ZenSafari wrote:

I am currently looking for a crystal filter in the CF range of 70 to
100MHz. I know that these are rare and are not standard for FM radio,
citizen's band, etc, but it would be most helpful for me to find one.
Ideally, the filter should have a passpand of +/-3.75kHz about the CF
(3dB). I've checked numerous manuf. who make these type of crystal
filters (FOX, ILSI, Raltron, MCF, etc) but most of their products are
vapor ware and have never been fabricated. Do any of you have a
suggestion of where I might find a filter that meets this spec? My goal
is to avoid another IF stage in my hardware...this is why I require the
narrow bandwidth at the high CF. Even if you have a suggestion of where
I might find a 70 to 100 MHz CF filter with a wider bandwidth I would
appreciate it very much.

Thanks for the help.


The only off the shelf 70 MHz CF filters I've seen were used in
Satellite TV or Telemetry receivers. Microdyne built their own IF
filters For narrow frequencies like this, with switching to select one
of up to 12 internal bandwidths, and a few models allowed 12 external
filters, as well. The SAW filters for Satellite receivers is generally
+/- 10 MHz, so those won't help you. Its too bad, because there are old
C-band and early KU band junkers almost everywhere.

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http://home.earthlink.net/~computersforvets/

Michael A. Terrell
Central Florida