Dave: The hobby is defined in the first section of PART97. No mystery there. It is quite plain, so there is very little wriggle room there for interpretation.
Double sideband is allowed to use 6 kHz of spectrum - and so are digital modes. But if the operator of either one interferes with an ongoing QSO because they can't find a clear bit of spectrum that wide, then they are in violation of PART97. You can go as wide as you want - as long as you do not interfere with anybody else's QSO. The spectrum is there on a first-come, first serve basis, and nobody owns or gets to reserve a frequency slot. The practical limit on bandwidth is how wide a swath of usable spectrum you can find that is not currently in use. - It's that simple. Note that the more useful frequencies will always tend to be more congested. The FCC has rejected several petitions regarding spread-spectrum on HF because it raises the noise floor for all, across a very wide area. Not being able to play well with others, it is not allowed on HF where weak signal work is common. This is a good thing. Forget spread-spectrum on the ham part of HF. - Ain't gonna happen. All of our amateur radio HF spectrum is shared spectrum, so it's not OK to screw up wide areas of it for other uses. - Not even just a little bit. They are not going to allow it for just two people, and as the number of spread-spectrum users goes up - so does the noise floor for everybody else on that band. - Think it through, and I'm sure you'll understand why spread-spectrum on HF is a non-starter. We may or may not get additional spectrum someday, but the chances of that occurring because some ham or another thinks that we are putting it all to 'better use' is vanishingly small. To see about the FCC's criteria for the use of our spectrum, see the first section of PART97, where the hobby is defined. You're probably right about 3kHz being an upper limit for practical use on HF... But I've seen times when the practical limit ( see definition above ) was either smaller or larger than that. - It varies with the current amount of utilization around a given frequency, at a given time on a given day. 73 DE Charles Brabham, N5PVL Prefer to use radio for your amateur radio communications? - Stop by at HamRadioNet.Org ! http://www.hamradionet.org ----- Original Message ----- From: Dave Sparks To: digitalradio@yahoogroups.com Sent: Wednesday, October 28, 2009 2:00 PM Subject: Re: [digitalradio] Fast/Wide Slow/Narrow The problem with worrying about "people interfering with this hobby", you have to narrowly define "this hobby". OK, staying with your analogy, we'd have to set surface street speed limits in concrete based on how fast a Ford Model T could have been safely driven, leading to a national maximum speed limit of what? 40 MPH? Lanes probably should be subsequently narrowed, too. Restricting research and innovation to VHF/UHF bands is not the answer. It's a little hard to test the NVIS or ionospheric characteristics of a new mode on 6 meteres and up. I've yet to hear a rational reason why a DSB AM transmission should be allowed to utilize 6 Khz of bandwidth, but not a digital one. Please note that I am not suggesting that hams should use 6 Khz. wide modes on a daily basis for ragchewing. From a practical standpoint, 3 Khz. is probably a PRACTICAL limit, for the time being, if we are discussing sound card modes modulating SSB signals. But I'd also like to see spread spectrum experimentation on HF, too. Maybe some fruitful experimentation would wind up earning us MORE HF spectrum, if we could show it could be put to good use. -- Dave Sparks AF6AS ----- Original Message ----- From: DANNY DOUGLAS To: digitalradio@yahoogroups.com Sent: Wednesday, October 28, 2009 11:38 AM Subject: Re: [digitalradio] Fast/Wide Slow/Narrow Back to the anology. Auto (ground based) speed have nothing to do with aircraft speeds. Aircraft were developed "off-road", and did not interfere with auto carriageways at all. To this day, new records are being made by aircraft, away from other aircraft users. Land speed records are normally made, again, away from normal roadway surfaces. When either of them are developed to a particular speed/saftey situation, then improvements are made as new planes are put in the air, or cars put on the road. They are still limited to the roads, or air spaces where everyone else is, and mandated to certain speeds/locations, just like the vehicles developed and in use that are already there. They will not, and cannot suddely go faster on the ground than the other cars on the road (and sometimes not in the air - remember the SST which was limited so that it would not break the sound barrier over US land?) If spectrum can be identified, which is not populated by other stations/services, and which will not interfere with other previously licensed , I would say go to it. Improvements are always welcome, as long as their developments do no interfere with other legal users. The devlopment of new modes and methodology is great, and should be encouraged, but should be targeted to use the bandwidth which is already legal, and not push to suddenly widen, therefore take over that which is presently being enjoyed by operators who use them as a hobby, and personal enjoyment. I salute those with the technical knowledge, ability, and drive to develop these new modes, but ask them to direct their long term targeting to share, not take over amateur radio, for purposes other than what the large majority are using it. The government welcomes enhancements for emergency servies, so let the government assign spectrum for its development and use. This stuff of pushing the legal limits by using several channels (each within the bandwidth limit) but needing those several to get a message across,: thus using up the space of several users, on the amateur bands, is just plain wrong. Having said all that: know that I served as a telecommunications officer in several different federal positions for some 29 years, and would have readily accepted and used some of the recent developments in that job. But I remind you - it was a JOB. We had our own spectrum, and one of the most aggrivating things I saw, and stopped, was our operators sliding into the ham bands when they thought those small pieces of spectrum were the best place to go. I did not and will not condone other users interfering with this hobby.
