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Deviation



"hasan schiers" <schiers@netins.net> wrote (about Doppler shift):
>As I recall, approximately +/- 3.5 Khz is the max. If your deviation is set
>low enough, you don't need to correct for it.

True, but my observations suggest that the RX on ISS needs a moderate deviation to give enough audio to its TNC.  In the first week of ISS packet operation I tried unsuccessfully to digi through.  I checked my deviation: it was around 4 kHz (and yes I was correcting for Doppler shift).  So I reduced it to about 2 kHz - enough to work into other terrestrial packet stations in my locality.  But last weekend, after four weeks of totally unsuccessful attempts to digi through the ISS station, I careful re-set my deviation to 3 kHz.  Now I can actually get a few packets digipeated!

I wonder how many other stations are using too low or too high deviation, and merely contributing to the congestion on the uplink (as I was), with no hope of success?

Neill
G4HLX

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