[HBR] Xtal filters

[Frederick W. Seibold]

I am in the middle of building a NorCal 40A for 160 (NorCal 160???).  Do a 
Google for "Cohn filters" or "ladder filters" for plenty of info on using 
the inexpensive xtals, and matching them tighter than the over-the-counter 
match.  Even the length of the ground lead for the xtal cases makes a 
difference.  The performance is improved by running the ground lead around 
the lower side of the cans rather than across the tops and then down to the 
circuit board.  The increased inductance of the top-soldered lead increases 
"blow-by" above the filter center frequency.

(I have more tube gear than solid state, so please tolerate the NorCal 
project.)

73

Fred W9FWS


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