a real challange?

[Yamamaya42]

hmmm

that blanking mod sort of works with the12lp4, but it also caused a shadow to appear on the top of the screen. that was not seen on the test CRT.
Weird as seen in the video.

no amount of vert resize would make it go away.
I removed it, hooked cathode back to GND, and its gone...
strange

[Yamamaya42]

snip/ paste
Try this:

1. Place a 47k resistor between pin 11(cathode) of the CRT and ground.

2. Connect a .05uf, 630v cap from pin 3 and 4(plate) of the 6K6 vertical output
to pin 11(cathode) of the CRT.

Basically you need a positive going vert deflection pulse at the CRT cathode in order to blank the picture during vertical retrace.
----
Pure speculation at this point, not really sure, the RCA 630ts service manual shows the wave at this point to be 700v ptp, perhaps that was too high for the cathode of the 12lp4 , and some resistor in the line is needed?

[Electronic M]

A resistor may be needed also adjusting the cap value may help...a good place for decade box engineering.

[Yamamaya42]

Originally Posted by Electronic M

A resistor may be needed also adjusting the cap value may help...a good place for decade box engineering.

I'm thinking the same...

from another thread...
-----
I often simply hunt for an appropriate waveform somewhere in the vertical oscillator or output stage and couple it through a small value cap to the brightness control of the set. If the video signal is on the CRT cathode and brightness control on the grid, then you want a sawtooth with a rising ramp and a vertical drop. If the video is on the CRT grid and the brightness is on the cathode, then you want a signal with a falling ramp and a vertical rise. Depending on the amplitude of the signal you are grabbing, something in the range of 50 - 1000 pF will usually do it, and typically you need to add about 50-100 K in series with the lead to the cathode or grid, and couple the signal to the cathode or grid end of the resistor.

I've had a few sets where this was not successful. Sometimes the problem is that the sawtooth rise or fall is too fast, and the retrace on the screen isn't done before the blanking pulse ends. The method shown here should solve that problem, since it pulls the blanking pulse off the actual current waveform in the vertical deflection yoke. I'll keep this circuit in mind for future reference!
-----

and seen in almost every RCA color set, CTC 10-20 , and so on.
https://imgur.com/ZH3uckS
I may try something more like seen here.

IE, VERT OUT-- RESISTOR -- CAP - RESISTOR -- CRT CATHODE --- RESISTOR-- GND

[JohnCT]

Originally Posted by JohnCT

Something's wrong. There's some annoying whine that is permeating the sound.

Edit: Never mind, that's Dr. Smith...

John

Originally Posted by Yamamaya42

that is the fans in my server..
2 of these

https://www.youtube.com/watch?v=on9pvkJ0P1w

Swing and a miss...




John

[Yamamaya42]

Originally Posted by JohnCT

Swing and a miss...




John

Yes, I do know what you meant, I happen to like the new Dr Smith better BTW, (June Harris)

I just happen to be of the school of when you turn on your PC, and if it does NOT need to be nailed down or glued to a horizontal surface to keep it from taking off like a 747, then you DON'T HAVE ENOUGH fans in it!!

[Electronic M]

Originally Posted by Yamamaya42

Yes, I do know what you meant, I happen to like the new Dr Smith better BTW, (June Harris)

I just happen to be of the school of when you turn on your PC, and if it does NOT need to be nailed down or glued to a horizontal surface to keep it from taking off like a 747, then you DON'T HAVE ENOUGH fans in it!!

Lol.
For my media PC I bought the quietest fans and case I could get for sane money and sized the heatsinks 2X the wattage the CPU etc would be able to put out....the result: my fans barely need to run under heavy load, don't make audible noise and if my fans die and I don't hear it the heatsink alone will prevent calamity and allow normal opperation under normal use.

[JohnCT]

Originally Posted by Yamamaya42

Yes, I do know what you meant, I happen to like the new Dr Smith better BTW, (June Harris)

Okay.

I feel a little better I guess.

So hard being an internet comedian. The pay is lousy and most people just flat out think you're nuts..

John

[Yamamaya42]

server specs...
NOT , my main system, not my media system...
Just the server...
Yes i have many PCs..

LSI MegaRAID SATA/SAS 6Gb/s PCI-Express 6 port
WD Red Pro 2TB NAS Hard Disk Drive - 7200 RPM Class SATA x4
WD Black 3TB Performance Desktop Hard Disk Drive - 7200 RPM SATA x2
Crucial M4 2.5" 256GB SATA III MLC Internal Solid State Drive (SSD)
pioneer BDR-208DBK
gigabyte GA-970A-DS3P mobo.
amd vishera FX-8320
G.SKILL Ripjaws X Series 16GB x2 DDR3 1600 (PC3 12800) total 32 gig
CORSAIR RM Series RM650 CP-9020194-NA 650W
EVGA GeForce GT 710 DirectX 12 01G-P3-2711-KR 1GB 64-Bit DDR3 PCI Express 2.0
RAIDMAX SMILODON ATX-612WBP Black 1.0mm SECC Steel ATX Mid Tower Foldout MB Computer Case
3 vantec tornado 80mm
2 vantec 120 mm

[Kevin Kuehn]

Originally Posted by Yamamaya42

I'm thinking the same...

from another thread...
-----
I often simply hunt for an appropriate waveform somewhere in the vertical oscillator or output stage and couple it through a small value cap to the brightness control of the set. If the video signal is on the CRT cathode and brightness control on the grid, then you want a sawtooth with a rising ramp and a vertical drop. If the video is on the CRT grid and the brightness is on the cathode, then you want a signal with a falling ramp and a vertical rise. Depending on the amplitude of the signal you are grabbing, something in the range of 50 - 1000 pF will usually do it, and typically you need to add about 50-100 K in series with the lead to the cathode or grid, and couple the signal to the cathode or grid end of the resistor.

I've had a few sets where this was not successful. Sometimes the problem is that the sawtooth rise or fall is too fast, and the retrace on the screen isn't done before the blanking pulse ends. The method shown here should solve that problem, since it pulls the blanking pulse off the actual current waveform in the vertical deflection yoke. I'll keep this circuit in mind for future reference!
-----

and seen in almost every RCA color set, CTC 10-20 , and so on.
https://imgur.com/ZH3uckS
I may try something more like seen here.

IE, VERT OUT-- RESISTOR -- CAP - RESISTOR -- CRT CATHODE --- RESISTOR-- GND

By all means feel free to experiment. Adding a series resistor is a good place to start. Every set is a little different so there's no exact science.

[Yamamaya42]

here it is w/o the shadow at the top
https://youtu.be/Fi4C6_bdXJk

[Yamamaya42]

now come the tough part,, trying to put it all into something

[Yamamaya42]

I just closely checked the coils I removed from the set, the 2 120uh coils, L22, L20 (wrapped around a 22k res) seemed to compare mostly OK to to new ones, but today, when removed the wax from them so I can open the coil on one end to measure the resistor, the core resistor from L20 tested at 52k and L22 at 31k.

At this point, I have only replaced 4 out of 6 coils, for video amp and output, have not touched video det yet, which has a 180uh coil around a 39k, this one most likely has also drifted up.

[Yamamaya42]

https://www.youtube.com/watch?v=xGH3LW2gUwE

retrace mod adjusted

vertout--100k--.01uf--56k---CRTcath---47k---gnd

[Yamamaya42]

front section done (almost, sanding and painting still needs to be done )
https://imgur.com/l89X293


this took a while, a few missteps, but came out OK!