Hi Bob, I could easily set up an Igate, but every time I've looked into it I've been turned off by the complexity of the software setup. Is there a one program, easy to configure solution? Audio in would be best, but tnc decode is ok as well.
73, Drew KO4MA Sent from my iPhone On Jul 10, 2012, at 3:45 PM, "Bob Bruninga" <bruni...@usna.edu> wrote: >> Unfortunately, 70cm UHF doesn't lend itself to unattended >> SatGate operations like 2m VHF does. I tried catching the >> ISS on UHF and only managed to hear, but not decode, one >> packet burst. I can't imagine anything short of a full >> satellite station with automatic azimuth/elevation control >> would capture many packets right now. > > Actually the problem is not antenna pointing but Doppler. With the 18 KHz > of dopper shift, you are only going to capture packets in the center 1/3rd > of the pass. But the good news is that the ISS is ten dB closer to you at > that time. > > Yes, you will not get as many packets, but they can be strong. The problem > is that very few people are using the UHF packet digipeater, so if no one is > transmitting then there is nothing to hear. > > In fact, listening on UHF (for the center of the pass) can be just fine, > especially on a 19" vertical whip. Here are the factors: > > 1) due to Doppler, you are only going to decode packets above say about 30 > degrees (without tuning) > 2) When it is above 30 degrees, the ISS is 10 dB closer than on the horizon > 3) When it is above 30 degrees the antenna pattern of a 19" whip (normally > used on 2 meters) acts as a 3/4 wave vertical for UHF and it has almost 7 > dBi gain above 30 degrees > > So everything is going in your favor and even better link margins on UHF > above 30 degrees and the packets should be plenty loud (assuming you > minimize your cable loss). > > The only BAD news is that the ISS spends more than 70% of all inview time > below 30 degrees. > > But the GOOD news is that such an IGate station can be natennteded, and with > no moving parts and I t can be replicated by lots more people due to this > simplicity. So instead of having only say 6 unattended APRS IGates on the > 2m downlink to cover the USA, we simply need more stations. Then the APRS-IS > system will still capture all packets, though any individual station will > only hear their own smaller "cone of strength".. > > So we simply need to encourage more IGates and lower "individual" > expectations while the larger quantity of IGates raises the "system > expectations". > > Something like that. > > Bob, WB4APR > > On 7/10/2012 10:42 AM, Lizeth Norman wrote: >> Are there any stations in South America to gate aprs packets to the >> net from the uhf freq? How does one do this? I've got a few Byonics >> TT4's from a balloon project. >> The story: I'll be driving the Panamerica Sur from Lima to Nazca Peru >> and would like to have the ability to be seen via the net. >> Norm n3ykf >> > _______________________________________________ > Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. > Not an AMSAT-NA member? Join now to support the amateur satellite program! > Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb > > _______________________________________________ > Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. > Not an AMSAT-NA member? Join now to support the amateur satellite program! > Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb _______________________________________________ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
