DSN=24GHzTestEquipment  Equipment on 11N0v2015 KC0P/R

My Frequency Counter is HP 5342A Microwave Frequency Counter. Two Inputs are
marked : 10 Hz to 500 MHz, selectable 50 Ohm or 1M Ohm DL 3.5 V fused, BNC
and 500Mhz to 18 GHz DL +25dBm, Type N. Maybe DL stands for Destroy Level ?

Option 5 extends to 24 GHz.

So I need a way to connect both a 10 GHz Horn Antenna and 24 GHz Horn Antenna
to that N connector to read outputs of 10 & 24 GHz Gunn Osc.