[TowerTalk] Antenna modeling question

[n0tt1 at juno.com]

Gents,

I'd like to build a 40m phased array "inside" my 160m
receiving-only 9-circle and I want to check for any
interaction between the two antennas.

I have the layout in EZNEC 6, but I'm not sure how
to "feed" the 160m array.  Do I let it "float", ground the
elements or what?

Also, vice-versa...float the 7mhz array or....?

Suggestions?

Thanks,
Charlie, N0TT