[amsat-bb] Re: The Mode B tradition

i8cvs domenico.i8cvs at tin.it
Fri Sep 15 05:20:41 PDT 2006

----- Original Message -----
From: "John B. Stephensen" <kd6ozh at comcast.net>
To: "i8cvs" <domenico.i8cvs at tin.it>; "george abbott" <ka1ajf at cox.net>;
"'Bill Ress'" <bill at hsmicrowave.com>; "G0MRF David Bowman" <g0mrf at aol.com>;
<brobertson at mta.ca>; "AMSAT-BB" <amsat-bb at amsat.org>
Sent: Friday, September 15, 2006 3:51 AM
Subject: Re: [amsat-bb] Re: The Mode B tradition

> The European contacts are similar to my experience in the U.S. Are you
> certain that the contacts outside Europe weren't cross-band -- one end UV
> and the other US or LS? These would also have been completed on UV.
Hi John KD6OZH

The US mode of OSCAR-13 was available only for short periods of time at
low squint angle while all the other modes where OFF
In addition there was not S downlink with L uplink on OSCAR-13

Uplink             435.603 to 435.639 MHz
Downlink      2400.711 to 2400.747 MHz
G.Beacon      2400.664 MHz was ON

> My biggest concern about the S downlink is that it is becoming
> harder to use in many parts of the world so that it becomes less and less
> useful over the life of the Eagle satellites (2010-2030).

Only God know  20 to 25 years from now......... I am 74 years old !

When AO-13 was
> orbit I could use the S downlink all the time, but by the time AO-40 was
> orbit, I had S9 WiFi interference for hours at a time -- even with 3-foot
> dish and feed. The dish was fairly deep (0.33 f/d) and the feed shielded
> sidelobes were low.

I also experienced an increase of noise floor beginning from OSCAR-13
and going to AO40 but here for the moment the S-band is still viable but
this is like to randomly fire a shot to my head with a revolver with only
one shot i.e. just in case a WiFi channel 1 will operate from the next door
no way !
> Some in the U.K. say that we'd be better off flyng an S2 downlink
> (3400-3410MHz).
The downlink of EAGLE in the S2 would be a great choise if we
Europeans in Region-1 could get ITU to allow operation in S2 but who
know if receiving only in a well protected and scarcely used band not
allowed to us or to unlicenced services should be good even without a 
rules changes ? ?

Unfortunately for the moment I don't own  a 3400-3410 MHz converter
with a feed for my dish to scan the band but just for curiosity I will try
using my spectrum analyser.

> 73,
> John
73" de

i8CVS Domenico

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