[TowerTalk] Antenna Problem

[Dick Flanagan]

Okay, here's where I could really use some help, fellas....

As some of you know, I finally got my antennas hung this past weekend.  The
arrangement is:

  Hy-Gain TH-11DX 11-element 10-12-15-17-20M yagi 1 ft above tower

  M2 6M7 7-element 6M yagi 6.5 ft above tower

  Cushcraft 40-2CD 2-element 40M yagi 13 ft above tower

The TH-11 was tuned for phone.
The 40-2CD was tuned for "high CW."

With the tower raised to 72 feet, all bands show good VSWR =except= both 12
and 40 are unacceptably high (2.8:1).  Both bands dip to minimum SWR where
they are expected to, but that SWR is simply too high.

The TH-11 and 40-2CD are connected to a common feedline via an Ameritron
coax switch that -grounds- the unused antenna.

With a minimum 10 ft separation between the TH-11 and 40-2CD, the
Conventional Wisdom said there would not be any significant interaction.
Me thinks I am seeing an interaction.

Any thoughts?  Words of wisdom?  Words of condolence?!  :)

73, Dick

--
Dick Flanagan W6OLD CFII Minden, Nevada DM09db (South of Reno)
Visit http://www.qsl.net/cvrc/



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