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AO-40 Update, Schedule Change

Please note that due to changing squint angles the K/S2 beacon-only segment 
has been moved ahead of RUDAK.  MB is off from MA=240 to MA=5 to conserve 
power during eclipse and bad squint angles.  The schedule will need 
frequent modification, as the ALON continues to change.

N  QST AMSAT OSCAR-40  ***SCHEDULE S2 Downlink***    2001-12-30
     MA       005   020   056   060   078   100   240   005
     MB        |  *  |  *  | S/K |     |  *  |  *  |     |
     RUDAK     |     |     |     |  *  |     |     |     |
     V-Rx      |  *  |     |  *  |  *  |     |     |  *  |
     U-Rx      |     |  *  |     |     |  *  |  *  |     |
     Passband  |     | UL1 |     |     | UL1 |     |     |

AO-40 is experiencing some intermittent RADAR-type pulse signal 
interference on both L-band and U-band.  Whether this is related to our 
negative ALAT, events after September 11th, or other is not clear.  Indeed 
the source of the interference, whether terrestrial or space, is 
unclear.  Virtually all earth footprints seem to be affected at various 
times, suggesting either multiple terrestrial sites or a space site for the 
source.  Although this interference is not noticeable on the passbands, 
except perhaps for the SSTV images, it often makes commanding 
difficult.  V-band does not seem to be affected by this.  Accordingly, the 
command team may occasionally have to switch on the V-band receiver for 
commanding during passband usage.  This has the effect of switching off the 
U-band receiver.  Therefore, U-band uplinks may occasionally go dead due to 
needing the V-band receiver for commanding.   These inconveniences should 
be of short duration.  If you suddenly lose your U-band uplink, check the 
telemetry which will show the U-Rx off and the V-Rx on.  L-band uplinks 
will not be affected.

----W4SM for the AO-40 command team.

  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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