Fall 2008 Issue
on the internet, and as you step back to admire your
massive mountaintop X-band system a diamondback rattler sinks its fangs into your left ankle. No cell phone
coverage, so you push the
SPOT satellite transponder “911” button and the rescue begins.
An Emergency Position Indicating Radio Beacon (EPIRB), left, and the orange SPOT distress signaling device side by side on a marine chart.
(Photo by Julian Frost)
If you are into VHF/UHF and microwave roving, there is a new, inexpensive satellite transponder system that might save your life. It will also keep your XYL back at home taking part in your adventure. She can track your progress going up the hills with Google Maps® showing your precise location. I wish this was on ham radio APRS, but no such luck. Nor is this commercial system an EPIRB (Emergency Position Indicating Radio Beacon) or a (PLB) Personal Locator Beacon.
This small satellite transponder, called “SPOT,” is a product of Globalstar USA, a Vodaphone Airtouch Pic company best known for those classic-looking satellite phones that many ham radio emergency responders used during the Katrina crisis along with the reliable ham radio communications gear.
This small orange transponder has plenty going for your safety when you head out on your next VHF/UHF rover expedition. The SPOT device itself sells for under $150, plus there is a basic service charge for a one-year contract that is $99 per year. Add $7.95 to include $100,000 last-resort evacuation service, and add $50 if you regularly go hiking and you want your SPOT unit to automatically update your position every few minutes or miles, independent of cell-phone coverage.
The seven-ounce SPOT portable position sender contains a built-in GPS receiver tied into the L-band transmitter, tuned to commercial Globalstar LEO satellites, 1611 MHz to 1618 MHz, digital code division multiple access (CDMA), running about a quarter watt out. Two lithium-ion AA batteries could allow for 1900 uplinks, or when key-entered into the automatic tracking mode, 14 days of continuous operation.
The orange SPOT satellite transponder floats in water, is waterproof up to 1 meter down for 30 minutes, carries military standard 810 E method 507.3, withstanding 100% condensation, and is shock resistant.
To conserve battery life, the GPS receiver built into the SPOT unit only powers on to retrieve a current position fix needed for a manual or automatic uplink to the chain of 48 LEO (Low Earth Orbit) Globalstar satellites. As long as the satellites have a mutual view of their associated ground Earth stations and the SPOT unit, the position goes onto the internet, along with the status of the SPOT transponder’s operator, such as:
• I’m OK; all is well.
• I could use some help (non-emergency).
• Dispatch emergency responders to this location now.
OK, as a ham operator well versed in satellite communications, you can quickly see that the SPOT device is an L-band one-way transponder, sending latitude and longitude and one of three messages, and has the capability for all this information to stream into the internet.
You can buy a SPOT transponder at your local
West Marine store or at a major camping store. Your registration, to
activate the service, is at: <http://www.
First, select a reliable phone number to
verify any emergency alert. Next, provide up to 10 e-mail addresses for
your friends and family members to receive your messages. You can even
put down cellular, short messaging-service numbers, too. You may change
any of these e-mail address at any time, at no additional cost.
© Copyright 2008, CQ Communications, Inc. All rights reserved. This material may not be reproduced or republished, including posting to a website, in part or in whole, by any means, without the express written permission of the publisher, CQ Communications, Inc. Hyperlinks to this page are permitted.