In 15.04 25/04/00 , G4JNT wrote:
On this subject, does anyone know of a low-cost source of 455 kHz
(series resonance) crystals. I want to make up a ladder filter for the
RA1792 with a much narrower bandwidth than the 300 Hz mechanical filter
included.
It's hard, I tried to have 455 kHz xtals built on order, but the producer
says that he had no 'blanks' (raw slices of SiO2, I presume) available
for frequencies under 1 MHz - nobody wants them, today !
Just a thought, but a ladder filter at 455 would be a lot easier.
My RA1792 has a 100 Hz xtal filter in place of the wire bridge on the
filter bank. This filter is rare, but sometime available.
73, Marco IK1ODO
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