From: woods@glas.rtsg.mot.COM (Simon Woodworth)
Newsgroups: rec.radio.amateur.misc
Subject: Sony PYXIS GPS receiver?
Date: 13 Oct 1992 02:28:32 -0700
Organization: UCSD Usenet Gateway
NNTP-Posting-Host: ucsd.edu

Hi,
   As promised, a quick round-up of all the portable GPS units
reviewed in September's Yachting World. This information is rep-
roduced without their permission.

Sony Pyxis IPS-360:
4 channels, auto fix only, water resistant, no NMEA interface, 99
waypoints, dist/bearing to wp, speed, ETA at wp, XTE, track plot-
ter, lock-on time 157 sec, battery life 20 MINUTES, price ST#725.
Case seems flimsy and fiddly. Useless without COG and SOG in my
personal opinion (as distinct from Yachting World's).

Magellan NAV5000
5 channels, auto/2D/3D fix, waterproof, NMEA 0180/3, 100 way-
points, dist/bearing to wp, SOG and COG, ETA at WP, XTE, VMG,
TTG, lock-on time 206 sec, batter life 1-2 hours, price ST#939.
Very robust. Allegedly floats if dropped in water.

Garmin GPS50
1 channel multiplexed to 8 sats, auto fix only, waterproof, NMEA
0810/2/3, 250 waypoints, d/b to wp, XTE, VMG and CMG to wp, ETA
to wp, lock-on time 215 sec, cost ST#801.
Loads of extra features.

Trimble Ensign
3 channel, tracks 8 sats, auto/2D/3D fix, waterproof, no NMEA,
999 wp, SOG, COG, VMG, ETA, XTE dist/head, lock-on time 206sec,
cost ST#695.
Very neat compact case. Apparently very power efficient.

Trimble TransPak II
6 channel, auto/2D/3D fix, waterproof, no NMEA, 999 wp, SOG, COG,
d/b to wp, XTE, VMG, loc-on time 206 sec, cost ST#1095.
As used in Gulf War. Virtually indestructible. Rotary/toggle con-
trols as distinct from buttons.

General notes (mine, not Yachting World's)
SOG=Speed Over Ground, COG=Course Over Ground, XTE=Cross Track
Error, VMG=Voyage(??) Made Good, CMG=Course(??) Made Good. COG
and SOG essential in my opinion. Garmin, Sony and Ensign units
have XTE graph which you can steer by. Magellan, Sony and Trans-
pacs generally accurate to within 100m or better. Garmin almost
as good but ver occasionally plots outside 100m. Approx 30% of
Ensign's plots are outside 100m circle around target.
   All units bar Sony have an integrated antenna. The Sony GPS
has a removable gimbal-mounted antenna.
   The five-sided funny farm in their wisdom have deliberately
REDUCED the accuracy of GPS since the Gulf War, so the limiting
factor in getting a good fix is the signal from the satellites as
against the accuracy of the receiver in many cases. My personal
opinion would be not to trust ANY unit as being accurate to less
than 100m.
   So there you go. Take your pick. I am not endorsing any part-
icular product but I think this review bears out previous posts
as regards negative feelings on the Sony and favourable comments
on the Ensign, Magellan and Garmin units. I have not used any of
these units (my only experience is with a Raytheon GPS) so feel
free to take my comments with a pinch of salt if you like.
   Cheers,
   Simon Woodworth.

=================================================================
Simon Woodworth.                |  woods@glas.rtsg.mot.com
Motorola (Ireland) Ltd.,        |  Don't blame my employers
Cork, Ireland.                  |  for anything I say! :-)
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"No matter where you go, there you are!"
- USS Excelsior bridge dedication plaque.
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