I read a broadcasting industry study last year (I'm sorry but I stink at
remembering sources so I can't cite it unfortunately other than to say I
think it was in IEEE transactions on broadcasting) that compared field
strengths for different length medium wave vertical radiators with different
ground systems in terms of no. of radials and lengths. There were
combinations evaluated using: 45, 90, 120 and 180 degree verticals, and 45,
90 and 180 degree length radials in numbers of 60, 120 and 240. The
conclusion I came away with from looking at the measurments was that while
height of the vertical is definitely a factor, the ground system was the one
single thing that made the biggest difference in field strength. The f.s.
of a 45 degree vertical was not much less than a 90 degree all other things
being equal. but a 90 degree stick with double the no. of radials had a
substantially stronger field. In other words, it is nice if you can go up
more than 50 or 60 feet but if you can't, then put down at least 60 radials
(90 if you want to feel good) and don't worry about the lack of 20 feet of
vertical height.
73,
rob / k5uj
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