Jim,
I just got off the phone with Graham Shirville in England. He, Howard Long
and others have been taking note of the controversy on amsat-bb and want to
offer help, if it would be productive.
Based on that conversation and conversations with you and Bob, I would like
to make a revised proposal for consideration by the Eagle team.
a) Move C-C Rider's primary uplink to the S2-band (3400-3410 MHz) with some
modest additional uplink capability on L-band (1260-1270 MHz).
b) Add another separate SDX transponder for mode L/S, essentially identical
to the U/S SDX transponder. This transponder would use fixed antennas and so
will be usable only at apogee. It would also serve as a backup command and
control access to the IHU. By being separate it would reduce the risk of
common component failures.
Graham will inquire of the local authorities in England about getting
matching Amateur Satellite status for their S2 band.
Graham will come to San Francisco prepared to discuss an evolving
comprehensive plan to petition the ITU for additional Amateur Satellite
frequency allocations. He will need our help with this and we will need
ARRL's help as our ITU representative.
Rick
W2GPS
AMSAT LM2232
-----Original Message-----
From: eagle-bounces@amsat.org [mailto:eagle-bounces@amsat.org] On Behalf Of
Jim Sanford
Sent: Monday, September 11, 2006 10:35 PM
To: Lyle Johnson
Cc: EAGLE
Subject: [eagle] Re: Team Speak tomorrow night
Lyle:
Per my notes, we did NOT kill the L uplinkfor SDX. We DID decide not to
use it for the digital package.
We need to decide on whether or not there will be an L-uplink for the
narrow band package or a dedicated L/S TSFR package.
I'd like to at least discuss, and maybe decide whethe or not to fly an L
uplink on the command/analog channel. Bob and Rick are proposing
OFFERING a L/S package to be developed by others and flown in a TSFR
space if it qualilfies. I see this as no cost, huge gain in both
perceptions and capability.
Please join tomorrow and comment. I want to hear your thoughts!
Thanks & 73,
Jim
wb4gcs@amsat.org
Lyle Johnson wrote:
We offer that anyone willing can develop and submit for
testing and qualification a stand-alone L/S transponder to fly in
one of the TSFR slots, using fixed antennas. It would be usable
at/near Apogee, like the microwave packages on AO-13 and A)-40.
What do you think? Les's discuss this.
Bad idea. We discussed having ONE SDX transponder and ONE digital
communications payload. If for some reason it is decided that the
DCP is on neither S1 nor L (which itself would be a bad idea...), AND
it was decided that there was a desire for old-style transponders on
L/S, then it makes sense to build it as part of the SDX, and not have
a THIRD payload.
Like Matt, I am not in favor of this. We need to design the system
for services, not design the spacecraft as a bus for a collection of
modules.
I recall two SDX payloads, but I'm old and my memory is failing. The
Eagle block diagram from Oct 2005 shows a pair of SDX modules, and the
SDX block diagram shows a U and an L uplink, an S1 and a V downlink.
Of course, at that time the digital payload was to be C/C.
Did we decide to kill the L uplink for SDX/analog use in San Diego? I
recall that we decided to not use an L uplink for the digital system.
73,
Lyle KK7P
_______________________________________________
Via the Eagle mailing list courtesy of AMSAT-NA
Eagle@amsat.org
http://amsat.org/mailman/listinfo/eagle