Powerflarm in a Libelle

Wallace Berry

unread,

Mar 21, 2013, 5:32:42 PM3/21/13

to

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

GM

unread,

Mar 21, 2013, 7:59:17 PM3/21/13

to

On Thursday, March 21, 2013 5:32:42 PM UTC-4, 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

Hi Wally,

have been flying with a PF brick and a panel mounted Butterfly display since last year's Parowan contest. I installed the antennas on either cockpit side wall where the wall-lining stops. That way, they are out of the way and still pretty much vertical. You can't get them apart any further in a Libelle.

Uli 'GM' H301 #14

daver...@gmail.com

unread,

Mar 22, 2013, 12:02:40 AM3/22/13

to

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

Wallace Berry

unread,

Mar 22, 2013, 10:46:45 AM3/22/13

to

In article <d08e1ef5-a7a7-440c...@googlegroups.com>,

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.

All the best,

WB

Martin Gregorie

unread,

Mar 22, 2013, 6:02:43 PM3/22/13

to

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 here:

http://www.gregorie.org/gliding/libelle/FLARM_dipole_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 |

Ramy

unread,

Mar 25, 2013, 4:13:07 PM3/25/13

to

I am getting similar results with my powerlfarm antennas installed in the nose of my 27a. IMHO the nose of the glider, if carbon free and far enough from the rudder pedals is probably the best place to put your antennas. I wouldnt worry too much about them being a bit tilted and a bit closer than the recommended distance. The most important is that they will have pretty much unobstructed half sphere view of the area in front of you which is where your threat will most likely be. An added benefit will be not to have to stare at antennas sticking out from the glare shield.

Ramy

uncl...@ix.netcom.com

unread,

Mar 25, 2013, 5:40:12 PM3/25/13

to

On Monday, March 25, 2013 4:13:07 PM UTC-4, Ramy wrote:
> On Friday, March 22, 2013 3:02:43 PM UTC-7, Martin Gregorie wrote: > On Fri, 22 Mar 2013 09:46:45 -0500, Wallace Berry wrote: > > > > > In article <d08e1ef5-a7a7-440c...@googlegroups.com>, > > > daver...@gmail.com 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 here: > > > > http://www.gregorie.org/gliding/libelle/FLARM_dipole_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 | I am getting similar results with my powerlfarm antennas installed in the nose of my 27a. IMHO the nose of the glider, if carbon free and far enough from the rudder pedals is probably the best place to put your antennas. I wouldnt worry too much about them being a bit tilted and a bit closer than the recommended distance. The most important is that they will have pretty much unobstructed half sphere view of the area in front of you which is where your threat will most likely be. An added benefit will be not to have to stare at antennas sticking out from the glare shield. Ramy

I'm not so sure I agree Ramy. I'm not so worried about who I"m going to hit as who is going to hit me.
Given this point of view, I prefer the PF antenna up on the glare shield where it sees "mostly" all around.
UH

Ramy

unread,

Mar 25, 2013, 8:16:00 PM3/25/13

to

Good point, but the main difference is the coverage behind, and since the closing speed from traffic behind you (assuming glider) is significantly lower than from the front or side, and as such reducing to coverage to one mile from behind should be plenty.

Ramy

Martin Gregorie

unread,

Mar 25, 2013, 8:35:43 PM3/25/13

to

On Mon, 25 Mar 2013 14:40:12 -0700, unclhank wrote:

> I'm not so sure I agree Ramy. I'm not so worried about who I"m going to
> hit as who is going to hit me. Given this point of view, I prefer the PF
> antenna up on the glare shield where it sees "mostly" all around.
>

Agreed, but remember the OP asked about installation in a Libelle, where
the equivalent to mounting the antennae "up on the glare shield" would
involve poking them up through holes in the nose that you'd drilled in
front of the canopy. Remember that the face of the panel is forward of
the canopy rim and locking mechanism.

uncl...@ix.netcom.com

unread,

Mar 26, 2013, 9:22:55 AM3/26/13

to

On Monday, March 25, 2013 8:35:43 PM UTC-4, Martin Gregorie wrote:
> On Mon, 25 Mar 2013 14:40:12 -0700, unclhank wrote: > I'm not so sure I agree Ramy. I'm not so worried about who I"m going to > hit as who is going to hit me. Given this point of view, I prefer the PF > antenna up on the glare shield where it sees "mostly" all around. > Agreed, but remember the OP asked about installation in a Libelle, where the equivalent to mounting the antennae "up on the glare shield" would involve poking them up through holes in the nose that you'd drilled in front of the canopy. Remember that the face of the panel is forward of the canopy rim and locking mechanism. -- martin@ | Martin Gregorie gregorie. | Essex, UK org |

Understood.
I was simple pointing out that there is a real benefit, in my view to trying to get a complete a field of view for the antennas as possible.
The idea of putting the antennas on the side walls in the Libelle seems like a good one,given available options.
UH

bumper

unread,

Mar 27, 2013, 12:01:25 PM3/27/13

to

Not sure about the Libelle, but on many gliders with the Flarm antennas mounted favoring forward looking, one can install a Flarm B (recieve only) antenna in a more aft looking position.

bumper

Roger Fowler

unread,

May 18, 2013, 6:52:07 AM5/18/13

to

I put mine in the oxygen bottle holder behind the cockpit. Haven't been in
the air with another PF equipped glider yet, though.

Roger

Darryl Ramm

unread,

May 18, 2013, 9:41:58 PM5/18/13

to

On Saturday, May 18, 2013 3:52:07 AM UTC-7, Roger Fowler wrote:
> I put mine in the oxygen bottle holder behind the cockpit. Haven't been in
>
> the air with another PF equipped glider yet, though.
>
>
>
> Roger

And where are the antenna(s)?

Darryl