[Hammarlund] Newly aquired HQ-129x

[Kenneth G. Gordon]

Concerning the Hammarlund crystal filter, especially in the SP-600: many, 
in fact I would say "most", people over the years who have attempted to 
align the crystal filter using either the information in the SP-600 manual, 
or "standard" techniques end up with a crystal filter that is NOT aligned 
correctly, and does NOT work as it should.

I have heard many complaints that the SP-600 crystal filter is a "piece of 
junk", "not designed properly", "never has worked", etc. This is all 
incorrect.

My Elmer, Woody Davey, W7CJB (SK), in Missoula, Montana worked for 
several weeks to figure out the proper procedure, and when he finally hit 
it, the crystal filter in his SP-600 worked far better than any other such 
filter either he or I had ever used.

One clue that I remember is that when the crystal filter is set to its 
narrowest position, IFF the filter is properly aligned, the "S" meter reading 
should increase since the S/N ratio improves at the narrower settings.

Ken Gordon W7EKB