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

Yamamaya42 · #**346** 08-12-2019, 08:41 AM

Quote:

Originally Posted by trinescope

+1, it's not going to work. There are no visual clues to know when the IFs are aligned, unlike in a radio where normally they are set for peak response.

I was not REALLY that serious about trying option 1, knowing that it would most likely do more harm than good.

I will most likely run it as is for now, for the distortion can be minimized by messing with fine tuning, IE,the ringing in the red DOES move when it's adjusted as does color intensity ( noise ), but the ringing never fully goes away, no matter what I try, when I input via tuner, but on the positive side, horz hold has no effect on color at all.

At this point, I still have re created the missing top cover to the IF section, tube shields are in place.
I can't really imagine the cover being off having THAT much of a drastic effect on things, I just have to find a way to have one made from the template I was given.

I just have to wonder, if I do get my hands on a sweep marker generator at some point, given the complexity of the procedure, could a noob at such a task like me do it.

trinescope · #**347** 08-12-2019, 09:18 AM

Quote:

Originally Posted by Yamamaya42

I just have to wonder, if I do get my hands on a sweep marker generator at some point, given the complexity of the procedure, could a noob at such a task like me do it.

As long as you have alignment equipment in proper working condition and the service data for the set I think you will do just fine. I was inexperienced once myself, and at 46 years old I did not have the benefit of having worked on these sets "back in the day" either.

I think I will have to do the alignment on my Mitsubishi Trinescope set since it displays the classic signs of misalignment; tunable ghosts and excessive hue shift with fine tuning. I will have to do this without an alignment procedure, I only have the various carrier frequencies known from the instruction manual (and they're not even the usual 45.75MHz either, I think it was 24 or 25MHz).

Electronic M · #**348** 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 · #**349** 08-12-2019, 10:02 AM

Quote:

Originally Posted by trinescope

As long as you have alignment equipment in proper working condition and the service data for the set I think you will do just fine. I was inexperienced once myself, and at 46 years old I did not have the benefit of having worked on these sets "back in the day" either.

I think I will have to do the alignment on my Mitsubishi Trinescope set since it displays the classic signs of misalignment; tunable ghosts and excessive hue shift with fine tuning. I will have to do this without an alignment procedure, I only have the various carrier frequencies known from the instruction manual (and they're not even the usual 45.75MHz either, I think it was 24 or 25MHz).

That's why I'm looking at the Heathkit over the B&K Precision , even though the B&K seems to be a better unit, it's useless w/o probes, which are impossible to find.
Heathkit, however even if you do not have any probes, has how to make them, and test / calibrate the unit in the manual.

"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."

I'll prob do that soon. Most likely seek aid from a friend who has more exp in the area, as my hands areattuned to more delicate work like soldering ( fine pitch ) and so on, and it also does not help that I have only partial use of the right hand

( De Quervain's) too many years of holding tools in the same position, like , soldering irons.
I can use the hand ( grasping and such ) for short bits of light work, and thus I was able to the TV work slowly over the months, but something like the shield would cause a flair up.

Yamamaya42 · #**350** 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 · #**351** 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 · #**352** 08-25-2019, 02:52 AM

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

Yamamaya42 · #**353** 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 · #**354** 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 · #**355** 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 · #**356** 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 · #**357** 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 · #**358** 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 · #**359** 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 · #**360** 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/