Zenith Color Roundie Alignment with B&K 415

[bhegges]

I am getting closer. I now am ensuring the sound detector (C2) voltage is at 2 volts and the video detector (C1) is at 6 volts. Over/under driving these voltages does affect the signal response. I also labeled the scope each time I snapped a picture so not to mix them up (label includes signal generator input and scope output). See below for where I am at:

The one concern I have is on the sound detector C2 response curve there is no real response dip like shown, my curve just starts to slope down continuously until it gets to the 41.75mc marker. Is it possible that I am still way off and need to push the 41.25, 41.75, and 42.75 further right on the wave form, that would put the 41.25 on the top of the first peak but currently is at 25% vs the spec of less than 5%.

[bhegges]

Out of curiosity I adjusted L1 (41.25mc trap) and L3 (39.75 trap) to their max and I was able to get the below curve, all other coils and transformers I left as-is. It seems like if I had a bit more adjustment in the coils I could get the response curve to dip between the 39.75mc and 41.25mc markers. Also not sure then why such a response around the 41.75mc marker, while the drawing shows a bit of a curve here my set exaggerates the response around this marker.

Would there be a particular capacitor in these trap circuits I should look at? All of these capacitors are precision low values that are not easy to measure, I would have to remove the capacitors and either try to measure or just replace.

I also could just move on. Maybe unrelated but after going through the power supply, horizontal and vertical circuits there was low sound and serious buzzing/noise in the sound circuit, the Quadrature, Intercarrier, and Sound Take Off coil all needed a good bit of adjustment. I still get buzzing/noise during screen changes such as when going to commercials.