This is an excellent question, I have also wondered what length a 1/4wl
buried radial theoretically is when referenced in various puplications.
There is no harm (except to your wallet) to using the physical 1/4wl wire.
N6LF did an excellent ground radial study which may help you decide what
you want to do.
GL,
John KK9A
To: "tower" <towertalk@contesting.com>
Subject: [TowerTalk] radial lengths ...
From: "StellarCAT" <rxdesign@ssvecnet.com>
Date: Wed, 30 Nov 2016 13:23:55 -0500
For the ‘experts’ out there ...
So question.... in ON4UN’s book it is stated in abundance that one should use
typically 0.25 wl radials... the length of course varies with the
properties of
the earth and the desired end results but somewhere around 32 1/4 wave
radials
seems to be within about 1 db of 100+ of the same length ...
but he also states, kind of “on the side” in one sections only (it seems) due
to the velocity factor attributed to the earth that 1/4 wave is actually
physically only 0.14 waves in length!
So which is it – when it is stated 32 1/4 wave is that physically 1/4 wave or
is it physically say 1/7th wave (and still electrically 1/4 wave)?!
so for example on a 160 meter vertical are we looking at 32 ~130’ radials or
more like 75’ radials (with the end of each of those not having enough
current
in them to contribute appreciatively to the current distribution)... ?
I know most will respond with 1/4 wave.... but I’d bet most would be going by
the generic statements of “1/4 wave radials for verticals”... if indeed
the VF
makes going beyond about 1/6th wave of very little value (again talking about
32 radials here – not 120) ... then why go through the effort?
if this is (more) clearly stated in John’s book please let me know where.
Gary
K9RX
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