PowerFLARM antenna mounts

On Jul 5, 8:49*am, JohnDeRosa wrote:
Googling "PowerFlarm antenna" I see both two antenna (thin or thick)
and single antenna installations.
But I still don't get the 3-4" hole. *Expiring minds want to know.

And then this rather interesting picture of a PowerFlarm "Perfect"
antenna location as mentioned by Craggy Aero. *;-)

http://www.google.com/imgres?hl=en&b...=isch&tbnid=UD...

Thanks, John

Because the glareshield jettsons with the canopy, and the whole mess
has to stay with the glider, not the canopy. If you feed it through
two holes, you've just permanently attached the canopy to the glider.
This is a BIG no-no. If you can't jettison the canopy, you can't get
out of the glider. This has happened, with pda cables holding the
canopy to the glider.

I understand from Dave Nadler that Flarm has tried lots of the
interesting antenna suggestions from this forum, including the rather
obvious idea of bottom-fed and bottom-mounted dipoles, and found they
don't work well enough. Given that fact, roll your own without
extensive testing is probably not a good idea. (Dave: A list of "here
are the antennas we tried that don't work" might be useful here.) That
also suggests that we not hold our breaths for more aesthetically
pleasing antennas any time soon, but perhaps Dave would rather comment
on that possibility.

John Cochrane

As Dave Nadler says, a vertical antenna "disappears". when focused at infinity - as long as you have two eyeballs and the antenna is dark colored, the brain doesn't pay any attention to it.

As to making the antenna out of very thin wire; from my Nave ET days, a thin antenna element has a more narrow bandwidth. Since flarm uses a frequency hopping protocol (I think from 885 to 915 Mhz), thin may not work very well.

Like Rex Mayes (Williams Soaring), I made the mount for my PF as a shelf that sits just aft and slightly below the glareshield. Power lead goes through a small hole in the top of the glareshield, then through a male to female in-line coaxial plug connector (Amazon - 5.5mm X 2.1mm, commonly used for CCTV) to allow clean canopy jettison. If the canopy goes away it takes the PF with it.

bumper

On Jul 5, 12:07*am, Ramy wrote:
On Wednesday, July 4, 2012 8:42:39 PM UTC-7, Dave Nadler wrote:
On Wednesday, July 4, 2012 12:16:38 PM UTC-7, (unknown) wrote:
Having a glare-shield mounted antenna is like sitting behind a support column at a basketball game.

Complete Nonsense. The antenna and any decent
mount are thin, and you won't notice them after
5 minutes. The angle blocked is only slightly
more than your yaw string.

Are you going to remove your yaw string too ?

Really now.

No doubt PowerFlarm USA can come up with more aesthetic antenna and solutions.
I will have to compromise meanwhile, but am expecting a better solution will followup shortly once they start shipping and have more time.
The pictures I saw so far hurt my eyes...

Ramy (who is eagerly waiting for his brick unit)

I guess I am not sure what you are seeing that is so ugly?


Here is what I see from my cockpit:

https://plus.google.com/photos/10893...22263754238914

I only see about one inch of the PowerFLARM antenna over my compass.

I have flown two nationals with the Brick now. I see aircraft up to
11 miles and could not imagine flying a contest without it. I had a
head on at my altitude alert with a closing speed of over 250 mph at
Parowan with W3. I would have never seen the other glider with the
light angle and speeds we were flying.

The common statement among pilots with PowerFLARM was "I can't believe
anyone would fly without PowerFLARM".

Tim (TT)

The original post describes how the antenna assembly is attached to the glare shield with velcro. Presumably from underneath with just enough velcro to get the job done, but not impede the jettison process. Knowing the quality of fabrication that Rex and the team does at Williams, I suspect this will be a nice solution for those of us with Schleichers. I'll be ordering one.


On Thursday, July 5, 2012 6:40:47 AM UTC-7, JohnDeRosa wrote:
On Jul 4, 10:50*am, Dave Nadler wrote:

Rex is looking into making glare-shield antenna mounts
for the PowerFLARM dipole antenna, especially for
gliders with glare-shields that jettison with the
canopy (Schleicher, LS).

If the proposed alternative glare screen antenna mount comes to
fruition, doesn't the coax between the unit and the antenna cause an
impediment to the jettisoning of the canopy? Or is there a breakaway
connection of some sort?

You'll cut a ~ 3-4" round hole in the glare-shield,
afix the velcro, then stick on the antenna so it
is vertical in flight attitude (with coax at
about 45 degrees away from the antenna).

Out of curiosity, why such a large 3-4" hole? Is that so both
antennas can stick through a single hole? Could you not drill two
smaller holes at the correct spacing? Or do the pictures of the
PowerFlarm I find at your site (which shows two small diameter
antennas) differ from reality and we are now only have one antenna?
Just don't want someone to needlessly emasculate their glare screen!

Thanks, John

The common statement among pilots with PowerFLARM was "I can't believe
anyone would fly without PowerFLARM".

Agree...no arguments. My point is anything protruding into the available plexiglass field-of-vision is not desirable and IMO not acceptable. Example: there appears to be three objects above TT's glare shield base; in a "perfect storm", an aircraft could easily "hide" in the shadow of TT's compass. Splitting hairs? Maybe...but all it takes is missing one thermaling bird or a glint off a wing to change your day from outstanding to average or to DNF or to (God forbid) even worse.

Respected manufactures, please do not recommend application of your products into one's field-of-vision.

On Thursday, July 5, 2012 4:34:34 PM UTC-7, (unknown) wrote:
The common statement among pilots with PowerFLARM was "I can't believe
anyone would fly without PowerFLARM".

Agree...no arguments. My point is anything protruding into the available plexiglass field-of-vision is not desirable and IMO not acceptable. Example: there appears to be three objects above TT's glare shield base; in a "perfect storm", an aircraft could easily "hide" in the shadow of TT's compass. Splitting hairs? Maybe...but all it takes is missing one thermaling bird or a glint off a wing to change your day from outstanding to average or to DNF or to (God forbid) even worse.

Respected manufactures, please do not recommend application of your products into one's field-of-vision.

"not acceptable" is very subjective and certainly an antenna installed up on the glareshield in return for the benefits of PowerFLARM is more than acceptable to me.

To get reliable, range and operation from PowerFLARM we need to get suitable antennas up high with good line of sight especially forward. They just cannot be buried below typical glareshields, etc. or in many of the other things that show up in the hall of shame. Please lets focusing on getting proper/high quality PowerFLARM installs and less on making a big thing out of something that is not.

Darryl

The human eye focuses at "infinity" from a around three meters on out. I don't think I can get a PowerFlarm antenna that far away from me unless I'm looking at it from the back of a tandem two seater. I mounted a mock up of the portable and its antennas on the glare shield of my ASW-15 and found it very distracting and obstructive (my compass is in the panel and my yaw string is only an inch and a half long and is mounted far forward on the canopy so only the string itself is visible when seated in the glider).

A friend of mine has been trying to purchase a portable for over a month but the dealer told him he wasn't shipping them because he was waiting for a(nother) fix from the manufacturer before selling any. He hasn't been able to get any updates on the situation since the initial contact.

I'm waiting until the brick is out and has gone through several revisions. I don't like the idea of being a retail customer and performing the duties of a beta tester. Whenever I get the brick I'm going to have to either ditch my mechanical vario so I can install the 57mm display or get a new electric vario/computer which can show the Flarm data on its primary display because there's no room left on the panel.

One question I have is if the range is seriously decreased by mounting the antenna at an angle, does banking the glider also result in reduced range?

On Friday, July 6, 2012 2:43:49 AM UTC-7, (unknown) wrote:
The human eye focuses at "infinity" from a around three meters on out. I don't think I can get a PowerFlarm antenna that far away from me unless I'm looking at it from the back of a tandem two seater. I mounted a mock up of the portable and its antennas on the glare shield of my ASW-15 and found it very distracting and obstructive (my compass is in the panel and my yaw string is only an inch and a half long and is mounted far forward on the canopy so only the string itself is visible when seated in the glider).

A friend of mine has been trying to purchase a portable for over a month but the dealer told him he wasn't shipping them because he was waiting for a(nother) fix from the manufacturer before selling any. He hasn't been able to get any updates on the situation since the initial contact.

I'm waiting until the brick is out and has gone through several revisions.. I don't like the idea of being a retail customer and performing the duties of a beta tester. Whenever I get the brick I'm going to have to either ditch my mechanical vario so I can install the 57mm display or get a new electric vario/computer which can show the Flarm data on its primary display because there's no room left on the panel.

One question I have is if the range is seriously decreased by mounting the antenna at an angle, does banking the glider also result in reduced range?

Why do you want to focus on the antenna? You are not supposed to be staring at it. Not focusing on it will (with the help of stereo vision) help it disappear from your view as you scan.

All of the vertically polarized radio signals we use (Airband VHF, transponders, FLARM, ADS-B, etc.) are affected by orientation differences between the transmitting and receiving antennas. By having antennas mounted as vertical as possible to begin with the largest extremes of relative antenna mis-alignment vs aircraft bank are minimized.

Darryl

I'm waiting until the brick is out and has gone through several revisions. I don't like the idea of being a retail customer and performing the duties of a beta tester. Whenever I get the brick I'm going to have to either ditch my mechanical vario so I can install the 57mm display or get a new electric vario/computer which can show the Flarm data on its primary display because there's no room left on the panel.


No need to wait for future revisions. The PowerFlarms are performing as advertised. I was mildly skeptical about the performance, but after flying with a brick unit for the past 2 weeks at a contest, it worked admirably. My only problem was a faulty Butterfly display (bad control switch). The unit worked, but the interface was toast. The display was replaced I was good to go.



One question I have is if the range is seriously decreased by mounting the antenna at an angle, does banking the glider also result in reduced range?


My PowerFlarm A antenna is mounted about 25 deg off of vertical on the top of my glare shield. I had no issues identifying ships out as far as 6 SM. When turning, a distant ship would infrequently drop out for a moment, but would reacquire very quickly as the turn progressed (carbon fiber cockpit blocks the signal). This was not a problem with closer in ships. I might revise my antenna installation with a more conventional mounting bracket than what I am currently using, but maybe not. It worked very well even though it wasn't set in the ideal position.

I took an in-flight photo of my PowerFLARM antenna installation (way
up in the nose of my DG-300). If you think the antenna obstructs too
much of your vision for safety, compare it to the yaw string! Glider
wings are much wider than either item, BTW - and I think you have a
better chance of seeing relative motion of the wings than picking out
the shape of a fuselage or vertical fin.

http://www.flickr.com/photos/noel_wade/7518094912/

For the record, my antenna sticks up slightly above my compass, and is
on a plastic arm that puts it 7" ahead of the compass so it has a
roughly 320-degree clear field-of-view. I can see targets 6-8 miles
away occasionally, and 4-6 miles away without any trouble - even at my
6 o'clock when the target is only 200 feet behind me, 100 feet below
me, and chasing my ass (ask me how I know!). The only time I lose lock
on sailplanes is when they're at least 2 miles away and thermalling
above my altitude. The target comes and goes; and I suspect that has
as more to do with their antenna and fuselage/internals than my
antenna.

My ADS-B antenna is mounted on the inside of my turtle-deck, and picks
up transponders at least 6 miles out.

I will admit that it took a solid day of work to install my PowerFLARM
and run all the wires and get all the cables working. There was
grumbling and cursing involved (mostly because I was having to mount
it under the seatpan as my DG-300 has no space left in the instrument
pedestal). However once I started flying with it, all was
forgiven. I flew with it in the Standard Class Nationals and I am
100% convinced that it was well worth the effort. I am VERY HAPPY I
have it. Because of the terrain and conditions, several tasks
included MATs with reciprocal headings - and on at least 2 or 3
occasions FLARM alerted me to head-on traffic near my altitude, flying
near cloudbase where I would NOT have seen the traffic until the last
moment.

I hope future generations of the product have a better form-factor and
become easier to install (or at least some enterprising distributor/
reseller starts offering custom wiring harnesses)... But the current
version is fine as it stands and offers a lot of value - and safety -
for the money!

--Noel
P.S. (OK, I _do_ wish they'd hurry up and get the logger
functionality working... I almost didn't have a valid flight trace at
the Nats and could have used a backup logger that's IGC-legal!)