[amsat-bb] Re: D-STAR repeater problems in Copenhagen
G0MRF at aol.com
Sun Dec 7 15:28:07 PST 2008
Interesting allocation for D-Star.
-60dB at 145.800 may sound suitable, but in practice what matters is how
many dB down it is at 145.800 minus one half of the bandwidth of your IF filter.
So -4kHz of doppler and -7.5kHz for a narrow FM filter gives your receivers
bandpass down to 145.7885 MHz just 10k above the D-Star
Which means the two are probably going to overlap.
In a message dated 07/12/2008 20:34:56 GMT Standard Time, oz1my at privat.dk
The theoretic spectrum should be more than 60 dB down
on 145.800 MHz,but that does not seem to be the case.
Including doppler the downlink from ISS is 145.796 MHz, when
it is going away from us to the East, which is the direction
of the repeater :-(
Personally I am just 6 km away from the repeater with
no obstructions on the pass from it.
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