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#1
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John Smith I wrote:
Over in RRAM there seems to be much debate on the need for HS data communications, strange ... Seems like in a REAL disaster, the need to xmit satellite maps of flood areas, earthquake damage to bridges, structures, fires, hostiles?, technical docs, medical documents/instructions/directions, signs, plans, email, web data, etc. would be most appreciated if not desperately needed. While VHF+ (satellite comms would be good!) may be suitable for some flat terrain and moderate distances, availability of HF communications, surely, would be a requirement in many situations A laptop consumes VERY LITTLE power and can turn any xceiver into a VERY powerful data transmission tool; most today would consider it a requirement rather than a luxury. However, PSK is highly unsuitable and the development of REAL tools remains for the future ... new minds with up-to-date technology, methods and skills will accomplishing this. The future is coming ... like it or not. JS |
#2
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On Mar 18, 9:26?pm, John Smith I wrote:
John Smith I wrote: Over in RRAM there seems to be much debate on the need for HS data communications, strange ... Seems like in a REAL disaster, the need to xmit satellite maps of flood areas, earthquake damage to bridges, structures, fires, hostiles?, technical docs, medical documents/instructions/directions, signs, plans, email, web data, etc. would be most appreciated if not desperately needed. Perhaps, JS, perhaps, but don't rule out the established infrastructure. Right after the 17 Jan 94 Northridge earthquake here, FEMA folks brought in a bunch of equipment doing pictures (in high speed, BTW) via satellite relay. One of those uses was a revolving pan around messages shown in video from way out of town...written in their own handwriting/printing. HF ham bands have typical TOTAL bandwidths of 500 down to 100 KHz. Unless you've got some "4th dimension" gizmotchy (as yet unknown to the rest of technical mankind), ya just ain't gonna get much "high speed" on HF. The bandwidth just does NOT exist for what you want. Now, if you have such a marvelous ultra-minimal bandwidth "high-speed" modulator for HF, run, do not walk to the nearest California Auxiliary Communications Service office and offer it to them. It ain't all that far from Stockton to Sacramento. The ACS considers *all* forms of communications for disasters, big or small, and will be eager for input on miracle methods. Dinna wurra, laddie, if ya win the Nobel Prize for it, I will volunteer to write your acceptance speech in Swedish to deliver to KIng Gustav and all the others in Stockholm. [a pronunciation guide will cost extra, though] Until then, amateur HF still has 60 to 300 WPM text data to send teleprinter communications, even en masse via packet. That DOES fit into the narrow confines of HF. What is left of the telephone network after a major, major disaster can send limited-frame-speed video like what was done from Kuwait-Iraq in 1991, all over the low- resolution, narrow-band circuits on the telephone system. 73, Len AF6AY While VHF+ (satellite comms would be good!) may be suitable for some flat terrain and moderate distances, availability of HF communications, surely, would be a requirement in many situations A laptop consumes VERY LITTLE power and can turn any xceiver into a VERY powerful data transmission tool; most today would consider it a requirement rather than a luxury. However, PSK is highly unsuitable and the development of REAL tools remains for the future ... new minds with up-to-date technology, methods and skills will accomplishing this. The future is coming ... like it or not. JS |
#3
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#4
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On Mar 19, 1:26 am, John Smith I wrote:
John Smith I wrote: Over in RRAM there seems to be much debate on the need for HS data communications, strange ... debate I call it whing maybe you are being polite The future is coming ... like it or not. ready or not too JS |
#5
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On Mar 19, 7:45?am, "an_old_friend" wrote:
On Mar 19, 1:26 am, John Smith I wrote: John Smith I wrote: Over in RRAM there seems to be much debate on the need for HS data communications, strange ... debate I call it whing maybe you are being polite Not "whining." It's a technical barrier to reach "high speed" approaching T1 rates on small slices of bandwidth. ALL radio services face that same problem. If at least 1 MHz of the 10m band could be used - at the expense of ALL users of that portion of EM spectra, there would be a chance for at least NVIS propagation at high rates. That is NOT likely to happen for a minority of High Speed fans to go against the overwhelming majority. Mere resistance to the establishment is NOT a "just cause." One MUST justify that resistance in order to begin changing things. That justification is what the Students Wildly Indignant about Nearly Everything (SWINE) usually overlook. For "high speed" (really medium-low speed), the commercial side of communications has developed the 56 KBPS modem that works on a 3 KHz bandwidth. That is starting to bump up against Shannon's Law, an extremely real technical barrier. [it doesn't exceed it but it is close enough to almost reach out and touch it...] All electronics and radio works by the same Laws of Physics. Those Laws are immune to the feelings, emotions, and general imprecations of mankind. One MUST learn those Laws and work WITH them in order to get them to work FOR you. 73, Len AF6AY |
#6
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#7
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On Mar 19, 1:26 am, John Smith I wrote:
John Smith I wrote: Over in RRAM there seems to be much debate on the need for HS data communications, strange ... Seems like in a REAL disaster, the need to xmit satellite maps of flood areas, earthquake damage to bridges, structures, fires, hostiles?, technical docs, medical documents/instructions/directions, signs, plans, email, web data, etc. would be most appreciated if not desperately needed. You are overlooking the digital modes already available, for example, SSTV and Fax for images. Although not fast, how many pictures of the same item do you really need immediately for example? It is not going to be a hardship if it takes a couple of minutes for the image to transfer rather than a couple of seconds. Text data (documents, instructions, directions, etc) are easily handled by error correcting modes now available. Granted these modes aren't used much but all the sender and recipient have to do is agree on which mode. While VHF+ (satellite comms would be good!) may be suitable for some flat terrain and moderate distances, availability of HF communications, surely, would be a requirement in many situations A laptop consumes VERY LITTLE power and can turn any xceiver into a VERY powerful data transmission tool; most today would consider it a requirement rather than a luxury. Depends on how hard up for power you are. In some cases, no problem. In other cases, power will be so limited that you would only send the most urgent of messages. However, PSK is highly unsuitable and the development of REAL tools remains for the future ... new minds with up-to-date technology, methods and skills will accomplishing this. There are tools that will meet these needs today. They are not as fast as you would like them to be but they do work. The future is coming ... like it or not. JS To shape the future, we need to understand the abilities of the present. I'd suggest getting out there and working SSTV (ATV on UHF), packet, RTTY, PSK31, AMTOR, PACTOR (I, II, and III), Hellschreiber and the rest of the myriad "flavors" of digital out there. There is even a variant of PSK that includes some error checking. Learn first hand their strengths and weaknesses. Without this background, a developer will be handicapped in coming up with something better. If he is not knowledgeable on what is out there, he may end up "re-inventing the wheel." If he is not knowledgeable about the strengths and weaknesses of current modes, his new mode may end up having some of the same issues. One can't just wave a magic wand and say "let it be so." Dee, N8UZE |
#8
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Dee Flint wrote:
... You are overlooking the digital modes already available, for example, SSTV and Fax for images. Although not fast, how many pictures of the same item do you really need immediately for example? It is not going to be a hardship if it takes a couple of minutes for the image to transfer rather than a couple of seconds. Text data (documents, instructions, directions, etc) are easily handled by error correcting modes now available. Granted these modes aren't used much but all the sender and recipient have to do is agree on which mode. Yes, like the "Model A" built by Ford, time to move up to new standards! Surely time for the "Model B" anyway! Depends on how hard up for power you are. In some cases, no problem. In other cases, power will be so limited that you would only send the most urgent of messages. Well if you are that hardup for power, you darn well are NOT going to let some waste it hammering out CW for EXTENDED periods of time, transmitting data at LOW speeds or attempting to use voice and wasting BOTH time AND power! There are tools that will meet these needs today. They are not as fast as you would like them to be but they do work. There are still horses around but I'd rather drive a car ... To shape the future, we need to understand the abilities of the present. I'd suggest getting out there and working SSTV (ATV on UHF), To shape the future we need progressive people to deal with it, the old, the lame, the outdated, the slow, etc. must be moved aside. However, when it comes to "antique people" they can be quite stubborn and difficult to move aside! Gentle force must be applied ... One can't just wave a magic wand and say "let it be so." No, and we are working on the changes ... well, some are just arguing that all is impossible, not worth doing, or is a waste of time ... but what doesn't have its' "Nay Sayers?" The future comes ... today it seems one day closer ... JS |
#9
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On Mar 19, 2:41 pm, John Smith I wrote:
Dee Flint wrote: [snip] To shape the future, we need to understand the abilities of the present. I'd suggest getting out there and working SSTV (ATV on UHF), To shape the future we need progressive people to deal with it, the old, the lame, the outdated, the slow, etc. must be moved aside. However, when it comes to "antique people" they can be quite stubborn and difficult to move aside! Gentle force must be applied ... It is more productive if these progressive people understand the present methodologies and their strengths and weaknesses. The strengths need to be conserved and the weaknesses eliminated, hopefully without introducing new weaknesses. Sometimes those "antique people" have valuable insights. Shoving them aside could actually be detrimental to the development of new modes. They are the ones who have the experience to supply information on what weaknesses may need to be addressed. From a less altruistic point of view, they may be the ones to have the money to fund the progressive people. Dee, N8UZE |
#10
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Dee Flint wrote:
... It is more productive if these progressive people understand the present methodologies and their strengths and weaknesses. The strengths need to be conserved and the weaknesses eliminated, hopefully without introducing new weaknesses. ... Dee, N8UZE Dee: This whole stance-proposal of yours is quite ridiculous, preposterous and obviously only formed to put forth your own personal preferences ... SSTV is but one GLARING example, sstv is stupid in the age of .mpg, ..avi, .divx, etc. with real-time encoding ... The least you could do is take a class or read a few good books on data compaction of speech, text, images, movies, etc. ... You appear as a child discussing college physics ... Don't even attempt to BS a fellow BS'er! 8-) Regards, JS |
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