TopBand: Elevated GP vs. Vertical Antennas - long

[CQ K8DO]

The history of contesting and DX chasing has shown unequivocally that higher
antennas having a (presumably) lower take off angle (TOA) of the main lobe, to
be better overall than a lower antenna with a (presumably) higher TOA... 
You will find anecdotes where arrival angles are (for a short time) higher
than the peak response of vertical arrays and the antenna/array with a higher
response angle will make Q's whereas the DX is not heard or heard poorly on
the vertical array at that time... What I have not seen published is a
systematic attempt to test which transmit TOA the DX hears better under those
conditions, i.e. the high TOA antenna or the low TOA antenna... It is fallacy
to assume that the antenna which hears best is the antenna which "always"
transmits best... For those who believe that, try transmitting on your
beverage... I suspect that even in the high arrival angle situations the lower
TOA antenna may be heard better on the other end, but I don't know that to be
fact... I, like most hams, transmit with the antenna that hears best
(excepting my beverages :)  content with making the Q... We as a group need to
schedule a series of TEST(s) ( not contests) where transmit and receive
signals can be explored between high TOA antennas and low TOA antennas in
various propagation conditions...

The other issue I wish to comment upon is elevated radials...  Reviewing the
published works of Christman, Moxon, Sevick, Devoldere, et. al., it is clear
that for minimizing local ground losses the NAB 120 radial screen is as good
as it gets for unsalty hams... Accepting that as a given and accepting that
few hams have the energy and will to put down such a screen under each of 1 to
4 driven elements on 160 ( ON4UN being the exception who comes to mind), one
raises the question,"How many elevated radials is the most bang for the
buck?"... I asked the same question of Tom recently and while I am still
attempting to parse the various dB's quoted it appears that somewhere between
32 and 64 ground radials  is the breakpoint compared to 4 elevated radials of
1/4wl... Christman is of the opinion that 8 elevated 1/4wl radials is the
"most bang for the buck" .... My 160 array is in the 8 elevated radials
catagory and seems to be competitive with the top tier of contest stations in
the upper midwest, even if the operator is not <sigh> ... 

It appears to me that 8 elevated radials are closer to reality for the average
topbander than  a ground radial system of more than 64 radials....   

Denny


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