[amsat-bb] Re: my strange observation on AO-40 S2 beacon

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

>Hi all
>
>      Today(Apr-28-2003), I observed some strange on AO-40 S2 beacon
>requency. Before 01z, everything is quite normal. But after on 01z until
>06z(LOS of today at my location), the beacon frequency was abruptly
>jumped up
>a few kHz many times.

[snip]


>73, Kazu  JJ1WTK
Kazu,

I believe that you have a downconverter problem.  Either the voltage is not 
steady or there is another oscillator stability problem with the 
converter.  Others have experienced problems of this type from time to 
time, and have traced them to downconverter problems.

I have been monitoring the telemetry all day with no difficulty.  A good 
test is to note the exact time of the jumps, then when the telemetry 
archive has been updated for that orbit, download that day's telemetry and 
check to see if there is a discontinuity in telemetry blocks related to the 
jump that you observed.  A few KHz is a HUGE jump and would unlock 
virtually every telemetry gathering station for a protracted period of 
time.   If the telemetry continues unaffected through the time that you 
observed the "jump" it's a sure bet that it's a local problem.




-- 
  ________________________________________________________________________
  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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