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
...
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.
--
The things that pop into my mind are why AM rather than FM, which tends to
be more local, and do you intend to 'over-broadcast' only the local channels
(how many?) - I assume you intend to make the channel(s) selectable - or the
entire band to ensure you get everyone? Assuming that there is a commercial
AM broadcast station in the vicinity (what, 10 miles? 20 miles?) you are
probably going to be flat out getting a mobile rig to ride over it. How do
you intend to do this?

Cheers.

Ken

On Mon, 3 Oct 2005 11:59:58 +1300, Ken Taylor wrote:

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.
--
The things that pop into my mind are why AM rather than FM, which tends to
be more local, and do you intend to 'over-broadcast' only the local channels
(how many?) - I assume you intend to make the channel(s) selectable - or the
entire band to ensure you get everyone?

The issue of selective vs full range broadcasting is a matter that has not
been decided either by client, company or possibility. There are plusses
and minus' to each.

Selective would entail less power but we are being told power of the fire
engine is not an issue.

Assuming that there is a commercial
AM broadcast station in the vicinity (what, 10 miles? 20 miles?) you are
probably going to be flat out getting a mobile rig to ride over it. How do
you intend to do this?

Cheers.

Ken

lol Good question, Ken. Any suggestions?
--
Drop the alphabet for email

there is no requirement that anyone listen to any broadcast radio. with the
rapid growth of satellite radio there are even less people listening to
either am of fm broadcast radio. add those who listen to cd's or dvd's and
you get even less.

There are systems that are used for local road emergency notification, the
560khz one comes to mind, something along those lines would be the best bet,
and add in signs on the backs of vehicles. i guess the real question is,
what are you trying to do by overriding local broadcast stations? and over
what size area?


"Ari Silversteinn" wrote in message
...
On Mon, 3 Oct 2005 11:59:58 +1300, Ken Taylor wrote:

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.
--
The things that pop into my mind are why AM rather than FM, which tends
to
be more local, and do you intend to 'over-broadcast' only the local
channels
(how many?) - I assume you intend to make the channel(s) selectable - or
the
entire band to ensure you get everyone?

The issue of selective vs full range broadcasting is a matter that has not
been decided either by client, company or possibility. There are plusses
and minus' to each.

Selective would entail less power but we are being told power of the fire
engine is not an issue.

Assuming that there is a commercial
AM broadcast station in the vicinity (what, 10 miles? 20 miles?) you are
probably going to be flat out getting a mobile rig to ride over it. How
do
you intend to do this?

Cheers.

Ken

lol Good question, Ken. Any suggestions?
--
Drop the alphabet for email

On Mon, 3 Oct 2005 16:20:40 -0000, Dave wrote:

there is no requirement that anyone listen to any broadcast radio. with the
rapid growth of satellite radio there are even less people listening to
either am of fm broadcast radio. add those who listen to cd's or dvd's and
you get even less.

The loss of listenership is not arguable.

There are systems that are used for local road emergency notification, the
560khz one comes to mind, something along those lines would be the best bet,
and add in signs on the backs of vehicles. i guess the real question is,
what are you trying to do by overriding local broadcast stations?

1) to grab those that are listening to AM/FM, it is still a hyooge market,
2) client request, 3) DHS preference 4) the number of people alerted by a
sign/sticker and independent warning channel is much less than both that
and AM/FM, 5) the possibility that once the AM/FM FCC/NAB bond is broken, a
precedent could be set for cell, sat, threading messaging, etc 6) spinoff
tech for local/reg/national emergencies.

and over
what size area?

1 mile radius max from point of incident, less most probably.
--
Drop the alphabet for email

A disadvantage I see is that a waiver is going to be required in order
not to violate FCC rules. In fact, in the state of Florida, interfering
with broadcast stations is against state law, so another hurdle to be
overcome. That being said, for this system to work, you have to blanket
the entire AM and FM broadcast bands. Even doing so will leave out the
motorists who use XM or Sirius, the Ipod listeners and those who are
driving with their cellphones plugged into their ears.



Ari Silversteinn wrote:

Crossposted to:

rec.radio.amateur.antenna,rec.radio.amateur.misc, rec,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.



--
Joe Leikhim K4SAT
"The RFI-EMI-GUY"

The Lost Deep Thoughts By: Jack Handey
Before a mad scientist goes mad, there's probably a time
when he's only partially mad. And this is the time when he's
going to throw his best parties.

On Sun, 02 Oct 2005 23:42:16 GMT, **THE-RFI-EMI-GUY** wrote:

A disadvantage I see is that a waiver is going to be required in order
not to violate FCC rules. In fact, in the state of Florida, interfering
with broadcast stations is against state law, so another hurdle to be
overcome.

Yes, the budget is rich with expected legal expenses. Since DHS has become
a player in this, we are hopeful that we can get the necessary punch to
overcome FCC and statutory issues.

That being said, for this system to work, you have to blanket
the entire AM and FM broadcast bands. Even doing so will leave out the
motorists who use XM or Sirius, the Ipod listeners and those who are
driving with their cellphones plugged into their ears.

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.

--
Drop the alphabet for email

In that case, simply modify the sign to "Tune to 560, it could save your
life" and use a discrete frequency low power transmitter.


"Ari Silversteinn" wrote in message
.. .
On Sun, 02 Oct 2005 23:42:16 GMT, **THE-RFI-EMI-GUY** wrote:

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, 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

"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

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??

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.