting place, or the dope before you installed the clover backwards so the green magnet is over the red gun and the red is over the green..... normally I wouldn't suspect the latter but the set that had that problem had new convergence diodes hacked in and resistors clipped out with " Ray Charles soldered this in with his feet" type craftsmanship...

Yamamaya42 · #8 08-27-2019, 09:58 AM

Quote:

Originally Posted by Electronic M

The diode pack is multi section and has its fingers in every part of the dynamic convergence pie...also most of those were selenium diodes which are not the most stable rectifier technology...

What I do when I repair a convergence board is change the caps and diode pack, and check resistors...if that don't fix it there can be 2 problems (the set I most recently did this on had both) 1 the convergence yoke happens to work better somewhere under .5" fore or aft of its intended resting place, or the dope before you installed the clover backwards so the green magnet is over the red gun and the red is over the green..... normally I wouldn't suspect the latter but the set that had that problem had new convergence diodes hacked in and resistors clipped out with " Ray Charles soldered this in with his feet" type craftsmanship...

I have had the Convergence yoke on and off a few time now, so I know that red is over red and green over green, I do not know however, if the Convergence Coils themselves were perhaps ever removed or put back in backwards or not, never thought of that possibility.

But as suggested, will replace diodes, caps go over the resistors, and see if gets better at a future date & go on from there.

Yamamaya42 · #9 08-27-2019, 01:15 PM

it seems the diode array can still be found for it.

ref.
http://www.nteinc.com/specs/100to199/pdf/nte120.pdf

Yamamaya42 · #10 08-27-2019, 11:32 PM

here is something not seen very often, anime from 2019 shown via windows 7 on an RCA CTC-16XL!

https://imgur.com/jvD36lr

Electronic M · #11 08-28-2019, 08:57 AM

Quote:

Originally Posted by Yamamaya42

here is something not seen very often, anime from 2019 shown via windows 7 on an RCA CTC-16XL!

https://imgur.com/jvD36lr

Nice. I do some similar stuff. Currently using a Windows 10 rig but my 7 rig is still on hand (forced to go to 10 because the new rig I built lacked driver support for USB on 7 so I couldn't use a keyboard/mouse to make the installer complete). I've ran downloaded copies of the original 1967 season of Lupin III, and cutie honey (1973), up through the series premiering on Animeshow.tv on everything from my RCA 21CT55 to my sony super fine pitch Wega.

I'm going to guess your watching fruits basket in that picture.

Yamamaya42 · #12 08-28-2019, 10:14 AM

Quote:

Originally Posted by Electronic M

Nice. I do some similar stuff. Currently using a Windows 10 rig but my 7 rig is still on hand (forced to go to 10 because the new rig I built lacked driver support for USB on 7 so I couldn't use a keyboard/mouse to make the installer complete). I've ran downloaded copies of the original 1967 season of Lupin III, and cutie honey (1973), up through the series premiering on Animeshow.tv on everything from my RCA 21CT55 to my sony super fine pitch Wega.

I'm going to guess your watching fruits basket in that picture.

Correct!

I am very very into Furuba, ( & all shoujo in general )
When I don't have my face burred in work and electronics, I'm spending time on Anime and fansubbing.
Our group is , http://www.live-evil.org/

Yamamaya42 · #13 09-03-2019, 11:04 AM

In regard to protecting the FBT, given that there is near zero chance of finding one for a CTC-16X series, going from the starting point that it seemed in excellent condition to start with, ( no wax loss seen, or arcing traces ), it seems I was lucky getting this.
From all the many threads I have read, the most important seems to be HOT (6JE6A) cathode current, & keeping it as low as one can w/o losing function ( below 200ma).
To aid in this, converting the focus to solid state helps, as it removes the draw from it's heater winding.

What also is said to help is more ventilation for the HV cage, to allow any generated heat from the FBT/ HV RECT to escape more easily , this is done by adding holes in key places and forced air via fans, perhaps on the back.

At this point, I can't think of anything more to do to try and protect the FBT, as shown in the thermal scan before, w/o the back on that has the fans on it, the HV on mine is very cold after an hour running.

https://imgur.com/3hZnlmW

What can't be seen there, and this kind of surprised me, is I drilled 4 large holes in the front of the HV cage, and there is no heat at all seen coming from them, I did not expect things in there to be so cool as not to be able to see the holes on infa red.

Yamamaya42 · #14 09-20-2019, 10:40 AM

How does one know if a FBT has ever been replaced in any given RCA? There really is no way to know, is there, w/o knowing the history of the set. You can make a guess by looking, but never know for sure.
I have 2 examples here, Rocket's CTC-16XL and Freakaftr8's CTC-16.
I will look at mine closer this weekend.
I suspect that Freakaftr8's is original and Rocket's a replacement.
Reasons...
Freakaftr8's , Darkened metal at base, same as chassis, doughnut color darkened, wires held with black tape ( common with oem )

Rocket's , metal at base much lighter than chassis, doughnut color cleaner looking, no black tape seen.

https://imgur.com/d4cpPzR
https://imgur.com/W4JoHPn

freakaftr8 · #15 09-20-2019, 11:11 AM

I would say Rockets is for sure a replacement. That tape is usually a giveaway. Also the red silicone as well.