I'm building the ADC-40 made by KD1JV.
I would like to know what kind of 10.7 FI is used as filter because there
are several type of FI with different characteristics spotted by different
color.

He says he used a Mouser 42IF123 "green" IF transformer but he notes
that 42IF122 "brown" works too. It's there primarily to be a easy 7
MHz resonant circuit although the impedance transformation is a useful
side effect here.

Thanks a lot Tim.
But it is amazing because the two FI have very different impedances :
42IF122 = 15K/0.3K
42IF123 = 25K/4K
Which are rather distant from one another...

OK I will try