R: [amsat-bb] Re: AO40 Orbit 778

["i8cvs" <domenico.i8cvs@xxxxxx>]

----- Original Message -----
From: Stacey E. Mills <w4sm@cstone.net>
To: Amsat Bulletin Board <amsat-bb@AMSAT.Org>
Sent: Thursday, July 11, 2002 1:50 PM
Subject: [amsat-bb] Re: AO40 Orbit 778


>
> >Hi All,
> >
> >During orbit 778 at MA 116 the L1 transponder was not switched OFF
> >and it continued to operate regularly in L1 band up to MA 120
> >
> >Surprised i  found no change in schedule in Amsat-BB  or in AO40 M blocks
>
> Dom,
> I am not sure what you mean about a schedule change that wasn't
> posted.  The satellite was functioning nominally.
> Orbit 778, MA 116-128 occurred during Wednesday (UTC).  Therefore,  the
> Wednesday schedule was in effect with no K-Tx session, but rather V-Rx
> testing.  We had the slightly unusual circumstance of two orbits in a row
> (777,778) within this 24 hour period, so there were two V-Rx sessions on
> the same day.
>

Stacey,

It was not clear to me that on Wednesday (UTC) MA 116-128 was V-Rx
testing with VL operating

Because of the complicated table of the schedule i belived that on
Wednesday MA 116-120 was only S/K beacons ON as usually and
only MA 120-128 should be VL transponders ON

Anyway the noise added by the V receiver + its V  IF increases the noise
floor on my spectrum analyser by about 6 dB  in comparisone to the noise
generated and transmitted by the UL transponder alone.

In this situation many weak signals with low power uplink in L1 where more
difficult to be received  in to the noise.

I had no time to verify the wideband extension of the added noise from V
band but if the V Rx has a filter to limit the uplink from 145.840 to
145.990 MHz than the V band noise should  reach a limit between  only
2401.275 to 2401.425 MHz

I will verify the above noise wideband  extension durind the next V-Rx
testing.

It should be very interesting to investigate if  the added noise came from
the man made noise generated on the earth and piked up by the V band
antenna or if  the above noise is locally generated in  the receiver itself
because the V antenna is damaged and  so badly matched to the receiver
 input.

73" de i8CVS Domenico

>
> --
>   _______________________________________________________________________
>   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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