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on what I belive was the low pass filter (a resistor cap to ground cap to grid of osc) from the sync separater/phase inverter I found a cap that was a .01 and per the schematic it was suppose to be a .002 (verified that on two other sets with the same chassis). It did not look original. I replaced it, still have the interlace instability (it jumps in and out). I put a scope on it and checked the input to the vert osc one check has it with the osc tube in and the other with it out (brt turned down). in both cases the wave seemed to move around on the scope, not so on the other set that is good. with the tube pulled you can see the sync pulse, on the good set it looks like the sams on the bad set the low part of the wave it thick, if I speed up the scan I can clearly see a hi freq wave in it. both sets have this, but on the bad set it in prob 4 times as big. I will post some pic later to try and make it clear what I am saying. the other scope readings of the sync sep and agc keying tubes were in conclusive, did not look anything like the sams, but neither did the working set. I will have to go back and take better notes, one ready I got was about a 3 order magnitude higher on the non working set than the working set.
checked it:
that was on the sync phase inverter grid, the non working set was much higher amplitude than the working set.
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12-08-2009, 08:54 PM
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