I know some thought went into that reply, and that it has merit if we are only concerned with short-range communications. However, no matter how wide, narrow, thick or thin the emission, you cannot expect the same range on 1 1/4m as you can on 20m - so I am not sure the statement has any merit in this discussion. This discussion has little effect on some, who have long since vacated the Amateur bands for their serious use of digital signals for anything other than entertainment. However, for those who are limited to the Amateur Radio Service Spectrum, pragmatic consideration should be given to the position the regulating body is in when other services that may offer a tangible and beneficial service petition for the spectrum we enjoy. Could it be used to be more of a benefit to mankind with wider bandwidth emissions, which can improve both accuracy and speed in moving traffic that is also beneficial to mankind? What are the basic requirements for moving traffic? I seem to remember Speed and Accuracy to be a major part of the definition... It is all a relatively moot point... As the average age of the Amateur Radio Operator continues to increase, attrition will ultimately be the deciding factor. Consequently, I appreciate the merits of 2KHz wide digital modes, which are used daily on NTIA spectrum - and enjoy using the keyboard modes as a form of entertainment where bandwidth is limited. It does boil down to a question of if we appreciate the privileges of the use of the spectrum afforded to us, and how we show that appreciation. Many only consider it a right for their enjoyment, some look to a higher calling that may help preserve the spectrum for their grandchildren. Wider bandwidth digital signals as a vehicle for efficient long range traffic handling is an unavoidable fact. It doesn't matter how many temper tantrums are thrown, how many stress-related conditions are created by those who know how to spell "automated" and "common carrier".
It is here, it will stay here, and it will be advanced to the point at any signal that meets the qualifications of providing 2 KHz of through put with a minimum guard band above and below it to prevent moving past the 3 KHz assigned to the channelized concept used in professional communications will be used by the less technical forms of transmitting that is afforded to the public. I don't much like being taxed into submission either. Neither do I like a lot of things that I must do in day to day life. The frog often wishes for wings. Some Amateur communicators will always fall back upon their comfort zone when faced with a new concept that doesn't square with what their grandfathers taught them. Maybe we would be a better service to mankind if we specialized in finding a way to send smoke signals without burning organic material or creating greenhouse emissions. That is a fairly narrow-band emission, and it would pay tribute to times gone by and also not be automated or considered common carrier. See, everyone could get their wish.... Cause and effect; what a concept... David KD4NUE -----Original Message----- From: digitalradio@yahoogroups.com [mailto:digitalra...@yahoogroups.com] On Behalf Of bruce mallon Sent: Thursday, March 26, 2009 6:45 AM To: digitalradio@yahoogroups.com Cc: wa4...@yahoo.com Subject: Re: [digitalradio] No FCC data bandwidth limit on HF Re: USA ham rules Things go round and around .... Back 70 years ago the FCC band SPARK GAP because it was wide and interfered with other stations. CLEAN NARROW signals became the standard. With bands like 220 MHz sitting there dead one would think wide band on 20 meters would be the last thing we see. ..... --- On Thu, 3/26/09, kh6ty <kh...@comcast.net> wrote: From: kh6ty <kh...@comcast.net> Subject: Re: [digitalradio] No FCC data bandwidth limit on HF Re: USA ham rules To: digitalradio@yahoogroups.com Date: Thursday, March 26, 2009, 6:00 AM The short answer, as Steve Ford likes to say, based on the Cohen paper, is that the "necessary bandwidth" appears to be "roughly" twice the frequency shift, although an exact calculation is obviously very complicated. More importantly, with regards to the amateur radio service is the summary statement, "The necessary bandwidth is the minimum emission bandwidth required for an acceptable quality of service." It has already been concluded, after many months (even years!) of debate, that radio amateurs are "amateurs" and not "professionals" and do not have either the ability or the means to measure "necessary bandwidth" of their signals. Their communications are casual "amateur"communicat ions and not "professional" communications. If the "necessary bandwidth is the minimum emission bandwidth required for an acceptable quality of service" were to be codified into the radio amateur service regulations, it would also be necessary to also define what "acceptable" quality is, in particular for the radio amateur service. That definition will obviously be different for casual conversation, DX exchanges, and contest exchanges, than it is for commercial or quasi-commercial "messaging" services. It will probably fall somewhere between PSK31 and MFSK16 or WSJT bandwidths, which provide "casual" communications quality in exchange for the higher bit rates needed for sending long messages. Even narrow bandwith modes, like PSK31, can be utilized to reduce the error rate to zero through the use of ARQ. It is just that the throughput is half that of the non-ARQ use of the mode, but that is generally "acceptable" for casual communications. What would NOT be acceptable is using a 150 KHz-wide signal on a band that is only 350 KHz wide merely in order to achieve faster throughput for two dominating stations at the expense of hundreds of others. Should 150 KHz-wide signals start being used on 20m, for example, it would not take very long for the FCC regulations to be changed (or re-interpreted) to protect the "casual" communications use of the 20m band. To infer that using "low power" would make that acceptable ignores the fact that "low power" to someone distant is "high power" to someone close by. The BPL debacle should have made that clear by now. The regulations already require that the minimum power necessary for communicatons be used, and if a similar requirement were made for emitted bandwidth, it could easily stifle innovation (at least with regard to using wider, or spread-spectrum modes), and not promote it. We might all then wind up having to be content with PSK31 plus ARQ for our casual communications! Better not ask for something you may not want! I agree that the regulations do not "specifically" limit bandwidth on the HF bands, but that does not mean this could not easily happen if there are enough abuses to justify it. It is true that the regulations have not kept up with technology, but the intent to protect casual communications is still there, and that intent could be codified if it becomes necessary. However, we may not be happy with the end result, especially considering the extremely minor interest in digital messaging or using digital modes other than PSK31, CW, and RTTY. With the advent of satphones, cell phones, and the Internet, the relevance of amateur radio as anything more than a hobby activity is rapidly diminishing and we can expect future regulatory changes to further support the hobby interests rather than quasi-commercial interests in amateur radio. 73, Skip KH6TY
