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Old 06-17-2007, 03:17 PM
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wa2ise wa2ise is offline
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Join Date: Dec 2002
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Quote:
Originally Posted by kbmuri View Post
So I did a complete IF alignment, by the book. With my crude tools, but I'm sure I nailed it. My Knight am signal generator made sine waves, and I set probe A of my tektronix dual-trace scope to monitor them, setting the sweep to 0.1 microseconds/div (or 1 microsecond per full frame of 10 divisions). Counted the waves by hand to make sure the 2nd-hand Knight generator was dead on. 21.25 Mhz where needed, 23.5, 25.3, 22.0.
Counting waves isn't really that an accurate way to measure frequency. But it does sound like all the circuits fundamentally are working, but at a somewhat wrong frequency.
Quote:
Originally Posted by kbmuri View Post
Then I used probe B to measure voltage deflection at test points. Had to build a detector probe per the Sams schematic and a resistor-capacitor filter test point and an insulated tube shield with test-clip loop (for injecting signals inductively into the 1st tuner tube). Quite a time-consuming affair.
...

After removing the filter test point and reassembling channel 13 of the turret tuner and replacing the tube shield, I re-applied VCR signal. Lost all my sound now, and made crap out of my crystal-clear picture.

How exhausting is that?
Been there at times... VCRs usually create a signal on either channels 3 or 4. I presume you didn't try to use channel 13 (I've made similar silly mistakes myself... :-) )
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