[BC] Franklin MW Antenna Ground Unneeded?

[peterh5322 at rattlebrain.com]

>>From what I understand the 1530 in Sacramento was built with
>>no ground radials, as the consultant said it did not need any.
> __________________
>
> For another point of view, consider that a paper* by Charles L. Jeffers
> (then a senior member of the I.R.E.) published in the November, 1948 issue
> of the Proceedings of the I.R.E. included field intensity measurements for
> the elevation pattern of a real world, reduced scale operating model of
> the
> Franklin type sectionalized MW antenna system used by WOAI in
> San Antonio, TX ...

KFBK's are 180 over 180 and have no connection whatsoever across the base
insulator, which is indeed located about 1.5 meters above grade level.

WOAI's (two were built, both were abandoned, but not for technical
reasons) were 120 over 120 and had a capacitor across the base insulator.

The measured values appear to be at variance with the modeled values as
the measured values were made when the radiators were installed a great
many decades ago, and modeled values have only recently become available.

In particular, the measured values of WHO's 180 over 120 is quite
different from the modeled values as not that many angles of elevation
were possible, and considerable license was taken in smoothing the curves
to "show" that the radiator was truly anti-fading.

Now, from modeled values for a 195 non-sectional, we know that it is about
as anti-fading as one can get (NO high-angle vertical lobe at all), yet
the 180 over 120 measured values appear to be quite similar to the 195.

Not that WHO (and others) made a great mistake. They did what they thought
was best, given the little theoretical information which was then
available at what, in retrospect, was the "dawn of vertical radiators" (of
any type).