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RE: [aprssig] Re: RE: AO16/LO19 Uplink w ANY PC!

So, would it be safe to say that by replacing some filters with 20 khz
bandwidth and a decent preamp, one could forget about doppler??


  Mark Schoonover KA6WKE	           IS Manager
  Trail Runner,HAM	             schoon@amgt.com
  http://www.qsl.net/ka6wke       ka6wke-1 145.05
                Mobile: 146.52 & 28.470
    Lat: 32.85380 Long: -117.00980 Grid: DM12LU

 >From: 	John W  Wilson[SMTP:z004391b@bc.seflin.org]
 >Sent: 	Sunday, September 19, 1999 1:06 PM
 >To: 	Bob Bruninga
 >Cc: 	Mark Schoonover; TAPR APRS Special Interest Group;
 >aprssig@lists.tapr.org; aprssig@tapr.org; amsat-bb@amsat.org
 >Subject: 	Re: [aprssig] Re: [amsat-bb] RE: AO16/LO19 Uplink w ANY PC!
 >You actually only need down tuning.  As the bird comes over the horizon 
 >toward you the doppler shift is greatest and only reduces to zero 
 >overhead and goes negative as it sails off to the other horizon.  I have 
 >found that max doppler shift has been less than 10 khz plus as it is 
 >first seen, and 10 khz minus as the satellite disappears.  The shift is 
 >much less than 10 khz if the satellite does not pass overhead.
 >John W. Wilson, KN4HX
 >On Sun, 19 Sep 1999, Bob Bruninga wrote:
 >> > > But of course, a $89 UHF downconverter and an old 10m SSB rig would
 >>make a
 >> > > great portable AO16/LO19 downlink..
 >> > 
 >> > Remember, most of the software that is out there on the market that does
 >> > rig tuning thinks it's going to see something nice and shiny-new, with
 >> > a computer post of some sort to talk to, so either you manual tune,
 >> > or get really familiar with C or whatever language your tracker/tuner
 >> > was written up in......
 >> I think most PSK modems generate up/dn key clicks.  My PSK1 only requires
 >> tuning initially at AOS, and from then on throuhgout the pass its hands
 >> off.  Since I was talking about portable operation, the assumption is that
 >> you manually tune out the doppler at the start of the pass until you get
 >> lock.  Most 10m SSB rigs (CB market) have microphone up/dn buttons..?  Im
 >> going to be using the RCI-2650 10m rig... (though not hooked up yet)...
 >> bob
 >> ---
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