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SEDSAT keps or freq off


Signals from SEDSAT on the last pass over Huntsville, Alabama brought
some good signals during the 30-OCT-98 05:42 UTC pass.

A few observations were made:

1. It is nearly impossible to zero the antenna on this bird to verify the 
    KEP's since it only transmits a short burst of data at approximately 
    1 minute intervals.

2. No data or signal was received after the middle of the pass, indicating
    an update may be needed on the KEP's or it stopped transmitting at
    that point.  It was certainly in darkness at that point and the solar
    panels would not have been seeing the sun.

3. The frequency was measured to be approximately 3.4 KHz higher than
    anticipated using the KEP's posted on the SEDSAT web page, indicating
    that the KEP's need adjusted.  I am no expert in this area and have not
    performed any calculations, but judging by the frequency offset accounting
    for the Doppler shift I would estimate that the KEP's may be about 2
    from those published on the SEDSAT site.  Any and all comment on this
    best guess is welcomed.  This assumes that the frequency on SEDSAT is
    true to 437.91 MHz.

    My next step is to start tweaking the element set from the SEDSAT web
    site to bring them closer to the actual unless anybody out there has some
    updated elements.


Tim - N8DEU
Huntsville, Alabama
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