Quote:
Originally Posted by old_tv_nut
Don't go ruining your bandpass to center the tint.
Is it correct that L31 connects to the bottom of A17 (doesn't jump over it?).
If so, this is the suspect area. I would first try setting the tint control to center range and tuning A17 to see if that will center the tint.
Also check if C138 (? can't read it clearly) on bottom of A17 is good.
Of course, ther is always the possibilty that the aligment procedure for A15 and A17 isn't right.
|
I tried the entire range of A17 and it doesn’t get the hue to the right phase. The reason I am going back to adjusting the chroma bandpass is that there are many variations of the bandpass slugs that create the right bandpass shape. Before I did the alignment, the bandpass slugs were set to peak max gain at 3.58mhz. The bode plot looked like a very tall and skinny triangle. That had the right hue, but caused the horribly bad smearing. The Pb and Pr bandwidth was far less than the 0.5mhz that it should have been.
If I could observe the phase angle and the bode plot of gain at the same time, I’d be able to align the band pass and land on a phase angle close to that of the color burst amplifier output.