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RE: Re: Thoughts on future "FM birds" (was: proposal for maximizing fm le o contacts)



> Yeah.  No one uses the SSB birds because all the advertising 
> and marketing
> effort is put into advocating the FM birds.  So people don't get the
> stations they really need.  It is sad.

I might have to make a small contribution towards correcting that, at least
on this side of the world.  Only drama is finding enough ops to be able to
make meaningful skeds. :-(

> Let's see:  With all the FM birds, no.  But we have RS-13, 
> RS-15 (barely

I miss RS-10, that was a brilliant beginners satellite, and I had some real
fun on it years ago, with very simple gear. :-)

> works), FO-20 (dying) and FO-29 as SSB leos.  FO-20 is 
> expected to be on its
> last leg.  RS15 is so weak that its difficult to use.  RS-13 
> is used quite a
> bit.  FO-29 is in digital mode or digitalker mode some of the time.

Not a great choice.  I would like to see more Mode A birds (despite the QRM
problems, the Asian interference is less of a nuisance on SSB than FM).

> 
> Let's see, we have the following "FM" or packet type birds up there:
> 
> AO16, LO19 (??), IO26, AO27, UO14, UO36, TM31, KO23, KO25, 

Please do not lump FM and packet together, they cater to quite different
groups of people.  I'm often frustrated that a lot of new offerings are
digital, which are useless to me at 9600, and of only limited use at 1200
AFSK (for APRS).  Packet is a low priority item here, so this is unlikely to
change.

For me, I see the following as available:

FM
UO-14
SO-35 (part time)

SSB/CW
RS-13
RS-15 (not useable, unless you have a good station)
FO-20
FO-29 (part time)

Then there's AO-10, which is in a class of its own, and then the
proliferation of digital birds.  If anyone asks where AO-27 got to, the
answer is simple.  I'm south of the equator, so it doesn't count. :-)
 
> Who's hogging the channels on 2 meter?  Certainly not the 
> linear transponder
> birds!  And the 1200 baud sats are hardly used these days 
> except for a small
> amount of APRS traffic.  They are taking up channels and have 
> very little
> use.  Probably less than the linear birds.

Seems the packet birds have the lion's share...  UO-14 and RS-13 share an
uplink band (I had one night, I was getting into both).  The 2 Fujis also
share the same uplink in 2m.

> > Another question I have is if a microwave transponder is 
> useful on a LEO
> > satellite.
> 
> Isn't experimenting what ham radio is all about?  Why don't we try it?
> Now in the microwaves, we DO have enough bandwidth to run a 
> multi-channel FM
> bird.  That would be interesting too.

Indeed.  Microwaves could be fun to play with up there.  

> Yeah.  With a lot of little used 1200 baud birds and a lot of 
> packet BBSes
> up there.

The analog useage of 2m here is 140 kHz, defined by the uplinks of RS-13 and
the Fujis.  The 2 FM birds fall inside these limits (I haven't included
RS-15 though).

> Could be.  We'll all find out on P3D.  However, at Apogee, I 
> will argue that
> the P3D doppler will be very little since the satellite 
> appears not to be
> moving.

The other thing is that the relative velocity will change much more slowly
for most of P3D's orbit, so even if there is several kHz of Doppler on P3D,
it will remain relatively constant, and one won't have to chase the bird all
over the band like you do with a LEO.
 
> > I think a better use would be to use the transponder more 
> for digital voice
> > as suggested my Phil Karn.
> 
> Interesting concept.  I think using spread spectrum would be 
> a great way to
> go.  A SS bird would be good as well.  And many people could 
> use it at the
> same time too.

I second this.  However, the success of SS will depend on being able to get
low cost, easy to build gear out in the field.

> > When was the last time AMSAT-NA built a transponder. Even 
> if the plans
> > were there for the ones they did build I am sure some of 
> the part they used
> > are unavailable today.
> 
> I think they helped with AO-10, AO-13 and P3D.

I thought that too.

> 
> > 
> >> I bet as many hams that
> >> get into satellites leave due to what they hear and see on 
> the FM birds.
> >> More won't help.
> > 
> > Well I think UO-14 took a lot of the load off of AO-27.
> 
> NOT!  The same guys that hang out on AO-27 move over to UO-14 
> when it's
> overhead and vice versa.  UO-14's just easier to work.

> Yeah, but if everyone went to an SSB bird, all those grids 
> would be there as
> well!  And you don't necessarily need a really wide 
> transponder bandwidth
> either.  Why make it 100 KHz.  Why not put a linear 
> transponder in the same
> 25 KHz bandwidth as an FM bird?  You'd take up less space and 
> have enough
> room for several Qs simultaneously.

Would you lead a publicity campaign to get more activity on the SSB birds?
I can try here, but we are dealing with far fewer satellite ops (most I know
of seem to be into packet).

As an aside, there is another issue down here.  Some of the Pacific islands
to our east don't have 70cm capabilities at all.  I don't know if they have
SSB (I suspect some of the hams there do, as there's opportunity for
terrestrial DX), but if they do, Mode A would be the ticket for them. 
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