The Tuners in FlightStick (green or red) are NOT tuned to any frequecy. It is the software using the dongle which tunes the dongles to 1090 Mhz or 978 Mhz (or any other frequency).
As far as I know, the AirNav software for Windows by default tunes the dongle to 1090 Mhz.
If my understanding is right, then if you plug in a green dongle or red dongle or a generic DVBT dongle, all are tuned to 1090 Mhz by AirNav software.
If these dongles are plugged in RPi, and used by software dump1090, these are tuned to 1090 Mhz. If used by software dump978, these are tuned to 978 Mhz.
Now the big question: Why these dongles are designated 1090 and 978 when their tuners are not pre tuned to these frequencies?
The answer is that the green dongle has a filter for 1090 Mhz and the red dongle has filter for 978 mhz. Since the Generic DVBT and Black microRadarbox do NOT have filters, these are not marked as 1090 or 978. These can be used for any of these frequencies, and even for Air Band, FM and Acars, or any other frequency in the range of their tuner chip R820T or R820T2 (24 Mhz ~ 1766 MHz).
Although richk107's 978mhz dongle is tuned to 1090 Mhz by AirNav software, he does not see even 1090 mhz adsb planes because his 978 Mhz antenna and red dongle's 978 mhz filter weaken the1090 mhz signals so much that these become unuseable.
CONCLUSION:
If my understanding is right, then to receive 978 Mhz UAT, use RPi and install rbfeeder with dump978-rb.
If my understanding is wrong, please ask support how to set AirNav Windows software to receive 978 Mhz.
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