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![]() Mike Coslo wrote: an old friend wrote: Dave Heil wrote: Mike Coslo wrote: Dave Heil wrote: You purport to be an active radio amateur and you didn't even have a realistic idea of how many hams there are in the United States? Do you think the FCC and ARRL are in collusion and they've whipped up some massive coverup of the number of licensees? Sheesh! This approach has been in evidence early on. Facts are of secondary importance to opinion. If we are told that there are not the number of hams claimed on the database, then that is the truth. If that means that the FCC is lying, that is the truth. If we are told that the only thing needed to go digital on HF is to hook up that 56K modem to the rig, then that is the truth. If we are told that Ham radio is dying, then that is true. You can't argue with someone who makes up the facts as they go along, so why do it? It is tough to beat an anonymous man with invisible sources for invisible facts. - Mike KB3EIA - BTW, CQ has an article on HF digital transmission. Seems that they have got it all wrong too. They have a method that works, but it is pretty slow for images (or files) of any appreciable size. HF will never be the place for high speed digital transmission. There is too much noise and signals are subject to the vagaries of wave propagation phenomena. really? gee it falls into the same catagory as when it was said that we ham had been banished to "useless frequencies" everything above 200M There are some pretty darn good reasons why high-speed digital HF won't work well. And they aren't related to early "knowledge" that caused hams to be relegated to those higher frequencies at the time. agreed there are reasons of course as there were then but it is folks like you with "it can not be Done.. therefore it should not be disused etc. that insure it can't be done I choose to look at a thorny problem and try to see if I can make lemonaide, maybe brew those throns in a decent cup of Tea Radio is a fairly mature field, and digital is getting there. Many people have a pretty good idea what will likely work, based on education and experience. And HF is an unruly beast, given to noisy and incredibly variable conditions. We don't have to be rocket scientists to gain that knowledge. Just as an exercise, how much information can be carried by a 1.8 MHz signal? How much error correction will be needed during the summer, and how much during the winter? Why is there a difference? Why would a wireless digital transmission system use UHF and above for data transmission? in sprict order asking I don't know, don't know, difering weather conidctions, and becuase comercail needs relaiblity where we hams are free to spend on trying stuff when was that Jim A long, long time ago. When almost nothing was known about propagation. and if folks had listene to experts of the day what would we have today Jim might note that they do some bandwidth tricks in similar manner as he proposed per our conversation in here earlier. Not exact, but along the same lines Hopefully we will see an article from those who know the right way to HF digital soon. 8^) I don't have my CQ handy, but it took them a fair amount of time (measured in minutes IIRC, to transmit some heavily compressed (beyond maximum jpeg compression), and therefore really poor quality (by almost everyones standard) pictures. Didn't I make a challenge with some of the HF high-speed digital believers in here to do a sked? I think the "answer" was that I was going to steal the technology. Not that that is likely, but how about say some of the believers among themselves, do a proof of performance of the technology? Or is this just one of those Wondertenna type ideas that crop up from time to time, only to be found lacking when introduced into th e real world? - Mike KB3EIA - |
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