Tacos Digest, Vol 33, Issue 22

[Michael Chisena]

Ian,
  No secret, just different.
   
  Lojack base stations send out a paging signal when it's time to trip a vehicle alarm. I don't know the exact format.
   
  When the vehicle transmitter kicks on it sends an ANI (Automatic Number Identifier) burst chirp.
   
  That chirp is decoded by the Lojack receiver in the police car and it's displayed as a four digit number, that way the cops lookign for the suspect car can follow chirps for a spicific one.
   
  Lojack tied a number of off the shelf gizmos into a fairly neat package.
   
  Later dude
  Mike in Kuwait
  

tacos-request at amrad.org wrote:
  Send Tacos mailing list submissions to
tacos at amrad.org

To subscribe or unsubscribe via the World Wide Web, visit
http://www.amrad.org/mailman/listinfo/tacos
or, via email, send a message with subject or body 'help' to
tacos-request at amrad.org

You can reach the person managing the list at
tacos-owner at amrad.org

When replying, please edit your Subject line so it is more specific
than "Re: Contents of Tacos digest..."


Today's Topics:

1. Off Topic: Lojack (Iain McFadyen)


----------------------------------------------------------------------

Message: 1
Date: Wed, 23 Nov 2005 15:00:09 -0800 (PST)
From: Iain McFadyen 
Subject: Off Topic: Lojack
To: tacos at amrad.org
Message-ID: <20051123230009.85887.qmail at web61120.mail.yahoo.com>
Content-Type: text/plain; charset=iso-8859-1

Does anyone on the mailing list have any technical detail on the modulation
scheme for the LoJack vehicle recovery system in use on 173.075MHz? (In USA).

Though the frequency allocation is public knowledge, it appears that the
modulation scheme is a closely guarded secret.

There is currently a report of a stolen BMW 4-door vehicle in the Springfield
VA area, and I'm hearing occasional squawks of data on 173.075 at 60+dB over
S9, here in McLean.

I trust everyone will enjoy a happy Thanksgiving, whichever country you might
find yourselves in...

Iain McFadyen KI4HLV




__________________________________ 
Yahoo! Mail - PC Magazine Editors' Choice 2005 
http://mail.yahoo.com


------------------------------

_______________________________________________
Tacos mailing list
Tacos at amrad.org
http://www.amrad.org/mailman/listinfo/tacos


End of Tacos Digest, Vol 33, Issue 22
*************************************
  



"You are, what you do, when it counts"
The Masso
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://amrad.org/pipermail/tacos/attachments/20051124/0427c159/attachment.html