"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

On 2005-10-02, Ari Silversteinn wrote:
This would be an "overbroadcast" (my term)
in that it would override local AM radio broadcasting to reach into cars,

My experience with AM (on the aircraft band) is that two transmitters
at the same time yields a horrible squeal and nothing else. The louder
station (usually on the ground with hundreds of watts) has no particular
advantage over the other station (usually in the air with 5-10 watts).
In other words, there is no effect like FM capture.

--
Ben Jackson

http://www.ben.com/

On Mon, 03 Oct 2005 13:37:49 -0500, Ben Jackson wrote:

On 2005-10-02, Ari Silversteinn wrote:
This would be an "overbroadcast" (my term)
in that it would override local AM radio broadcasting to reach into cars,

My experience with AM (on the aircraft band) is that two transmitters
at the same time yields a horrible squeal and nothing else. The louder
station (usually on the ground with hundreds of watts) has no particular
advantage over the other station (usually in the air with 5-10 watts).
In other words, there is no effect like FM capture.

Are you saying that if I am attempting an overbroadcast on, say, 680 AM and
the station is doing the same, and I am 12 db + greater, that all we will
get is squeal?
--
Drop the alphabet for email

Ari Silversteinn wrote:
Are you saying that if I am attempting an overbroadcast on, say, 680 AM and
the station is doing the same, and I am 12 db + greater, that all we will
get is squeal?

One signal is the Beat Frequency Oscillator. I am amazed
that no one has thought of this perfect solution before.

If Morse code were required for all driver's licenses, then
all you have to do is furnish a CW carrier wave. The two
signals would mix and the squeal would be Morse code which
would carry the emergency information.
--
73, Cecil, http://www.qsl.net/w5dxp

On Mon, 03 Oct 2005 20:53:17 GMT, Cecil Moore wrote:

Ari Silversteinn wrote:
Are you saying that if I am attempting an overbroadcast on, say, 680 AM and
the station is doing the same, and I am 12 db + greater, that all we will
get is squeal?

One signal is the Beat Frequency Oscillator. I am amazed
that no one has thought of this perfect solution before.

If Morse code were required for all driver's licenses, then
all you have to do is furnish a CW carrier wave. The two
signals would mix and the squeal would be Morse code which
would carry the emergency information.

What if your fat as a whale and your DL is wedged up your crack in your
back pocket?
--
Drop the alphabet for email

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

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