[TowerTalk] 40M 4-Square on 30M

Dick Green Dick Green" <dick.green@valley.net
Mon, 4 Oct 1999 15:28:59 -0400


I have a ground-mounted 40M 4-square with 60 radials per full-sized element.
The feed points have current baluns connected to RG-11/U phasing lines and
the phasing box is an old Colatchco unit. Everything is rated for legal
limit on 40M.

I'm not much of a 30M user, so it took a couple of years to get around to
playing with this antenna on that band. Turns out it's got decent
directivity and is about 20dB louder in the favored direction than my old
GAP Titan (is there any antenna that's *not* 20dB better than my Titan???)
Dumped power is from 6.5% to 5.5% across the band. Not too bad. SWR,
however, is about 1.6:1, indicating that not all of the refelected power is
making it into the KW dry dummy load.

I'm tempted to wire my automatic band switching equipment to make the
4-square the default antenna on 30M. My dumb question is, will the mismatch
cause damage to any of the components in the chain at the 200W limit on 30M?
I'm not even likely to run that much power -- the rig only puts out 100W and
I'd be embarassed to fire up the amp to get another 100W. Then again, if an
all-time new one showed up on 30M...

73, Dick WC1M


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