Software-Defined Radio (SDR) is a radio communication system which uses software instead of the more traditional hardware components like filters, amplifiers, mixers…
The RTL-SDR USB dongles can receive live radio signals using a Realtek RTL2832U chipset and send them digitally as raw I/Q (Inphase and Quadrature components) to any software like TXAdvance which can then perform any operation on them.

There are many SDR receivers but in order to work with TXAdvance, the SDR dongle needs to have the RTL2832U chipset and the R820T2 tuner. It is highly recommended to get a model with a TCXO. They are very common and can be easily found in amateur radio shops or Amazon.

To learn more about SDR and the RTL-SDR, please visit : https://www.rtl-sdr.com/

So to run a scan on TXAdvance, you need the following hardware:
– an Android device running at least Android 6 and OTG compatible
– an SDR USB dongle
– an OTG adapter cable
– a compatible antenna

The following links are affiliate links of recommended SDR dongles for TXAdvance and if you purchase something on Amazon using one of them, you will pay the same price that you would normally find on Amazon but a small percentage will go to Compasseur for sending you to Amazon.