| Page 2 of 2 | 1 | 2 |
|
|
Ari Silversteinn wrote:
Do we have to blanket or only blanket each locale, that is, the broadcasting stations of each locale? Not only will we miss those no AM/FM listeners, we will miss those that don't have their radios on. An aggressive, road sign campaign is planned something like " Turn On Your Radio, It Could Save Your Life" type of thing near each incident site. On Mon, 03 Oct 2005 12:58:40 -0400, J. Teske wrote: While Florida may have laws to this effect, in fact they are unenforcable because of federal preemption for all radio matters. Still illegal, just the wrong enforcement entity. A state or locality cannot for example legislate on TVI matters (though many have tried.) When they try, the FCC will send a notice to the locals that they are in charge and will handle enforcement. Unfortunately the FCC is unwilling to get involved in the matter of private contracts such as antenna exclusions in housing developments. Is there a reason that the locals try to overwrite Fed law then? That said, be aware that when it comes to radio useage in the US, the FCC is actually NOT the ultimate authority. They are responsible only for those frequencies which a military controlled panel has ceded to the FCC for administrative purposes. I can't remember the name right off hand, but during my federal career, I had to work with them and we actually were able to override an FCC allocation because it interfered with a military application. While the FCC played ball with the DOD outfit I worked for, the ultimate beneficiary of that allocation (a TV station) sued and the matter wound up in Federal Court. The court reaffirmed the DOD's ultimate sovreignity in this matter. It ultimately got resolved by some allocation juggling when a combination of the Court, The FCC and the DOD gave the plaintiff some "religion." W3JT Excellent point, in my research I saw this handoff or spectrum management authority of the DoD and it makes sense. This is a serious, additional consideration and is all the more reason to get the DHS' blessings. Thanks. Actually the DOD does not have any authority over radio spectrum. There are two federal agencies that do. One is the FCC, which we all know and love, the other is NTIA, the National Telecomunications Information Agency. NITA controls all federal radio frequencies. Since the DOD is a Federal Agency their frequencies are controled by NTIA the same as the FBI, CIA Secret Service, Dept of Homeland Security and any other federal alphabet soup agency. Dave N a FCC and a NTIA user |
Wonder no longer, because broadcasing at IF frequencies has been for
year the standard in the US. In spite of some rather silly speculative posts, this mechanism has proved itself for more than 10-years here. In a confined space such as a tunnel, a transmitter of 10-watts more than sufficint to get the job done, and using nothing more sophisticated than a simple wire radiator running the length of the tunnel. In Boston, we also retransmit commercial radio broadcasts into our tunnels, but that requires equipment dedicated to each radio channel that we re-broadcast, and that becomes very costly after 10 stations or so, hence there is a limit. The real challenge is in maintaining emergency communications to the outside from within our tunnels. All are serviced by the traditional leaky coax that runs along the top of the tunnel, but considering that all of these emergency services operate on their own indepdendent frequency bands, so servicing them simulteously becomes somwhat problematic. particularly when hand-held, low power devices enter the big picture. Harry C. |
wrote in message
oups.com... Wonder no longer, because broadcasing at IF frequencies has been for year the standard in the US. In spite of some rather silly speculative posts, this mechanism has proved itself for more than 10-years here. In a confined space such as a tunnel, a transmitter of 10-watts more than sufficint to get the job done, and using nothing more sophisticated than a simple wire radiator running the length of the tunnel. In Boston, we also retransmit commercial radio broadcasts into our tunnels, but that requires equipment dedicated to each radio channel that we re-broadcast, and that becomes very costly after 10 stations or so, hence there is a limit. The real challenge is in maintaining emergency communications to the outside from within our tunnels. All are serviced by the traditional leaky coax that runs along the top of the tunnel, but considering that all of these emergency services operate on their own indepdendent frequency bands, so servicing them simulteously becomes somwhat problematic. particularly when hand-held, low power devices enter the big picture. Harry C. All agreed, but that is in a tunnel, which has the advantage of not having to overcome the still-received commercial stations. The OP wants to do this out in the open, anywhere, any time. He also wanted to do it while driving at high speed for some reason, but I think he's quietly shelved that part of the idea. Cheers. Ken |
Suggestion: Why don't you also broadcast such "emergency" information over
the entire spectrum of wireless network frequencies? That way, you could post the information into every Usenet group on the globe. Just like you have done with these postings. "Ari Silversteinn" wrote in message ... Crossposted to: rec.radio.amateur.antenna,rec.radio.amateur.misc,r ec,radio.amateur.equipment Novitiate he I am learning AM broadcast basics in particular the issues regarding the geo-targeted broadcasting of alert messages from moving vehicles. Would most appreciate any assistance. 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. 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. 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? All comments appreciated. -- Drop the alphabet for email |
"Ari Silversteinn" wrote in message ... On Mon, 3 Oct 2005 12:01:14 -0400, Fred W4JLE wrote: In that case, simply modify the sign to "Tune to 560, it could save your life" and use a discrete frequency low power transmitter. I assume you mean to take up an unused local channel? Or to bargain for time on a used one? Both ideas make sense. -- Drop the alphabet for email On Mon, 3 Oct 2005 21:47:29 -0000, Dave wrote: if this is for real time notification you don't have time to bargain or to find an unused channel... and who would listen to you anyway if it was unused? how often do you turn the knob on your car radio?? Often actually and I agree about the unused channel, at first blush what about the emergency broadcast system? that would seem to be the 'proper' method of emergency notification, its already set up for all sorts of local, regional, and national notifications. The EBS is voluntary, this is not. -- Drop the alphabet for email |
On Mon, 3 Oct 2005 17:58:33 -0400, Fred W4JLE wrote:
There are a couple of frequiencies for unlicensed low power am stations. You can see them in use by real estate folks selling houses. There are no commercial stations on the frequency. Yes, and at Disney World, etc. This is a very doable idea and may well solve FCC/DoD issues. -- Drop the alphabet for email |
Excellent point, in my research I saw this handoff or spectrum management authority of the DoD and it makes sense. This is a serious, additional consideration and is all the more reason to get the DHS' blessings. Thanks. On Mon, 03 Oct 2005 17:55:13 -0500, David G. Nagel wrote: Actually the DOD does not have any authority over radio spectrum. There are two federal agencies that do. One is the FCC, which we all know and love, the other is NTIA, the National Telecomunications Information Agency. NITA controls all federal radio frequencies. Since the DOD is a Federal Agency their frequencies are controled by NTIA the same as the FBI, CIA Secret Service, Dept of Homeland Security and any other federal alphabet soup agency. Dave N a FCC and a NTIA user Know of the NTIA but I believe that what is the reality is that the mil gets first dibs on frequencies, then hands off the rest and in a state of national emerg, they can pretty much takeover the airwaves. -- Drop the alphabet for email |
On Tue, 4 Oct 2005 14:57:01 +1300, Ken Taylor wrote:
All agreed, but that is in a tunnel, which has the advantage of not having to overcome the still-received commercial stations. The OP wants to do this out in the open, anywhere, any time. He also wanted to do it while driving at high speed for some reason, but I think he's quietly shelved that part of the idea. Cheers. Ken MOF, it has reared its ugly hi speed head again. -- Drop the alphabet for email |
On Mon, 03 Oct 2005 14:31:36 -0700, Richard Clark wrote:
On Mon, 3 Oct 2005 16:33:52 -0400, Ari Silversteinn wrote: OK, so we supply the amplification. OK, this is just a re-run of previous speculations. You don't know the depth of your energy budget crisis, do you? Open coffers. -- Drop the alphabet for email |
On Tue, 04 Oct 2005 14:54:42 GMT, Wayne P. Muckleroy wrote:
Suggestion: Why don't you also broadcast such "emergency" information over the entire spectrum of wireless network frequencies? That way, you could post the information into every Usenet group on the globe. Just like you have done with these postings. Usenet being a place that only a few people access, aside from that, it's not a bad idea, actually. -- Drop the alphabet for email |
"Ari Silversteinn" wrote in message
... On Tue, 4 Oct 2005 14:57:01 +1300, Ken Taylor wrote: All agreed, but that is in a tunnel, which has the advantage of not having to overcome the still-received commercial stations. The OP wants to do this out in the open, anywhere, any time. He also wanted to do it while driving at high speed for some reason, but I think he's quietly shelved that part of the idea. Cheers. Ken MOF, it has reared its ugly hi speed head again. -- Sorry, what's 'MOF'? Ken |
"Ari Silversteinn" wrote in message
... On Mon, 3 Oct 2005 17:58:33 -0400, Fred W4JLE wrote: There are a couple of frequiencies for unlicensed low power am stations. You can see them in use by real estate folks selling houses. There are no commercial stations on the frequency. Yes, and at Disney World, etc. This is a very doable idea and may well solve FCC/DoD issues. -- When was the last time you listened to one of those frequencies? It won't get the message out where it's needed. Ken |
"Ari Silversteinn" wrote in message
... On Mon, 03 Oct 2005 14:31:36 -0700, Richard Clark wrote: On Mon, 3 Oct 2005 16:33:52 -0400, Ari Silversteinn wrote: OK, so we supply the amplification. OK, this is just a re-run of previous speculations. You don't know the depth of your energy budget crisis, do you? Open coffers. -- He wasn't referring to your finance budget, but your energy budget. I hesitate to say it can't be done in any practical sense, but that's my thought. The idea of one poster to transmit on the IF's is a good one but I didn't suggest that because you'll also kill your emergency services comm's. Incidentally, do you plan to have every loco in the US fitted out or are you going to fly the loco's to the incident site to do their stuff? Cheers. Ken |
I can't find the part of the FCC regs that provide these frequencies for
unlicensed stations. Can anybody share the chapter and verse? Jim There are a couple of frequiencies for unlicensed low power am stations. You can see them in use by real estate folks selling houses. There are no commercial stations on the frequency. Yes, and at Disney World, etc. This is a very doable idea and may well solve FCC/DoD issues. |
On Wed, 5 Oct 2005 08:09:19 +1300, "Ken Taylor"
wrote: "Ari Silversteinn" wrote in message .. . On Mon, 03 Oct 2005 14:31:36 -0700, Richard Clark wrote: On Mon, 3 Oct 2005 16:33:52 -0400, Ari Silversteinn wrote: OK, so we supply the amplification. OK, this is just a re-run of previous speculations. You don't know the depth of your energy budget crisis, do you? Open coffers. -- He wasn't referring to your finance budget, but your energy budget. I hesitate to say it can't be done in any practical sense, but that's my thought. Hi Ken, His terse reply refers to the public coffers - troughs - open for this fabulous pork barrel feast. You know, crack dealer capitalism. Nothing has to actually work, or be useful, or even be used. It just has to generate paper in one direction, and cash in the other. Ari is mining us as a dry run for all the terms, shortfalls, and fits to the jigsaw to rummage up into a proposal. 73's Richard Clark, KB7QHC |
It can be found under the section that allows a transmitter as long as it is
less than some number of milliwatts per meter. If you really need the exact section, I will drag out the regs and get it for you. "RST Engineering" wrote in message ... I can't find the part of the FCC regs that provide these frequencies for unlicensed stations. Can anybody share the chapter and verse? Jim There are a couple of frequiencies for unlicensed low power am stations. You can see them in use by real estate folks selling houses. There are no commercial stations on the frequency. Yes, and at Disney World, etc. This is a very doable idea and may well solve FCC/DoD issues. |
That is part 15 and it isn't just a couple of frequencies, it is any
frequency in the AM broadcast band (and the FM broadcast band, for that matter). Specifically, 15.219 allows operation on any frequency in the band so long as (a) the input power to the final stage is less than 100 mW and (b) the antenna "system" (radiating element, coax, and ground lead) is less than 3 meters long. 15.221 also allows operation with an unspecified power level into leaky coax with a field strength limitation. Power is not milliwatts per meter. Power is milliwatts. Field strength (also an allowed measurement) is in volts per meter. The OP said that there were a "couple of frequiencies(sic)for unlicensed low power am(sic) stations." That implied that there were a couple of frequencies that were unused in the AM band by commercial stations, and I just wanted to have a reference to WHAT they were and WHERE in the regs they were delineated. Jim "Fred W4JLE" wrote in message ... It can be found under the section that allows a transmitter as long as it is less than some number of milliwatts per meter. If you really need the exact section, I will drag out the regs and get it for you. "RST Engineering" wrote in message ... I can't find the part of the FCC regs that provide these frequencies for unlicensed stations. Can anybody share the chapter and verse? Jim There are a couple of frequiencies for unlicensed low power am stations. You can see them in use by real estate folks selling houses. There are no commercial stations on the frequency. Yes, and at Disney World, etc. This is a very doable idea and may well solve FCC/DoD issues. |
In this case the milliwatts per meter refers to frequencies stated in
meters. Volts per meter only applies to the E component, the magnetic component is always stated in amps per meter. I will get back to you on the specifics. I am pretty sure that my brain is not suffering from a senior moment as to my recollection of the regs. "RST Engineering" wrote in message ... Power is not milliwatts per meter. Power is milliwatts. Field strength (also an allowed measurement) is in volts per meter. |
On Tue, 4 Oct 2005 17:31:37 -0400, "Fred W4JLE"
wrote: In this case the milliwatts per meter refers to frequencies stated in meters. Hi Fred, Is this to suggest that for 300MHz it is 1mW total input power as say compared to 1MHz allowing 300mW? This would be uncharacteristically generous of the FCC whose regulations would ban emissions from dummy loads. Seems it would hardly serve Ari's search for pork, but I suppose grantsmanship would jump at sending a marathon of runners through the spill area - each carrying sub-Watt handi-talkies to provide the aggregate power, and spectrum, and lung volume necessary to "get the warning out." 73's Richard Clark, KB7QHC |
Richard the value changes per band and is stated in part 15. For example in
the broadcast band the formula is 24000 /F for microvolts at 1000 feet. There are certain bands that no emissions are allowed from a low powered device. For example setting up your neighborhood micro Rap Station on 121.5 MHz (aircraft emergency) would probably bring a swift shut down. I am still searching for the reg that allows fixed information stations. IIRC they can be run on 530 and 1750 KHz. I know in the past I had looked at the regs and the particular station I was researching was indeed legal. In the low freqs (140 KHz area) you can run up to 1 watt CW with out a license. "Richard Clark" wrote in message ... On Tue, 4 Oct 2005 17:31:37 -0400, "Fred W4JLE" wrote: In this case the milliwatts per meter refers to frequencies stated in meters. Hi Fred, Is this to suggest that for 300MHz it is 1mW total input power as say compared to 1MHz allowing 300mW? This would be uncharacteristically generous of the FCC whose regulations would ban emissions from dummy loads. Seems it would hardly serve Ari's search for pork, but I suppose grantsmanship would jump at sending a marathon of runners through the spill area - each carrying sub-Watt handi-talkies to provide the aggregate power, and spectrum, and lung volume necessary to "get the warning out." 73's Richard Clark, KB7QHC |
Not quite. That is the limit in 15.209, with the following caveat
"...except as provided elsewhere in this subpart..." Elsewhere in the subpart (15.219 and 15.221) we have the limit for the band 525-1705 kHz. (AM broadcast band) the 100 mW and 3 meter antenna restriction OR a 15 uV/m restriction at a distance of (47.715/(frequency in kHz.)) meters (which is also lambda/(2 * pi)) from leaky coax. BTW, it is 24000/F uV/m at 30 meters from 490 to 1705 kHz., which is more like 100 feet, not 1000 feet (15.209). Jim "Fred W4JLE" wrote in message ... Richard the value changes per band and is stated in part 15. For example in the broadcast band the formula is 24000 /F for microvolts at 1000 feet. |
On Wed, 5 Oct 2005 08:07:40 +1300, Ken Taylor wrote:
There are a couple of frequiencies for unlicensed low power am stations. You can see them in use by real estate folks selling houses. There are no commercial stations on the frequency. Yes, and at Disney World, etc. This is a very doable idea and may well solve FCC/DoD issues. -- When was the last time you listened to one of those frequencies? It won't get the message out where it's needed. They suck, I was hoping it was my rental car! -- Drop the alphabet for email |
On Tue, 4 Oct 2005 16:09:19 -0400, Fred W4JLE wrote:
It can be found under the section that allows a transmitter as long as it is less than some number of milliwatts per meter. If you really need the exact section, I will drag out the regs and get it for you. Does this fall under LPFM/LPAM? -- Drop the alphabet for email |
On Tue, 4 Oct 2005 13:51:06 -0700, RST Engineering wrote:
The OP said that there were a "couple of frequiencies(sic)for unlicensed low power am(sic) stations." That implied that there were a couple of frequencies that were unused in the AM band by commercial stations, and I just wanted to have a reference to WHAT they were and WHERE in the regs they were delineated. Jim Truth is, I was thinking about reserved but not yet assigned AM/FM frequencies. -- Drop the alphabet for email |
On Tue, 04 Oct 2005 14:46:33 -0700, Richard Clark wrote:
Seems it would hardly serve Ari's search for pork, Hey, I'm Jewish, sort of. -- Drop the alphabet for email |
On Tue, 4 Oct 2005 15:09:50 -0700, RST Engineering wrote:
Not quite. That is the limit in 15.209, with the following caveat "...except as provided elsewhere in this subpart..." Elsewhere in the subpart (15.219 and 15.221) we have the limit for the band 525-1705 kHz. (AM broadcast band) the 100 mW and 3 meter antenna restriction OR a 15 uV/m restriction at a distance of (47.715/(frequency in kHz.)) meters (which is also lambda/(2 * pi)) from leaky coax. BTW, it is 24000/F uV/m at 30 meters from 490 to 1705 kHz., which is more like 100 feet, not 1000 feet (15.209). Jim So if I need to go out 3500 feet or so, this won't work. Correct? -- Drop the alphabet for email |
On Wed, 5 Oct 2005 08:04:25 +1300, Ken Taylor wrote:
MOF, it has reared its ugly hi speed head again. -- Sorry, what's 'MOF'? Matter of fact..... -- Drop the alphabet for email |
On Wed, 5 Oct 2005 08:09:19 +1300, Ken Taylor wrote:
OK, this is just a re-run of previous speculations. You don't know the depth of your energy budget crisis, do you? Open coffers. -- He wasn't referring to your finance budget, but your energy budget. I hesitate to say it can't be done in any practical sense, but that's my thought. The idea of one poster to transmit on the IF's is a good one but I didn't suggest that because you'll also kill your emergency services comm's. lol What;s being tossed around is the ability to allow FEMA et all to kill the ability to transmit and/or we can upon knowing that the emerg comms are in use. Incidentally, do you plan to have every loco in the US fitted out or are you going to fly the loco's to the incident site to do their stuff? Cheers. Ken -- Drop the alphabet for email |
On Tue, 04 Oct 2005 12:55:29 -0700, Richard Clark wrote:
Open coffers. -- He wasn't referring to your finance budget, but your energy budget. I hesitate to say it can't be done in any practical sense, but that's my thought. Hi Ken, His terse reply refers to the public coffers - troughs - open for this fabulous pork barrel feast. You know, crack dealer capitalism. Nothing has to actually work, or be useful, or even be used. It just has to generate paper in one direction, and cash in the other. Ari is mining us as a dry run for all the terms, shortfalls, and fits to the jigsaw to rummage up into a proposal. 73's Richard Clark, KB7QHC Considering that we have many technologies in use, mof, all technologies that are not in development are in use, this is a load of horse****. If we build it to spec, whatever that spec is, it will be proprietary and how and when they use it is not in our hands. -- Drop the alphabet for email |
Incorrect.
Jim "Ari Silversteinn" wrote in message ... BTW, it is 24000/F uV/m at 30 meters from 490 to 1705 kHz., which is more like 100 feet, not 1000 feet (15.209). Jim So if I need to go out 3500 feet or so, this won't work. Correct? -- Drop the alphabet for email |
You are correct Jim, mistyped the extra zero.
"RST Engineering" wrote in message ... Not quite. That is the limit in 15.209, with the following caveat "...except as provided elsewhere in this subpart..." Elsewhere in the subpart (15.219 and 15.221) we have the limit for the band 525-1705 kHz. (AM broadcast band) the 100 mW and 3 meter antenna restriction OR a 15 uV/m restriction at a distance of (47.715/(frequency in kHz.)) meters (which is also lambda/(2 * pi)) from leaky coax. BTW, it is 24000/F uV/m at 30 meters from 490 to 1705 kHz., which is more like 100 feet, not 1000 feet (15.209). Jim "Fred W4JLE" wrote in message ... Richard the value changes per band and is stated in part 15. For example in the broadcast band the formula is 24000 /F for microvolts at 1000 feet. |
Which zero?
On Tue, 4 Oct 2005 19:44:44 -0400, Fred W4JLE wrote: You are correct Jim, mistyped the extra zero. "RST Engineering" wrote in message ... Not quite. That is the limit in 15.209, with the following caveat "...except as provided elsewhere in this subpart..." Elsewhere in the subpart (15.219 and 15.221) we have the limit for the band 525-1705 kHz. (AM broadcast band) the 100 mW and 3 meter antenna restriction OR a 15 uV/m restriction at a distance of (47.715/(frequency in kHz.)) meters (which is also lambda/(2 * pi)) from leaky coax. BTW, it is 24000/F uV/m at 30 meters from 490 to 1705 kHz., which is more like 100 feet, not 1000 feet (15.209). Jim "Fred W4JLE" wrote in message ... Richard the value changes per band and is stated in part 15. For example in the broadcast band the formula is 24000 /F for microvolts at 1000 feet. |
| All times are GMT +1. The time now is 11:53 AM. |
|
Powered by vBulletin® Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
RadioBanter.com