R: [amsat-bb] AO40 Orbit 778

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

Hi Joe K0VTY,

Installing a L band uplink is a good idea because the L1 and L2 bands
operates most of the time with U band and the noise added by the V band
receiver is only one day per week from MA 120 to MA 128

In addition the L band uplink is not affected by LEILA

The 6 dB noise added by the V band receiver ON suggest that the 2 meter
receiver is working but probably the 2 meters antenna is damaged.

Since the V band receiver operates close to the apogee from MA 120 to MA 128
and actually the ALON/ALAT=0/0  the 2 meter antenna is very well directed
to the earth during VS session.

The 2 meter antenna on AO40 is made by 3  folded dipoles oriented at 120
degrees and connected RHCP

If this antenna is not damaged  we must get a strong signal using an RHCP
antenna on the ground for the V band uplink .

If changing to LHCP on the ground  the difference is small or nothing at all
it probably means that the AO40 antenna is damaged.

If the RHCP antenna is damaged we should get a  very deep QSB using linear
polarization for the V band uplink on the ground since AO40 spins in to the
Z axis

In conclusion there are many ways to investigate on this matter
and this is what i detect to be important in regards.

73" de i8CVS Domenico

----- Original Message -----
From: <k0vty@juno.com>
To: <domenico.i8cvs@tin.it>; <amsat-bb@amsat.org>
Sent: Thursday, July 11, 2002 3:32 AM
Subject: Re: [amsat-bb] AO40 Orbit 778


> Dang Dom ,     I was just thinking about installing a L band up link.
>
> Since VS band is not very favorable to normal up link ERP and it is now
> found adding 6 dB
> of noise to the down link that gives me pause.
>
> Please let all know what you detect in regards to the above.
>
> Joe   K0VTY
> =======================================
> On Thu, 11 Jul 2002 03:04:41 +0200 "i8cvs" <domenico.i8cvs@tin.it>
> writes:
> > 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
> >
> > At MA 120 the VL transponder was switched ON and i noted  more than
> > 6 dB
> > increase of the noise floor on my panoramic receiver due to the
> > noise added
> > by the 2 meter receiver.
> >
> > There was no operation from  V band uplink during the above VL
> > session from
> > MA 120 to MA 128 but the S2 downlink S/N ratio coming from the L1
> > uplink
> > was highly degraded because of  the noise added by the V band
> > receiver
> >
> > 73" de i8CVS Domenico
> >
> >
> >
> >
> > ----
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> >
>
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