Flarm range

There are anecdotal evidence that PowerFlarm range was significantly reduced after the last upgrade. I've seen 50% reduction in range in all directions with the flarm range tool in all my flights after the update when comparing to last year. Perhaps this is coincidence so I wonder if others experience the same as I haven't seen discussion about it. The sooner the flarm folks are aware of it the better.

Ramy

On Wednesday, May 6, 2015 at 9:14:37 AM UTC-7, Ramy wrote:
There are anecdotal evidence that PowerFlarm range was significantly reduced after the last upgrade. I've seen 50% reduction in range in all directions with the flarm range tool in all my flights after the update when comparing to last year. Perhaps this is coincidence so I wonder if others experience the same as I haven't seen discussion about it. The sooner the flarm folks are aware of it the better.

Ramy

I also have this impression. Last year 4 nm to 9 nm now rarely over 5 nm.


Richard

On Wednesday, May 6, 2015 at 1:07:55 PM UTC-4, Richard wrote:
On Wednesday, May 6, 2015 at 9:14:37 AM UTC-7, Ramy wrote:
There are anecdotal evidence that PowerFlarm range was significantly reduced after the last upgrade. I've seen 50% reduction in range in all directions with the flarm range tool in all my flights after the update when comparing to last year. Perhaps this is coincidence so I wonder if others experience the same as I haven't seen discussion about it. The sooner the flarm folks are aware of it the better.

Ramy

I also have this impression. Last year 4 nm to 9 nm now rarely over 5 nm.


Richard

This seems to me to be more than adequate for the intended purpose as a collision risk warning device.
UH

It's the minimum range we are concerned about not the max range. Last year I don't recall seeing a glider before my flarm detect it, this year it happened few times already. Again, could be anecdotal, so I would like to hear from more.

Ramy

On Wednesday, May 6, 2015 at 12:14:37 PM UTC-4, Ramy wrote:
There are anecdotal evidence that PowerFlarm range was significantly reduced after the last upgrade. I've seen 50% reduction in range in all directions with the flarm range tool in all my flights after the update when comparing to last year. Perhaps this is coincidence so I wonder if others experience the same as I haven't seen discussion about it. The sooner the flarm folks are aware of it the better.

Ramy

Hi Ramy, since I upgraded to 6.02, I've seen a range increase from 5.4 km average to 6.4 km average (over about 23 hrs flying so far this season), and also an increase in max range. I use a Core and centre-fed dipole FLARM antenna. Each of these were in the vicinity of 1,100 flarm events on single flights. I would check my antenna - particularly if you shortened it - with a known good antenna (connector tightness, etc). I crewed at the Chilhowee contest, and the consensus there was that the ranges had increased, and thermalling false alarm rate had dropped.

Dan
2D

On Thursday, May 7, 2015 at 6:25:20 AM UTC-5, Dan Daly wrote:

Hi Ramy, since I upgraded to 6.02, I've seen a range increase from 5.4 km average to 6.4 km average (over about 23 hrs flying so far this season), and also an increase in max range. I use a Core and centre-fed dipole FLARM antenna. Each of these were in the vicinity of 1,100 flarm events on single flights. I would check my antenna - particularly if you shortened it - with a known good antenna (connector tightness, etc). I crewed at the Chilhowee contest, and the consensus there was that the ranges had increased, and thermalling false alarm rate had dropped.

Dan
2D

Dan, I'm getting ready to shorten my PF antennas (as part of a cockpit wiring "clean-up" effort), so I'm curious about your comment above. Are you suggesting that shortening the antenna wires can cause range issues, or is it a matter of making sure the shortening is done properly?

I'm planning on doing it at the antenna end (as described by 3U on his web site).

Kirk
66

Hi Kirk; shortening (a la 3U method - same as I used) the wires is a good thing, but you have to make sure the solder joints are good, and that the physical length isn't changed significantly - so measure the tip-to-tip distance carefully before unsoldering). Coiled wires give losses, particularly where they're close to wires carrying significant load; shortening them is good, but you have to make sure that you're careful.

For my FLARM A antenna I used a centre-fed dipole with a nice cable from amazon - "RP-SMA Male to RP-SMA Female RF Connector Pigtail Cable" which is just the right length for my installation. At some time, I'll replace the ADS-B antenna as well, though I guess I'll need a ground plane since no dipole is available. The transponder/ADS-B signal is so strong, I may just stay with the factory antenna.

Distance between antennae and distance from other transmitter/receivers (GPS for example) also can affect FLARM range. I turn off my cell phone in flight since it is pretty electromagnetically 'dirty' and bothers my radio and GPSs (I was involved in EMC/EMI avionics testing and had access to state of the art testing equipment).

Your reported ranges can also be hugely affected by the installations of other FLARMs you are interacting with... so Ramy's RF ranges may be their problem, not his. Are they old Portables?

So, what I was saying was the latter - it's a matter of ensuring you do it properly. Buying the pig-tail for about $5US and the antenna for about 8 bucks was economical, and I picked up a bit of gain from the antenna change (1.2dBi according to the datasheet); it also looks a lot nicer, which should count for something!

Nice to see that some of the info I published is useful to others.

It is important to recall here the recent RAS post from WX about his range analysis findings at the 15m Nats at Yreka.(https://groups.google.com/d/msg/rec....k/AAsFX6OLij4J)
Note that WX had IGC files with 11000 contact point, resulting in a very even pattern and good range.
I consider about 2000 point the minimum to draw good conclusions from the pattern from the Range Analysis Tool.
I updated my webpage to emphasize the importance of having sufficient contact points.

I have had only 2 flights with the V6 firmware that produced valid data. I ran both through the analysis tool. One flight had only 150 contact points, the other about 400. They showed both heavy skew to one side, due to the lack of sufficient contact points.
However, with this limited set of data, I did not observe a significant change in the best range. Was about 6km with V3.4 and still about 6km with the latest V6 firmware.

3U