Re: Unhappy with DeLorme USB GPS

On Fri, 17 Oct 2003 22:45:45 -0700, "Walker" <[EMAIL PROTECTED]>
wrote:

>I just got a new DeLorme USB GPS receiver and tested it today. I am not
>impressed. DeLorme claims that it has superior signal receiving capability
>but it sure didn't show it today. It takes forever to find satellites and
>even when it had 6 or 7 in view, with decent signal strength, it went into
>the 'yellow' or 2D mode several times. That didn't effect the display map,
>other than change colors, but it makes me wonder about what it will do in
>close spaces such as a canyon or a forest canopy. My Garmin 12Map isn't
>great under those conditions but it's still effective. I had it on the dash
>within inches of where the external antenna for my Garmin sits. It had an
>unobstructed view of the sky through the windshield. I was at a gas station
>and it lost all of the satellites and went into the red while under the edge
>of the canopy. That has never been an issue with the Garmin.
>
>I'll pack the Garmin along for backup but I'm going to give this a good try
>before putting it away. It's very convenient and I want it to work. I'm
>definitely not a novice but I've never used a 'mouse' receiver and maybe I'm
>missing something or doing something wrong. I'll gladly trade the
>inconvenience of setting up the Garmin for the reliability if it comes down
>to a choice.
>
>Is it possible that the lower power from the USB port affects the signal
>amplification? Does using the optional 'power pack' make a difference? Does
>the speed of the laptop have any bearing?
>
>Bob Walker
>[EMAIL PROTECTED]
>

This is a bit dated but I ran across your message in archives and
thought I'd put in my two bits worth.
Won't go into the specifics unless you're interested, but I found that
the usb Earthmate was given more signal sensitivity like they
advertise, but at the cost of being less able to handle interferance.
Newer high powered laptops love to leak rf at the frequencies that jam
gps. You either need to move the receiver much further away from the
computer ( I couldn't get far enough away from inside the cab of a
pickup ) or use a slower computer. For instance, my newer Thinkpad
runs at 1.2 ghz and the Earthmate won't work unless I leave it outside
on the roof of the truck. My older Thinkpad runs at 233 mhz and the
Earthmate does everything they advertise it can do, even sitting on
top of the computer.

Unfortunately, the Delorme software won't run on that machine because
it's such a resource hog. I got around it by putting the Earthmate on
a 10ft usb extension cord and tossing it in the back of the truck
where the walls shield it from the computer, then tossing the usb
earthmate in the junk drawer where it belongs when I got home. The
older serial port Earthmate works fine on the dash and the slightly
lower accuracy isn't a problem since the Delorme maps are between
400-1000 feet off for most of this area anyway.