Topband: caveats when feeding two short verticals?

[doktorij at bellsouth.net]

I'm working on feeding two short top-loaded verticals that are mechanically within and 1/8 wave of each other. Hopefully, I can get some switchable directivity... But, I'd be tickled with an efficiency improvement feeding them in phase.

Is there anything in the way of problems I should be watching for? Gope to give it a dry run during the SP warm up.

73,
Julius
n2wn