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On Sun, 02 Oct 2005 20:49:50 -0400, J. Teske wrote:
Due to Katrina/Rita, the company I work for has been given the opportunity to demonstrate a messaging system that would reach out approximately 1 mile +/- in transmission deliverance. This would be an "overbroadcast" (my term) in that it would override local AM radio broadcasting to reach into cars, trucks etc. In particular, we are working with a stationary site (a chemical spill for instance) and an emergency vehicle that would move back and forth at and through the site, at up to 70 mph, broadcasting an alert, voice and tone message. And what makes you think anyone is going to be listening on AM. I think the vast majority of radio listenings in urban areas listen to FM except possibly for drive time shows, 24 hour news stations and the comparatively few people enamored of talk or religious radio. FM of course is subject to the capture effect wherein the strongest signal prevails to the exclusion of others (at least that is the theory). AM, particularly at night is subject to strong skywaves. We are making no preference as to AM or FM as in that we will be attempting to overbroadcast on each. The AM skywave issue is exactly that but the system need not be perfect, only as perfect as possible. Reading about LPAM, this looks technically possible but one concern I have is antennae size. A fire truck, for instance, could have an antenna mounted on its front, and up to 4 feet over the top of its roof, so we might look at as much as 20 feet of length. I realize this places us over the 3 meter max so one of the ???? is whether LFAM is realistic. The 3 meter limitation is clearly is a problem here, we haven't modeled a 3 meter yet. I also wonder what, if anything, LFAM gets us in terms of FCC approvals and state regulations. Am I way off base here, can any antennae, fractal or other, or any AM antennae technology, be utilized to design an antenna and propagate this type of signal? I think the problem here is not the technology, but a fundamental misconception of what it is you are trying to prove and who is likely to be your audience. At this point you do not need an engineer, you need a sociologist. W3JT A sociologist? -- Drop the alphabet for email |
#2
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On Mon, 3 Oct 2005 11:52:49 -0400, Ari Silversteinn
I think the problem here is not the technology, but a fundamental misconception of what it is you are trying to prove and who is likely to be your audience. At this point you do not need an engineer, you need a sociologist. W3JT A sociologist? Yeah, to figure out what has to be done to get the audience to listen to you. A psychologist might also work. |
#3
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On Mon, 03 Oct 2005 12:44:20 -0400, J. Teske wrote:
On Mon, 3 Oct 2005 11:52:49 -0400, Ari Silversteinn I think the problem here is not the technology, but a fundamental misconception of what it is you are trying to prove and who is likely to be your audience. At this point you do not need an engineer, you need a sociologist. W3JT A sociologist? Yeah, to figure out what has to be done to get the audience to listen to you. A psychologist might also work. Gee, are you trying to hurt my feelings? -- Drop the alphabet for email |
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