FBC Tuners

[Iya]

Hi All
This question probably applies to all fbc tuners...not just the Gigabyte one.
I have my fixed dish (28 degrees, with Inverto Unicable II LNB IDLU-24UL40-UNBOO-OPP) plugged into one of the "F" sockets, and all is configured correctly (B thro H connected to A), and can record 8 broadcasts.
Silly newbie question is...What can I plug into the other F socket? I'd like to use a second (non Unicable) LNB pointing at Astra 19 deg).
Will I then be able to seemlessly receive either 28 or 19 broadcasts? If so, how does this second F socket appear in the setup....do I have to sacrifice Tuner H (or other) to use this second LNB?

Excuse the elementary nature of the question...as I say, I'm a newbie and am fascinated by this technology

Thanks
Iya