[RodB]

I guess I would start with a connection to the freq counter. If it's a BNC, then use that, whatever it needs. Next use a coax cable that has the same impedance as the freq counter input, probably 50 or 75 ohms. Then,, since the RF has 2 sources, attach aligator clips to the free end of the coax. Now you can switch between the two RF sources. If you want to have it permanent then you need a switch to select RF or HI RF. The switch may make the HI RF act strange or induce noise. Be very careful as to how the grounds of the 2 units are handled.

Rod