This weekend I impulsively took the filter out of the system, leaving just the prostick plus.
Number of aircraft jumped from 80 - 95 up to 110 - 125. This increase in aircraft has remained, so I am clearly picking up more aircraft. But range has remained about identical with no appreciable improvement.
Left gain the same as optimized previously. Will shortly run gain configuration on the filterless setup.
As we noted in the product launch announcement, filtering results are highly dependent on the environment at your antenna location.
If you are in the low RF noise environment, it is possible for the Pro Stick Plus to underperform vs. a Pro Stick (with no external filters used). In our testing this was found to be the case in rural environments.
Also, in the opposite scenario (high RF noise environment, more common in urban areas), the Pro Stick Plus performs best with the external filter installed.
I live in an urban area with lot of cell phone antennas on top of my builing and on many buildings around, and I confirm that what Eric Carlson has described matches exactly with my own experience when I use high gain 26" FA antenna (6 dB as marked on antenna lable).
However when I use a low gain (1.5 ~2 dB) 1/4 wavelength ground plane antenna like Spider or Cantenna, Blue ProStick Plus WITH and WITHOUT External Filter performs same as Orange ProStick+Filter.
I have an opinion, but I am not sure of it unless I measure signal levels at various stages of signal flow, which I cannot do due to lack of necessary test instrument.
My opinion is as follows:
In urban areas, the total RF signal output (RF noise + adsb signal) of FA antenna is very high due to its high gain. This results in overloading/saturation of front-end RF pre-amplifier chip. Reducing gain stting does not help in reducing overload of RF pre-amplifier, as gain is reduced in tuner chip which is after the pre-amplifier. Adding an external filter chops-off the noise component, bringing total signal level down, eliminating or reducing the overload/saturation of front-end RF pre-amplifier chip.
With a low gain antenna, the sum of RF noise and adsb signal is low enough to eliminate or considerably reduce frond-end RF pre-amplifier overload/saturation. Hence the external filter is not required. The internal filter eliminates the Amplified RF noise from reaching the tuner chip and prevents overload/saturation of tuner chip.
I am considering purchase of 3 dB and 6 dB attenuators, and test the performance with (1) Filter (2) 3db attenuator, and (3) 6db attenuator, placed between FA antenna & Blue ProStick Plus.
How do I change my gain settings? I am not Raspberry PI user as of yet?
Quote from thread āSmall internal aerial to large external aerial.ā:
Quote from radioforeveryone.com/
(For full details, visit the above page)
Frankly, Iām just as surprised as you are, as Iāve only seen the results when double-checked which IP address belongs to which receiver combo.
15.17% percent more position reports with a Pro Stick Plus, which costs half as much as a premium dongle and preamp. Granted, it will be pretty much unusable for general use due to filtering, but the same 1090 MHz filter also does wonders for ADS-B reception.
Significantly less position reports than usual; other FA feeders in my area did not experience such a downturn, so the only explanation is long coax length. Minimize coax length for best signal, or completely eliminate it with direct connections.
Itās only one test
Your location, preamp, antenna, cable and retina is different from mine. The āLNA at the antennaā mantra comes up so often that I wanted to see what happens for ADS-B use. Thatās all.
The fact is that a receiver built for a specific task with a preamp and filter, costing $21, beat a combo built for general use costing $46. Adding a filter for $20 might narrow the performance gap, but spending $66 when the same job can be done for $21 seems a bit stupid. If you can run coax to a remote location and mount an antenna there, you should be able to run Ethernet cable and mount Pi3 with PoE at the antenna. Ethernet cable is so much cheaper than coax.
Itās all about the dataā¦
Iāll repeat some things from my early posts on this forumā
(1) track your data, day by day. Keep a spreadsheet.
(2) Look at the Nearby ADS-B Sites list and pick a station near you with similar numbers (that stays up!).
(3) Record the daily numbers from this station in your spreadsheet to use as a reference. Gather a weekās worth of data and see if things track before you start messing about with your own station.
(4) A precipitous drop is usually detectable in a day, possibly half a day. More subtle variations with respect to your reference, as theyāre coupled to normal daily traffic variations in your area, may be harder to spot, but will clear up over time.
An alternative to using a nearby ADS-B site as a reference is to put a GOOD splitter on your antenna. If youāre using 50-Ohm coax (such as LMR400, LMR200, or something with good performance at 1GHz) then use a Mini-Circuits splitter. Set up two RPi ADS-B boxes connected to the splitter. Collect data as above for a few days to insure they really do perform similarly. When they do, you can declare one your reference (leave it alone!) and one your test bed (change one variable at a time).
Collect data ā look at data ā make decisions based on data ā and tell us what you learn!
ā¦and have fun ā itās a hobby, right?
bob k6rtm
So, Iām running two separate but similar setups on my roof and I installed the PSP on the lower-performing one. I saw an increase in the total number of aircraft tracked per day of about 100. Iām thinking itās probably because iām regaining that couple db loss by removing the inline filter. Picture shows where I installed the new PSP.
I been using the orange prostick with the fa filter all the time with the 8dbi fa antenna piaware gain setup to 48, using raspi 3 running piaware 3.1.0. Best range about 300nm, and average of 180nm. also installed the pfclient and fr24feed. At the pfclient normal data rate is very good. Both pf and fr24 daily with 67k reports data.
Two days ago, i got my blue prostick, installed it and without or with the fa filter there is no different, setup the gain to variable 43 until 50 still getting the same status, normal distance is less than 120nm, and most far is only about 180nm. The stat display at the pfclient was totally low, i only can get about 45k of position report to fr24 and pfclient.
From the details, the blue one should be more powerful than the orange, but once installed, very disappointed. I am from malaysia, it is hard for me to get this and yet result was disappointed.
After tested a day, i decided to put back the orange with fa filter, then all the data rates was back to normal before the blue prostick.
Any idea which i been wrong or any suggestion ?
Thanks.
I got a ProstickPlus and hooked it to my collinear (Moonraker Radar 100, supposedly 6.5dBd) and it seemed seriously overloaded. I was getting almost no messages, and even with gain stepped way down it was just a trickleābasically the same overloaded performance as my Orange Prostick without a filter.
Adding the external FA filter, blue and orange seemed comparable. I donāt have a splitter so I canāt do an exact comparison.
If you live in a really noisy environment then you may need a filter.
I use cavity filter in addition to the hab/amp filter/amp on my radarcape(inbuilt filter too).
You could also try using one of the RTL-SDR metal cases to shield the dongle itself.
Did more testswith the Pro Stick Plus, full details here:
radioforeveryone.com/p/more- ā¦ tests.html
I think that some users might get worse performance with the Plus because the dongle overloads with high-gain antennas in an electrically noisy environment.
Every amplified RTL-SDR receiver balances on a thin red line between maximum signal reception and plain overload, so the end user should adjust gain in small increments. Try using the PS or PS+ on a signal like commercial FM, and see it for yourself what just one slider change does to received station.
Akos
Just make sure you add aftermarket thermal pads, enclosing a heat-sensitive and heat-generating object into a metal case is not really a good idea.
Iāve been using a 26" FA antenna with an orange stick for some time. I bought the pro stick plus, and after doing some reading here, I installed it in place of the orange stick, but I kept the external filter. Iām close to the center of Austin, so Iām in the category of lots of EF noise. I did see a slight boost in messages, maybe 5-10% improvement. Iām using the default gain, which is -10 (autogain).
Using the website to view my local activity, I can view the RSSI. They often exceed -2 for planes that are within a few miles of my location, especially if they fly directly over my house, which they do regularly. This can result in the track for the loud plane being lost temporarily, but it doesnāt seem to negatively affect other tracks, so I have not adjusted the gain downward. Well, I have tried, but I didnāt see a benefit, so I returned it to the default. I usually see several hundred positions over 250 miles daily.
Iāve also recently elevated my antenna a few feet higher on the mast. That increased messages most noticeably to the airport. Interestingly, watching planes travel down the main runway, RSSI is often between -2 and -5 at the ends of the run way but -10 to -15 in the middle. There must be some sort of obstruction between my position and the airport that blocks the center of the runway. Itās probably a low hill in the neighborhood just to the SE of my location. Thatās why I figure a small difference in antenna elevation makes such a difference in close-in positions. Itās simply picking up more activity at the airport. Number of messages from the airport can get really high if aircraft sit on the ground for long periods while continuing to transmit messages.
I notice the same thing here except that I provide my data through Plane Plotter. My numbers went down when two things occurred, I started sharing my MLAT data through Plane Plotter and when I switched from RTL1090 to DUMP 1090 for control program.
Here is my settings on DUMP 1090; dump1090.exe --interactive --net --net-ro-size 500 --net-ro-rate 5 --net-buffer 5 --net-beast --mlat
pause --gain -10
I am running the Pro Stick Plus.
The windows dump1090 is pretty ancient and unmaintained.
I have recently installed Flight Aware Pro Stick to my set up. It runs on a raspberry with the flightaware band pass filter, Uptronics preamp and LMR 400 cable. So far the greatest distance is 539klm, could some one tell me what is the expected max distance?
Maximum possible range depends on location. You can find maximum range at your location by following instructions in the First Post of this thread:
Thanks for that info. Range indicated on that site for my location doesnāt come near to the range Iāve managed. Cheers anyway
