On Sat, 31 Oct 2015 15:28:07 -0700, bensoaring wrote:

On Saturday, October 31, 2015 at 4:21:12 PM UTC-4,
wrote:
Well, this is an old discussion.
I already published my home built bottom fed Flarm (and ADSB) dipole
antennas 2 years ago.
https://sites.google.com/site/threeu...rm/powerflarm-
antennas
By now, my antennas are painted black.

Thanks 3U for contributing. Yes I'm familiar with your work and
website. I wish you would expand your article to include "how to"
details so DIY guys like me could fabricate their own antennas.

Regarding PowerFLARM antenna A, what amount of signal degradation would
be experienced if there were two "A" antennas by means of some sort of
splitter?

A thought: you can pick up nylon-covered steel trace (1.3mm OD, the steel
trace is 1.0mm diameter from eBay (10m for $8.95) and good fishing shops
also stock it. Crimp the end over and add a blob of epoxy for eye
protection and there's a very thin antenna. On a glare shield one of
these would be almost invisible. The older Swiss FLARMs, used antennae
which were just a 1/4 wave length of what looked like 0.8mm (1/32") music
wire mounted at the centre of a circular 80mm diameter metal ground
plane.

The fox-hunting crowd, i.e. orienteers who run XC in search of a hidden
radio beacon) make Yagi DF antennae from steel tape-measures and plastic
plumbing pipe which seem to work pretty well, so would this nylon-coated
steel trace be any good for making up PowerFLARM dipoles or bottom-fed
antennae?

I'd be interested to hear what somebody who understands antennae thinks
about using this stuff or even thinner trace material: it is available
down to 20 lb breaking strain.


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