See "Ladder Crystal Filter Design", by J. A. Hardcastle, November 1980, QST
and "A Unified Approach to the Design of Crystal Ladder Filters", by Wes
Hayward, May 1982, QST.

Joe
W3JDR


"Ken Scharf" wrote in message
. ..
I just got a deal on ebay for 8.3886 mhz crystals (414 pcs for $9.99).
Should be able to make a few good ssb and cw filters out of that!
They look like std microprocessor types (hc49/u holders) though this
isn't a common microprocessor frequency. Guess I'll start with 100pf
coupling caps, any good guess on what the termination resistance might
be? (I'm looking for a bw suitable for ssb, probably about 2.1khz).
Hope this frequency doesn't have any bad mixer products (but I can
always pick either high or low side injection if necessary).