June 2015 - AMSAT-BB - mailman.amsat.org

SO-50
by Steve Kristoff 29 Jun '15

29 Jun '15

I still can't hear SO-50. I've checked out the receiving radio and it works just fine. Has anyone ever had a problem with the UHF portion of an Arrow antenna going bad? Loose connector? Steve Kristoff AI9IN skristof(a)etczone.com

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PSAT is ready to be used on Fieldday 2015
by PA3GUO 29 Jun '15

29 Jun '15

We just turned the APRS digipeater back on, so you can test your systems. (PSAT APRS was off for 2 days to adjust some internal parameters.) Everyone should be able to use it: uplink & downlink for APRS 145.825 (UNPROTO APRS VIA ARISS) !S 19:23:35 !PSAT-1>ARISS>APOFF:!25 . N\003 . WS040/999/W3ADO s#043610,0z290 !S 19:26:53 !IS0EBO-4>PSAT>ARISS*>APRSAT>WIDE>4P4TX3:'~<.l i/]73 FROM SPACE !T 19:27:04 !PA3GUO>APRS,PSAT,ARISS*,qAR,DK3WN-8::test APRS !S 19:27:06 !IS0EBO-4>PSAT>ARISS*>APRSAT>WIDE>4P4TX3:'~<.l i/]73 FROM SPACE !T 19:27:13 !PA3GUO>APRS,PSAT,ARISS*,qAR,DK3WN-8:Ready for Filed day !! !T 19:27:24 !PA3GUO>APRS,PSAT,ARISS*,qAR,DK3WN-8:Ready for Field day !! !S 19:27:39 !PSAT>ARISS>APRSON:!36 . N\005 . ES060/999/W3ADO s#043614,0z290 !S 19:27:40 !PSAT>ARISS>APRSON:s#043614,0z290,MLkMJlMHmMCmMemMhmLkmJlmHmlDnjanghnA !T 19:27:43 !PA3GUO>APRS,PSAT,ARISS*,qAR,DK3WN-8:PSAT is ready to be used on Field day 2015 !T 19:28:00 !PA3GUO>APRS,PSAT,ARISS*,qAR,DK3WN-8:U APRS VIA ARISS !T 19:28:38 !PA3GUO>APRS,PSAT,ARISS*,qAR,DK3WN-8:Also try thew PSK31 transponder ! !S 19:28:40 !PSAT>ARISS>APRSON:!39 . N\009 . ES060/999/W3ADO s#043615,0z290 !S 19:28:41 !PSAT>ARISS>APRSON:s#043615,0z290,knGlmKmlLmjNmgOm0OmEOlJOgLOdMNaNMDNK !S 19:29:23 !IS0EBO-4>PSAT>ARISS*>APRSAT>WIDE>4P4TX3:'~<.l i/]73 FROM SPACE Also try the PSK transponder ! Have fun! Henk PA3GUO

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APRS Satgate Antenna page (dB's)
by Robert Bruninga 29 Jun '15

29 Jun '15

OK, I did a quick look and the gain of the 3/4 wave vertical is a real winner over the basic 1/4 wave vertical for OMNI Satgates with no moving parts optimized for high elevation gain above 30 deg. Low elevations are simply covered by another SATgate 600 miles away.... We will write it up in detail, but here are the rough figures. 1/4 wave vertical with radials: -2 at 30 and -6 at 60 ==> Basically a dipole pattern 3/4 wave vertical with radials: +2 at 30 and -1 at 60 ==> 4 to 5 dB better, 2 dBi max 3/4 wave vertical w 6' gndpln: +2 at 30 and +3 at 70 ==> 4 to 9 dB better, 5.5 dBi max 3/4 wave vertical w 9' gndpln: +3 at 30 and +3 at 65 ==> 5 to 9 dB better, 5.3 dBi max 3/4 wave vertical perfect gnd: +3 at 30 and +3 at 68 ==> 5 to 9 dB better, 6.9 dBi max We are going to do a 3' ground plane too for comparison, but even the 3/4 vertical with just the four 19" radials gives a huge 4 to 5 dB improvement over a classic ground plane for omni satellite SATgate work. Notice too that the Lilenblatt, eggbeaters, and all other "omni"s that try to keep their gain down on the horizon, are equally as poor as the 1/4 wave vertical at these higher elevations. This is OK for strong satellits like the ISS with 5 to 10 watts, but abisimal when all that gain on the horizon is completely wasted when you cannot hear the satellite anyway because it is 6 to 10 dB farther away! The result is these "omni's" give up the 4 to 9 dB at higher elevations where the satellite is much stronger. Ill eventually put all this on the Omni SATGATE page: http://aprs.org/aprs-satellite-igate-antennas.html Summary: The 3/4 wave vertical makes it so you CAN hear LEO satellites 5 to 9 dB better when they are closer and does this by giving up on hearing them when they are so far away you can't hear them anyway! Bob -----Original Message----- From: Robert Bruninga [mailto:[email protected]] Subject: RE: [aprssig] APRS Satgate Antenna page > One question,what constitutes a large ground plane? > Is it 12"or 12'? Is it a multiple of the vertical whip? Good question. Most people think that four 1/4 wave radials make a ground plane. But if you model a 1/4 wave vertical over 1/4 wave radials, all you get is the exact pattern of a DIPOLE. The radials are just providing a "groundplane" to complete the electrical part of the antenna and give a good match. They do not affect the pattern at all. I modeled verticals over 6' or larger ground planes and only found that you get the added "reflection" gain when the ground plane starts getting that big or more. I wish I had time to use EZNEC to show the added gain (skyward) versus the size of the ground plane. And how "radials" (above actual ground) have nothing to do with the "pattern". SO, the bigger the better. It should be worth 2 to 3 dB if you could make it very large... This is the page in question: http://aprs.org/aprs-satellite-igate-antennas.html Bob, WB4aPR On 6/19/2015 3:57 PM, Robert Bruninga via aprssig wrote: > Subject: APRS Satgate Antenna page > > Since the ideal APRS Satellite IGate OMNI antenna is exactly the > opposite of the typical terrestrial IGaate antenna, I prepared the > following WEB page: > > http://aprs.org/aprs-satellite-igate-antennas.html > > It shows how a vertical ¼ or ¾ wave VHF omni equals the performance of > a full OSCAR class array (over half the sky) but does it with no > moving parts. > It makes up for the weak-signal horizon part of the sky by there > simply being more omni-IGates. The APRS-IS cloud with all of its > IGates is probably one of the largest spatially distributed satellite > receiver system in the world (?). > > But with people used to the 10W transmitter on the ISS, just a few > IGates can capture just about every packet from the ISS horizon to > horizon on a whip. But with the 14 dB weaker signal from PSAT, we > need more SatGates to make up for their smaller skyprint. For the USA > we need more than a dozen such Omni-SATgates. > > To see the significance of the weaker downlink from PSAT, look at the > successful IGates on the http://pcsat.aprs.org page compared to the IGates > that hear the ISS packets on http://ariss.net Both are listening on > 145.825 and passing along every packet they hear. But only TRACKING > IGates or good vertical gain satgates hear PSAT. And since we want > these running 24/7/365, we do NOT expect people wearing out motors > when an omni will do fine (if we have enough). > > The page also shows how every SATgate with a HIGH and terrestrial type > antenna actually creates a DEADZONE around it, effectively blocking > any nearby user heaerd direct from appearing on any of the APRS-IS > cloud satellite web pages. Hence, Omni-satgate antennas should be low > to everything surrounding it w hile still seeing the sky above 30 degrees. > > If your TH-D7 HT is just sitting there, not in use 99% of the time, > then just hook it to a vertical whip and let it be an IGate. With the > low antenna it will also probably be safe from all weather lightening too. > Put > the UHF side on 435.350 and turn up the speaker. When PSAT PSK31 > comes into view, you can watch the PSK31 activity as a bonus! > > Bob, WB4APR > _______________________________________________ > aprssig mailing list > aprssig(a)tapr.org > http://www.tapr.org/mailman/listinfo/aprssig

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Typical SO-50 exchanges
by Koos van den Hout 29 Jun '15

29 Jun '15

I'm trying to improve on my number of successful satellite QSO's (at the moment: 3) and because I'm quite good at forgetting a callsign in the heat of the moment I am trying to build a working setup to record FM QSO's. The setup with a splitter from my HT to the line-in of a mp3 device does record something but it's still distorted. I will try on the FT-857 again but that's a bit heavy for satellite contacts. It can give more output power than the default 5W (.. if the specs are to be believed) of the HT which may improve the chance of actually getting across. I noticed (again) that there seems to be a fixed format in action for exchanging callsign / signal report / locator. But I'm not sure of the right order. Can someone explain this? I haven't seen this mentioned on amsat-bb. My latest recording where I heard this type of exchange twice is linked from http://idefix.net/~koos/newsitem.cgi/1435521672 Koos -- Koos van den Hout, PGP keyid DSS/1024 0xF0D7C263 via keyservers koos(a)kzdoos.xs4all.nl Weather maps from free sources at http://idefix.net/ http://weather.idefix.net/

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Field Day
by Paul Stoetzer 29 Jun '15

29 Jun '15

How did everyone's Field Day go? Heard quite a bit of QSOs made. Heard quite a bit of struggling too! Weather was awful, so I was just operating from the grounds of my apartment building here in DC. I managed 20 QSOs with 5 watts, which wasn't easy with how overloaded the transponders were with strong signals. Next year maybe I'll help out a local club on the sats. 73, Paul, N8HM

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Satellite Software
by Mike Jones, W6GYC 29 Jun '15

29 Jun '15

Hello. My name is Mike Jones, W6GYC. I help out with content on the AMSAT.ORG web site. The software pages currently on AMSAT.ORG are a bit out of date I it has been decided to bring them a bit more current. What I would like to do is hear from the satellite community on what software they are using for their Amateur Satellite operations. Remember I would like to hear not just a list of software apps, but what you actually use in your day-to-day operations. Please include the following: Title Website (if available) Type of software (commercial, shareware, freeware, etc) Cost if appropriate Platform (Windows, MAC, Linux, mobile (Android, iOS, other, multiple) What distribution you use if applicable Is the software included in your distribution repositories, or third party download, build, etc Short description if possible Please feel free to include any additional information you may feel important. I have created a special, personal email account for this, please do not spam the mailing list. Please send to: satsoft(a)w6gyc.com Thank you in advance -- 73 Mike Jones W6GYC - AMSAT Number: 38250 Home Grid: DM04rl http://w6gyc.com

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Fwd: Field Day
by Bill Dillon 29 Jun '15

29 Jun '15

I made my first via-satellite contact attempt on two afternoon SO50 Saturday passes. I suppose Field Day is probably the worst time to try for a first contact. ;-) I also had a bunch of people come out to watch me (No! Go away! I hardly know what I'm doing! I want to fail in peace, without an audience!). I do appreciate fellow BVARC hams who helped hold the antenna, make a recording, and call out az and elevation, while I shifted frequencies and tried to make a contact. I was absolutely thrilled (and I think others were impressed) to start picking up voices at a slant range of 1500 miles. I couldn't bust the pile up with my little HT, but I can't wait to try again (and again, and again)! 73, --Bill, KG5FQX (operating as KK5W for Field Day) On Sun, Jun 28, 2015 at 9:00 PM, Paul Stoetzer <n8hm(a)arrl.net> wrote: > How did everyone's Field Day go? Heard quite a bit of QSOs made. Heard > quite a bit of struggling too! > > Weather was awful, so I was just operating from the grounds of my > apartment building here in DC. I managed 20 QSOs with 5 watts, which > wasn't easy with how overloaded the transponders were with strong > signals. > > Next year maybe I'll help out a local club on the sats. > > 73, > > Paul, N8HM > _______________________________________________ > Sent via AMSAT-BB(a)amsat.org. AMSAT-NA makes this open forum available > to all interested persons worldwide without requiring membership. Opinions > expressed > are solely those of the author, and do not reflect the official views of > AMSAT-NA. > Not an AMSAT-NA member? Join now to support the amateur satellite program! > Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb >

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Need help with SatPC32 - WinAOS
by Greg Higgins 29 Jun '15

29 Jun '15

I updated my SatPC32 from 12.8b to c during field day and everything ran fine. Used WinAOS for pass predictions. This morning I tried to run WinAOS and am suddenly getting an error message in German: Listenindex uberschreitet das Maximum (-1). Does anyone have any ideas what the error is and how to fix it? Thanks!! Greg Higgins

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Field Day
by Bill ACITO, W1PA 29 Jun '15

29 Jun '15

Ran the satellite station for W1BIM (6A central MA). Nothing fancy -- FT-847, tripod mounted arrow, no computer (full manual). Worked KA4H on the very first AO-7 pass (but out of habit used my call instead of the club call --- idiot), then worked Wyatt at W0GQ on the next FO-29 pass. Tried a few more times Saturday afternoon but no luck. Packed up the gear and moved to one of the HF stations. We were on a high plateau football field with a single Winnebago and multiple tents/easy ups. Started raining around 7pm, turned to horizontal rain by 11pm, and then at 3am the wind gusts toppled multiple station tents -- one of the easyups was found 30ft up in a tree, with the aluminum structure. Horizontal rain, and 30mph gusts the rest of Sunday morning -- a real Nor'easter. No injuries, but we may have lost one rig and one laptop. I was sleeping in my car when it happened. Winnebago stations kept going; what was left of the tent stations were packed up by 6am. Btw, these were all properly staked and secured... in at least one case, the bottom flanges of the easyup post stakes were torn from the metal masts --- metal welds torn off. Found during FD: the UHF internal pre-amp on my FT-847 had failed. Before I go through the schematics, anyone ever had one fail and can identify the MAR or FET device I am most likely going to have to replace? Bill W1PA

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Re: [amsat-bb] APRS Satgate Antenna page (5/8 wave)
by Robert Bruninga 29 Jun '15

29 Jun '15

> I have actually received APRS packets from the ISS and for that matter have been digipeated using a simple 5/8 mag mount antenna oriented 90 degrees off vertical. I only mention that to offer some background. Ah, but the ISS is 10W compared to PSAT’s 0.3W, so it is 15 dB stronger and any piece of wire as an antenna can hear ISS, even in the very strong NULL that a 5/8 wave antenna has above 15 degrees. All of my comments are trying to help SatGates hear the weak ones… > I'm not aware of how to forward anything useful to the database that populates the map you provided a link to. That is simple or hard. Depending on your patience with software. Any APRS software just about automatically becomes a SatGate if you leave your radio tuned to 145.825 and leave your PC running th software connected to the internet. Then your station feeds the pcsat.aprs.org satellite downlink data base. Hope that helps. Bob, WB4aPR ------------------------------ ------------------------------ ----- Original Message ----- *From:* Robert Bruninga <bruninga(a)usna.edu> *To:* amsat-bb(a)amsat.org *Sent:* Sunday, June 28, 2015 17:13 *Subject:* [amsat-bb] APRS Satgate Antenna page (More work needed) Well, someone with time to burn might want to check all these numbers. Today I am getting inconsistent results and probably because to make a 9' ground plane at 2m with good segment sizes, I need more than the 500 point limit in EZNEC. Also, to cover the USA with omni satgates with good gain above 25 degrees will need almost 9 times as many satgates compared to the number with full AZ/EL OSCAR arrays. But then the omni satgates are 10? Times simpler... (just your HT while you are not actually using it)... At this point we need to simply see what a 1/4 wave over a large ground plane can actually HEAR. It is easy to just run it for days and see how many PSAT packets are received per 24 hours. And then compare antennas based on that number. If a 1/4 wave can hear down to 25 degrees, then there is no need for the higher 3/4 wave gain at higher angles. Anyway, a great opportunity for study. -----Original Message----- The gain of the 3/4 wave vertical is a real winner over the basic 1/4 wave vertical for OMNI Satgates with no moving parts optimized for high elevation gain above 30 deg. Low elevations are simply covered by more SATgates.... New: If we can get the angle down to 25 degrees then still need 9 times more stations) 1/4 wave with radials: -2 at 30 and -6 at 60 ==> Basically a dipole pattern 3/4 wave with radials: +2 at 30 and -1 at 60 ==> 4 to 5 dB better, 2 dBi max 3/4 wave w 3' gndpln: +3 at 30 and +1 at 60 ==> 5 to 7 dB better, 3.3 dBi max 3/4 wave w 6' gndpln: +2 at 30 and +3 at 70 ==> 4 to 9 dB better, 5.5 dBi max 3/4 wave w 9' gndpln: +3 at 30 and +3 at 65 ==> 5 to 9 dB better, 5.3 dBi max 3/4 wave perfect gnd: +3 at 30 and +3 at 68 ==> 5 to 9 dB better, 6.9 dBi max Even the 3/4 vertical with just the four 19" radials gives a huge 4 to 5 dB improvement over a classic ground plane for omni satellite SATgate work. Also, this antenna does not need to be high. Just see sky above 30 deg. In fact, is better to be low to reduce terrestrial QRM. Notice too that the Lilenblatt, eggbeaters, and all other "omni"s that try to keep their gain down on the horizon, are equally as poor as the 1/4 wave vertical at these higher elevations. This is OK for strong satellits like the ISS with 5 to 10 watts, but abisimal when all that gain on the horizon is completely wasted when you cannot hear the satellite anyway because it is 6 to 10 dB farther away! The result is these "omni's" give up the 4 to 9 dB at higher elevations where the satellite is much stronger. Ill eventually put all this on the Omni SATGATE page: http://aprs.org/aprs-satellite-igate-antennas.html Summary: The 3/4 wave vertical makes it so you CAN hear LEO satellites 5 to 9 dB better when they are closer and does this by giving up on hearing them when they are so far away you can't hear them anyway! THE BIG QUESTION though is What is the lowest elevation angle at which an OMNI can hear PSAT? Bob, WB4APR -----Original Message----- From: Robert Bruninga [mailto:[email protected] <bruninga(a)usna.edu>] Subject: RE: [aprssig] APRS Satgate Antenna page > One question,what constitutes a large ground plane? > Is it 12"or 12'? Is it a multiple of the vertical whip? Good question. Most people think that four 1/4 wave radials make a ground plane. But if you model a 1/4 wave vertical over 1/4 wave radials, all you get is the exact pattern of a DIPOLE. The radials are just providing a "groundplane" to complete the electrical part of the antenna and give a good match. They do not affect the pattern at all. I modeled verticals over 6' or larger ground planes and only found that you get the added "reflection" gain when the ground plane starts getting that big or more. I wish I had time to use EZNEC to show the added gain (skyward) versus the size of the ground plane. And how "radials" (above actual ground) have nothing to do with the "pattern". SO, the bigger the better. It should be worth 2 to 3 dB if you could make it very large... This is the page in question: http://aprs.org/aprs-satellite-igate-antennas.html Bob, WB4aPR On 6/19/2015 3:57 PM, Robert Bruninga via aprssig wrote: > Subject: APRS Satgate Antenna page > > Since the ideal APRS Satellite IGate OMNI antenna is exactly the > opposite of the typical terrestrial IGaate antenna, I prepared the > following WEB page: > > http://aprs.org/aprs-satellite-igate-antennas.html > > It shows how a vertical ¼ or ¾ wave VHF omni equals the performance of > a full OSCAR class array (over half the sky) but does it with no > moving parts. > It makes up for the weak-signal horizon part of the sky by there > simply being more omni-IGates. The APRS-IS cloud with all of its > IGates is probably one of the largest spatially distributed satellite > receiver system in the world (?). > > But with people used to the 10W transmitter on the ISS, just a few > IGates can capture just about every packet from the ISS horizon to > horizon on a whip. But with the 14 dB weaker signal from PSAT, we > need more SatGates to make up for their smaller skyprint. For the USA > we need more than a dozen such Omni-SATgates. > > To see the significance of the weaker downlink from PSAT, look at the > successful IGates on the http://pcsat.aprs.org page compared to the IGates > that hear the ISS packets on http://ariss.net Both are listening on > 145.825 and passing along every packet they hear. But only TRACKING > IGates or good vertical gain satgates hear PSAT. And since we want > these running 24/7/365, we do NOT expect people wearing out motors > when an omni will do fine (if we have enough). > > The page also shows how every SATgate with a HIGH and terrestrial type > antenna actually creates a DEADZONE around it, effectively blocking > any nearby user heaerd direct from appearing on any of the APRS-IS > cloud satellite web pages. Hence, Omni-satgate antennas should be low > to everything surrounding it w hile still seeing the sky above 30 degrees. > > If your TH-D7 HT is just sitting there, not in use 99% of the time, > then just hook it to a vertical whip and let it be an IGate. With the > low antenna it will also probably be safe from all weather lightening too. > Put > the UHF side on 435.350 and turn up the speaker. When PSAT PSK31 > comes into view, you can watch the PSK31 activity as a bonus! > > Bob, WB4APR > _______________________________________________ > aprssig mailing list > aprssig(a)tapr.org > http://www.tapr.org/mailman/listinfo/aprssig _______________________________________________ Sent via AMSAT-BB(a)amsat.org. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb

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