I was tearing out my hair trying to align my SX-28's IFs at 455 kc when I
remembered this note in my old SX-28 notebook from about six years ago:

"Be aware that the crystal filter alignment instructions are wholly
incomprehensible. Bottom line is you do a rough IF alignment to 455 Khz
(bandpass set to IF narrow). Then you center the phasing cap and switch to
crystal sharp. Crank up your generator and try to find the center of the
crystal frequency. It's not easy, VERY twitchy, since the bandpass is about
100 Hz. Once you have the generator centered dead bang on the crystal, don't
touch it and go back and tweak the IF alignment on that frequency (at IF
narrow bandwidth). A counter helps."

I believe the note came from A.B. Bonds. In any case, once I followed this
advice, my squealing monster aligned on the IF just fine. According to my
frequency counter, the magic number for my set is 456.9, not 455.0.

Any other useful tricks to know? I tried aligning the AVC by the book, but
didn't get good results. The AVC actually seems to work better when I set it
by ear, although I'm sure that sends a thrill of horror down the back of a
serious restorer.

Regards,

Phil Nelson
Phil's Old Radios
http://antiqueradio.org/index.html