Suggestions for optimization

Hi guys,

I’m currently in the process of optimizing my ADS-B flight tracking setup. Before I start this I’d like to see if you guys can spot specific optimizations in my setup.

My current setup:

[antenna] --(10m 50ohm cable)-- [FlightAware 1090 MHz ADS-B Bandpass SMA Filter] - [FlightAware Pro Stick Plus] - [Raspberry Pi 3]

Stats: https://flightaware.com/adsb/stats/user/Weppel

Antenna I have: https://shop.jetvision.de/epages/64807909.sf/en_GB/?ObjectPath=/Shops/64807909/Products/67020
10M cable I have: https://shop.jetvision.de/epages/64807909.sf/en_GB/?ObjectPath=/Shops/64807909/Products/70400

The cable runs through a duct besides a power cable (230V). In addition to that it’s 10 meters, which is quite long imho.

I’m specifically wondering if reducing the cable length to say 1-2m and placing the Raspberry Pi close by will help with reception. This also means the cable will not be running besides a powerline (230V).

Any thoughts?

Wessel

Light blue or dark blue filter.
Dark blue is much better for Europe, the light blue is too wide.

I usually suggest using this LNA because of the superb filters that are integrated: https://rtl-sdr.com/new-product-rtl-sdr-blog-1090-mhz-ads-b-lna/
(no other filters are required)

Requires power delivery via the coax: a bias-t.
Either external or builtin (rtl-sdr blog v3 dongle has builtin bias-t)

This LNA could be mounted in the box where you are proposing to put your RPi.
(it would likely even be an improvement mounting it in the current location due to the better filtering with less attenuation in front of the LNA and double stage LNA/SAW filter design)

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Light blue or dark blue filter.

Dark blue, sorry should have mentioned that.

I usually suggest using this LNA

Looks good, but I just bought the FA Pro Stick Plus. Would the RTL-SDR v3 dongle be better/same/worse than the FA Pro Stick Plus?

I’ve been running some graphs for the past 6 hours, here are the findings. I’m worried about the noise levels.

It’s convenient because it can supply power to the LNA.

Might be very slightly better, hard to say.
It’s perfectly feasible using the rtl-sdr LNA with an external bias-t and the pro stick plus.

Gain then needs to be set around 10 probably because of all the amplification.
But it’s been done successfully.
The external bias-t can be powered from the 5V on the RPi.

Example for an external bias-t:
Bias Tee Wideband 1mhz-3ghz for Ham Radio RTL SDR LNA Low Noise Amplifier 50vdc for sale online | eBay

Well you have the gain all the way up it seems.
What’s your current setting?

Try 42 as a start.

See this post for rough guidelines regarding gain:
Thoughts on optimizing gain - #2 by wiedehopf

I currently have it set to “-10”, the default setting after installation of PiAware 3.7.1 it seems.

I’ll adjust this to 42 and see what the results are, thanks for pointing out that setting.

About 24 hours have passed with gain at 40 (first 42, lowered it a bit after 2 hours or so). How does this look?

The possible gain values are:

0.0 0.9 1.4 2.7 3.7 7.7 8.7 12.5 14.4 15.7 16.6 19.7 20.7 22.9 25.4
28.0 29.7 32.8 33.8 36.4 37.2 38.6 40.2 42.1 43.4 43.9 44.5 48.0 49.6
-10

So i’d try 43.4 and 43.9 to be honest.
But the difference to a gain of 40 in regards to message count will probably be low.
(also the range difference will probably be negligible)

Hard to say how much improvement can be achieved by an LNA.

You should check this:
What is the Maximum Range I can Get?

If you have buildings close by they can also be limiting.