SO I got my prostick today, my config prior was a RTL-SDR dongle, a HAB Supplies AMP/Filter and a FA antenna
Today I swapped the Amp/Filter with a prostick and FA filter.
Looking at the results the prostick is pretty darn close with the HAB amp. I am going to let it run like this all day tomorrow. Then I can compare stats. But from just looked at some of the collectd stuff, its really close.
Thanks for posting the quick review!
I’m seeing similar results. Still need to play with the gain settings, but I suspect I’m seeing a decent improvement already. Friday will be the big tell as that’s the heavy air traffic day in the DFW area.
what gain are you currently at?
and were you using an amp before?
Actually back up to 45dB. Could probably go a little bit higher without getting bad data. No amp for quite a while. I fried my last one.
so my setup with the Prostick AND the Hab Supplies amp is pretty stunning
flightaware.com/adsb/stats/user/daverdfw
gain currently set to 35
First review on Amazon:
I am not normally one to write reviews, but this thing is quite amazing. Instantly had an increase in range and in number of positions per second. Messages per second nearly doubled, and the range increased anywhere from 10-30% (depending on the direction). Using a third party high gain antenna, the flightaware filter, (which I installed about a month ago, and also provided about a 10-15% boost), and about 50 feet of LMR 400 cable. Very impressed so far, just installed, so these are preliminary results, but the early results are looking promising. Furthest distance seen in the first hour of operation was 240 miles (but not consistently), with the average consistent distance being about 190 miles!
Still early, only running since around mid afternoon.
Normally, the previous weeks daily stats are pretty close to the current week.
Last Week - old SDR/AMP/filter
255 264 228 217
This Week - new SDR/filter
289 295 297 281
Yeah - honestly the new dongle is pretty great. Best stats yet.
Annoyingly when I rebooted to install the new dongle I had to re-image my card from backup, but about 7pm is the first full hour when I had the new FA amped dongle installed. This is using a 26 foot run of LMR-195 to the 1090-only (short) FA antenna mounted on a 6ft mast off the side of my building, which sticks up maybe 3 feet above the roofline of a 3 story structure.
Dongle connected through FA filter and running at 42db gain.
the cable is longer than it needs to be. I have a 15 foot run of LMR-400 cable on order - I can’t wait to see what THAT does for the range 
With the new dongle probably going to be #1 in nyc. Already #55 overall. Really itching for that first page haha.
But anyway - great job with this prostick, guys. so incredibly ridiculously good for the price - considering its CHEAPER than it’s un-amplified competitors!
After 20 minutes even as my local traffic begins to wane… ¡me gusta mucho!
Switched just the dongle on my system with the highest antenna (a FA coco) in the attic but that wasn’t amped or filtered, I’ve seen an immediate bump over my filtered and mildly amped quarter wave that is about 10 ft lower but that out performs the attic antenna. Not this time. Instant gratification with this change. Never gonna match daverdfw, but can’t wait to see the results for a full day.
http://flightaware.com/adsb/stats/user/crkbday#stats-8850
Question: I calibrated the frequency error (around ~60 PPM in my case), but has anyone quantified how much of a difference that translates into in either a/c tracked or messages processed?
[edit: typo]
I received my pro stick today. I should be able to get a pretty good apples to apples comparison.
Prior setup: Homemade 8 Seg CoCo → Approx 12ft RG6 → FA Filter → HabAmp → NooElec Mini 2 → PI2
New setup: Homemade 8 Seg CoCo → Approx 12ft RG6 → FA Filter → ProStick-> PI2
So far, the stats are very close to the HabAmp. Right now gain is at 44.5 and PPM of 55. flightaware.com/adsb/stats/user/ … stats-6173
My setup is under the eaves of a two story house:
Before: http://i.imgur.com/Fgwz7bKm.jpg After: http://i.imgur.com/JfZG1Tsm.jpg
daverdfw: Nice results. I will have to give that a try this weekend. I did not have a sma coupler to connect the HabAmp to the prostick. Coupler on order and it will be here on Saturday.
–Steve
I have my gain at 35 with both the amp and stick, I think it will end up being a lot of trial and error on that front. Let me know what you find out as well.
I doubt it will make a measurable difference.
The oscillator frequency error affects two things: the exact frequency tuned and the exact sampling rate.
60ppm at 1090MHz is 65kHz of tuning error. The Mode S signal is at least 2MHz wide so 65kHz is going to have almost no effect. The spec for transponders actually lets them be up to 3MHz out (fortunately, few are actually this far out - when they are, dump1090 can miss them entirely since it is only looking at a 2.4MHz slice around 1090MHz).
At a 2.4MHz sampling rate, each Mode S message is up to approx 300 samples long. The drift due to 60ppm error in the sampling rate over 300 samples is something like 0.02 samples - this will have no effect on the demodulator.
About the only thing the frequency error might affect is multilateration, if you have a dongle that is very far off spec; the server allows for at most 200ppm difference between a pair of receivers. It seems to be rare for a dongle to be >100ppm out though.
thank you obj! very valuable info. I was wondering about that myself.
So I swapped out my old dongles with the prostick on two sites at 2Pm EDT today.
Both have sub-optimal antenna locations and one has a really cheap antenna.
Both showed significant improvement.
Both are running Dump1090-mut with mode AC decode
Both have gain set to max.
Basement(3’ off the ground on side of with $5 antenna with Fa filter) Site 20037
message rate up from 200/sec to 400-500/sec.
A/C track up from 40 to 70
2nd floor(US) bedroom(1st floor elsewhere) FA antenna, inside, with FA filter. Site 17065
message rate up from 300/sec to 500-600/sec
A/C track up from 50 to 80-90
Messages per AC increased from 5 to about 8 or 9
The reported noise level shot up from -37-40db to -23db. Peak signal levels are a little high at -0.7db.
Last Friday - old SDR, Vision AMP, FA filter
This Friday to date - New Prostick, FA filter
**Your mileage may vary, but I’d take that noise level with a grain of salt.
**
What’s happening with the noise floor reporting with my rig is interesting. I’m running the FA antenna pretty nicely situated up above the roofline, but still sub-ideal as it’s on the side of my building, not at the tip of the peaked roof. (although, for an apartment, it’s really not bad)
After installing the prostick the daytime noise floor is being reported as -15dB with the gain at 42 up from -25dB on the old dongle with no amp and the gain at 48.
The NIGHTTIME noise floor is down to -35dB down from -30 with the old dongle.
Message rate is up to 13-1400 from 1000-1200. Unique tracks are up, range is up, ac tracked is up - and single message tracks are DOWN.
(I wish I had better comparison graphs to illustrate - I had to re-image my card and the backup is a week old. Comparison charts not so stark)
Anyway - I’m not sure what the reported noise figure is actually a function of - but I have a feeling what’s reported is artificially high and is coming from the sheer volume of messages coming in. I’m not sure it’s “noise” per se, I think it’s just a lot of overlapping messages.
even during periods where the noise floor is being reported as -15dB I’m tracking aircraft cleanly down to -25 even -27dB RSSI.
Also a telling statistic: Even with the increased message rate, cpu usage is slightly down, or maybe just flat. but still.
New york is very busy airspace, and with this setup i’m averaging over a million position reports a day - I’m still a bit of a noob at this, but I think that a lot of what is reported as noise are actually just overlapping messages. I was a little unnerved by the noise figures at first, but the other numbers don’t lie.
I may restrict access if y’all crash my pi, but if you want to see the graphs: radarcontrol.woodside.jonhanford.com
The reported noise is the total power of everything that’s not part of a successfully decoded message.
Ditto. Thanks Oliver.
