[aprssig] Hidden tracker with laptop access

[Stephen H. Smith]

Hinton Gary-MCG30554 wrote on 11/30/2004, 2:53 PM:

 > The laptop connector will be placed somewhere on or under the dash.  When
 > I need to display APRS in the car or make configuration changes, I will
 > simply plug in the laptop.  When the laptop is not connected, a plug
 > could
 > be installed that would select between the UHF or VHF radio.
 >
 > Any suggestions on selection of the tracker?

You will need more than a simple tracker if you want to "display APRS in 
the car".  The essence of a tracker is that it is a TRANSMIT-OMLY 
device. If you want the ability to receive as well, you will need a full 
TNC.

You could use a KPC3+ in the standalone tracker mode, and then plug in 
the PC when needed, but the KPC tracker doesn't do smart beaconing and 
doesn't do Mic-E transmit format.

The new AGW pocket-sized USB-interfaced TNC has the ability to operate 
as a stand-alone tracker or digipeater, or act as a full TNC when 
conected to a computer.  It's USB interface would be an advantage for 
newer "legacy-free" laptops with no serial ports. I don't know anything 
whether it can do smart beaconing or Mic-E format however.   More info here:
      http://www.elcom.gr/index.htm

The cheap way to get Mic-E and smart beaconing is with the Byonics 
TinyTrak which has both but is strictly a transmit-only device -- 
connect one end to your GPS serial data output and connect the other end 
to you radio's mic and PTT lines. It also features a power control 
output line which can control a relay to turn on the GPS/radio before 
sending a beacon, and then shut them down again.  A naked board kit (you 
package it) is  about $35.  Details at:
      http://byonics.com


Stephen H. Smith                wa8lmf (at) aol.com

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