[TowerTalk] 40-30m dipole design

[john at kk9a.com]

You probably could make a dual band rotatable dipole with two of these:
http://www.dxengineering.com/parts/dxe-4030-trap

John KK9A


To:	towertalk reflector <towertalk at contesting.com>
Subject:	[TowerTalk] 40-30m dipole design
From:	N1BUG <paul at n1bug.com>
Date:	Thu, 17 Mar 2016 11:29:47 -0400

While trying to figure out how to move up a notch from my inverted V
antennas on 40 and 30 meters I came up with a crazy idea. I was looking at
building a rotatable dipole for 40 meters, either full size or possibly
shortened. A 70% of full size linear loaded 40 meter dipole is nearly a
full size 30 meter dipole. Various articles claim only about 1 dB
reduction in "gain" from a full size dipole on 40. Could relays be used at
the dipole feed point to short out the linear loading, making a two band
antenna? It seems good in theory but if it were that easy, wouldn't
someone have done it already? I have no idea whether RF voltage across the
relay contacts when operating on 40 meters would be high enough to make
this impractical. Any comments, wisdom, or wild guesses?

Any alternative thoughts on building a 40 and 30 meter rotatable dipole?

73,
Paul N1BUG