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After a full evening's work on IF alignment, the video IF response looks better. Not an exact match to what Sams thinks would be ideal (rolloff slope on high end of passband is too steep), but hopefully OK?
The first photo is the bench setup. Second is the connection to the tuner I used for injecting the IF sweep for quite a few of the alignment steps. This has very short leads (less than 1" beyond the shield). The third picture is the IF response from injection point at the diode in the tuner through to the video detector. Although I don't show my markers here (they are not very photogenic on the scope), I have the scope carefully calibrated, with the center being exactly 44 MHz, and each division exactly 1 MHz. The null point on the low end is 41.25 MHz, and the top end goes to zero just under 47 MHz.
Alignment of this set is quite an undertaking compared to a typical black and white set, which I can usually align in a pretty short time. And there's still plenty more to do in the color circuitry.
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