(ΦωΦ) Catudp's blog
I installed the RTL-SDR Blog V4 on January 30.
The following morning (January 31), I compared the results against the baseline from January 28.
For this setup, I chose the USB Type-C version.
One important note: the V4 requires the official V4-compatible driver from the RTL-SDR Blog website. https://www.rtl-sdr.com/V4/
Updating the Drivers on the FlightRadar24, FlightAware and OpenWebRX Raspberry Pi4 Images
Set up your FlightRadar24 image as normal, then either log into SSH or attach a monitor.
The FlightRadar24 image has default credentials pi/raspberry, pi/flightware for FlightAware and pi/adsb123 for ADSBExchange. Not on the FlightAware to enable SSH, you need to create a file with filename "ssh" on the boot folder of the SDcard.
Once logged into the terminal, run the following commands to update the librtlsdr packages.
sudo apt update
sudo apt install libusb-1.0-0-dev git cmake build-essential
sudo apt install debhelper
git clone https://github.com/osmocom/rtl-sdr
cd rtl-sdr
sudo dpkg-buildpackage -b --no-sign
cd ..
sudo dpkg -i librtlsdr0_*
sudo dpkg -i librtlsdr-dev_*
sudo dpkg -i rtl-sdr_*
sudo reboot
The guide says “Now reboot your Pi4 and it should work.”
Even though it mentions Raspberry Pi 4, it also worked on my Raspberry Pi Zero 2 W.
After installing the driver, I searched for the best gain setting.
I tested from 38 dB up to 49 dB, observing a few minutes at each step.
I ended up using 48 dB.
However, compared to my previous clone dongle, the V4 didn’t perform as I expected.
Short comparison (same time of day)
To reduce time-of-day bias, I compared the morning window on Jan 31 with the same morning window on Jan 28.
The difference becomes clearer when viewed visually. Example (simplified):
Same morning window (UTC 00:00–06:00) used for comparison.
Note: Y-axis differs because these are FR24 screenshots.
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Jan 28: HITS 1000 / POSITIONS 500
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Jan 31: HITS 400 / POSITIONS 200
(Weather conditions were comparable on both days, reducing environmental bias.)
On Saturday morning, with many aircraft expected, I decided to revert.
Because the V4 driver is backward compatible, I kept the driver installed, kept 48 dB, and swapped back to the clone dongle, then rebooted.
I was in a hurry—thinking “I’ll fine-tune it later.”
But when I checked the PiAware map, I paused.
“Why am I suddenly seeing aircraft over Toyohashi?” That had never happened under the same conditions before. (About 200 km / 124 miles from my location.)