PowerFlarm v3.40

[Auxvache]

Went to update to the latest version of PF--3.40--and one item in the release note made me hesitate:

"Known issues:
- Mode C targets at own altitude may be suppressed."
(http://www.flarm.com/powerflarm/updates/3.40/final/Release_Notes_3_40.txt)

My non-engineer brain assumes that this is related to one of the Fixes in this version:

"FIX: More aggressive suppression of own Mode C XPDR (reverted to 2.60
behaviour)."

Since I don't yet have a transponder in this glider (wag of the finger), and would like better Mode C PCAS alerts than what I'm currently getting (v3.0), I'm wondering if this particular update is one I should skip. Any thoughts/experiences/advice appreciated.

[Ramy[_2_]]

Since you don't have a transponder just set the transponder parameter to negative in the config file and nothing will get suppressed.
You will need to switch to latest firmware sooner or later since previous one will expire.

Ramy

[RuudH]

Op zondag 13 april 2014 20:05:26 UTC+2 schreef Auxvache:
> Went to update to the latest version of PF--3.40--and one item in the release note made me hesitate:

With this update Flarm hopes to reduce the numerous nuisance "dangerous traffic warnings" (DTW).
A nuisance DTW could be described as a warning with red beeping Flarm V3 display or DTW on Butterfly while the traffic that is causing this warning is still at a safe distance.

See photo of such a situation on https://dl.dropboxusercontent.com/u/35654093/flarm-danger-traffic-warning.jpg
At that time I was climbing in a thermal and the gilder that caused this waring (equipped with transponder with ADS-B out) was flying past me at a distance of 1200 meters.

In Europe a lot of gliders are flying around with mode-s transponders with ADS-B out.
PowerFlarm does not treat the ADS-B signal in the same way as the Flarm signal for a number of reasons.

I have been flying with PowerFlarm for almost a year now and have seen many many nuisance DTW's caused by gliders that have transponders with ADS-B out.
In the mean time I have delivered diagnostic data to Flarm that enables them to improve the firmware and hopefully reduce the number of nuisance DTW's

I certainly hope that Flarm is able to solve this problem soon, because nuisance warnings are also dangerous. I you get used to so much warnings you might not react to a real DTW.

[[email protected]]

On Tuesday, April 15, 2014 6:51:16 AM UTC-4, RuudH wrote:
> Op zondag 13 april 2014 20:05:26 UTC+2 schreef Auxvache:
>
> > Went to update to the latest version of PF--3.40--and one item in the release note made me hesitate:
>
>
>
> With this update Flarm hopes to reduce the numerous nuisance "dangerous traffic warnings" (DTW).
>
> A nuisance DTW could be described as a warning with red beeping Flarm V3 display or DTW on Butterfly while the traffic that is causing this warning is still at a safe distance.
>
>
>
> See photo of such a situation on https://dl.dropboxusercontent.com/u/35654093/flarm-danger-traffic-warning.jpg
>
> At that time I was climbing in a thermal and the gilder that caused this waring (equipped with transponder with ADS-B out) was flying past me at a distance of 1200 meters.
>
>
>
> In Europe a lot of gliders are flying around with mode-s transponders with ADS-B out.
>
> PowerFlarm does not treat the ADS-B signal in the same way as the Flarm signal for a number of reasons.
>
>
>
> I have been flying with PowerFlarm for almost a year now and have seen many many nuisance DTW's caused by gliders that have transponders with ADS-B out.
>
> In the mean time I have delivered diagnostic data to Flarm that enables them to improve the firmware and hopefully reduce the number of nuisance DTW's
>
>
>
> I certainly hope that Flarm is able to solve this problem soon, because nuisance warnings are also dangerous. I you get used to so much warnings you might not react to a real DTW.

Hmm... interesting that gliders are equipping ADS-B out in Europe. So far
the US has been insisting on a GPS source that costs more than the rest of
the instruments put together. I wonder if this will ever change?

Matt

[Ramy[_2_]]

Just to clarify, the DTW described while can indeed be an issue with ADS-B out equipped gliders, has nothing to do with suppression of own mode C transponder which the OP describes.

Ramy

[Andy[_1_]]

On Sunday, April 13, 2014 6:18:09 PM UTC-7, Ramy wrote:
> Since you don't have a transponder just set the transponder parameter to negative in the config file and nothing will get suppressed.
>
> You will need to switch to latest firmware sooner or later since previous one will expire.
>
>
>
> Ramy

Do you know if FLARM are working this? The suppression of same altitude mode C targets is a really poor solution to the spurious own transponder alerting problem.


GY

[darrylr]

On Friday, April 18, 2014 7:16:26 AM UTC-7, Andy wrote:
> On Sunday, April 13, 2014 6:18:09 PM UTC-7, Ramy wrote:
>
> > Since you don't have a transponder just set the transponder parameter to negative in the config file and nothing will get suppressed.
>
> > You will need to switch to latest firmware sooner or later since previous one will expire.
>
>
> > Ramy
>
> Do you know if FLARM are working this? The suppression of same altitude mode C targets is a really poor solution to the spurious own transponder alerting problem.
>

Suppression of the local Mode C transponder is done by suppressing same-altitude Mode C targets. That's the main bit of info that the system has to use to do that suppression of the local transponder. Flarm can do things to try to minimize suppression of other transponders but unlike Mode S there is no hard-guaranteed way to suppress only the local Mode C transponder. So this is always going to involve a lot of art as well as science.

Mode S is a different beast where you have a unique ICAO address on each Mode S interrogation. But even a Mode S transponder has to reply to legacy Mode A/C interrogations, and if those are happening then you are back in the same boat. Given that Flarm have been tweaking stuff related to this in recent firmware releases and are warning about same altitude Mode C suppression in 3.4 then I'd assume they are still working on improving all this.

If your or other gliders in the area have Mode S transponders make sure that PowerFLARM and the Mode S transponders in all the gliders are properly configured with the correct ICAO address for those aircraft. And if there is no local transponder follow the advice Ramy already offered.

[Ramy[_2_]]

I suspect that in practice, suppressing transponders at the exact same altitude will have no much affect on PCAS reliability, as relative altitude between aircrafts fluctuate all the time, especially with gliders, and I suspect the suppression algorithm can detect altitude fluctuation and does not suppress it. This is just my guess based on the fact that my PF seem to do good job with PCAS alert even when flying at the same altitude as someone else.

Ramy

[Andy[_1_]]

On Friday, April 18, 2014 7:31:57 PM UTC-7, darrylr wrote:
"Suppression of the local Mode C transponder is done by suppressing same-altitude Mode C targets. That's the main bit of info that the system has to use to do that suppression of the local transponder. Flarm can do things to try to minimize suppression of other transponders but unlike Mode S there is no hard-guaranteed way to suppress only the local Mode C transponder. So this is always going to involve a lot of art as well as science. "

ZAON worked how to do it without suppressing all same altitude signals but FLARM cannot. That's why I keep my MRX.

[Andy[_1_]]

On Saturday, April 19, 2014 1:31:15 AM UTC-7, Ramy wrote:
> "I suspect that in practice, suppressing transponders at the exact same altitude will have no much affect on PCAS reliability, as relative altitude between aircrafts fluctuate all the time, especially with gliders, and I suspect the suppression algorithm can detect altitude fluctuation and does not suppress it. This is just my guess based on the fact that my PF seem to do good job with PCAS alert even when flying at the same altitude as someone else."

The relative altitude between gliders may be subject to large fluctuations. The relative altitude between powered aircraft is quite likely not to vary by more that the typical 100ft resolution of the altitude encoder interface.

I have first hand experience of being on a same altitude, opposite heading, less that 500ft lateral offset threat. ZAON PCAS alerted. I acquired the aircraft visually then checked PF portable. The target was never indicated or alerted.

ZAON used, perhaps inter alia, the signal strength to determine if a mode C signal is own ship. That is why there is provision in the calibration menus for adjusting each unit for own transponder signal strength. To the best of my knowledge FLARM units have no such provision for user calibration.

Andy

[[email protected]]

It would be nice to have the option to include a list of transponder codes that were always suppressed. For example, 1202. One could make the determination if a majority of the local gliders with a transponder also had FLARM. If that was a reasonable assessment for your location, then suppressing all the 1202 hits would potentially reduce the false alarms based on transponders and would rely on the more reliable FLARM data.

[darrylr]

On Saturday, April 19, 2014 2:49:22 PM UTC-7, wrote:
> It would be nice to have the option to include a list of transponder codes that were always suppressed. For example, 1202. One could make the determination if a majority of the local gliders with a transponder also had FLARM. If that was a reasonable assessment for your location, then suppressing all the 1202 hits would potentially reduce the false alarms based on transponders and would rely on the more reliable FLARM data.

Ah the trouble there is you cannot definitively associate a Mode A squawk reply with the same transponder doing a Mode C reply. And there will be situations where targets are doing Mode C only replies (e.g. any time a target is being interrogated by TCAS I or II but out of range of ground SSR... which I'm guessing happens a fair amount).

The 'best' you could do in that situation is stop all PCAS warnings. That may be/is likely too drastic, you can also so try adjusting the PCAS height/range parameters. Ultimately there is nothing you can do that is goign to work that well with Mode C transponders. Hopefully over time this will go away as an issue as Mode S transponder use keeps growing in the USA glider fleet.

There is no need/strong justification to replace a Mode C today, they work great for letting ATC know where you are and with TCAS, TCAD and PCAS in GA aircraft etc. but on the other hand there is no sane reason to buy a new Mode C transponder today. The possible issues here with PowerFLARM interoperability is just one of those reasons. Over time and as equipment ages and gets expensive to repair and new Mode S transponder technology hopefully keeps falling in cost and size etc. we'll just see the current Mode C usage in the glider fleet migrating over to Mode S. I'm much less worried about Mode C vs. Mode S than I am to encourage *any* transponder use in areas of high airline, fast jet, and even GA traffic.

Anybody who what my opinion on what the FAA should have really done with Mode S vs. Mode C transponders and ADS-B Out carriage mandates, etc. is welcome to buy me a six pack of beer and put up with an hour of whining.

[Dan Marotta]

Of course you all know that I'm not a Flarm guy.

Having said that, it strikes me funny that nobody seems to have noticed that
it's the "same altitude" aircraft that's going to hit you. Why would you
want all transponders at co-altitude to be suppressed? And the notion that
you're going to be OK since the Flarm will point out other Flarm traffic.
Listen up, Guys: GA, military, and airlines are NOT using Flarm. Oh, and
we have at least one guy at Moriarty who has a Flarm but not a transponder.
So he and the half dozen or so Flarm equipped gliders can avoid each other
but he's cruising along blissfully unaware that ATC can't see him, nor can
the airliners or military flights that buzz in and out of ABQ daily.

Hopefully Flarm will work this out as Zaon did several years ago.


"darrylr" > wrote in message
...
On Saturday, April 19, 2014 2:49:22 PM UTC-7, wrote:
> It would be nice to have the option to include a list of transponder codes
> that were always suppressed. For example, 1202. One could make the
> determination if a majority of the local gliders with a transponder also
> had FLARM. If that was a reasonable assessment for your location, then
> suppressing all the 1202 hits would potentially reduce the false alarms
> based on transponders and would rely on the more reliable FLARM data.

Ah the trouble there is you cannot definitively associate a Mode A squawk
reply with the same transponder doing a Mode C reply. And there will be
situations where targets are doing Mode C only replies (e.g. any time a
target is being interrogated by TCAS I or II but out of range of ground
SSR... which I'm guessing happens a fair amount).

The 'best' you could do in that situation is stop all PCAS warnings. That
may be/is likely too drastic, you can also so try adjusting the PCAS
height/range parameters. Ultimately there is nothing you can do that is
goign to work that well with Mode C transponders. Hopefully over time this
will go away as an issue as Mode S transponder use keeps growing in the USA
glider fleet.

There is no need/strong justification to replace a Mode C today, they work
great for letting ATC know where you are and with TCAS, TCAD and PCAS in GA
aircraft etc. but on the other hand there is no sane reason to buy a new
Mode C transponder today. The possible issues here with PowerFLARM
interoperability is just one of those reasons. Over time and as equipment
ages and gets expensive to repair and new Mode S transponder technology
hopefully keeps falling in cost and size etc. we'll just see the current
Mode C usage in the glider fleet migrating over to Mode S. I'm much less
worried about Mode C vs. Mode S than I am to encourage *any* transponder use
in areas of high airline, fast jet, and even GA traffic.

Anybody who what my opinion on what the FAA should have really done with
Mode S vs. Mode C transponders and ADS-B Out carriage mandates, etc. is
welcome to buy me a six pack of beer and put up with an hour of whining.

[Ramy[_2_]]

I am pretty sure that the suppression is based on power as well, in addition to altitude. So only a strong signal at the same altitude will be suppressed. Which mean you will still get warning for same altitude until the other aircraft is very close, giving you enough warning. I assume this is the same way that Zaon works. But again this is just my guess. Will be nice if Flarm folks will comment on this.

Ramy

[noel.wade]

Dan -

The statistics show over and over that glider-to-glider collisions are more of a threat than glider-to-GA/Miliatry. FLARM isn't intended to be a perfect solution; it's intended to provide a very reliable, medium-cost, low-power solution for the biggest collision threat: other maneuvering gliders.

Mode C and even Mode S systems are not well-suited for combating glider-on-glider carnage when the craft are in close proximity and maneuvering.

There simply is no perfect solution; but I for one will take the single solution that reasonably covers the broadest range of targets and situations - and right now that's a PowerFLARM.

--Noel

[Darryl Ramm]

"noel.wade" > wrote:
> Dan -
>
> The statistics show over and over that glider-to-glider collisions are
> more of a threat than glider-to-GA/Miliatry. FLARM isn't intended to be a
> perfect solution; it's intended to provide a very reliable, medium-cost,
> low-power solution for the biggest collision threat: other maneuvering gliders.
>
> Mode C and even Mode S systems are not well-suited for combating
> glider-on-glider carnage when the craft are in close proximity and maneuvering.
>
> There simply is no perfect solution; but I for one will take the single
> solution that reasonably covers the broadest range of targets and
> situations - and right now that's a PowerFLARM.
>
> --Noel

Hopefully that decision gets made by each pilot for the conditions they fly
in. And it's not necessarily a choice between a transponder or PowerFLARM.
And the decision should not always come down to PowerFLARM being the first
choice for all pilots. And having both provides very broad technology
assistance. And if in busy airspace areas establishing local procedures,
radio contact with ATC etc. with or without a transponder may be
appropriate.

Around busy airspace with lots of airliners and fast jet traffic the
PowerFLARM is just not going to be of much use. Except maybe highlighting
how much airline etc. traffic is around to be worried about as you see them
via 1090ES (around 1/3rd of airliners are currently 1090ES Out? I am not
sure).

Worrisome areas include those with lots of fast aircraft, all of who are
are in touch with ATC and everybody expects TCAS to just work because
'everybody else has a transponder'. The consequence of being the invisible
glider without a transponder that gets run into by an airliner is not going
to be pretty, so hopefully there is a local flying situation risk x
consequence part of any decision of what to equip with.

But yes clearly for glider-glider collision risks PowerFLARM is by far the
best choice. PCAS in PowerFLARM gives you useful help around GA traffic,
but for the big/fast conflicts you want to be seen by ATC and the TCAS
aboard those aircraft. Which means you need a transponder. ADS-B remains
largely a complex mess/futureware.

Darryl

[Dan Marotta]

That's what I would hope. I recall that, when I installed my Mode S
transponder and had it tested, it was putting out over 175 watts to the test
equipment antenna. Don't we have an inverse cube function of power density
to distance? I think that's right, though I probably didn't say it
correctly. Anyway, an aircraft a couple of hundred feet away would be
received in the milliwatt range, maybe somewhat more, but certainly not at
100+ watts.


"Ramy" > wrote in message
...
I am pretty sure that the suppression is based on power as well, in addition
to altitude. So only a strong signal at the same altitude will be
suppressed. Which mean you will still get warning for same altitude until
the other aircraft is very close, giving you enough warning. I assume this
is the same way that Zaon works. But again this is just my guess. Will be
nice if Flarm folks will comment on this.

Ramy

[Dan Marotta]

Good points, Noel.


"noel.wade" > wrote in message
...
Dan -

The statistics show over and over that glider-to-glider collisions are more
of a threat than glider-to-GA/Miliatry. FLARM isn't intended to be a perfect
solution; it's intended to provide a very reliable, medium-cost, low-power
solution for the biggest collision threat: other maneuvering gliders.

Mode C and even Mode S systems are not well-suited for combating
glider-on-glider carnage when the craft are in close proximity and
maneuvering.

There simply is no perfect solution; but I for one will take the single
solution that reasonably covers the broadest range of targets and
situations - and right now that's a PowerFLARM.

--Noel

[Mike the Strike]

Well, I can report that the PowerFlarm core fails to warn me of commercial traffic most of the time. In the past week, I have been within distances of concern to a Boeing 737 and a Canadair Regional jet - they descend over our gliderport into Tucson International. My transponder seems to work, though - both these aircraft took evasive action to avoid me. The Canadair was at my altitude and had to make a very steep turn away from me. Not a peep from the Flarm!

Mike

[kirk.stant]

On Sunday, April 20, 2014 10:14:46 AM UTC-5, Dan Marotta wrote:

> Listen up, Guys: GA, military, and airlines are NOT using Flarm. Oh, and
>
> we have at least one guy at Moriarty who has a Flarm but not a transponder.
>
> So he and the half dozen or so Flarm equipped gliders can avoid each other
>
> but he's cruising along blissfully unaware that ATC can't see him, nor can
>
> the airliners or military flights that buzz in and out of ABQ daily.

Blissfully unaware? Well, since GA, military, and airliners are pretty much all using either Mode A/C, Mode S, or ADS-B, that PFlarm-only guy is probably fully aware of the location of any potentially threatening traffic in his vicinity - even that VFR doctor in the Bonanza squawking 1200 and not talking to anybody...

And he is also aware of where all his gliding buddies are - and that's a lot of fun, too! - even the clueless new guy who it trying to run into him under his nice Cu in the middle of nowhere.

So while I agree that if you routinely mix in with high-speed airline traffic (common out West, not as common in most of midwest or east) a transponder is a smart thing, I think that a PFlarm is even more of a good thing. Both is best.

Try it - you might like it. Seriously.

Cheers,

Kirk

[Dan Marotta]

While I agree with what you said about the fun of knowing where your buddies
are, you missed my point that it's ATC and other aircraft that can't see the
Flarm-only glider. Sure he (might be able to) see them, but they can't see
him. I also had to draw the line at mounting a device that can only either
block my panel or my outside view. Sometimes more is not necessarily better
but I know opinions vary on what to have.

Finally at the risk of starting a flame war, I would not install a device
that I consider to be still in beta test. XCSoar releases beta software but
they identify it as such and ask experienced users to "gorilla test" it and
identify problems. From the level of complaints I've read regarding Flarm
firmware updates, missed targets, suppression, antennae, displays, etc., I
believe it's still a beta product. Sure it does great things, but it would
not yet receive a TSO. Happy testing!


"kirk.stant" > wrote in message
...
On Sunday, April 20, 2014 10:14:46 AM UTC-5, Dan Marotta wrote:

> Listen up, Guys: GA, military, and airlines are NOT using Flarm. Oh, and
>
> we have at least one guy at Moriarty who has a Flarm but not a
> transponder.
>
> So he and the half dozen or so Flarm equipped gliders can avoid each other
>
> but he's cruising along blissfully unaware that ATC can't see him, nor can
>
> the airliners or military flights that buzz in and out of ABQ daily.

Blissfully unaware? Well, since GA, military, and airliners are pretty much
all using either Mode A/C, Mode S, or ADS-B, that PFlarm-only guy is
probably fully aware of the location of any potentially threatening traffic
in his vicinity - even that VFR doctor in the Bonanza squawking 1200 and not
talking to anybody...

And he is also aware of where all his gliding buddies are - and that's a lot
of fun, too! - even the clueless new guy who it trying to run into him under
his nice Cu in the middle of nowhere.

So while I agree that if you routinely mix in with high-speed airline
traffic (common out West, not as common in most of midwest or east) a
transponder is a smart thing, I think that a PFlarm is even more of a good
thing. Both is best.

Try it - you might like it. Seriously.

Cheers,

Kirk

[John Carlyle]

Dan,

A famous science fiction writer, Jerry Pournelle, once wrote that "perfect is the enemy of good enough". That applies to PowerFLARM in spades. Even in its present "beta" stage (your words), it works very, very well. It hasn't risen to the level of "saved my butt" yet, but it has certainly helped me avoid some very close encounters, including one with a 747 sneaking up on my rear 400 feet above me!

I agree with Darryl and Kirk - you should get both a PowerFLARM and a Mode S transponder if you possibly can. They were tough to shoe-horn into a LS8 cockpit, but believe me, they repaid my sweat (and my monetary) investment!

-John, Q3


On Monday, April 21, 2014 9:52:10 AM UTC-4, Dan Marotta wrote:
> While I agree with what you said about the fun of knowing where your buddies
> are, you missed my point that it's ATC and other aircraft that can't see the
> Flarm-only glider. Sure he (might be able to) see them, but they can't see
> him. I also had to draw the line at mounting a device that can only either
> block my panel or my outside view. Sometimes more is not necessarily better
> but I know opinions vary on what to have.
>
> Finally at the risk of starting a flame war, I would not install a device
> that I consider to be still in beta test. XCSoar releases beta software but
> they identify it as such and ask experienced users to "gorilla test" it and
> identify problems. From the level of complaints I've read regarding Flarm
> firmware updates, missed targets, suppression, antennae, displays, etc., I
> believe it's still a beta product. Sure it does great things, but it would
> not yet receive a TSO. Happy testing!

[[email protected]]

On Sunday, April 20, 2014 9:17:30 PM UTC-5, Dan Marotta wrote:
> That's what I would hope. I recall that, when I installed my Mode S
>
> transponder and had it tested, it was putting out over 175 watts to the test
>
> equipment antenna. Don't we have an inverse cube function of power density
>
> to distance? I think that's right, though I probably didn't say it
>
> correctly. Anyway, an aircraft a couple of hundred feet away would be
>
> received in the milliwatt range, maybe somewhat more, but certainly not at
>
> 100+ watts.
>
>
>
>
>
> "Ramy" > wrote in message
>
> ...
>
> I am pretty sure that the suppression is based on power as well, in addition
>
> to altitude. So only a strong signal at the same altitude will be
>
> suppressed. Which mean you will still get warning for same altitude until
>
> the other aircraft is very close, giving you enough warning. I assume this
>
> is the same way that Zaon works. But again this is just my guess. Will be
>
> nice if Flarm folks will comment on this.
>
>
>
> Ramy

Dan, radiation diminishes according to the inverse square law, just as gravitational forces or sound:
http://en.wikipedia.org/wiki/Inverse-square_law
If you double the distances, intensity falls to a quarter.

[Dan Daly[_2_]]

On Monday, April 21, 2014 12:45:44 AM UTC-4, Mike the Strike wrote:
> Well, I can report that the PowerFlarm core fails to warn me of commercial traffic most of the time. In the past week, I have been within distances of concern to a Boeing 737 and a Canadair Regional jet - they descend over our gliderport into Tucson International. My transponder seems to work, though - both these aircraft took evasive action to avoid me. The Canadair was at my altitude and had to make a very steep turn away from me. Not a peep from the Flarm!
> Mike

Mike - you have either installation or configuration problems. I have an original brick, and I see every airliner, towplane, glider with transponder, and GA with transponder nearby - we're under the most-used approach path for a major Canadian airport, and see traffic all day, every day. I use the standard centre-fed dipole that came with my brick. Try swapping with a known good antenna and see if the problem is cured...

[Mike the Strike]

On Monday, April 21, 2014 9:49:36 AM UTC-7, Dan Daly wrote:
> On Monday, April 21, 2014 12:45:44 AM UTC-4, Mike the Strike wrote:
>
> > Well, I can report that the PowerFlarm core fails to warn me of commercial traffic most of the time. In the past week, I have been within distances of concern to a Boeing 737 and a Canadair Regional jet - they descend over our gliderport into Tucson International. My transponder seems to work, though - both these aircraft took evasive action to avoid me. The Canadair was at my altitude and had to make a very steep turn away from me. Not a peep from the Flarm!
>
> > Mike
>
>
>
> Mike - you have either installation or configuration problems. I have an original brick, and I see every airliner, towplane, glider with transponder, and GA with transponder nearby - we're under the most-used approach path for a major Canadian airport, and see traffic all day, every day. I use the standard centre-fed dipole that came with my brick. Try swapping with a known good antenna and see if the problem is cured...

Dan:

I was coming to the same conclusion and will review my installation!

[noel.wade]

Definitely keep us posted, Mike. If not an antenna issue, maybe there's also a configuration setting you have that must be tweaked?
(I definitely agree with the grumbles about the PF folks not being great at customer communications & documentation)

The PF "brick" in my '300 definitely warned me about mode C GA traffic many times!

--Noel

[Dan Marotta]

John, fair enough regarding perfect being the enemy of good enough. Please
send me one and I'll try it out! :-)


"John Carlyle" > wrote in message
...
Dan,

A famous science fiction writer, Jerry Pournelle, once wrote that "perfect
is the enemy of good enough". That applies to PowerFLARM in spades. Even in
its present "beta" stage (your words), it works very, very well. It hasn't
risen to the level of "saved my butt" yet, but it has certainly helped me
avoid some very close encounters, including one with a 747 sneaking up on my
rear 400 feet above me!

I agree with Darryl and Kirk - you should get both a PowerFLARM and a Mode S
transponder if you possibly can. They were tough to shoe-horn into a LS8
cockpit, but believe me, they repaid my sweat (and my monetary) investment!

-John, Q3


On Monday, April 21, 2014 9:52:10 AM UTC-4, Dan Marotta wrote:
> While I agree with what you said about the fun of knowing where your
> buddies
> are, you missed my point that it's ATC and other aircraft that can't see
> the
> Flarm-only glider. Sure he (might be able to) see them, but they can't
> see
> him. I also had to draw the line at mounting a device that can only
> either
> block my panel or my outside view. Sometimes more is not necessarily
> better
> but I know opinions vary on what to have.
>
> Finally at the risk of starting a flame war, I would not install a device
> that I consider to be still in beta test. XCSoar releases beta software
> but
> they identify it as such and ask experienced users to "gorilla test" it
> and
> identify problems. From the level of complaints I've read regarding Flarm
> firmware updates, missed targets, suppression, antennae, displays, etc., I
> believe it's still a beta product. Sure it does great things, but it
> would
> not yet receive a TSO. Happy testing!

[Dan Marotta]

OK, I was picturing the power as on the surface of an expanding sphere from
the point of transmission (4/3 * pi * r **3) but, as I said, I wasn't sure.


> wrote in message
...
> On Sunday, April 20, 2014 9:17:30 PM UTC-5, Dan Marotta wrote:
>> That's what I would hope. I recall that, when I installed my Mode S
>>
>> transponder and had it tested, it was putting out over 175 watts to the
>> test
>>
>> equipment antenna. Don't we have an inverse cube function of power
>> density
>>
>> to distance? I think that's right, though I probably didn't say it
>>
>> correctly. Anyway, an aircraft a couple of hundred feet away would be
>>
>> received in the milliwatt range, maybe somewhat more, but certainly not
>> at
>>
>> 100+ watts.
>>
>>
>>
>>
>>
>> "Ramy" > wrote in message
>>
>> ...
>>
>> I am pretty sure that the suppression is based on power as well, in
>> addition
>>
>> to altitude. So only a strong signal at the same altitude will be
>>
>> suppressed. Which mean you will still get warning for same altitude until
>>
>> the other aircraft is very close, giving you enough warning. I assume
>> this
>>
>> is the same way that Zaon works. But again this is just my guess. Will be
>>
>> nice if Flarm folks will comment on this.
>>
>>
>>
>> Ramy
>
> Dan, radiation diminishes according to the inverse square law, just as
> gravitational forces or sound:
> http://en.wikipedia.org/wiki/Inverse-square_law
> If you double the distances, intensity falls to a quarter.

[Dan Marotta]

Despite all my current misgivings, I AM keeping my eye on progress with
Flarm...


"noel.wade" > wrote in message
...
> Definitely keep us posted, Mike. If not an antenna issue, maybe there's
> also a configuration setting you have that must be tweaked?
> (I definitely agree with the grumbles about the PF folks not being great
> at customer communications & documentation)
>
> The PF "brick" in my '300 definitely warned me about mode C GA traffic
> many times!
>
> --Noel
>

[John Carlyle]

Dan,

Can't provide the goods, because I'm not giving mine up! I will give you a prediction: when you finally fly with a PowerFLARM you're going to be asking yourself over and over "why did I wait so long to get one"?

-John, Q3


On Monday, April 21, 2014 8:46:40 PM UTC-4, Dan Marotta wrote:
> John, fair enough regarding perfect being the enemy of good enough. Please
> send me one and I'll try it out! :-)

[Ramy[_2_]]

My earlier PCAS issue was an antenna issue. Try another antenna.
I assume you have the latest firmware.

Ramy

[Ramy[_2_]]

Following this discussion I took a note to pay attention for traffic alerts at the same altitude. Today my PF alerted me of another plane flying at the same altitude as mine showing 0 altitude difference for at least 10 seconds while the aircraft was at the same altitude. So I suspect the suppression is indeed also based on power level. BTW, I few with Zaon since they first came out nearly 10 years ago. It was never as reliable and accurate as my PF is nowadays.

Ramy

[Andy[_1_]]

On Sunday, April 20, 2014 8:14:46 AM UTC-7, Dan Marotta wrote:
> it strikes me funny that nobody seems to have noticed that
> it's the "same altitude" aircraft that's going to hit you.


It's not that nobody has noticed. I have posted about this issue before.

The reason FALRM implemented this change is that it is less bad than having continuous alerting to ownship transponder.

>Why would you want all transponders at co-altitude to be suppressed?

Because they have not figured out how to suppress the only co-altitude transponder that needs to be suppressed - the one in the same aircraft as the Power FLARM.


Andy

[Dan Marotta]

Zaon figured it out years ago. My PCAS does not alert on my transponder.
In fact, with a simple button hit, it displays my squawk code to verify that
it's giving me alerts based upon my transponder altitude rather than its own
internal pressure sensor.

Why can't the PFlarm simply eliminate the most powerful transponder
received? That would have to be your own unless another aircraft is parked
with his transponder antenna closer to your PF antennae than your own
transponder antenna and that ain't bloody likely.

"Andy" > wrote in message
...
> On Sunday, April 20, 2014 8:14:46 AM UTC-7, Dan Marotta wrote:
>> it strikes me funny that nobody seems to have noticed that
>> it's the "same altitude" aircraft that's going to hit you.
>
>
> It's not that nobody has noticed. I have posted about this issue before.
>
> The reason FALRM implemented this change is that it is less bad than
> having continuous alerting to ownship transponder.
>
>>Why would you want all transponders at co-altitude to be suppressed?
>
> Because they have not figured out how to suppress the only co-altitude
> transponder that needs to be suppressed - the one in the same aircraft as
> the Power FLARM.
>
>
> Andy

[Andy[_1_]]

On Wednesday, April 23, 2014 3:11:32 PM UTC-7, Dan Marotta wrote:
> Zaon figured it out years ago. My PCAS does not alert on my transponder.

No need to tell me that. I own a ZAON MRX and have used it as the benchmark for side by side testing of Power FLARM mode C alerting. I have reported my results several times on this group.

When the MRX is working it does a very good job of distinguishing between ownship and other transponders. I, and other MRX owners, have had reliability issues though. ZAON gave outstanding customer support and repaired my MRX twice for no change despite the fact it was years out of warranty. There was a time when my MRX did alert to my own transponder. This was caused by 2 factors. First my altitude encoder was unstable with temperature and, second, my transponder had marginal power output.

Since fixing those issues the MRX works as advertised. My Power FLARM portable does not.

I'm tempted to say I wish FLARM supported their customers like ZAON did. However, ZAON is out of business and I hope FLARM does not follow.


Andy

[Dan Marotta]

Thanks for that, Andy. I just must be very lucky having bought one of the
last MRXs. Its performance has been (so far) flawless.


"Andy" > wrote in message
...
On Wednesday, April 23, 2014 3:11:32 PM UTC-7, Dan Marotta wrote:
> Zaon figured it out years ago. My PCAS does not alert on my transponder.

No need to tell me that. I own a ZAON MRX and have used it as the benchmark
for side by side testing of Power FLARM mode C alerting. I have reported
my results several times on this group.

When the MRX is working it does a very good job of distinguishing between
ownship and other transponders. I, and other MRX owners, have had
reliability issues though. ZAON gave outstanding customer support and
repaired my MRX twice for no change despite the fact it was years out of
warranty. There was a time when my MRX did alert to my own transponder.
This was caused by 2 factors. First my altitude encoder was unstable with
temperature and, second, my transponder had marginal power output.

Since fixing those issues the MRX works as advertised. My Power FLARM
portable does not.

I'm tempted to say I wish FLARM supported their customers like ZAON did.
However, ZAON is out of business and I hope FLARM does not follow.


Andy