Having been on a few DX-peditions, I can't imagine the sense of failure that would go with running a DX-Net on a satellite, However, I nearly missed the following great idea from Bruce.
Actually we can do split on AO-51. If anyone felt a DX-depition was worth the effort and resources, we just tell the DX to use one uplink channel and the people replying to use the other. It would maximise QSO rate and even a handheld with low audio would be Q5 without any interfering signals.
73 es gud DX
David G0MRF / 9H0WW / C56DX / ZC4DX / 3B9C
In a message dated 24/02/2009 15:02:29 GMT Standard Time, [email protected] writes:
Very interesting Bob..... I had just sent this to a friend of mine to look at before sending to the bb. It is basically the same thing. However, taking checkins is too time consuming, this is a much easier plan.
When dx stations are working HF and they are operating split, they can very easily move up and down the band to find a station that is in the clear. Also, no one has a problem hearing them (except for the occasional guy that forgets to hit split). However, when on the satellite, you do not have the luxury of split operations on FM.
Actually we can do split on AO-51. If anyone felt a DX-depition was worth the effort and resources, we just tell the DX to use one uplink channel and the people replying to use the other. It would maximise QSO rate and even a handheld with low audio would be Q5 without any interfering signals.
We considered doing this, but unless they used two receivers, how would anyone know when to shut up and when to call? Even though there is a capture effect, when 20 signals come up at once, usually no one wins. Now if we'd used the SSB receiver on the user uplink?
This whole DXpedition was on a space and operator available basis. We looked at sending a 817 for the transponder sats, but the space and operators unfamiliar with current satellites kept us to the HT and Arrow. I think it's still a positive that so many made QSOs considering the alternative.
Rest assured I've learned from this, and future efforts will benefit from those lessons. Meanwhile, I've identified the jerks among us from some of the really out of line negative comments directed at me and the expedition members ;-).
73, Drew
Hi Drew!
Actually we can do split on AO-51. If anyone felt a DX-depition was worth the effort and resources, we just tell the DX to use one uplink channel and the people replying to use the other. It would maximise QSO rate and even a handheld with low audio would be Q5 without any interfering signals.
We considered doing this, but unless they used two receivers, how would anyone know when to shut up and when to call? Even though there is a capture effect, when 20 signals come up at once, usually no one wins. Now if we'd used the SSB receiver on the user uplink?
Or just a second FM receiver with an unpublished uplink frequency for the DXpedition - just like how it is done with the ISS school contacts we hear on 145.800 MHz? This is not a perfect alternative, but might give them a fighting chance to be heard and still keep it FM on the uplink and downlink.
This whole DXpedition was on a space and operator available basis. We looked at sending a 817 for the transponder sats, but the space and operators unfamiliar with current satellites kept us to the HT and Arrow. I think it's still a positive that so many made QSOs considering the alternative.
It's been good to see your posts listing who made it into the K5D satellite log. Despite whatever was happening on those passes, QSOs were being made. I didn't work any SO-50 passes over the last few days where K5D was in the footprint with me, and avoided the second AO-51 repeater so K5D could be the focus of attention on those passes.
Rest assured I've learned from this, and future efforts will benefit from those lessons. Meanwhile, I've identified the jerks among us from some of the really out of line negative comments directed at me and the expedition members ;-).
Thanks for your efforts to get K5D to be on the satellites - even though I won't have K5D in my log this time. Maybe we will have opportunities to work future DXpeditions on whatever satellites we have at that time. More equipment would be needed, but we have options on that front like we've never had in the past with the small rigs and portable antennas.
73!
Patrick WD9EWK/VA7EWK http://www.wd9ewk.net/
We can't tie two receivers to the same transmitter.
73, Drew
Or just a second FM receiver with an unpublished uplink frequency for the DXpedition - just like how it is done with the ISS school contacts we hear on 145.800 MHz? This is not a perfect alternative, but might give them a fighting chance to be heard and still keep it FM on the uplink and downlink.
While in theory anyone with a kilowatt output and good antenna system could control access to a single channel FM sat by instituting some form of net procedure in practise nobody has done so.
What I beleive people want to have are random QSO's that they initiate themselves and that are aren't controlled by anybody else.
If you get more than half a dozen Amateur operators active in the footprint of a single channel FM satellite they'll inevitably be congestion issues.
We'll just have to live with that for those satellites that have already been designed, but for future designs a linear transponder seems the obvious choice. A 40 kHz linear transponder would allow for multiple SSB QSO's over areas with a high Amateur population but would still enable the use of FM in the many areas of the world where there are few Amateurs.
73 Trevor M5AKA
Hi!
What I beleive people want to have are random QSO's that they initiate themselves and that are aren't controlled by anybody else.
Agreed. Like we do on HF to work a DXpedition - i.e., K5D.
The drawback, or shortcoming, to the "take a list of calls and confirm the list" approach is that - unless the station taking the list hears a confirmation to his/her report from each of those stations in the list - I'm not sure that is really a contact. It's more like an exchange of SWL reception reports. Having one station act as a net control etc. to orchestrate the activity then brings the same questions into play as on HF.
If you get more than half a dozen Amateur operators active in the footprint of a single channel FM satellite they'll inevitably be congestion issues.
This is true, just like on a terrestrial repeater. Either everyone cooperates or there is congestion that makes it useless. With cooperation, there could be many more stations on a pass that get a chance to make a contact with someone in a rare country or grid (I've worked as many as 26 on one AO-51 pass, last November from DM22/DM32).
We'll just have to live with that for those satellites that have already been designed, but for future designs a linear transponder seems the obvious choice. A 40 kHz linear transponder would allow for multiple SSB QSO's over areas with a high Amateur population but would still enable the use of FM in the many areas of the world where there are few Amateurs.
This is a good idea, as demonstrated by VO-52 where hams in South Asia are encouraged to try it in FM and the rest of us are to use SSB or CW. But don't overlook the interest in FM satellites for the areas with high ham populations, also. Otherwise, there goes a low-cost entry to amateur satellites in those areas. KiwiSAT is interesting, in that it will have an FM repeater and a linear transponder.
73!
Patrick WD9EWK/VA7EWK http://www.wd9ewk.net/
We'll just have to live with that for those satellites that have already been designed, but for future designs a linear transponder seems the obvious choice. A 40 kHz linear transponder would allow for multiple SSB QSO's over areas with a high Amateur population but would still enable the use of FM in the many areas of the world where there are few Amateurs.
This is a good idea, as demonstrated by VO-52 where hams in South Asia are encouraged to try it in FM and the rest of us are to use SSB or CW. But don't overlook the interest in FM satellites for the areas with high ham populations, also. Otherwise, there goes a low-cost entry to amateur satellites in those areas. KiwiSAT is interesting, in that it will have an FM repeater and a linear transponder.
I think Patrick raises an important point here. The FM sats are a very good entry point into satellite operation.
I got into satellites as a result of seeing just how easy it was to make contacts on AO-51 with a radio shack HTX-242 and an FT-817 that I already owned. Since I have been bitten by the satellite bug, I've gone out an bought an FT-847 and pre-amps, and I will hopefully be putting up a better antenna array soon to help with linear satellites.
If it hadn't been for AO-51 and its "Easy Sat" reputation, (helped along by K7AGE's videos on YouTube), I probably would have never gotten started and kept on thinking satellite operation was "too hard".
73,
-- Sean - VA5LF
I like it!
73, Joe kk0sd
-----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of [email protected] Sent: Tuesday, February 24, 2009 1:45 PM To: [email protected] Subject: [amsat-bb] The Tragedy of the commons / split frequency working
Having been on a few DX-peditions, I can't imagine the sense of failure that would go with running a DX-Net on a satellite, However, I nearly missed the
following great idea from Bruce.
Actually we can do split on AO-51. If anyone felt a DX-depition was worth the effort and resources, we just tell the DX to use one uplink channel and
the people replying to use the other. It would maximise QSO rate and even a
handheld with low audio would be Q5 without any interfering signals.
73 es gud DX
David G0MRF / 9H0WW / C56DX / ZC4DX / 3B9C
In a message dated 24/02/2009 15:02:29 GMT Standard Time, [email protected] writes:
Very interesting Bob..... I had just sent this to a friend of mine to look at before sending to the bb. It is basically the same thing. However, taking checkins is too time consuming, this is a much easier plan.
When dx stations are working HF and they are operating split, they can very easily move up and down the band to find a station that is in the clear. Also, no one has a problem hearing them (except for the occasional guy that forgets to hit split). However, when on the satellite, you do not have the luxury of split operations on FM.
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