From mujibur.inmind.com!martin Tue Feb  6 10:53:46 1996
Path: mujibur.inmind.com!martin
From: martin@inmind.com (Bob Martin)
Newsgroups: sci.geo.satellite-nav
Subject: Re: Eagle, Trimble, or Garmin?
Date: 6 Feb 1996 15:02:27 GMT
Organization: In Mind, Inc.
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   Bob CAN be more informative.  Tim is right, I have possession of a LOT
of GPS receivers, it's a job thing.  As long as someone else will pay for
them, I will play with them.  

    The low end of performance is a scanning receiver, it requires some
effort to lock unless the whole sky is just outright visible.

    The high end is multiple parallel receivers..  They come in 3, 5, 6, 10,
and now from Garmin, 12 channels.   The penalty is that you have to feed
batteries to more receivers...

    My accumulated experience ( I HAVE a lab notebook, but this is pure
subjective babbling) indicates that the most likely to lock and stay locked
radio that John Doe can buy in the boat store is the Eagle Accunav. It
cantains a Rockwell engine.  Rockwell knows some stuff about GPS, both ends
of it.  Other consumer units may also use Rockwell, and the PCMCIA card
version may behave identically.

    Anecdotaly, last night I dropped the Eagle on the desk after coming
home and forgot it..   It had maintained lock lying on the car seat for the
past half hour but had lost it when I stuffed it in my coat pocket and
came inside.  After a few minutes the wifemate informed me that my "thing"
was beeping for me, and I should pay attention to it..  Sure enough, it had
locked on 4 sats lying on the desk with the antenna closed.... There is
still 12 inches of snow on the roof.  The old G45, which I sold, would not
lock indoors ever.   It was bought as a group grab of 4,  they are all
alike, mine wasn't BROKE.  (maybe all 4 were)

    The Eagle is a battery HOG... it also doesn't speak UTM but not every
actually cares... (contrary to some posting that indicate the lack of UTM
constitutes grounds to totally ignore it)  I use a pack of D-Cell NICADS
plugged in the external power (standard off the shelf connector) socket.

    The Eagle software is antiquated, features do NOT abound, but it is
very useful and easier in some respects to use than G45.  More keys are
better than less keys... eapecially when intering names and nimbers...
the STEER, PLOT, ZOOM IN/OUT and ceratin other oft used functins are
very easy.  Route management isn't.  Also, passing a waypoint and not
actually going within the currently set radius causes n emergency route
management button pressing frenzy, because you have to RESTART the route
at the waypoint folowing the one you just missed...  This in spite of
the fact that the NMEA messages report passing the perpendicular. A
serious oversight IMHO.  

    For serious money making work stuff, I use Trimble SV6CM3 boards and
their nice FOG antennae. That 6 channel board also works great, but TSIP
is is rats nest, and Trimble's C code (supplied) is "Early Borlund" at
best.  At least they fully document their protocol... Garmin not only
keeps theirs secret, but isn't better than marginally polite refusing
inquiries about it..  I wonder what it is they imagine I would do if I
knew EVERY detail... rush out and buy some Rockwells I suppose. Oh well..

    I have made three calls to Lowrance customer service.... I would hope
that my own company's response were as polite and informative.

   Bob, is that enough yet ??