Howdy, i'm still fairly new to aprs and I was wondering why can't it be possible to have the same frequencies as europe or atleast a world known accepted vhf freq, and even a couple of satellites that use the same frequencies to really open this thing up? For "poor" hams like me with one vhf rig in the house which is used both as a scanner, qso rig, and for aprs...having to sit and wait to switch back and forth to different freqs is a pain just to catch a different satellite and then back to 144.39 for local traffic. I do realize some sats should have a more private frequency for pure satellite operation, but it really would be nice if a couple of them were on a world wide frequency to link vhf operations with other parts of the world. Gateways to me just seem to be so limited. Of course, I think of this more and more now since I moved to Montana and there is absolutley no vhf activity where I am at. If a couple of sats were geostationary or just came around 144.39 then lots of other isolated folks an me still would have some decent activity. Aprs on 30m seems boring with less then half the stations being active on that band as apposed to vhf, and since I have only one hf rig in the house...I don't like tying it up to just hf aprs. Signed spoiled, l. allen kb5ecv
There are several reasons for the differing frequencies used for APRS work. First, the various ITU regions have different frequency ranges and band plans, so the frequency used in any given area has to mach that region's plan. For instance, the frequencies used in most of Europe, 144.800 & 144.825, are repeater input frequencies in North America. It wasn't that long ago that the U.S. APRS frequency changed from 145.79 to 144.39 in order to avoid interference with the satallite sub-band. This brings up the second reason, namely there is a world-wide sat. sub-band in which all amateur satellite operations must take place. See this link for the frequency request by Bob Bruninga, WB4APR, for the operation of PCSAT: http://web.usna.navy.mil/~bruninga/pcsat/freqs.txt AFAIK, the APRS-capable sats are unique in being allowed to use 144.39 as a downlink frequency. All other operations have to be in the internationally recognized sat. sub-band, and no terrestrial-only operations are allowed in the sub-band, in order to avoid any possible interference. As for geostationary amateur sats, you are talking about major money for expenses. Geostationary sats are 22,000 miles up, vs. the 100+ mile LEOs. This requires more powerful sats, more powerful launch operations (currently most amateur sats are launched "piggy-back" with a commercial launch to save money), and a much larger outlay for the amateur who wishes to use them. I had the same thoughts as you awhile back, and got royally reamed by some of the amsat people. Sometimes, there are no easy solutions. Mark Schneider K5MAR
Expense would be a killer. Currently, INSMARSAT has four geos in orbit at 22,000 miles up. They cover most of the earths navigable waters for GMDSS and other communications. Couldn't imagine how the amateur community would sustain those costs seeing the charges on using an INSMARSET system. Not that I wouldn't scoff at an amateur system like that if it existed. Best I do is on NO-44 and some occasional store and forward on ISS. 73 Greg
I think a VHF repeater on the surface of the moon would be just fine. It would be easy to see if it's in the line of sight and solar power would still work. How much would THAT cost?
:-> the vhf repeater on the moon is a great idea and it's not the cost of the equipment it's the million's that it would take to get it up there .. you know the old saying build it and they will come! well think it and it may happen !!never know ============================== i'll keep this short so every one can tell me i'm crazy "i already know this" hi hi aren't all hams p.s A.P.R.S is a great form af communication i have been active on there for around 3 years and enjoy it a lot ================================ . you might look into U.I.VEIW i think that is how it's spelled and it works with the newest version of precision streets 32bit version does cost $16.00U.S to register but it's worth it .... 73 c ya on the map KCØEUJ
Well, actually I guess it wasn't for me so much as to why we don't have similar freqs and satellites, but rather what would it take to rally support to centralize them...???
