help me ID this mystery GE roundy plz! - Page 4 - Videokarma.org TV - Video

Yamamaya42 · #46 10-01-2020, 10:22 PM

Quote:

Originally Posted by damen

Thought you might like to see what a NOS CTC16X board looks like before it gets cooked.

I thought those were unobtanium!

Yamamaya42 · #47 10-01-2020, 10:57 PM

I have replaced all the resistors in the video output area, 2 of them were most like out of tol, as they were 10% ones and they tested out of the 10% range, not sure how much that matters. but they must have had 10% in there for a reason and not 20% like every place else.
I also replaced 1 orange drop that may have been flaky.

Yamamaya42 · #48 10-02-2020, 10:16 PM

The cataract on the 21fjp22 in the GE set has been removed :P
but it's now a 21FBP22...

Yamamaya42 · #49 10-03-2020, 12:06 PM

https://i.imgur.com/CiFcyr0.jpg

here is my new cataract free "21FBP22"...

and this is mess I made doing it .

https://i.imgur.com/1Jdtyha.jpg

Yamamaya42 · #50 10-03-2020, 12:44 PM

https://i.imgur.com/pfo5lwV.jpg

new pads on mounting bracket, now also CAT-A R-act free, for now.

Yamamaya42 · #51 10-03-2020, 05:09 PM

https://i.imgur.com/QlvvjAb.jpg

CRT installed

Yamamaya42 · #52 10-03-2020, 07:48 PM

https://i.imgur.com/0WkjdtZ.jpg

convergence asy and purity magnets NOT on at this point.

HV is a little low, about 21kv HOT & HV rect may be tired ( orig tubes )

all pots cleaned now

EDIT
NOS tubes for HOT and HV rect ordered, I'm kind of surprised that they were still the orig GE ones in there, given that how hard they are driven, once I get them hopefully I can get it to around 24kv where it should be.

Electronic M · #53 10-04-2020, 01:48 PM

Quote:

Originally Posted by Yamamaya42

https://i.imgur.com/CiFcyr0.jpg

here is my new cataract free "21FBP22"...

and this is mess I made doing it .

https://i.imgur.com/1Jdtyha.jpg

Quote:

Originally Posted by Yamamaya42

The cataract on the 21fjp22 in the GE set has been removed :P
but it's now a 21FBP22...

Not really...The 21FBP22 had a safety glass by design, but it wasn't glued to the screen. The safety glass on a FBP is held on by the front fingers of the mounting band and a rubber gasket around the perimeter.
Really it's a still 21FJP22 just without a safety glass.

I've done a few 21FJP to FBP conversions and I always reinstall a safety glass...but not always the one it came with...

I feel your pain. The majority of RCA cataract removals I've done ended up like that...It sucks having broken glass and in my case having to come up with replacement safety glass (though the first couple of times I was lucky enough to have dud CRTs to pirate from).
Did this happen from a slip up with the water method?

Yamamaya42 · #54 10-04-2020, 04:12 PM

Quote:

Originally Posted by Electronic M

Not really...The 21FBP22 had a safety glass by design, but it wasn't glued to the screen. The safety glass on a FBP is held on by the front fingers of the mounting band and a rubber gasket around the perimeter.
Really it's a still 21FJP22 just without a safety glass.

I've done a few 21FJP to FBP conversions and I always reinstall a safety glass...but not always the one it came with...

I feel your pain. The majority of RCA cataract removals I've done ended up like that...It sucks having broken glass and in my case having to come up with replacement safety glass (though the first couple of times I was lucky enough to have dud CRTs to pirate from).
Did this happen from a slip up with the water method?

Yes, I was removing some of the white gunky stuff from around the edges with spudger tool Friday, I got a lot out, and I stuck 4 of them across from each other between the safety glass and tube in order to open the gap a bit more, I could see the gap flexing as I did, but as it was being out back into the water, one spudger bumped the edge of the tube and the safety glass cracked.

Sucks, but no REAL big deal, was able to get the rest off w/o too much trouble, and as I have nothing to replace it with, and am very unlikely to ever get one, I put it in as-is.

Looks pretty OK.

Right now, I'm more zeroed in on the HV problem, why I can't get it to 24kv like it should be, if I try, focus goes to hell, which MAY be because the CRT socket is crappy, and all carbon arced around the pin for focus, AND/OR as mentioned the HOT/HV rect tubes are all old, new socket and tubes ordered.

Am also seeing symptoms of bad caps in the Y amps, the level of red is jumping all over the place, just like blue was before I replaced them in my CTC-16

Yamamaya42 · #55 10-05-2020, 12:56 PM

Although I am working on the video circuits right now, and getting them up to par, and will move on to sweep later, I do wonder what could be causing that odd tilt to the left at the top of the screen, horizontal problem? Vertical? Pincushion?

old_tv_nut · #56 10-05-2020, 01:22 PM

Looking at https://imgur.com/0WkjdtZ I don't see a tilt?

The bend in the vertical lines is probably due to non-standard sync from the pattern generator. Just check that it goes away with a better source - DVD player or cable box.

Yamamaya42 · #57 10-05-2020, 01:50 PM

Quote:

Originally Posted by old_tv_nut

Looking at https://imgur.com/0WkjdtZ I don't see a tilt?

The bend in the vertical lines is probably due to non-standard sync from the pattern generator. Just check that it goes away with a better source - DVD player or cable box.

here is the same pattern generator on my CTC-16XL
https://imgur.com/jtYPypZ
And on a SS sony,
https://imgur.com/O7D8fqq

I guess it could be that this set just does not like it.

Tom9589 · #58 10-05-2020, 03:05 PM

Try adjusting your horizontal hold on your GE. You will most likely get rid of the bending. My dot-bar generator I used for 20 years did the same thing. If I wanted the top of the cross hatch to look good, I just adjusted the horizontal hold slightly.

Yamamaya42 · #59 10-05-2020, 09:31 PM

I believe I have found something

https://i.imgur.com/MLth8s2.jpg

the signal going into pin 2 ( Sams got it wrong ) of V5 is hardly 6v PtP, should be 8.5, this is no doubt a cause of dim video,
https://i.imgur.com/VoNAr6d.jpg
signal going into pin one V4 point B is almost 5v PtP, I don't have another 6LF8 to try, I have one on the way, the one in there is also an original GE. it is obviously not working as it should be.

While I wait for the new one, I will check the resistors and caps around there as well.

Good thing that happened today is that the CRT socket came and is wired in, BAD thing is, the thermistor did NOT come, even though USPS SAYS that it did,,, they LIE.

Yamamaya42 · #60 10-06-2020, 02:18 PM

Now that the new CRT socket came in, focus is now a lot more stable, the focus voltage was literately trying to corona into the carbon burned areas of the old one, and with the new high voltage rectifier, (3AT2) , I'm able to get to almost 23kv, the HOT is not here yet.
Still no idea what happened with the thermistor I ordered, I'm gonna be very pissed if USPS lost it and said it was delivered anyway, it was one of the last few of that type to be found.
And as mentioned, I will have to wait till I get the new 6LF8 to try and find out the video level is about 30% or more below where it should be, I KNOWthat it's not the video output, 12BY7A, cause I had more than 1 known good one, and tried that first, but the only other 6LF8 I have is in my CTC-16XL, and I'm not about to go yanking it out right now.