Best Reception Possible?

[kd9gud]

I’m just wondering if anyone has done a comparison with a Generic RTL2832U and the Flight Aware USB product. I’m currently running one of the external flight aware antenna’s and a Nooelec dongle. I’m seeing planes out as far away as 226 miles ish. I live where the crickets have banjos in southeastern indiana on a farm and don’t have much around me. Has anyone had any luck adding the bandpass filter and seeing better range.

Looking for ideas to optimize and not break the bank. Or, maybe I should shut up leave it alone etc.

Current Setup.
Pi3b
external flight aware antenna
Antenna height 12 feet
850 ft above sea level
Nooelec Generic SDR Dongle.

[Dxista]

@kd9gud

Or, maybe I should shut up leave it alone etc.

Sounds like deep inside you already know the answer.

Jokes aside, you are doing well. If you can afford the FA Pro+ stick, I would say go for it, but not more.

[chrislfa]

Hehe, I agree, the Pro Stick Plus would extract as much as it can focused on 1090Mhz, and if you can get the antenna up a few more feet that might extend the horizon a little in the SW/NE directions (although that’s just based on this one image, it might be fine already). But I agree, that’s a nice coverage already.

If you install Virtual Radar Server (quite tricky) or OL3 (easier) you’ll be able to create a coverage map over time which shows where your gaps are. Let us know if this is of interest.

[foxhunter]

The blue ProPlus Stick is a good option which offers almost the maximum. An additional Filter or Amp can help, but that’s not necessarily the case.

It depends on your max range you can get. If you already reach this (like me) there will not be that much what you can do. You need to check heywhatsthat.com and compare to your current results.
Beside that there are tons of threads here which made comparisons.

Here is mine with the blue ProPlus stick only. To the left the blue border shows the max range i can get based on geography, the right shows the current range the last seven days. Pretty similar, so i would not see large improvements.

[kd9gud]

It doesn’t appear as I am that far off. I think I’m going to go up and try to move it up a few more feet. Nice tool by the way on heywhatsthat.com

[kd9gud]

Current antenna situation, yes I know I have to cleanup the coax situation. I made a little standoff for it, It’s on the same pole as my GMRS repeater antenna.

[chrislfa]

That’s a nice antenna setup!

A quick note on HeyWhatsThat – if you’re using it online always make sure to specify ?refraction=1 in the URL, in otherwords this:

HeyWhatsThat

That enables the Refraction box on the website where you can enter the value 0.25 which is correct for our use, ie 1090 Mhz through air. If you don’t do this then it won’t show an option for Refraction and by default under the hood will use 0.14 which is the correct value for visible light through the air, that being the primary purpose of the site.

See this post from me where I found this out when getting to the bottom of a discrepancy.

[kd9gud]

I’d like to go up on the tower with the TV antenna with it, but… It’s not the climbing that scares me, it’s the sudden stop when I fall and I hit the roof or the ground. Plus, if I survived, my wife would kill me for messing with something trivial and getting hurt

[foxhunter]

@kd9gud

Plus, if I survived, my wife would kill me for messing with something trivial and getting hurt

No worries, that’s normal. If i tell my wife “I am going to improve my antenna” she always starts rolling her eyes and asking me “What’s the outcome of all your stuff”?

@kd9gud

Nooelec Generic SDR Dongle.

Just seen that. You might start thinking about an additional Filter or LNA
Could improve other things like message rate and reduce unwanted noise.
An alternative could be a replacement with the blue FA Pro-Plus USB Stick. Filter and amplier is included

[kd9gud]

@foxhunter I ordered the proplus stick. I’ll have to advise once it comes in how it affects the reception.

[chrislfa]

Nice one, it’s a great bit of kit at a good price. It’ll be interesting to hear how it performs against the Nooelec now that you have a baseline. It might be worth whacking the OL3 html replacement onto your Pi; that way you’ll be able to create a range plot over a few days, like this one posted on Reddit. You’ll be able to see how the Nooelec compares for one week then the Pro Stick Plus.

To install it’s easy. SSH onto PiAware (I’m assuming you’re using the image). In your home directory grab the OL3 zip.

$ wget https://github.com/alkissack/Dump1090-OpenLayers3-html/archive/master.zip

Unzip it.

$ unzip master.zip

Move its html directory to the dump1090 directory, call it html-ol3

$ sudo mv Dump1090-OpenLayers3-html-master/public_html /usr/share/dump1090-fa/html-ol3

Change to the dump1090 directory

$ cd /usr/share/dump1090-fa

Rename the existing html as html-original

$ sudo mv html html-original

Rename html-ol3 as html

$ sudo mv html-ol3 html

That’s it, the PiAware bit is done. Now in your browser, close any PiAware pages and clear the cache and cookies. The easiest way is to just clear the lot, but if you have other sites you want to keep the cache and cookies for, just selectively clear them for the IP of your PiAware. How you do that depends on your browser.

Now load up the IP in your browser and you’ll have the OL3 version which includes the range plot feature. Hover over the blue icon to select options. If you’re in the UK there’s a load of military stuff which is of interest to some people which is why this OL3 mod exists, but the range plot is useful anywhere.

You’ll need to repeat the process of installing upintheair.json and any mods you made to config.js or script.js, etc, as those mods are inside your original html directory. That’s still there should you need to change back in the future. To do that just rename things back the other way around and clear the browser’s cache and cookies again.

$ sudo mv html html-ol3
$ sudo mv html-original html

[kd9gud]

Got the Prostick+ and it seems to have expanded the range just a bit. I’ll look through some of these other analyzers but from what i’m seeing it pretty much lines up with heywhatsthat

[chrislfa]

Cool, let it run for a while to get a feel for the baseline and how it compares to the one before. Then you can play with the gain, install graphs1090 to look at message rates, etc and try the OL3 html to generate a range plot.

[kd9gud]

@chrislfa imperial miles but still impressive, i wasn’t seeing that before.

[chrislfa]

That is impressive, it’s a worthwhile upgrade to your site. If you look at your stats page you’ll find yourself climbing up the 30-day ranking for a while as you move up away from your previous position.

[kd9gud]

@chrislfa yeah it’s been on its way up https://flightaware.com/adsb/stats/user/kd9gud#stats-119653

[chrislfa]

I was looking for you but you’re not there – don’t worry, that happens with quickly moving sites; they have already moved out the top in the time it takes to compile that block. As you find your new level you’ll reappear with a nice new higher ranking.

[kd9gud]

@chrislfa fortunately i’m located within a decent range of 3 airports, Indianapolis, Cincinnati, and Louisville. I also see a ton of planes going north up to Chicago as well.

[foxhunter]

You should install the graphs1090 provided by wiedehopf.
Additionally to some other fancy graphs it gives you also a long term overview about your range.

GitHub - wiedehopf/graphs1090: Graphs for readsb / dump1090-fa / dump1090...

Check the first graph for a while. It shows you a value named “Messages > -3dBFS”
This is a value indicating some very strong signals, can be interpreted as “noise”

You should target for a value around 5% of all messages, this is an indicator for your gain setting.
The default installation of dump1090 is setting the gain to -10. This is way too high in normal conditions for the blue stick.
You should search here in this forum for gain settings, there are tons of threads.

This is mine for the last 24 hours:

[chrislfa]

@foxhunter

Check the first graph for a while. It shows you a value named “Messages > -3dBFS”
This is a value indicating some very strong signals, can be interpreted as “noise”

You should target for a value around 5% of all messages, this is an indicator for your gain setting.

That’s often repeated but is there a source for that number being ideal? I’m certainly not disputing it but I’m curious to understand what’s special about 5%. Mine have been 20%+ without any apparent detriment, but then again my antenna is indoors so perhaps that attenuates any negative effects, and in open space it would matter more? That kind of thing. I’d also be interested to know where the -3dBFS itself comes from as some kind of threshold.

A handy tip with graphs1090 when you’re experimenting and looking at the effects of site mods – edit /etc/default/graphs1090 and set all_large=yes. That makes all the graphs wide like the top one. That’s really useful when you make a change, you can locate it in time and then scroll down the page and keep the mouse cursor horizontally fixed to locate the exact same point in time in every metric recorded. Makes it really easy to see things like “I changed my coax here, I see strong messages increased but maximum range decreased ever since”.