[amsat-bb] MB only on AO-40, S2 Tx

["Stacey E. Mills" <w4sm@xxxxxxxxxx>]

"Gary \"Joe\" Mayfield"  wrote:

>Now that the squints are better does anyone know why the middle beacon is
>still being used?  Why not use the general or engineering beacons?  I
>believe they are not in the passband (that gets rid of one problem), and I
>also believe they are at a strength similar to what our downlinks should be
>giving us a good target.
>
>73,
>Joe
>ka0yos@amsat.org

ONLY the middle beacon is functional on the S2 Tx.  We sure would use the 
EB or GB if we could.  In the matrix only the MB can be hooked directly to 
the S2/K Tx.  We once thought that we had a way around this by going 
through one of the Leilas in "bent pipe" mode.  However, this was tried and 
does not work.  On further study, the reason is that the passband for the 
S2 has sharp edge filters which greatly attenuate the GB/EB beyond the 
upper and lower edges of the passband.  The reason for the filters, as I 
understand it, is because the K Tx and the S2 Tx share the same IF 
connection and the edge filters were added to keep the K Tx signal nice and 
clean.



-- 
  ________________________________________________________________________
  Stacey E. Mills, W4SM    WWW:    http://www.cstone.net/~w4sm/ham1.html
    Charlottesville, VA     PGP key: http://www.cstone.net/~w4sm/key
  ________________________________________________________________________

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