PowerFLARM updates and installation notes

On Friday, June 1, 2012 3:25:27 PM UTC-7, Matt Herron Jr. wrote:
For a product specifically designed for gliders, the designers don't
seem to have paid much attention to the form factor of either the
brick or the antenna as relates to gliders. Maybe a shorter antenna
with less gain would be better than a long antenna with no place to
install properly. Also (Darryl may correct me on this) a dual antenna
configuration on the brick (not the dipole) will be very directional,
with most of the signal radiating fore an aft of the plane of the
antennas. So be careful how you orient them. I will eventually get
flarm, but this is just another reason to wait until the bugs are
shaken out. Incorrect polarization of the butterfly display is
another one.

Hi Matt

I suspect the Flarm developers have a good understanding of antenna gain and radiation pasterns (remember the more on-axis gain the less off axis gain and Flarm has to optimize all this to detect threats that may be on the horizon or significantly angled below or above the glider) to optimize their product. The lower gain stubby little antenna of a Zaon MRX by comparison only has to receive relatively powerful transponder signals (compared to the flarm-flarm signals) and how PCAS operates means its only really interesting to work at relatively short range whereas the 1090ES data-in capability of the PowerFLARM means you probalby want higher antenna gain PCAS/1090ES antenna than just for a PCAS only device).

I am not sure what you mean by the "dual antenna configuration on the brick". But maybe I can try to see if I can cover that.

Both the PowerFLARM portable and brick units have connectors for Flarm A and Flarm B antennas. The Flarm A antenna transmits an receives flarm messages, the Flarm B antenna only receives flarm messages. The Flarm B antenna is really intended for mounting in a location to give improved reception in directions that would be largely shielded today when using a single Flarm A antenna (ideally located on top of the glareshield). That shielded direction is mostly rearward (and also below the glider), with areas shielded by the pilot's body and carbon fiber fuselage etc. I see a Flarm B antenna mounted in future under or on top of my glider tail boom (on top to potentially avoid being too close to the transponder antenna). In a configuration like this overall signal sensitivity may or may not be that directional. It might be much more isotropic than a single antenna blocked to the rear by a pilots body and carbon fuselage.

The 1090ES/PCAS antenna next to the Flarm A antenna on the PF Portable will result in some directionality of both antennas (weaker signal towards the otehr antenna -- I'd wild guess several 10% signal reduction) but I am sure that is all well understood as a part of many tradeoffs the developers have to live with.

Or am I missing what you meant?

Darryl

On 6/3/2012 6:51 PM, RAS56 wrote:
But c'mon now...for those of us who don't like to spend our time off
upside down in our cockpits chasing wires, fussing with antennas,
seeing if maybe the re-programming took "this" time or wondering if I
just "smoked" my new gizmo in an install error .

But c'mon now ... the stuff you mention, and what I've seen in Dave's
pictures and in person, comes from not following the simple directions
for placement of the portable PowerFlarm, which basically are "put it on
top of the glare shield". There is only one cable (power) - how hard is
that?

My portable PF would not quite fit directly on top of the glare shield,
so I built a simple bracket out of aluminum that holds it just aft of
the glare shield, and 1/2" lower. The PCAS works as well as my Zaon PCAS
did, I get the airliners' ADS-B, and an hour long encounter with another
PF equipped glider convinced me it enough range for collision avoidance
(about 1 NM), about 2 NM of range for "buddy flying" purposes
(intermittent loss of the other glider, but still easy to track), and
about 3 NM range if we within 1000' vertically. He also had a PF mounted
on the top of the glares shield.

I expect all those ranges to improve with ongoing changes; until then,
I'm hoping _everyone_ I thermal with has one, because it was a very
comfortable, stress-free experience compared to the usual neck-craning
and radio chit-chat, trying to keep tabs on each other in thermals and
when flying close to each other.

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to
email me)

On Jun 3, 6:51*pm, RAS56 wrote:
But c'mon now...for those of us who don't like to spend our time off upside down in our cockpits chasing wires, fussing with antennas

RAS56 - Sounds like you're worrying about alot without even
investigating things. You want to keep it simple?

STEP 1: Buy a Portable PowerFLARM
STEP 2: Stick it on top of your glareshield
STEP 3: Make sure the antennas are pointed straight up.
STEP 4: (Optional?) Run a wire from your power-bus/battery to the
PowerFLARM.

How hard is that?

--Noel

"Evan Ludeman" wrote in message
...
On Jun 1, 6:18 pm, RAS56 wrote:

WOW! Who wouldn't want one???

The pilot that hasn't tried one.

-Evan Ludeman / T8


....Or the pilot just faced with a $2,500 expense for a new parachute.

Yeah, yeah... I know... How much is my life worth?

I have eyes and ears, but I don't have wings.

But, to be positive, I've had pilots whith FLARM installed tell me that they
see my Trig TT22 transponder (which I just installed a few months back) on
their screen. That's impressive!

On Jun 4, 1:59*am, "noel.wade" wrote:
On Jun 3, 6:51*pm, RAS56 wrote:

But c'mon now...for those of us who don't like to spend our time off upside down in our cockpits chasing wires, fussing with antennas

RAS56 - Sounds like you're worrying about alot without even
investigating things. *You want to keep it simple?

STEP 1: Buy a Portable PowerFLARM
STEP 2: Stick it on top of your glareshield
STEP 3: Make sure the antennas are pointed straight up.
STEP 4: (Optional?) Run a wire from your power-bus/battery to the
PowerFLARM.

How hard is that?

--Noel

I think most people will find that the brick is an easier, more
cockpit friendly install. I would recommend against buying a portable
unless you are 100% confident that you have a good place to put it.

-Evan Ludeman / T8

The optimum FLARM antenna installation:
http://www.airforce-technology.com/p...2-aircraft.jpg

Sorry, couldn't help myself.


"Darryl Ramm" wrote in message
...
On Friday, June 1, 2012 3:25:27 PM UTC-7, Matt Herron Jr. wrote:
For a product specifically designed for gliders, the designers don't
seem to have paid much attention to the form factor of either the
brick or the antenna as relates to gliders. Maybe a shorter antenna
with less gain would be better than a long antenna with no place to
install properly. Also (Darryl may correct me on this) a dual antenna
configuration on the brick (not the dipole) will be very directional,
with most of the signal radiating fore an aft of the plane of the
antennas. So be careful how you orient them. I will eventually get
flarm, but this is just another reason to wait until the bugs are
shaken out. Incorrect polarization of the butterfly display is
another one.

Hi Matt

I suspect the Flarm developers have a good understanding of antenna gain and
radiation pasterns (remember the more on-axis gain the less off axis gain
and Flarm has to optimize all this to detect threats that may be on the
horizon or significantly angled below or above the glider) to optimize their
product. The lower gain stubby little antenna of a Zaon MRX by comparison
only has to receive relatively powerful transponder signals (compared to the
flarm-flarm signals) and how PCAS operates means its only really interesting
to work at relatively short range whereas the 1090ES data-in capability of
the PowerFLARM means you probalby want higher antenna gain PCAS/1090ES
antenna than just for a PCAS only device).

I am not sure what you mean by the "dual antenna configuration on the
brick". But maybe I can try to see if I can cover that.

Both the PowerFLARM portable and brick units have connectors for Flarm A and
Flarm B antennas. The Flarm A antenna transmits an receives flarm messages,
the Flarm B antenna only receives flarm messages. The Flarm B antenna is
really intended for mounting in a location to give improved reception in
directions that would be largely shielded today when using a single Flarm A
antenna (ideally located on top of the glareshield). That shielded direction
is mostly rearward (and also below the glider), with areas shielded by the
pilot's body and carbon fiber fuselage etc. I see a Flarm B antenna mounted
in future under or on top of my glider tail boom (on top to potentially
avoid being too close to the transponder antenna). In a configuration like
this overall signal sensitivity may or may not be that directional. It might
be much more isotropic than a single antenna blocked to the rear by a pilots
body and carbon fuselage.

The 1090ES/PCAS antenna next to the Flarm A antenna on the PF Portable will
result in some directionality of both antennas (weaker signal towards the
otehr antenna -- I'd wild guess several 10% signal reduction) but I am sure
that is all well understood as a part of many tradeoffs the developers have
to live with.

Or am I missing what you meant?

Darryl

....
.....You want to keep it simple?

STEP 1: Buy a Portable PowerFLARM
STEP 2: Stick it on top of your glareshield
STEP 3: Make sure the antennas are pointed straight up.
STEP 4: (Optional?) Run a wire from your power-bus/battery to the
PowerFLARM.

How hard is that?

--Noel

This (Noel's comment) is what I "planned/hoped" to do in my Genesis.

Interested if there have been any reports of interference between a CAI Model 20 mounted near Portable Flarm(?). My Model 20 is mounted behind instrument pod with antenna ~flush with top. The portable would be about 10" ahead on top of pod (so antenna bases would be ~1" above GPS-20 antenna). Flarm antennas can easily stand vertical.

Any comments appreciated!

Curt - 95

On Jun 3, 1:53*pm, Dave Nadler wrote:
Hi All - I've added more installation info:http://powerflarm.us/powerflarm-installation-notes/

Also, a few pilots have posted notes about their
PowerFLARM experiences (and we encourage you to
do likewise) hehttp://powerflarm.us/2012/05/powerfl...fflin-and-elsw...

Hope you find these helpful,
Best Regards, Dave "YO electric"

Quoting from Dave's website:

Suggestion for Glare-Shields that Jettison with Canopy [i.e.
Schleicher -JC]

Make an antenna mount with a large base shaped to match glare-shield
(hint: lay up a fiberglass base on top of the glare-shield). Cut a
small hole through the glare-shield for the antenna and cable. Fasten
the base of the mount to the underside of the glare-shield with a
small amount of velcro. This makes it easy to remove the canopy/glare-
shield, and safe in a bail-out.

Comment: C'mon Dave. This is supposed to be a consumer product ready
for release to the glider market. And you really are suggesting that
half this market needs to go lay up fiberglass to install it? That's
beyond half-baked.

We really need to see one decent Shleicher install picture!

Again -- the world is full of dipole antennas with physical and
electrical connectors at the base. Why oh why are you not using such
an antenna in this most obvious place for it?

John Cochrane

On Jun 4, 9:46*am, CLewis95 wrote:

This (Noel's comment) is what I "planned/hoped" to do in my Genesis.

Interested if there have been any reports of interference between a CAI Model 20 mounted near Portable Flarm(?). *My Model 20 is mounted behind instrument pod with antenna ~flush with top. *The portable would be about 10" ahead on top of pod (so antenna bases would be ~1" above GPS-20 antenna).. *Flarm antennas can easily stand vertical.

Any comments appreciated!

Curt - 95

Curt,
I have a Model 20 located under the glareshield of my Nimbus 3. It is
less than a foot ahead of and below the portable FLARM mounted on top
of the glare shield. Only time I had a problem was at the end of one
day, when pushing back to the tiedown spot, the FLARM came loose from
it velcro mount and slide to the front of the glareshield. The GPS
location in the Cambridge took a big jump away from Garner Field
(during the Open Nationals last year, at Uvalde). Seemed to have as
good a FLARM reception and transmit as anyone else there.

I also have a flight with the portable installed on top of the panel
on my BS1. Cambridge Model 20 secured to the top of the panel,
probably not more than 2-3 inches between the boxes. No problems with
the Cambrigde log. Not sure of the FLARM performance with that
installation. Couldn't get my antenna vertical and there was only one
other FLARM equipped plane flying, so I need to make a different
mount. Anyone interested in making cables in standard lengths (6 inch
increments, maybe?) to go from the portable to a base mount for the
supplied antenna? Yes, YO, I am working on getting more seperation of
the two.

If the prefered antenna seems to be the dipole with a simple plastic
angle bracket for mounting, are we going to see this become the
standard antenna shipped with FLARM units at some point in the
future? Less m ounting height required than the rubber duckie that
had to be mounted at the top of the portable because of the batter
box. Just a thought.

Steve Leonard
ZS, VJS, KN, PN, and a few others.

On Jun 4, 7:25*am, Evan Ludeman wrote:

I think most people will find that the brick is an easier, more
cockpit friendly install. *I would recommend against buying a portable

Evan - I was specifically responding to RAS56's complaints about
complexity. The Portable is (by definition) a self-contained unit
with no worries about an external display or other wiring.

--Noel