roth@macom1.UUCP (dennis paul roth) (01/13/88)
From article <875@micomvax.UUCP>, by ray@micomvax.UUCP (Ray Dunn): > In article <2534@killer.UUCP> allen@sulaco.UUCP (Allen Gwinn) writes: >>In article <829@tahoe.unr.edu> malc@tahoe.unr.edu.UUCP (Malcolm L. Carlock) writes: >>>Sorry Bret, but it's AM (lower frequency) transmissions that bounce off the >>>ionosphere, not FM. >> >>I'll have to remember that, Malcolm, the next time I use my aircraft >>radio (+- 110-130 MHz AM). To think that I might have been cleared for >>takeoff by L.A. Tower when I was in Dallas makes me mighty nervous :-) It could happen, see below. > I'm surprised at your 10meter comment. As I remember, the transition from > bounce to no-bounce takes place at about 18Mhz, i.e. 16 meters, so 10meters ^^^^^^^^ > talks to the stars! ^^^^^^^^^^^^^^^^^^ Sorry not so, as a radio amatuer I can tell you from personal experiance that 10 meters talks to the world. During solar storms and sun spot maxima 6 meters is capable of skip. I've contacted a Brazilian station at 50.125 Mhz. SSB and stations in Florida and Louisiana at 52.525 Mhz FM. Other radio amatuers I know have done much better. Some operators exploit the refraction phenomena that takes place when a weather front moves through and make long distance contacts on 2 meters at 144 Mhz. One more point, some aircraft do use AM (Amplitude Modulation) at VHF frequencies. The reasons they use this inefficient mode are historical. Sorry to post FACTS to alt.flame. I know it's against the rules. If you don't like it. FLAME ME! -- Dennis Roth @ CENTEL Information Systems, Inc. 5515 Security Lane, Rockville, Maryland, 20852, (301) 984-3636 A.R.S N3AZB listen for me at 53.25 Mhz FM abUSENET {decuac, grebyn, netsys}!macom1!roth Don't look a gift computer in the MIPS.