This is a question that seem very basic, but in fact it is not.
What is the input impedance of the FlightAware Pro Stick and Pro Stick Plus ?
SMA connectors are 50 ohms so it should be 50 ohms. However, the R820T2 chip has an input impedance of 75 ohms according to RTL-SDR. This is because it was meant for TV receivers which use 75 ohms antenna systems.
However it is possible there is an impedance matching in the stick.
And unfortunately the specifications do not list the input impedance so it is not possible to know… so I have to ask ! I think only FlightAware can answer as they are the only ones to know what hardware they did put (or not put) inside.
Why does it matter ? Because I am trying to impedance match my antenna and I need to know what impedance the receiver is expecting…