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RE: P3D information



> Sure, amateur satellites like P3D move. But I'm sure the same people
> who have devised all the rotor mounts, cabling schemes and computer
> tracking systems for the large Oscar-class arrays now in use are
> clever enough to do the same for much smaller antennas where the
> reduced wind loading, weight torques and the like will more than
> outweigh the tighter pointing accuracies required.

That's all fine and dandy for those who are in a position to put up
sterrable antennas.  I'm not, so I need to be able to operate on bands which
are more tolerant of pointing inaccuracies inherent in hand held antennas.
With the light weight of antennas (meaning easier to aim :) ) for the higher
bands, 1.2 and 2.4 GHz should be practical for portable use.  I can't see
myself in a position to install steerable antennas of any kind for at least
several years, unless it can all be put on a tripod, and I can get someone
to look after the mechanics...

> Of course, the numbers are a little different for voice, especially
> since the analog mode is AM/SSB, not FM. Speech encoders operating at
> 4800 bps have been available for some time, and in my opinion they
> give much better voice quality than SSB even at high SNR. 4800 bps
> operating over our same 4 dB Eb/No modem requires a C/No of 40.8 dB.

And there are people playing with 2400 bps speech, including one G amateur
who's using it in an experimental digital HF voice system.  Audio quality,
from his demos is more than acceptable.

> So if minimizing the cost of generating RF power (on any band) is your
> goal, it sure seems like digital is the way to go.

Certainly worth a play, IMHO.
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