I have brought open wire line, 6" spacing, through an aluminum storm window and
fed it with 700 watts on 75 meters with no problems. In the ARRL Antenna Book,
at least my older editions from the 1950's, state that open wire will not
radiate unless an unbalanced current condition exists or the spacing exceeds
one percent of the wavelength. As long as the spacing is held to less than one
percent of the wavelength, I do not see how the frequency would matter? On
vhf, if my math is correct, one percent of the wavelength on two meters would
be about 20mm or about 3/4". This is why TV foam type transmission line makes
great balanced transmission line for 160 through 2 meters for moderate or low
power. What Mr. Maxwell was refering to about his statement " A low vswr will
kill you ! " is the fact that many hams will only operate their transmitter
within a narrow bandwidth based on the vswr characteristics of their antenna
and are completely hostile and close minded to the correct idea of tuning
antenna system to resonance so they can operate anywhere. Of course, this
attitude is still very pervalent amoung hams including this reflector. - Corn
k4own.
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