Have been running the Prostick for two weeks and it is looking good for range
However since starting to use it I have been getting lots of. “Unstable clock reports”
Running pi2 and Piaware
Same antenna as before
Anyone got ideas to resolve this issue please
I think I saw it mentioned back in the beginning that it’s a 50ohm input… on the LNA…
Very happy with the Pro Stick so far. I’m getting between 25% and 75% more messages than previously.
So, i installed my ProStick on friday and compared now Saturday - Monday. I adjusted the gain from -5 (with which i could see some planes) to 40. The results are just crazy:
http://fs5.directupload.net/images/160419/et6ticbl.jpg
Since i don’t know how i received some planes from 250+ mi with my old setup, i also calculated the increase without this range.
Also the increase in the range 150-200 mi should only be 10500%, i don’t know why my excel is calculating 19272%, however these numbers are just gorgeous!
I’m so curious how the setup will perform with the filter which i will receive on friday (any recommendations to the gain adjustments? Should i leave the gain as it is?)
With or without the 1090 filter?
[quote=“webstar”]
This is without the filter.
The filter is going to arrive today, so i check this out and let you know how the performance is.
I have two setups running happily at max gain with a prostick and filter.
I received my first pro stick, and replaced the generic dvbt by pro stick.
I had to drop the gain of dump1090 from “max” to 35 dB for a meaningful performance, and now it is performing like the generic dvbt without any amplifier. I increased gain to 38 dB, and performance dropped.
Conclusion: For my location, with pro-stick, a filter is a must, but this is additional expenditure of $22, and eclipses the “value for money” charm of pro stick.
In past when I used a Satellite amplifier with the generic dvbt, and NO FILTER, It gave excellent results even at dump1090’s gain setting of “max”. I dropped gain to 44dB to reduce signals > -dBFS, but even then it gave excellent results.
The pro stick’s rf amplifier is very broad band (300 Mhz to 2400 Mhz) and amplifies all signals in this band which includes TV vhf/uhf, ham, walkie talkies, Cellular, WiFi & other communications like police, fire, taxi etc. This saturates the amplifier & tuner, and makes it essential to add a filter.
On the other hand the Satellite amplifier has a limited bandwidth of 950 Mhz to 2050 Mhz (L-band), which prevents amplification of signals of TV vhf/uhf, ham, walkie talkies, Cellular, WiFi & other communications like police, fire, taxi etc.
I suggest Flight Aware to use another rf pre-amplifier chip in next generation of pro stick, which should have narrower bandwidth (L-band).
I am now considering to solder 2 SMDs on the pcb strip connected to SMA connector centerwire. The other terminal of SMDs will be soldered to ground strip of pcb/SMA body.
SMD 1 = 22nH inuctor
SMD 2 = 1 pF capacitor
This will form a parellel resonant circuit (tank circuit as hams call it), resonantat 1075 Mhz. Since the Q factor of SMDs is generally low, it will not be sharply tuned at 1075 Mhz,but will have bandwith say ± 100 Mhz around 1075 Mhz. This should be sufficient to block TV & lower frequency cellular & other signals.
Hi abcd,
I think perhaps the prostick has a resetable protection fuse just like the rtl sdr.com dongle
When you have the case open, can you please confirm this.
I see a number of people saying they are getting no luck from prostick from time to time.
It could be the protection fuse kicking in.
Unplug for a while and pop back in restart system and it works again.
If there is a fuse, it will be at the sma end below the led on the prostick this would be in the area of the amplifier circut.
Details of the internals were posted here
http://discussions.flightaware.com/post190742.html#p190742
The prostick
and the rtl sdr.com metal dongle internals, where the fuse is also at sma end , this time above the led near the top
Please see image 3 below. This is how I plan to add a LC Parallel Resonant Circuit (Tank Circuit) at antenna input of my Pro Stick.
Sure it will not be as good as a SAW or Cavity Filter, but much better than the original super-wide-band pro stick.
Exact bandwidth and insertion loss will depend on Q-factor of SMDs used.
Due to inductor’s self capacitance, and self capacitance of pcb strips, the value of inductor may be much less than calculated 22 nH. Different values such as 15 nH & 10 nH should also be ttried.
Image 1 of 3: Parallel Resonant LC Circuit.
Image 2 of 3: Bandwidth & Amplitude vs Q-factor
https://farm1.staticflickr.com/648/21318592182_787144e766_o.png.https://farm2.staticflickr.com/1714/25960024553_6f7264c83b_o.png
Image 3 of 3: Physical placement of 2 SMDs
Note: Addition of 2 SMDs (1 pF Capacitor & 22 nH inductor) is not actual. I did it by Photoshop 
PROG_ARGS=“–quiet --net --gain 30 --net-fatsv-port 0”
This and…
Pro Stick w/1090 MHz Mode S Filter seems to work fine for me.
Hi Mike,
Great to know about the fuse. I will sure check it when I open the pro stick cover. However this will not be soon, as for next 2days I have some urgent persoal business to attend, and then on Saturday I will travel to UK for one week’s visit. Will resume this crazy hobby upon return.
The Pro Stick has been inline with my FlightAware antenna for several weeks. The Pro Stick has improved the range of reception and also the density (number) of flights logged.
FINALLY have an update. I ran zadig as someone suggested. In zadig, there was an “install driver” button so with RTL2838UFA selected, I installed the driver and it works now.
I still stand by the fact the Pro Stick may not be a hotswap, but at least the fix appears to be as painless as running zadig for about 2 minutes.
It’s a hotswap on a Pi; the manufacturer IDs are unchanged and that’s what linux/udev/etc use to identify it.
Windows apparently uses the manufacturer string somehow, which seems pretty fragile.
Can you give more detail on that 50’ cable?
50 ft active usb purchased from Amazon.
It is not online now, Can’t keep the 30 ft PVC pole up. Running on a home made spider for a little while.
Be advised that extremely long USB cables have been found to be causing problems with MLAT getting refused for some users, due to the higher noise ratio causing more USB packet transmissions. MLAT requires very precise timing and the packet retries cause the timing to become inaccurate.
Just swapped in my new prostick. Noticeable increase in coverage already. Just needed to restart my Pi Zero and it worked. I havent played with the gain yet.
Got new results with the filter:
8-legged spider antenna → 5 meter 75Ohm cable with F-connector → F to SMA connector → FA filter → FA ProStick → Raspberry Pi 2
Gain is setup to max and the setup is currently inside. The next step for me is to move it outside and i’m really curious how it will perform!
