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It's 0200 central and I'm out of ideas. A picture can be worth a thousand words so I did my best to grab a few and crunch them down, if you want larger originals they're available. I named the files to be self explanatory, if something doesn't turn out please let me know.
So what I have is endless frustration with the horizontal and to a lesser degree vertical sync. I've run thru the IF response several times tweaking here and checking for symmetry there, replaced the AGC/Sync sep 6GH8 with several NOS tubes fresh from the cartons and checked resistor values along with probing in capacitors on top of the originals with no changes to the bending.
The signal into the 1st video amp is strong, over 2.5V P-P from the detector and I'm seeing signal levels on the various test points that are very near the spec'd levels in the schematics, horizontal lock is very strong but the vertical is dependent on the size control settings, stretch the vertical to fill the screen and it wants to lock on the black band within the picture itself unless I run a 4:3 image in which case it attempts to lock onto a something near black. Tube is new and I've sub'd in several different NOS tubes with the same results.
Power supply voltages are within 5 to 10 volts of spec and I can't pick out any ripple on the scope. AGC is set conservatively however going for overload doesn't affect the bending as much as it does the overall black and contrast as expected.
Horiz out cathode is shy of 200ma at medium brightness and the 6LQ6 tests at 90% give or take.
In the group of pictures I've included the test pattern I'm using to demonstrate running in as both composite and CH-3 RF. The scope screen shot is direct from the test point TP2 using a 10:1 100 MHz probe and the test pattern itself comes from my Newtek Tricaster TC-550 which is essentially a studio control room in a box. All the output levels conform to NTSC standards and verified using a Leader waveform monitor and vectorscope.
So what this all comes down to really is what am I missing?
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