I believe that the ARRL is suggesting that "symbol rate" is not the best way to define a protocol. The symbol rate of most any modern protocol is going to be much less than it is currently defined. For example, Pactor 1 has a symbol rate of 200 baud and a speed of max speed of 200 bps, while Pactor 3 has a symbol rate of 100 baud (SN8) and an uncompress max rate of 2733 bps (uncompressed.) The ARRL petition is simply requesting that digital rates be defined by bandwidth rather than symbol rate. I think this is certainly a more modern approach.
Steve, k4cjx --- In digitalradio@yahoogroups.com, "Dr. Howard S. White" <[EMAIL PROTECTED]> wrote: > > Good question... > > Several Answers.. > 1. The rest of the world can already experiment on HF.. and will do so..whether we change our regs or not... > 2. HF has very different propagation characteristics that necessitate different DV solutions than those on VHF and UHF. > 3. HF is much more crowded and not channelized - which will necessitate different DV solutions than those on VHF/UHF > 4. HF DV has to be able to work in QRM and very low S/N ratios... not usual conditions on VHF/UHF. > 5. HF space is much smaller... necessitating DV solutions that fit the much smaller bandwidths... > > So while you might be able to design something at VHF/UHF... you need to be able to test it on HF...and the best way to test it is for many people to become Beta testers....hence the need to change the rules.... > __________________________________________________________ > Howard S. White Ph.D. P. Eng., VE3GFW/K6 ex-AE6SM KY6LA > Website: www.ky6la.com > "No Good Deed Goes Unpunished" > "Ham Antennas Save Lives - Katrina, 2003 San Diego Fires, 911" > ----- Original Message ----- > From: list email filter > To: digitalradio@yahoogroups.com > Sent: Friday, February 03, 2006 2:10 PM > Subject: Re: [digitalradio] Re: ARRL proposal removes baud rate limitations on HF > > > Gentlemen, > > Like many of the members of this forum, I've been following this thread with a great deal of interest. Please allow me to (perhaps playing devil's advocate) ask a simple question. I understand the propagation and fading issues which are unique to HF, but from an experimental point of view, why couldn't USA hams do their development of new digital modes on say UHF? Once the technological hurdles have been cleared on UHF by the masses of USA hams that apparently aren't even allowed to experiment because of the repressive government regulations they are burdened with, couldn't the then proven technology be ported to HF? > > Our HF spectrum is extremely limited, to put it bluntly, hams all over the world are happily using it all now, that is to say, it's full up. Until we have a digital solution that will help solve that issue, and allow for more qso's in our little playground, why can't we experiment on UHF, and not bother displacing the existing HF activities? Just because we can use more bandwidth on 70cm, doesn't imply that we have to, just consider one of the design criteria to be a band width restriction. > > As they say, 'Inquiring minds want to know?" > > 73, > > Erik KI4HMS/7 > > PS. I'm a no-code tech who has run Amtor, Pactor, rtty, and cw on both 2m and 440, just because I could run 9.6k packet instead, doesn't mean I have to. I for one would be happy to run experimental digital modes with other local hams on UHF, I see it as an underutilized resource, perhaps we can help justify keeping it, if we start using it to 'contribute to the advancement of the radio art.' > > On Feb 3, 2006, at 11:48 AM, Dr. Howard S. White wrote: > > > JIm: > > You have made a very good case as to why we need to experiment and come up with new technologies... > > Instead of concentrating on all the potential and imaginary negatives... which very much reflect the old anti SSB and anti FM arguments...you need to look at the positives... > > There are a myriad of technologies for squeezing high baud rates into tiny channels... there are a myriad of new and not so new technologes out there ... such as TDMA, CDMA and Spread Spectrum... > > It's going to take some clever hams to develop these into a practical DV system for HF on Ham Radio... > > I believe that the technology is there to allow multiple QRM free multiple QSO's to share a standard HF voice bandwidth... some ham needs to put it together... and some ham (likely not in the USA under current baud rate limited rules) will likely do it.. > > Equipment.. Anything Hams develop will likely be computer based... maybe even sound card based as that is the cheapest technology.... and it is likely that you will still be able to use your HF transceiver.... > > New Modes: Stop being so negative.....Heck... new modes is what this Reflector is all about... Olivia, Contestia...new versions of DV...we welcome new modes as they improve things.... > > I do not have all the answers.. I just know that there has to be a better way..... > > DV... has lots of potential to give us more channel capacity with less QRM... we just need to legal framework in place so that we can experiment with it to dispell all those imaginary negatives.... > > __________________________________________________________ > Howard S. White Ph.D. P. Eng., VE3GFW/K6 ex-AE6SM KY6LA > Website: www.ky6la.com > "No Good Deed Goes Unpunished" > "Ham Antennas Save Lives - Katrina, 2003 San Diego Fires, 911" > Need a Digital mode QSO? 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