Carl. I quantified ground loss in the near field. Now it's your turn. Numbers please, not adjectives or hand waving. _______________________________________________ It is undesirable to believe a pro
Carl, What we do in the near-field to control ground loss affects the far-field signal equally at all elevations. Therefore there is no need to measure far-field field strength at more than one eleva
Carl, why would we need a helicopter when we have simulation software? How much ground loss, or if you prefer, what difference in field strength do you calculate for a half wavelength vertical with a
Dave... would it be a fair extrapolation to take your last sentence, and draw the conclusion that if adding radials changes feed impedance, then there was actual ground loss in the near field? Or tha
It seems to me that a 1/2 wave monopole would need longer radials than a 1/4 wave vertical to help accomplish that. The point of current max on radials under a 1/2 wave ground-mounted vertical would
I've seen lots of reference to Kraus, Brown et al., and others in this discussion, but this is the first time I've seen anyone trot out a philosopher to support their position regarding radials. I wo
Tim, I believe those are valid conclusions. Referencing *Vertical antenna ground system experiment #1*, by Rudy Severns: 1) Table 1 shows that going from 8 radials to 64 radials increases field stren
Dave... would it be a fair extrapolation to take your last sentence, and draw the conclusion that if adding radials changes feed impedance, then there was actual ground loss in the near field? Or tha
Gentlemen-- I am learning a LOT, but there is a Great Deal of confusion (at least in my mind) because at least three quite different conditions are involved. We have the base fed 1/4 wave vertical; t
Tom is correct in that a half wave vertical wouldn't have zero current at the base feed point; I should have said "near-zero", since if it actually had zero current there would by definition be zero
If the issue of have "something to push against" were critical, the obvious work around would be to feed the vertical dipole in the center. Apparently, this issue is not all that critical because hal
Tim, I ran some sims using a work-around I developed to allow NEC-2 to mimic NEC-4 ground loss results. This sim is for a 90 degree, 1.8 MHz vertical over Medium ground. I get correlation within 0.06
In 1937, Brown, Lewis and Epstein of RCA Labs published a benchmark experimental study of this in the Proceedings of the IRE - still covered by copyright. But clips from it have been available on lin