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Old November 14th 10, 02:25 AM posted to rec.radio.amateur.antenna
Owen Duffy Owen Duffy is offline
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First recorded activity by RadioBanter: Dec 2006
Posts: 1,169
Default Which is better: 5/8 wave vertical or J pole?

Owen Duffy wrote in
:

"Peter" wrote in
:

....

My current 5/8 wave ground plan project is simply to get something on
air, however I plans to construct an improved version with the tapped
coil approach.


That lets you shorten it for a bit more gain, and a good match.

If you cut the vertical for 0.6 wavelengths, you should think of
starting with an inductor with reactance towards 1000 ohms.


I meant to elaborate on this a bit more. (Did I hear someone groan?)

If for example, the feedpoint Z of a 0.6 wave vertical over four quarter
wave radials was 150-j500, your tapped coil matching network can be
designed using bulk standard circuit theory to transform 150-j500 to 50
+j0, and nowhere do you use the missing 54° in those calcs. That might
suggest that the "missing degrees" are some kind of explanatory crutch
(or ham speak) that is not directly related to solving the problem.

Owen