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
At 06:28 AM 12/13/2007, 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.
Agreed. For us in the Southern Hemisphere, there's also the issue of having someone to work. FM sats attract a few, but once you get outside of the major countries (i.e. VK, ZL), finding anyone with 70cm gear gets very difficult. On the linear birds, I did have some success on FO-29 once at a hamfest satellite demo (I don't have the gear to do U band myself, unfortunately, as I know there are some locals on VO-52). On RS-12/13, the only QSOs I had were pre-arranged with locals on 2m before the pass. Obviously, a HEO is of more interest in these parts, given that it's thousands of miles to any other country with significant satellite activity. Excercise, grab a globe of the Earth, draw a circle 6000km radius, centred on Melbourne and note the countries inside the circle. For satellites with 2m uplinks, exclude anywhere that can only be reached when Indonesia is in the footprint. And note that very few of the Pacific island nations have any 70cm gear on them, so they'd be relying on satellite DXpeditions to activate them. Count the remainder... ;) (Note, the problem with Indonesia is a population in the hundreds of millions and a high level of long range cordless phone usage - UO-14 was a dogpile of phone calls whenever Indonesia was in the footprint).
Back in the early 90's, I did have a bit of fun on RS-10/11 using a jury rigged setup. :)
So far, my experiences have been:
RS-10/11 - Some VK activity, I miss this bird, it was a lot of fun.
RS-12/13 - Some pre-arranged QSOs, didn't seem quite as sensitive as 10/11. Some Asian QRM noted in latter years, but could fit QSOs in between.
SO-35 - a LOT of VK/ZL activity, with some P29. Another bird I really miss, this was a very fun one to work, and could be reached by a HT in unusual situations (Sat QSO from a train anyone? - Yes, I've done that MANY time! ;) ).
UO-14 - some VK/ZL/P29 activity, 3D2 reported by others. Performance limited by Asian QRM on the uplink and lack of receive sensitivity of new stations.
AO-51 - Some VK/ZL activity, issues similar to UO-14
SO-50 - I haven't worked anyone on it, though have tried a few passes.
FO-20/29 - One or two VK QSOs at hamfest demos.
VO-52 - Haven't worked, due to lack of U band SSB gear (and no hamfest demos in recent years). U/V operation holds promise, and I know of several regular users in this region.
AO-7 - Another one I haven't tried, since its resurrection.
73 de VK3JED http://vkradio.com
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 ======================================
Just listen to 80m at nite and this is what you will get with channelized P4 digital venue.
What a waste of MONEY and man power.
On Dec 13, 2007, at 1:55 AM, Edward Cole wrote:
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
On Dec 13, 2007 5:28 PM, MKM starlight04@gmail.com wrote:
Just listen to 80m at nite and this is what you will get with channelized P4 digital venue.
This whole line of discussion is doing a wonderful job of turning the reflector into an email version of the same. Congratulations.
I myself happen to be one of the volunteer developers of the digital software, and am in a state of continual astonishment at the sense of self-righteous entitlement expressed by some of the commentators here. What is the point of amateur satellites if not the advancement of the radio art?
If you ain't part of the solution, you *are* the problem.
73 Frank AB2KT
Quoting Frank Brickle brickle@pobox.com:
On Dec 13, 2007 5:28 PM, MKM starlight04@gmail.com wrote:
Just listen to 80m at nite and this is what you will get with channelized P4 digital venue.
This whole line of discussion is doing a wonderful job of turning the reflector into an email version of the same. Congratulations.
I myself happen to be one of the volunteer developers of the digital software, and am in a state of continual astonishment at the sense of self-righteous entitlement expressed by some of the commentators here. What is the point of amateur satellites if not the advancement of the radio art?
If you ain't part of the solution, you *are* the problem.
Without getting into the personal aspects of this, I think it is important that one point be made clear for those who haven't been closely following the design of software defined transponders and the advanced digital package. The former technology (abbreviated as 'SDX'), in its usual configuration, provides a linear transponder which, to the ground station, will be functionally equivalent to the ones we use now. It is easy to get confused and think that SSB/CW, etc. will not work on this because it is 'software defined'. I understand we'll have a chance to try this out in space on Suitsat2; can't wait -- got a school class all lined up, too.
In contrast, the digital package will support various digital modes including a messaging system that will make much less demand on the ground station from a radio standpoint.
Around here, 80m facilitates some excellent conversations and some poor ones. That's the nature of human communication, in my experience. I don't expect Frank Bickle and others to solve *that* problem, too :-)
73, Bruce VE9QRP
participants (6)
-
Bob Stewart -
Bruce Robertson -
Edward Cole -
Frank Brickle -
MKM -
Tony Langdon