At 10:28 AM 12/12/2007, Bob Stewart wrote:
With the "range war" that's going on right now, it seems like there are at least two communities of satellites users: one that wants simple, easy to use transponders and doesn't mind the windows of availability (and perhaps enjoys it for the added simple technical challenge), and another that wants an HF band type of experience with perfect propagation. There may be other subsets that I haven't noticed, yet, but these seem to be the two main groups. Both have their merits.
Bob - AE6RV
Bob,
I by simple you mean single-channel FM Leos and HF you mean linear passband Heos...
Well it sounds to me like you haven't worked a Heo. Working AO-10, AO-13 and AO-40 were certainly not "perfect propagation". Setting up a station that will be successful for the old mode-B took some work and operating took some skill. Mode-US was a technical step above that of AO10/13.
In comparison to a HT and the Arrow "wave", there is quite a bit more technical challenge (in my view) to Heos. Operating under the current pile-up operating conditions on the Leos is no comparison with the ability to hold a round-table of 6-12 stations that we enjoyed on the Heos. The point is that there are Leos available since AO-40's demise. AO-7 is the only satellite close to being an Heo (and crippled with no battery system and highly subject to overload FMing).
The Heo community has shown great patience in waiting a decade for AO-40 after AO-13 re-entered and burned up. Then it only lived about 3-years with highly reduced performance (though I really enjoyed mode-US). Now we are waiting, again.
P3E and Eagle are needed. If the only way to get them launched is to re-package them for Intelsat piggyback...then that is what we will have to do. Hopefully, rides can be found for P3E and Eagle to fulfill their original mission and P4A specific packages built for Geostationary service.
P4A concept is the next evolutionary step after P3. It was long thought unattainable, so it is exciting that it may now be more than a pipe-dream. P4A (mode-SC digital voice) offers the restricted apartment dweller a real alternative. It also provides a real opportunity for ham radio to fulfill the emergency comms world-wide role that amateur radio promises. Technically, ground stations may be easier than the P3 birds. Of course mw bands present a challenge but not so much as one may think.
All the naysayers about mode-S found that the surplus equipment route actually worked out not too bad. Not hugely difficult with the ample sharing of experience by fellow satellite operators. Cost was not bad, either.
Anyway, there is room for both communities if there are satellites available.
73, Ed - KL7UW ====================================== BP40IQ 50-MHz - 10-GHz www.kl7uw.com 144-EME: FT-847, mgf-1801, 4x-xpol-20, 185w DUBUS Magazine USA Rep dubususa@hotmail.com ======================================