What is the input impedance of the receiver stick?

[abcd567]

@uski
Here is your answer

FlightAware Pro Stick, revolutionary USB ADS-B/MLAT receiver

All R820T2 radio chips are 75ohms. There is no way around this unless they redo that chip. The input for the prostick is 50ohms which is then fed into the amplifier which is then fed into the 75 ohm radio chip.