Heikki wrote:
Having built several ladder filters for SSB (8.. 10 MHz, 4 .. 8 poles)
with BW abt. 2 kHz (mainly for TX applications) I would like to try a
narrow filter (BW 500 or even less). One thing I am worried about is
the insertion loss. Has anyone any experience regarding the maximum
number of poles (= crystals) in such narrow filters. I have seen designs
for SSB with 14 poles but some doubts exist if this would be excessive
in a CW filter.
73 de oh2lzi (Heikki)

Heikki - See QST for 8/78, 12/78 and 11/80 for answers.
If I have room, I put a mini trimmer cap in series with each xtal
to tune all the xtals to the exact same frequency.
This helps the bandwidth and reduces the insertion loss.
73 W7ZFB