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Re: S-band receiving requirements



At 11:04 AM 5/17/2001 , you wrote:
>I think I now understand why so many of us had unrealistic expectations 
>about our S-band receiving systems.  It boils down to a series a cascaded 
>assumptions that were incorrect.
>
>Many of us discovered through trial and error that "pre-launch example" 
>S-band receiving setups are woefully inadequate for reception of the 
>existing spin-stabilized S2 transponder.  More uplink power will result in 
>a readable downlink signal, but a higher authority has (correctly) decided 
>for us that the solution must be to use receiving setups that are 
>significantly better than the pre-launch examples.
>
>It remains to be seen if "pre-launch example" receiving setups will be 
>adequate part of the time with the final satellite configuration.  Squint 
>near perigee will improve dramatically if 3-axis stabilization is 
>successful.  There may be seasonal periods when the S1 antenna can be used 
>for a portion of each orbit.  It is certain, however, that RELIABLE S-band 
>reception requires a SIGNIFICANTLY BETTER receiving system than the 
>"pre-launch examples".
>
>In retrospect, the only thing that mystifies me is why today's "alligator 
>critics" were SILENT when months of amsat-bb traffic was dominated by 
>discussions about building helixes, modifying surplus converters, 
>etc.  One or more of these silent experts should have spoken up to explain 
>why those setups won't be good enough.  Then for the last few weeks the 
>experts remained silent when several people reported modest success 
>hearing the Middle Beacon.  Again, the experts should have pointed out 
>that we need to hear much weaker signals than the Middle Beacon.  The 
>"alligator critics" are vocal now, but they were strangely silent when 
>their advice would have been most helpful.

 From what I have been reading ... unless the situation with AO-40 
drastically improves (hopefully by changing [improving] its orbit and 
deploying the solar panels for more transmit power on S band), that AO-40 
will NOT be an "easy sat" for beginner hams to work. But it will still be 
possible to work.

W4SCO



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