At 20:18 10 August 2011, Darryl Ramm wrote:
This should not surprise anybody and I can think of a lot more to be
"highly disturbed" about in life than this. C'mon we really are not
whining about this are we?

You cannot undo the laws of electrodynamics. The compass is going to be
affected by components in the PowerFLARM and by electrical currents.
Cautious advice like this from a vendor is entirely appropriate for a
device that might well get put up on a glareshield near the compass in a
certified (even IFR) aircraft.

Now why is it a worry? How many of us rely on our compasses? To high
accuracy? The manual is just providing a suitable caution and covering
FLARM's ass.

What is actually much more important is the correct installation with
respect to the antennas being free of conductive obstructions/surfaces
as the manual warns. Still I just know we'll stumble across these units
and antennas buried behind panels with owners unsure why they don't work
properly.

Darryl


Who said anyone was "highly disturbed"? I didn't.

Can you cite any other GPS based gliding equipment that requires the GPS
antenna to be installed more than 30cm from any other GPS antenna? I don't
give a rat's arse about the compass but I do care that my other GPS
receivers (currently 3 of them behind or on the panel) continue to work and
there are reports from Uvalde of interference to other GPS based equipment.


Sure FLARM is covering their arse. If there are problems of interference
with other equipment the first question will be "Did you meet the antenna
separation requirements?"

Why would anyone buy a piece of equipment knowing that they could not meet
the installation requirements? Why would anyone build equipment with
strict antenna separation requirements and then make the radiating antenna
non removable thus preventing it's relocation?

PowerFLARM has to work with closer antenna separation that 30cm. If it
cannot, it needs a design change. If it can, the user manual needs to be
revised.

Andy