Noted Antenna authority and modeler, L. B. Cebik notes that the end fed
Zepp, with ladder line feeder, (balanced line), shows only 10 per cent
imbalance for this extreme end fed case where one side of the line is open
circuit. Of course, the usual practical length of line must cause some of
this; but the 15 per cent as the point where you first might see imbalance
might not be far off the mark.
Lamp intensity is a very good indicator, if you have good eyes and back up
the lamp on each side with a flat black card. Particularly if you can do
the comparison in low ambient light, such as after dusk.
73,
Stuart
K5KVH
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