[amsat-bb] Re: geo stationary bird
nate at natetech.com
Wed Oct 31 13:17:41 PST 2007
Bob Stewart wrote:
> I was thinking the same thing. One of the things that brought
> me back into ham radio was the challenge and new experiences.
> But a geosat sounds like it would be nothing more than
> an internet chatroom - all it takes is a connection. Don't get me
> wrong, it will be great for EMCOMM. But, other than that, meh.
The challenge with geosat birds due to the higher orbit (distance) and
what not, is in how ACCURATELY you can send the proper uplink signal
into the bird without trying it first.
(GRIN... can you calculate your uplink gain to the geosync belt
accurately enough to send the right signal level up the first time?)
Sure, it's a one-time trick pony... but it's still a nice little math
and knowledge of your own system setup kind of challenge.
I'm sure there'll be plenty of people blowing away the uplink and/or not
heard until some folks do the math for them. :-)
(Thus, LEILA on AO-40... when really, if people were doing their math
homework and measuring their systems ahead of time -- she shouldn't have
been necessary -- right? There's always challenges available in RF
systems if you look for them...)
Ask the 70's and 80's TV folks if uplink power into the video bird's
transponders was important! (GRIN)
They have some good war-stories of remote trucks blowing away whole
transponders while the control rooms yelled at them on the phone to
knock it off.
(Nowadays, the TV folks use automated systems that set their uplink
power automatically from the control rooms that use a data channel from
the control room through the birds that the truck systems monitor,
unless that's changed since I last saw one in action.)
Wouldn't that be nifty? A server/automated system that can "see" the
bird via it's own receivers, and could command the uplink power
automatically from mobile ham's stations so uplink tuning/aiming and
power levels for portable stations could be automated?
Now, there's a challenge for ya!
And of course, since it's hams here, and not commercial companies that
have control over the uplink equipment, it'd have to be a very flexible
system, and be designed in such a way so that hams could assemble/build
it on their own (like hams like to do) or if they're a little more lazy
or too busy, they might be able to buy a pre-built box that someone else
assembled, with connectors for various radios and trackers...
(Sounds like too big a project, but might be fun to try to go do on a
limited basis by limiting which trackers and radios are supported.)
Automated anti-QRM... neat-o!
There's always cool stuff to try to do on ham radio! :-)
More information about the AMSAT-BB