Grommet Mounting Method for PowerFLARM Core Dipole Antennas

One comment and one question:

- Question: It was my understanding that neither pole of the dipole antenna was supposed to come into contact with the glider. I drew that conclusion from the statement in the manual: "The antennas must
not be subjected to physical pressure and may not be bent. Ensure
the antenna does not touch the cockpit windscreen." I would think that touching the instrument shroud is equal to touching the windscreen (canopy), no?

- Comment: In many modern gliders where the shroud needs to depart with the canopy in an emergency, such a mounting doesn't seem feasible. FWIW, my breakaway mounting uses two magnets (one on the stalk holding the dipole antenna and the other one glued to the underside of the shroud). Makes a very clean install (no holes, velcro, glue residue, etc.) and take only a few pounds to break away. No obvious problems with the magnets impacting any RF or GPS signals (at least none I've been able to find).

P3

On Sunday, October 26, 2014 11:27:49 PM UTC-4, Paul Remde wrote:
Hi,

A customer suggested this approach to mounting the PowerFLARM Core ADS�B and
FLARM dipole antennas. It is clever, simple and makes for a clean looking
installation. 3 or 4 simple rubber grommets are used. I found the grommets
at a local hardware store. The grommets have a hole diameter of ¼� and fit
in a 3/8� hole. They seem to hold the antennas quite securely. If I find
that they are not tight enough I’ll put some shrink tubing on the end of the
antenna to make the fit more snug. The installation was very easy. The only
slightly tough part was getting the 2 SMA connectors through the center
grommet (before it was installed). After the first SMA connector was pushed
through the grommet its cable made it more difficult to get the 2nd SMA
connector through. Another approach would be to use a total of 4 grommets so
each cable would go through its own grommet. The PowerFLARM Core’s GPS
antenna is mounted just under the instrument panel cover – on top of a
variometer.

You can see a photo of the final installation and the grommet dimensions and
additional PowerFLARM Tips he
http://www.cumulus-soaring.com/flarm...FLARM-Tips.pdf

What do you think?

Best Regards,

Paul Remde
Cumulus Soaring, Inc.

I believe the issue with having an antenna touch the canopy is more about static electricity build up that could conceivably couple over to the antenna.

Bumper