[TowerTalk] 80 Meter Quad Bandwidth

[W5PR]

Two questions about an 80 meter Quad.  

Two element quad with .15 wavelength spacing one element on each side of the tower in a "diamond" configuration (points up, down, L & R) bottom about 10' off the ground, feeding the DE at a corner for vertical polarization.

1.  How much might the vertical tower in the middle of a                         vertically polarized quad degrade its performance?

2. What kind of a bandwidth should I expect?  Can I tune it for             3.7 MHz and work from 3.5 to 3.9 MHz?

Thanks,

Chuck W5PR