On Sat, Jul 26, 2014 at 10:24:15PM -0700, Phil Karn wrote: > On 07/22/2014 07:49 AM, wa4...@comcast.net wrote: > > > SSB/CW birds are the only way to go and if you build it they will > > come . > > Think about what it would be like to tune for Doppler while working SSB > through a LEO satellite on microwave. > > Before you say "computer control", work out the effect of even a tiny > error in your clock or orbital elements on a high elevation pass and > remember that SSB has no carrier or pilot tone for closed-loop frequency > tracking. > > Sure, you could have a second receiver track the satellite's beacon. But > if you're going to all that trouble, why not just have it track a > single high speed data stream from the satellite, one that's much less > affected by Doppler in the first place?
Exactly. It makes much more sense to go digital. The crucial thing is *not* the complexity of the groundstation it is the lifetime of the satellite. - 73 Diane VA3DB -- - d...@freebsd.org d...@db.net http://www.db.net/~db _______________________________________________ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
