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Old 03-17-2010, 04:04 PM
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bandersen bandersen is offline
RCA 741PCS
 
Join Date: Mar 2009
Location: Chicago, IL
Posts: 8,808
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I've got sound

After performing the audio IF alignment, I started working my way back towards the antenna. I discovered that the trimmer cap in parallel with the fine tuning control was rotated fully clockwise which bottomed it out. I slowly backed it out and briefly heard some sound. Slowly I zeroed in on the sweet spot. This is a really critical adjustment - just slightly off and no more sound. It also allowed me to shift the best picture and sound to the center of the fine tuner control. Previously, I had to rotate the fine tuning fully clockwise to get a good picture.


I also replaced that old shielded audio cable with the crappy splice. I have plenty of volume now, but there's a faint buzz. I think that's coming from the horizontal / HV circuit. Maybe some better shielding will help


I also accidentally smoked a resistor While working on the sound, I had push some parts to the side and shorted two leads together. Instant flash and smoke. What a horrible stench It's a day later and still stinks in my workshop.
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