[amsat-bb] Re: OH2AUE P3E transponder demo video
8p6sm at anjo.com
Mon Oct 15 21:21:23 PDT 2012
On 10/15/2012 10:18 PM, Ben Jackson wrote:
>> It may be easy to reliably work a future generation of satellites with
>> an HT and a rubber duckie. But that won't be challenging. And we (the
>> operators) won't be learning anything new.
> But instead folks are promoting an anachronism. They're discussing
> learning something new at the same time saying we should be using a
> technology that has been in use since the 1960s.
> So then instead of focusing on linear transponders how about deploying
> HSMM nodes into space, TDMA, or DMR technology? (No idea how feasible
> any of of this is)
I'm in favour of all this. But as Robert WB5MZO said, you want to
maximize usability as well. A linear transponder allows more people to
use the satellite, and is probably less demanding on the satellite as
well. I'd like to see a satellite that operated in FM mode around
perigee so simple equipment could work the bird, and as the slant-range
and path losses, as well as the size of coverage circle and potential
numbers of hams within the circle increases, as the bird heads on up to
apogee, it could switch to linear mode.
Newer technology and more advanced modes can be made available for
experiment, either simultaneously, on (say) bands L, S, C, etc, and also
on more accessible bands (U, V) by having the bird switch mode accordingly.
As far as meshed networks, etc, are concerned, I fear that multiple
birds will be necessary (obviously) and I don't know how practical it is
to consider this, when we have so much difficulty getting a single bird
in the sky. But I'm all in favour! If orbits could be coordinated, and
sat-2-sat links established, your uplink could appear as coordinated
downlinks in several parts of the globe simultaneously.
> How about something that supports TCP/IP? People were discussing how
> a AMSAT could generate interest in a kickstarter for a HEO? Promise a
> bunch of hackers and geeks that with a small donation, sitting for a
> ham radio test, and buying some kind of kit, they can get a (slow)
> network connection in far flung locations I'm feel fairly confident
> that they would start hurling their wallets at you screaming "Shut up
> and take my money!"
I'm not convinced that slow TCP/IP is much of an inducement. You may be
right, but I think there are precious few places that you can't obtain
connectivity at a reasonable price, and the places that you CAN'T are
not likely to be inhabited by people who can finance a satellite launch.
I think it is a laudable goal, to make connectivity available in such
locations, but I don't see it as a potential source of funding. But
I've been wrong before...
What I think might work is to build a big satellite, and "rent" or
"sell" space on board to people who want to perform space-born
experiments without messing about with communications hardware. Data
from various experiments can be stored, and downloaded an orbit at a
time as the satellite passes within range of selected amateur
ground-stations. The data can be separated out into individual feeds
for the individual "tenants" and forwarded to them via terrestrial
internet. Telecommand can be via the reverse path. If the satellite is
one that operates at higher altitudes with a longer anticipated
lifespan, educational institutions may find it an opportunity to perform
experiments that a short-lived, LEO bird can't support.
> However, the SSB mafia is firmly entrenched in their ways and will
> simultaneously bemoan the easy sats, yet pooh-pooh "hard sats" that
> won't support the divine mode.
I should be mad at you for making this comment, because I suspect "SSB
mafia" is targeted directly at people just like me. But I'm not mad,
because the other SSB mafia probably feel just as I do. I won't
apologize for enjoying SSB, CW and even RTTY (once, tried but no
response) via satellite. I don't groan about the "easy sats" because
they are "easy sats". I gripe about the fact that there aren't anything
BUT "easy sats". Where are these "hard sats" you mention? And why
DON'T they support the divine mode, damnit?!?? I have a divine-mode
transceiver here that I'd love use, even if as nothing more than a
gateway mode to these "hard sats" you speak of. And if I remember
correctly from my days on the Microsats, the divine mode was the basis
for many digital encoding schemes.
Naturally, I would also enjoy doing some DXing and ragchewing with the
divine mode as well. (Enjoying ragchewing and DXing is, I'm told,
another thing I need to apologize for.)
By the way, what is so easy about these "easy sats?" Don't you have to
stand in the yard, in the dark, with the rain falling on your head,
operating two HTs and a voice recorder with one hand and waving a
broomstick yagi with the other, while your laptop gets wet? In
comparison, sitting back comfortably in my chair, with the mic/key in
one hand, a Planters Punch in the other, the cat in my lap and Fido at
my feet, while I work DX or ragchew with a friend (There! Those
expletives again!) doesn't sound all that hard!
73, de Gus 8P6SM
The Easternmost Isle
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