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:
anyone know about kit modifation to CW rigs for RTTY or other digital modes
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July 24th 05, 06:47 PM
Paul Keinanen
Posts: n/a
On Sat, 23 Jul 2005 04:33:05 -0000,
(Dave Platt)
wrote:
You might be able to do something similar to this with a
crystal-controlled QRP rig, but I suspect that pulling a crystal that
far with a varactor might be somewhat difficult.
The RTTY offset is only 170 Hz, so the required detuning on 160 m
would be about 100 ppm (parts per million), at 80 m 50 ppm, at 40 m 25
ppm and at 20 m 12 ppm. This should not be too hard for a VCXO, which
usually can be pulled to several hundred ppm with only some spectral
purity or stability problems. Shifts less than 100 ppm should not be
too hard.
Paul OH3LWR
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