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ACRO E-mail Archive Thread: [Acro] WOW---from RV list. why EXTRA'S cost so ...


Thread: [Acro] WOW---from RV list. why EXTRA'S cost so ...

Message: [Acro] WOW---from RV list. why EXTRA'S cost so much

Follow-Up To: ACRO Email list (for List Members only)

From: Phil Sisson <sisson at>

Date: Tue, 30 Jul 2002 14:27:05 UTC


> Dan Checkoway wrote:
>> --> RV-List message posted by: "Dan Checkoway" <dan at>
>> In the specs for the UPSAT GX60 IFR GPS/Comm, it says:
>> "Acceleration 4G maximum"
>> Anybody know what the deal is with this?  Is this horizontal
>> )_( Dan

> Dan--
> Obviously, you've never operated a high-energy particle
accelerator!  Ah, the
> memories of Brookehaven and Switzerland at CERN.  Electrons have
mass (let's
> say about 10 GeV (giga electron-volts) and mass is affected by
gravity.  We
> also know that a GPS receiver is nothing more than a VERY sensitive
> Now, then, when you exceed 4 g, the electons get bogged down in the
> receiver and get out just a tad slower--but slow enough to be
detected by the
> GPS clock.  If you're tracking more than four GPS satellites, some
of them
> will be to the West and some of them to the East of you.  The slow
> will make the GPS clock think that you are farther away from the
> satellites and perversely conversely farther away from the easterly
> satellites so that the triangulation calculations in the software
will not
> reconcile.  GPS receivers that are rated for aerobatics have
thicker wires
> and a series of small op-amps that will "accelerate" the electrons
> on the internal g-meter reading (manufacturers call this "g-force
> drift").  This is why airplanes such as the Extra 300 cost so much
more.  You
> also made a major mistake in actually reading one of the manuals
> electronic equipment, since they have to be back-translated from
> character figures--what's the Chinese character for electron-volts?
> Just trying to help.
> Boyd.


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