Contrary to the belief of many, a beam located at a lower level on the
tower does not "shield" any top loading which is above that level. The
lower beam merely has less top loading effect than if it were mounted
higher. I can see no difference in this if the beam is side-mounted.
N0FP's measurement of 400 + j160 ohms for his shunt feed means that the
shunt feed tap onto the tower was far too high above ground. At some
lower point on the tower he would've found an impedance of 50 + jX ohms
which, after tuning out the reactance with a series capacitor, would
yield a perfect match to 50-ohm coax.
73, de Earl, K6SE
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