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Mike Coslo wrote on Sat, 17 Mar 2007
18:32:21 CST Often people will wonder why Hams don't run to every new mode that comes along. Some assume that we are not adaptable as a group. I would say it has a lot more to do with simply having someone on the other end to talk to. We need an early following to get the ball rolling, then there needs to be a good reason to use the mode. Mike, you've seen enough other licensed radio amateurs by now to understand that, technically, they are rather conservative in adopting "new" things. My own opinion is 'uber-conservative' but that is just personal. :-) PUBLICITY on new things, new modes is the key to getting attention. I'll recite that PSK31 was innovated in the UK and air-tested by many amateurs in Europe for years before it got its first write-up in QST for USA amateur radio consumption. Why? I don't know for sure but I will start shining some light on editors and frequent contributors to QST. I think that they were honestly unaware of it. It isn't like they are unaware of the RSGB periodicals. Another case is Mike Gingell's polyphase audio network. Mike, now a resident and ham licensee in the USA, did his PhD dissertation on that network. It enabled four quadrature-phased audio outputs with excellent phasing accuracy using lower-tolerance parts. It was publicized in Pat Hawker's column in Radio Communication magazine in 1973, the experimenter trying it out was Peter Martinez, G3PLX, the guy who would come up with PSK31 later. European hams have been trying it out for SSB modulation and demodulation ever since; makes for a smaller SSB sub-assembly. It got some attention from 1974 onwards over here, but not a lot. It even got lots of attention in the IEEE Communications magazine for frequency- multiplexed telephony but that was displaced by up and coming digital time-multiplexing right afterwards. Long-distance wired telephony was the first user of SSB, BTW. :-) Conservative USA amateurs tend to stay with what they know and learned when young...except for the few who actually work with higher-tech modes for a living...and some of those tend to "relax" with tried-and-true modes off-work. That re-enforces the conservative approach to "state of the Art" advancement. Part of that conservatism may be the "made only in America" thinking. Look at D-Star that's been getting publicity by the Big3 amateur radio makers of Japan. D-Star has been around for three years, innovated by the JARL. It seems to be very good in providing flexibility to connect with the Internet through VHF-UHF repeaters. [I got a demo of it just recently] No, it's not a "practical" thing on "the bands" (what so many amateurs call the HF bands) but it seems to work just dandy on handling both voice and data together on VHF-UHF. The difference between say Spread spectrum and say PSK31 is that PSK apparently serves some purpose for a growing number of Hams, and SS doesn't. Ummm...PSK31 was originally designed for HF ham bands and was deliberately narrow-band. Spread-Spectrum modes are for wider bandwidths available only on UHF and up in frequency. DSSS is already a proven winner in multiple-user WLANs in other radio services (no discernable interference or catastrophic BERs) but is good only for LOS radio paths. As a result, it will see application only in more densely populated urban areas in the USA. Conservative radio amateurs here stay on HF and all its narrowband limitations. Now, it MIGHT be that FHSS could be adapted to HF, even if only to 10m with that band's 1.7 MHz total bandwidth. That is uncertain since it absolutely requires a higher-accuracy timebase than is found in most upscale HF+ transceivers. [think timing update and correction via GPS] It will NOT be "tunable" like the older analog modes, at least that I can envision. Neither will it cause much interference to those legacy-mode users already there. However, it does have a potential of getting more users in the same bandwidth for higher throughput than is possible with analog modes. Many, many things are possible, even the digital voice and music on HF now being used for BC purposes. But, that's a niche thing and only proves the mode is practical and viable. On the other hand, there's some "comfort" in staying "establishment," of not having to spend time finding out how those new-fangled things work; i.e., survivalist conservatism. :-) 73, Len AF6AY |
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