[Elecraft] K3 Splitter for Loop RX Antenna ?

[F5vjc]

 I'd like to build an RF Splitter for my K3 to use my RX loop antenna for
either for diversity reception, connected to AUX RF (BNC) or use it for my
Main RX antenna connected to RX ANT.

I understand there is a suitable RF transformer splitter available from
Mini-Circuits Labs,
 ZFSC-2-1-75, but has anyone any details on how to build such a splitter?
 Core, windings etc.
Or why not just use a resistive splitter, too much insertion loss?

Anyone any ideas?

73, Deni F5VJC