Question: since there is no amateur radio allocation at 149.985, "we" (hams) would be asking the Navy, to whom the downlink frequency is allocated, to transmit one-way amateur communications thru this satellite, correct?
Doesn't anyone else see potential legal problems involved here? George, KA3HSW ----- Original Message ----- From: "Robert Bruninga" <bruni...@usna.edu> To: <amsat-bb@amsat.org> Sent: Wednesday, August 25, 2010 11:27 AM Subject: [amsat-bb] New Satellite Downlink? > Possible new AMSAT Application? > > We may have access to two old TRANSIT navigation satellites with > a 50 baud downlink at 149.985 (and 400 MHz). (presently coming > over in the mid afternoon). My problem is, coming up with any > meaningful application to use them for communications that would > capture the interest of students, hams or volunteers in support > of education, public service or emergency comms or just plain > fun... > > The downlink can be heard on an OMNI antenna (though I would > suggest a 3/4 wave (55") vertical) and could be decoded by a > simple software only application with a sound card. (someone has > to write it)... > > The total useful message capability is about 500 bytes > transmitted every 2 minutes (at 50 baud). The uplink is very > specialized and can ONLY BE DONE from one (or two) very special > commmand stations. These satellites of course were the original > Navy Navigation satellite system (also called OSCARS) and so the > message would be in-place of the normal navigation data. SO in > a sense, this is a downlink BROADCAST application. Since ham > radio is two way, I'm stumped for applications. > > The total message capability of 500 Bytes can contain one long > ARRL bulletin, or 20 APRS position/status reports, or say 20 or > so APRS text messages, or say 50 "callsign exchanges" or maybe > even 1 thumbnail image... but what's the application? > > Even if we allow say, INTERNET link to the command station for > "anyone" to contribute to the twice per-day upload, then > everyone's receiver application can receive them... For what? > > So Im looking for ideas. All I can come up with so far is: > 1) ARRL Bulletins? (I don't even know how often ARRL sends > bulletins...) > 2) Navy/Army/AF MARS broadcast bulletins... > 3) Internet message in-to-command-upload-to message RF downlink. > Two stations do this to each other and it counts as a two-way > QSO? > 4) ... > > Every scenario of interest usually begins with the much higher > value of UPLINK from the individual field station, not > downlink.. Hence I am stumped. > > HUMMH... Maybe purely educational? If the software can run on > any PC with a sound card connected to any scanner... Then every > school can use it as a satellite downlink signal of interest.. > What kind of thumbnail image can fit in 500 bytes? Send in your > picture and get it downlinked on a given day? > > Etc.. > > Will need a DSP volunteer to write the sound card decoder. > > Bob, WB4APR > > _______________________________________________ > Sent via amsat...@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...@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
