On Fri, 22 Mar 2013 09:46:45 -0500, Wallace Berry wrote:

In article ,
wrote:

On Thursday, March 21, 2013 2:32:42 PM UTC-7, WB wrote:
I am curious about Flarm installation in Libelles. I can see that I
will

have to install one at some point. Either a rental or bite the
bullet

and buy one. Where do you Libelle drivers mount the antennas?



Thanks



WB

H301 #19

Wally,
I put mine on an acrylic angle cantilevered off the front of the
instrument tray. With the libelle it's cramped and dark in there.
I'll have to see how folks receive me once the season gets going.

Regards, OD

Thanks, Dave, Uli,

Great suggestions. I was thinking along Dave's lines, since that I what
I initially did with the antenna on my pcas unit. I like Uli's idea
since it gets the antennas well apart.

I use a standard RedBox FLARM in a Libelle, rather than a Power FLARM,
but hopefully this will be a useful starting point.

I am using the optional dipole antenna mounted on a non-conductive
assembly I made from a section of fibreglass fishing rod and a moveable
wooden block using nylon screws to lock it onto the rod section and to
hold the dipole in place. This projects roughly horizontally forward from
the front of the instrument tray so the dipole is as high up as possible
inside the nose and roughly half-way between the front of the tray and
the rudder pedals. This is my version of a mount design I got from
Thorsten Mauritsen, a Danish Libelle driver. Details and the rationale
behind this set-up are he

http://www.gregorie.org/gliding/libe...ole_mount.html


I've checked the coverage using the FLARM tool at:

http://www.flarm.com/support/analyze/index_en.html

A little experimentation showed that the fore and aft placement is quite
critical: moving the antenna even 6mm (1/4") makes a noticeable
difference. The analyser shows my coverage is approximately 6km round an
arc that extends +/- 120 degrees from straight ahead. Behind that, the
coverage forms a roughly straight line between these points and with a
worst case range of 2km directly behind me. Even the worst case is twice
the recommended minimum for speeds of up to 200 km/h (110 kts).


--
martin@ | Martin Gregorie
gregorie. | Essex, UK
org |