Nav splitter for GTN650 / SL30

[Azpilot]

Whilst wading through my panel, I’ve noticed my GTN and SL30 share a Nav antenna (combined VOR/LOC/GS) with a simple tee splitter (BNc) connections. When I first bought the plane, it had the GTN and a GPX300xl (no nav), so I’d assume the person who installed the SL30 installed the tee.

Upon consulting the book or armaments (the GTN install manual), I see they actually want a fancy splitter (not a simple tee). The mini-circuits zfsc-2-1b+ Is acceptable, per the install manual.

https://www.minicircuits.com/WebStore/dashboard.html?model=ZFSC-2-1B+
For Those in the know, what does such a box actually do for you (beyond comply with the Word According to Garmin), versus a simple tee in a Nav arrangement?

 

[EchoDelta]

 

[reb]

 

[Azpilot]

 

[Jesse Saint]

 

[kshaw]

 

[Jesse Saint]

 

[NorthernAviation]

 

[Jesse Saint]