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.

"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

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.

"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 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

"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

On Mon, 3 Oct 2005 11:28:32 -0400, Ari Silversteinn
wrote:

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.

Hi Ari,

The various pieces of this jigsaw puzzle is beginning to reveal a
picture here. With the introduction of two governmental
organizations, and their regulations, your "plan" has all the
appearances of being suitably crafted to work on paper. It responds
to the individual issues that any squinty-eyed bureaucrat would demand
be satisfied for his postage sized turf, but in the overall it would
fail miserably, or drive costs so high as to be tainted with the plea
that "aren't people's lives worth the price?"

Let's see, the original spec calls for a disaster situation that is
confined to within 1 mile; that demands the local population be
informed; that over-rides their usual paths of communication; that
reaches them even when they are not engaged in listening.

As already pointed out, big sound trucks do wonders, and have worked
well since the beginning of the last century for this purpose. That
kids inside their home can hear the ice-cream truck a mile away is a
testimony to this simplicity.

Knocking on the door of the local broadcasters and commandeering their
air-time has a time honored tradition of working quite well too. This
involves no more time than getting that expensive mobile power plant
rigged with wide band transmitters working into hugely lossy antenna
systems into the same danger area. After-all, you could as easily
call the first most obvious radio station as them, and you could be
calling the others before they even got on the road.

The solution demanded is that all radio stations respond to a disaster
network alert and citizens tune to the Civil Defense frequency when so
warned by them. Is this another administration cut-back that was
shelved as one of those unnecessary "entitlements?" Have they clipped
all the wires to those old Air Raid sirens? When did the lights go
out in FEMA?

73's
Richard Clark, KB7QHC