Boost PowerFLARM Range with Better Antenna?

[chip.b...@gmail.com]

Have seen lots of comments about where and how to mount PowerFLARM antennas. Any stories of the effect of changing the TYPE of antenna used: e.g., from (in my case) the short, stubby Portable PowerFLARM rod antenna to, say, the center-fed dipole that comes with the core?

The question is with regard to the FLARM antenna only (not ADS-B or GPS), and specifically on its effect on receive range.

Primarily interested in commercial-off-the-shelf components but have built various antennas in the past and not averse to doing so again. Thx.

Chip Bearden
ASW 24 "JB"

[stu8...@gmail.com]

Usually a 'better' antenna means one with more gain.
Which means one that is more directional.
Which means less sensitive in some areas in exchange for more sensitive in others.

Less sensitive in some areas might not be better for a collision avoidance.
Perhaps you could focus more on a pancake at you altitude.
Maybe a longer vertical dipole would do this.

Instead of a dipole made of 2 back to back 1/4 wave elements,
I wonder how 2 back to back 5/8 or 1 1/4 wave elements would do?

Also, the WiFi folks seem to have settled on a coaxial configuration for the dipole. This fixes the problem of the feed getting in the way of the elements. I'm not sure if it affects the pattern from underneath.

[Tango Eight]

http://tinyurl.com/l7tkpnh

Use one each on Flarm A & B inputs. Addition of 2nd antenna on Flarm B improves RX range.

T8

[chip.b...@gmail.com]

T8,

My understanding is that unlike the PowerFLARM core, the Portable PowerFLARM (which I have) requires a standard (vs. reverse polarity) connector for the "B" FLARM antenna. Mouser has such a version, too. Thx!

[bythes...@gmail.com]

So 2 of us have FLARM CORE - and we put it in Stealth a long time ago and then back to normal - but when we get about 1 or 2 miles apart the other glider disappears - I can see 747's but can't see the other glider? any suggestions? here is my config


$PFLAC,S,DEF
$PFLAC,S,NMEAOUT2,71
$PFLAC,S,BAUD2,2
$PFLAC,S,NMEAOUT1,71
$PFLAC,S,BAUD1,2
$PFLAC,S,RANGE,65535
$PFLAC,S,VRANGE,500
$PFLAC,S,ADSBRANGE,65535
$PFLAC,S,ADSBVRANGE,65535
$PFLAC,S,PCASRANGE,7000
$PFLAC,S,PCASVRANGE,600
$PFLAC,S,MODEC,0
$PFLAC,S,OWNMODEC,0
$PFLAC,S,PCASCALIBRATION,30
$PFLAC,S,XPDR,2
$PFLAC,S,MODESALT,0
$PFLAC,S,PCASBEEP,1
$PFLAC,S,PCASPFLAU1,0
$PFLAC,S,PCASPFLAU2,0
$PFLAC,S,AUDIOOUT,0
$PFLAC,S,AUDIOVOLUME,100
$PFLAC,S,ACFT,1
$PFLAC,S,PILOT,William Hanson
$PFLAC,S,LOGINT,4
$PFLAC,S,GLIDERID,N723PJ
$PFLAC,S,GLIDERTYPE,Pegase 101A
$PFLAC,S,COMPCLASS,Standard
$PFLAC,S,COMPID,WH
$PFLAC,S,PRIV,0
$PFLAC,S,NOTRACK,0

WH

[bythes...@gmail.com]

ps - we both have 2 antennas :)

WH

[Richard]

Increase Vertical range for PowerFlarm to max 2000 Meters.

$PFLAC,S,VRANGE,2000

You also need this sentence for your mode S Code A9AFFF

$PFLAC,S,ID,A9AFFF

Richard
www.craggyaero.com

[David Kinsell]

You've got ADSB horizontal and vertical range set to max. Since you're
generally dealing with 250 watt transponders, yes you can get incredible
range. But for collision avoidance, it's ridiculous. Do you really want
to see an airliner four miles above you at 50 miles? Cut it down to
something more reasonable like 10,000 and 1000 meters, keep your display
zoomed in to 5 miles or less, and concentrate on collision avoidance.

Maybe if the hardware is not processing so many irrelevant targets, it
will perform better with the close in FLARM traffic.

-Dave

[Luke Szczepaniak]

On Friday, 22 July 2016 16:05:10 UTC-4, bythes...@gmail.com wrote:
> So 2 of us have FLARM CORE - and we put it in Stealth a long time ago and then back to normal - but when we get about 1 or 2 miles apart the other glider disappears - I can see 747's but can't see the other glider? any suggestions?

I've had issues with my FLARM since putting the in stealth mode at the 2015 15m Nationals at Harris Hill. After the contest the range dropped considerably. This morning completely blew away my config by loading a flarmcfg.txt that only contained a single line;

$PFLAR,99


After that I put in a fresh config file generated using the flarm website and my ranges came back to what I was seeing before Elmira.

FWIW
Luke Szczepaniak

[Morgan]

I'm running a center fed dipole off the A connector on my Powerflarm portable. Noticeable improvement in range over the stubby antenna. This is just the $30 or so antenna from Rich at Craggy and definitely works better than the stock antenna, but still lacks the sensitivity I think people get with the Core.

Morgan

[chip.b...@gmail.com]

Thanks! I now have the center-fed dipole for the "B" connector (not the same antenna connector as for the "A" connector for US Portable PowerFLARMs, btw) but haven't flown with it yet. I'm hoping this boosts the range.

I'll also take a look at Luke's method as the range I got on a few test flights last summer before the Elmira stealth contest seemed to be higher than what I've experienced since then.

[Richard]

#$PFAR,99 = Reboots the device, all settings will reset to default values,
#user configuration is lost
$PFLAR,99

Richard

[Papa3]

Interesting. I seem to be having a similar problem. I thought it might be due to the firmware update. I'll go do a little more digging and compare a couple of log files from before/after using the range analyzer.

It looks like the single sentence just "reinitializes" the unit to default settings?

[JS]

If the output of the FLARM configurator would have an explanation of each of the parameters we might have a chance of figuring out what is going on.
This is the document link:
http://flarm.com/wp-content/uploads/2015/12/FTD-14-FLARM-Configuration-Specification-1.03.pdf

Here's my latest config file. Vorsicht! It still warns me of myself...
Thanks to John Carlyle and Chris Hostettler, Evan Ludeman and Tim Welles for providing info.
Jim

########################################################################
# This configuration file must be text only and reside in the top
# directory of the USB stick. It must be named FLARMCFG.TXT
# Insert stick before power up, remove when normal display is seen,
# (but don't do this if you are writing a debug file - see below)
########################################################################

# clears PowerFlarm, sets all parameters to default values
$PFLAC,S,DEF

########################################################################
# dataport configuration
########################################################################

# nmeaout1 = RJ45 connector, nmeaout2 = DB9 connector
# 71 = v7 GPS + Traffic, 72 = v7 GPS only, 73 = v7 Traffic only
# baud1 = Baud rate on RJ45, baud2 = Baud rate on DB9
# 0 = 4800, 1 = 9600, 2 = 19200, 3 = 28800, 4 = 38400, 5 = 57600

# configure RJ-45 port
$PFLAC,S,NMEAOUT1,73
$PFLAC,S,BAUD1,5

# configure D-SUB 9 port
$PFLAC,S,NMEAOUT2,73
$PFLAC,S,BAUD2,5

# warning horizontal range and vertical range in meters

$PFLAC,S,RANGE,65535
$PFLAC,S,VRANGE,2000
$PFLAC,S,ADSBRANGE,6000
$PFLAC,S,ADSBVRANGE,1000
$PFLAC,S,PCASRANGE,3000
$PFLAC,S,PCASVRANGE,800

########################################################################
# transponder and PCAS configuration
########################################################################

# do Mode C signal processing, ie, PCAS mode (0=no, 1=yes)
$PFLAC,S,MODEC,1

# own Mode C signal filtering (to eliminate your own xpdr)
# 0=aggressive (use w/ Mode C Xpdr), 1=normal (no Xpdr or Mode S)
# normal in my ship results in false PCAS alerts about every 10 min
$PFLAC,S,OWNMODEC,0

# PCAS antenna gain (30=default, higher makes PCAS targets closer)
$PFLAC,S,PCASCALIBRATION,30

# transponder type (0=None, 1=Mode C, 2=Mode S)
$PFLAC,S,XPDR,2

# use Mode S barometric altitude for PCAS height calc (0=no, 1=yes)
$PFLAC,S,MODESALT,1

# create PCAS beeps (0=no, 1=yes)
$PFLAC,S,PCASBEEP,0

# PCAS output to RJ45 (0=no, 1=yes)
$PFLAC,S,PCASPFLAU1,1

# PCAS output to DB9 (0=no, 1=yes)
$PFLAC,S,PCASPFLAU2,1

# audio out (0=no, 1=yes)
$PFLAC,S,AUDIOOUT,0
$PFLAC,S,AUDIOVOLUME,100

########################################################################
# aircraft configuration
########################################################################

# aircraft ICAO code (hex)
$PFLAC,S,ID,A2F493

# aircraft type (1=Glider, 2=Towplane, 8=Reciprocating Powerplane)
$PFLAC,S,ACFT,1

$PFLAC,S,PILOT,Jim Staniforth
$PFLAC,S,LOGINT,4
$PFLAC,S,GLIDERID,N292JS
$PFLAC,S,GLIDERTYPE,ASG29-18
$PFLAC,S,COMPCLASS,18m
$PFLAC,S,COMPID,JS

# Stealth Mode (0 no, 1 yes)
$PFLAC,S,PRIV,0

# Third Party Tracking (0 Track, 1 No Track)
$PFLAC,S,NOTRACK,0

[WaltWX]

On Monday, August 1, 2016 at 7:25:31 PM UTC-7, Luke Szczepaniak wrote:

WX, Walt Rogers here...

Luke, I've had a similar problem all year (2016 north american season) ever since I installed firmware 6.06.

My PowerFLARM seems to act like it's constantly in stealth mode. When I run the analyzer from FLARM on the Nephi contest for 65 glider over 7 days... my PF shows 0.5-1km range! ... just like it's in stealth mode. The SYSTEM FLARM setting from my Buterfly v3.4 firmware display shows stealth is OFF. Yet over the previous 3 years, my PF consistently detected 5-9 km range.

I've just did a factory reset using $PFLAR,99 this evening. Tomorrow I will fly with another PF buddy, Jim Staniforth JS. Perhaps I have found the fix.

BTW, I'm driving my SN10B from the PF . The PF is also driving a Butterfly v3.4 display. Could this be the cause of the problem... two devices that can talk to PF?

Anyone else out there with the same limited range symptoms who have TWO devices hooked up... a PF display and another flight computer?

Walt Rogers WX

[kirk.stant]

Walt, I think I've been having the same problem with my PF, also hooked up to a BF display, an SN-10, and an Oudie2.

There is only one other PF equipped glider where I fly, so data is a bit scarce, but the detection range seems a lot closer (like Stealth) since the 6.06 load. I too will try the PFLAR 99 trick and see if it helps.

Kirk
66

[WaltWX]

Results of PF hardware reset then test flight today with Jim Staniforth JS:

Strange...

We flew together from separated frequently less than 1-2km... sometimes 0.1km and up to about 10km.

I "WX" never saw Jim's PF target on my Butterfly display... except before takeoff when we were 150 feet apart on the ground.

Jim saw my PF target most of the day. Jim's FLARM analyzer results for our flight averaged 2-3km... max 7.6km.

Both of us show STEALTH OFF

My, "WX", Analyzer FLARM graphic showed "Not Enough Data"

Very strange result.

BTW, I also changed my FLARM antenna... but I don't think this has any bearing on the results.

Walt Rogers WX

[Steve Koerner]

Just guessing here...

Some of this strange behavior being reported could be due to RF noise interference from other devices on your panel. All of the digital stuff on our panels can and will emit lots of RF noise. The amount of noise in any particular radio band can vary by huge amounts depending upon clock frequency harmonics and nuances of how your gadgets are wired up and how close the offending emitter is located with respect to your PF antenna. The presence of a closeby RF noise source can potentially overwhelm the low level radio signal from another PowerFlarm unit that's a few kilometers away. In such an instance, your PF transmissions would be unaffected while your reception performance is diminished.

One way to investigate this is to turn stuff off and see if you can get back to decent range performance. If a particular offender is thus identified, then you can start thinking about how to deal with it (and that may not be easy). At the design level it's often possible to slightly shift the clock frequency of the device processor with a simple code change. At the wiring level, sometimes using ferrites and twisting wires together can make a big difference. Or the answer may be to get the PF antenna further away from the offender(s).

My remarks here are based on related industry experience; I have no actual experience of PF noise interference to base this on. My own PF is working pretty good.

[chip.b...@gmail.com]

Discouraging, Walt. I had only a few flights last summer to play with my new PowerFLARM but the range seemed OK. Not so much shortly after at Elmira under stealth (expected) but about the same at Fairfield a few months later without stealth (unexpected). Identical avionics. And no better this summer with the software upgrade at Nephi (frustrating).

I haven't flown with the dipole antenna yet. And I will definitely do the reboot/reset that Luke suggested. Hoping to get back where I was.

[WaltWX]

Just received an email from Dave Nadler who reassured me that having two devices connected to the PF, in my case (and it's his setup also), an SN10B and Butterfly display... absolutely works fine.

I was beginning to think that might have been my range issue.

He suggested I swap out my PF core with a known good one. Perhaps the receiver is faulty. That would account for my friends seeing my PF on their displays just fine... but I'm not getting reliable received PF tracks. Finding a local "friend" to swap out their PF core may be difficult since these are the same people I have to fly with to test things in the air. My next step may be to re-install the PF v6.06 firmware (can firmware be rolled back to earlier version?) and firmware on the Butterfly display (v3.4).

BTW, Steve Koerner... thanks for the "heads up" on the RF interference. I did get an increased issue with RF interference that caused a vhf radio squelch break ... that has since almost disappeared. You are right, the slightest changes in wiring routing can cause problems. My panel wiring was changed in a big way and that's when the problem started. In my case it was the power converter causing RF that converted 12V to a usb input on my PDA (Vertica V2).

Walt Rogers WX

[bythes...@gmail.com]

I didn't really look at this thread much, as I have 2 antennas and didn't think that was my issue.

But many of us seem to have a range issue - I can see a friend's glider for about 2 miles (similar to the stealth mode range) then he disappears - but I can see a 747 40 miles away and 15,000 ft above me.

PF is becoming like SPOT - it was something everyone was on board with and now more and more I hear pilots spreading negative experiences. This will not help safety and PF.

I am amazed I have not seen anything from the manufacturer telling us how to fix the issue. (they have my email address and I have written them about the issue........)

WH

[Dan Marotta]

On 8/4/2016 11:15 AM, WaltWX wrote:
> He suggested I swap out my PF core with a known good one. Perhaps the receiver is faulty. That would account for my friends seeing my PF on their displays just fine... but I'm not getting reliable received PF tracks. Finding a local "friend" to swap out their PF core may be difficult since these are the same people I have to fly with to test things in the air.

Walt, give the above a try, anyway. If it's your receiver that's
faulty, the problem will move to the other glider.

You probably already knew that...
--
Dan, 5J

[Charlie M. (UH & 002 owner/pilot)]

OK, sorry to point out the "obvious" to some here.

When crossing power and data wiring, at least make it close to 90* to limit signal/power EMI crossover.
DON'T run power next to data.
Twisted pair wiring is good.
If shielded, ONLY GROUND ONE END.
If grounding, try to use a single ground point (to avoid ground loops, thus noise......).

In general, low power (battery loads and/or transmit swamping) is close wiring. Follow basic ideas and limit some issues.

[WaltWX]

FYI...

An update from "WX" Walt Rogers...

After contemplating my poor or nonexistant range detection with my PF even though my buddy pilot PF sees my Flarm just fine, I've decided to do more detective work on transmit range versus receive range.

First, Dan... thanks for the suggestion to swap PFs with a friend and do a fly off. I checked with my neighbor here in Palmdale, CA, Britton Bluedorn and although he's willing to do a swap of our core PFs, both are schedules make it very difficult to do a fly off. Perhaps by the end of the season, we'll get around to it. Since my PF is providing good range to other PF gliders and warnings to them, keeping my PF in the ship for the 2016 season makes sense. It seems like I do get a PF warning when in very close encounter with another glider. So, I'll probably keep flying it through the season and after convinced it's a hardware receiver defect, send back the unit for repair/replacement.

My neighbor, Britton Bluedorn has set up a portable PF installed in a easily carried box than can be used for signal strength with PFs. He's attenuated the transmit/receive so that very short distance checks can verify differences in PF detection both to the transmit and receive performance. I'll be playing around with that in the next few days and report back my results.

Perhaps this problem with failed or greatly reduced PF receiver chip performance is more widespread than we realize.

Walt Rogers WX

[WaltWX]

"WX" Update on range performance...

Interesting note. Here are the cumulative Nationals competition FLARM Analysis performance average range:

2014 - Montague 15M Nats - 7.0km
2015 - Hobbs Club Class Opens - 2.2km
2016 - Nephi Std Open 15M - 0.5 km (approx - will recalculate soon)

This shows a steady decline... hmmmm PF receiver sensitivity degradation?

No changes in antennae location or coax layout during this period.

I will recalculate my Moriarty NM Super Regions PF performance for 2013 later...

Walt Rogers WX

[WaltWX]

Over the last two weeks I think that my PF Core transmission range problem has been resolved. As with many of these PF problems, it appears to be a combination of factors, errors and reception/transmission problems with other PF equipped gliders. Just remember... the PF equipped glider you may be testing with... may have it's own problems. My recommendation is to get a Portable PF In-A-Box with an attenuator to test your ship's PF on the ground. Also, try resetting the unit with $PFLAR,99 and reloading a CORRECT FLARMCFG.TXT file.

If you go back to my earlier posts in "Boost PowerFLARM Range with Better Antenna?" you will notice that I had terrible detection range issues during the Nephi Nationals 2016... averaging 0.5-1km detection range for all days. It seemed as if my PF was in Stealth Mode, but I could not confirm this from the settings on my Butterfly display. After a consultation with Richard at CraggyAero, he noticed an error in my FLARMCFG.TXT which would have prevented the unit from using default setting. Then I discovered Luke's recommendation to run the $PFLAR,99 command which reset the PF, then reloading a correct FLARMCFG.TXT.

This probably solved the problem, but I was unable to verify it on the next comparison flight with Jim Staniforth's "JS" ASG-29. Unfortunately, it appears (based on a subsequent test with a ground Portable PF unit), that Jim's PF was not transmitting. He was able to SEE my PF... but I could not see him.

A week later I tested my PF Core in the ship by using my friend, Britton Bluedorn's Portable-PF-in-a-box unit and discovered that my transmit range from the ship PF was working ok... testing at about 5.8nm range. Here's a description on his box:

https://www.dropbox.com/sh/yjzhe8wgoh4lgh9/AAAlmglHIhwbpqIZjIrESm4Fa?dl=0

A week after that, I flew with two different PF Core equipped gliders. The FLARM analysis showed decent range of detection varying between 3-14km.

Go figure!

Walt Rogers "WX"