Thread: ART'S ANTENNA
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Old July 16th 08, 03:11 AM posted to rec.radio.amateur.antenna
Richard Clark Richard Clark is offline
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First recorded activity by RadioBanter: Jul 2006
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Default ART'S ANTENNA

On Sun, 13 Jul 2008 13:48:52 -0700 (PDT), derek
wrote:

he took some swr readings they were as follows.

SWR
1.8 = 1.2 :1
3.75 = 1 :1
7.075 = 1.7 :1
14.075 = 4 :1
21.075 = 6 :1


On Tue, 15 Jul 2008 17:18:22 -0700 (PDT), Art Unwin
wrote:

The SWR meter he is using is referenced to 50 ohms so his readings are
false.


What a curious indictment of this design. When it "works" (built to
the authur's specification too) it is a false antenna.

Of course, there are any number of oddities struggling for oxygen in
this goldfish bowl.

he can put the up and down wires in parallell

and it thus fails:
1. to be the loop Guss designed;
2. to be in equilibrium.
such that the 1100 feet of wire
which is two wavelengths of the top band when wound in series is now 1
wavelength and the impedance will change accoringly.

Equilibrium demands 1 wavelength, but the authur allows up to 100%
error. Pretty loose equilibrium there.

So what does equilibrium mean when both a loop of 1100 feet (not a
wavelength at 160M) and half that, 550 feet (not a wavelength at 160M)
are prescribed simultaneously?

When a half-wave, thin-wire dipole is called for, millions of radio
operators for 3 centuries understood that to be 95% of 262 feet
(accounting for end effect). A full wave loop was similarly closer to
525 feet than 1100 feet.

The oddities abound, but those above are enough to ignite a bonfire of
the vanities.

73's
Richard Clark, KB7QHC