Subject: [NEXTEL-1] Re: FCC Rule Violation? AlertCast system for Police, Fire, EMS overide...

From: "Steven J. Makky, Sr., ENP" <[email-masked]>
Date: Wed, 11 Dec 2002 08:14:07 -0600

Dave Emery wrote:

>         No idea of how one might radiate such an AM signal, but I
>am sure there are tricks...

In the Lincoln and Holland Tunnels, we used Radiax; one "head end," and a 
linear amplifier per tunnel. Seven years ago when I worked there, it was AM 
only, but last week I drove through and it carried FM, as well. The system 
did have instant all channel override and digital message storage/ 
scheduling capabilities originally. The signal was contained to the tunnel 
and had sufficient isolation to be brought down to an IF where preemptive 
messages could be done, then brought back up and rebroadcast on the same 
frequency. The original system required discrete channel cards for each AM 
station intended to be sent into the tunnels.

Not sure how that could be done outside of a contained area. Maybe buried 
or roadside Radiax with fiber distributed signal and amplification/ 
retransmission nodes along the right of way?

Steve
KA2AYR

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