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Old August 13th 07, 07:17 PM posted to rec.radio.amateur.antenna
John Ferrell John Ferrell is offline
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First recorded activity by RadioBanter: Jul 2006
Posts: 199
Default Two Good Days Spent with Quads


Of course I will be trying this next idea even if no newsgroup answer is
forthcoming: What happens if I tap off quad #1 on the side _opposite_
where I'm feeding it and connect quad #2 there? Wouldn't this additional
load reflect back to feed #1 and lower its impedance toward 50 ohms? I
don't know what feed #2 would be. Perhaps a jury-rig parallel line
calculated to be 100 ohms would do it. (# 10 AWG wires on 5 mm centers would
do it.) Phasing will be an issue.
[I probably don't have a suitable test environment to tell success from
failure.]

73,
"Sal"


It is easier and cheaper to do phasing/matching harnesses with open
wire. Make it, don't buy it. Considering that a 1/4 wave is only about
19 inches you can make experiments with whatever wire is handy using
popsicle sticks ("craft sticks" at the craft store) and masking
tapefor the spacers.

Make a field strength meter with a diode and dipole connected to a
multi meter. space it about 30 feet in front of the quad. While
transmitting verify the elements are all working by touching each
element with a screwdriver.

Operate the transmitter at lowest possible power.

Too much fancy equipment gets distracting.

John Ferrell W8CCW
"Life is easier if you learn to
plow around the stumps"