[NLRS] Rovers & GPS

[John P. Toscano]

W0ZQ@aol.com wrote:

> OK rovers, what GPS system(s) are you using ?   Do they provide a six digit 
> Maidenhead location ?  What is the cost ?   Do you have recommendations ? 

I started with a Delorme Earthmate, a flat rectangular box with a cable 
on the end, no display at all.  So what it provides is completely a 
function of what computer software is plugged into the end of the serial 
cable.  Works pretty well on the dash of my van, but I agree with Donn 
that an external antenna would be better.  This unit won't accept one. 
It sucks batteries pretty fast, and I swear that sometimes it drains 
them even when I use the special serial adapter that supplies the GPS 
with power from either a cigarette lighter plug or by stealing DC from 
you laptop's PS/2 (mouse/keyboard) port.  Map storage is ZERO in the 
unit, as is waypoint / track storage.  Of course, all those features can 
be provided by the software running on whatever is plugged into it.  The 
Delorme TopoUSA DVD ROM holds the entire USA on one disc in excellent 
detail, and the software works quite nicely with this GPS (and others 
too, I must add).  However, it uses a non-NMEA data format, so some 
software (especially freeware) may not be able to interface to it.
This unit is also discontinued in favor of their new USB version, which 
uses a new chip set for the GPS engine that is supposed to give 
noticeably better performance.  I have no experience with such, however.
It lists for $99, however you'll need to invest some more money if you 
have no compatible software to read it with.  And obviously, it is 
worthless unless plugged into SOMETHING.  (Some programs for the Palm 
handheld work with it, and some don't, but that's about as small as you 
can go with this GPS.)

http://www.delorme.com/earthmate/

I bought a Garmin eTrex Vista around the time of last year's 10 GHz 
contest.  Nice, small, has a base map of the whole USA and 24 Mb of RAM 
for accepting additional map data from CD-ROM.  It has WAAS for higher 
precision position location, but I have never managed to capture a 
usable signal from the one or two WAAS birds that are up in the sky now, 
so that's a feature for the future I guess.  It's waterproof, has a 
built-in barometer and compass that operate even when the GPS receiver 
is turned off or not available due to poor satellite signal or too slow 
of a velocity for a heading.  The compass came in real handy during my 
last ill-fated Rover outing, so I could re-calibrate my antenna position 
each time I parked.  Has a phenomoninal number of options for the 
display (including 6-digit Maidenhead grid squares), the earth model, 
and a whole lot more.  (The current firmware even includes an option to 
help you plan and execute a parachute jump!)  Free firmware upgrades 
from the Garmin web site.  Map CD's are not as cheap as I'd like, but 
that's partly distorted by my prior investments in Topo USA and 3D 
TopoQuads etc. from Delorme.  And bummer of bummers, no way to connect 
an external antenna.  This one is a bit more of a challenge to use in my 
vehicle, since it needs to be "standing up" so you can read the screen. 
  And 24 MB is not enough RAM to hold all the maps of the NLRS Service 
Area, for example, so I can't fit "everywhere I might go roving" at 
once.  But, as mentioned, there is a low resolution basemap of the whole 
country, so I wouldn't get badly lost using only it for navigation.

http://www.garmin.com/products/etrex/

$349.99 at Best Buy today, minus a $50 rebate good until 07/06/03.  Lots 
of other dealers, and therefore probably lots of other prices.

Recommendations:  From the other postings, it sounds like some of the 
other Garmin models would be easier to view while roving, and do a 
better all-round job with one unit.  But I am pretty happy with my pair 
-- the Earthmate on the dashboard, my laptop next to me with its large 
color LCD display, and 3D TopoQuads or TopoUSA running is great for use 
while in motion, and the eTrex is great for a handheld unit to carry 
around, take position readings, check bearings, hiking, etc.  I wish 
BOTH of them had an antenna port, however!  (I even have a GPS active 
antenna for another project, but that's a whole 'nother story.)

Good hunting.
W�JT