Quote:
Originally Posted by old_coot88
In regards to those trailing ghosties, be sure and check peaking coils L105 and L106 for continuity.
Seems like the tearing/'flagging' is related more to signal overload than horiz. adjustment since it straightens up as you lower the contrast. This set doesn't appear to have any AGC (automatic gain control) at all. The contrast ('Picture') control adjusts the gain of the 2nd IF tube, requiring you to manually adjust it for varying signal strengths. Too strong a signal and the pic gets the bends. Just one of the charms of the old beasties, sorta like riding the gain on an old TRF radio.
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L105 and L106 read a bit low on my voltohmist but they are in the neighborhood.
I've shot a couple of videos of what the set is doing. The first one is from the B&K 1077 and shows that the two problems seem to be interrelated. When I adjust the picture control I can get a steady picture with ghosting, or a ghost free picture with tearing, but not both. The ghosting is much easier to see in the black blocks at the bottom of the screen (is there a proper name for those blocks?).
http://www.youtube.com/watch?v=rLJRdzFB-yU
The other video displays the occasional horizontal tearing towards the top of the screen with full video that I described before.
http://www.youtube.com/watch?v=28X9hkIWCQE
I'll check the resistors and voltages in the video and if stages next to see if anything jumps out there.
02-19-2012, 03:17 PM
Hybrid Mode
