Greetings all, first post and new PiAware feeder here.
Quick summary of my issue/question…
Started out with standard RTL-SDR stick and decided to get the FA Pro Stick Plus. Noticed markedly lower performance on the FA stick. Researched and figured it needed a filter. Ended up getting another FA Pro Plus as well to rule out hardware issues.
My observations… RTL-SDR Stick/No Filter - Better than FA Stick #1 and #2 in general. FA Stick #1 and #2 + Add’l Filter - Many more local planes/messages than RTL-SDR Stick, but less distance.
And finally…
FA Stick #1 seems to perform better than FA Stick #2. It’s not a huge difference, but my concern is why the difference between two identical sticks? From the same batch ordered two days apart.
Also, as stated above, the standard RTL stick seems to pull signals from more distant planes, but with fewer planes locally (within 50mi).
Is the internal filtering after the amp in the FA Pro Stick Plus somehow attenuating signals from more distant planes? Would I get better results with the Pro Stick without the internal filter?
Again, I’m still new to all this so any help would be appreciated!
Thanks!
Luther
Thanks for the response!
Yes, my antenna setup isn’t great. I’ve been testing different antennas/configurations as well the past few days. Monday I put a homebrew coco in the attic, on which I have been testing the sticks. My testing method probably isn’t good, but I basically let each stick run for a while then switched them out. I rotated through the configurations several times as well. Same antenna, cabling, position relative to other equipment. Running a RPi over PoE into attic. About 3 feet of coax to the antenna. Eventually I will improve the antenna setup, but just using it to test hardware at the moment.
Why don’t you let each stick run for at least a day or change it around midnight.
Then you can compare the bar graph (Positions Reported by Distance from Receiver) by selecting the data.
Just looking at the map it’s hard to see small differences.
I would be very surprised if the rtl-sdr stick really is better than the Pro Stick.
I tested them for a few hours, but I know things can change throughout the day. I’ve left it on FA stick #2 + filter since yesterday so I’ll change it tonight. Yes, I’m using the FA Filter as well.
As far as the antenna, I’ve actually already built and tested that antenna. Didn’t have the range of the coco of course, but it did allow me to see more very close aircraft. I also built a ground plane with 8 radials soldered to an SO239. Still wasn’t as good as the collinear coax. Had issues with planes within a few miles due to the low takeoff angle of the antenna, but the FA Stick + additional filter seems to have solved that.
Well it’s really hard to compare antennas in the attic, reception can vary quite a bit just by moving the antenna literally one inch.
Do you know what material the insulation is? Some include metal foil.
A bad antenna on the roof is likely going to be better than good antennas indoors.
I suppose you should also try running fixed gain settings.
Try 44 on the ProStickPlus as a start.
With the normal stick without builtin amplifier it’s probably best to leave it at -10.
Yeah I’ve been reading up on the gain and attempted to run the optimize-gain script, but it’s giving me errors for some reason.
And yes, ultimately I will get the antenna outside at least above the roof. Thinking of hoisting it up a tree, but I’m sure it will block those signals at that high frequency.
Awesome, thanks so much for the help! Adjusting the gain to 40 seemed to have helped a bit, and I’m going to start using that percentage stat you posted. Does that measure percentage from the time of dump1090 restart?
Edit - I guess it would since you need to restart it to change the gain settings.
(Especially with roof and wall in the way having differing attenuation in different directions adjusting gain will be even more of a tradeoff than otherwise)
