info request about "up/down converter" and "if frequency"

[ik1wvq]

HI SV8ARI,
I am Mauro IK1WVQ from Italy,
can you please explain me the use of "up/down converter" and "if frequency" ? (version 0.19a)
I am a microwaver and I use the SDR-RTL dongle as output of a LNB tvsat, with OL 9750MHz.
It is possble to read on the spectrum windows the true frequency??
example: setting 700MHz, reading 9750+700 = 10450 MHz ...
thanks a lot for your attention and compliments for this VERY nice software...
kalimera.
73 de Mauro IK1WVQ

P.S.: if I try to put any value on the "if frequency" box, when I press ENTER key the software
hangs-up completely .. if Itry to write this value into "config.csv", this is ignored !!