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Re: Ground Post Fitting Problems



Bob,

Here's what I would suggest:

The reason the antenna manufacturer wants you to mount the antenna in a hole in
the ground is to provide support so it won't tip over.  You can get that
support from a deep small diameter hole in the ground or from a shallow large
diameter hole in the ground.  Why not dig a two foot deep four foot diameter
hole rather that a four foot deep 1 foot diameter hole.  You could anchor the
"pad" really well by using the electric company's slurry fill method beneath
your hole and then pour concrete to fill the hole.  ( I hope you don't have
earthquakes.  That shingle is like ball bearings in a quake!)

As for your grounding problem.  The only way to get an RF ground is to use a
ground screen or radial system around the base of the antenna.  It will help if
you also connect a 1/4 wavelength stubs for your operating frequencies to the
base of the antenna.  This will not provide a DC or lightning protection ground
unless you also connect to the earth.  (I have assumed that the shingle layer
is not wet.  If it is connect to it.)

To get the correct size of the antenna base you might want to consult a local
civil engineer who knows the local conditions.

Good Luck on you project.  Let us know how it turns out. :^}

73's de Rich @ WC8J

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"Bob Wolk (G7SUU)" wrote:

> Thanks everyone for your replies, but perhaps I have not explained my
> problem clearly.
>
> My back yard consists of only loose pebbles down to at least 10 foot with
> nothing to bind them together, so the sides of any hole just fall in untill
> a stable slope is obtained. The local electricity company used to put there
> poles in by pouring a sand/cement slurry into the shingle and letting it go
> off over night before drilling out with a very powerfull drill.
> Unfortunately I don't think a hand held post digger would cope with it.
> Bob
>
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