[UK-CONTEST] GM1J EU92 IOTA Report

[mm0bqi]

Hi Chris
Very much the same way as Ian.
 I locate the base by driving in a couple of three foot rods and use rope to
create the flexible swivel joint. Very important it is well secured because
as you walk the pole up all the base wants to do is to lift out of the
ground.  As you can imagine if it does spring out of the ground it has a lot
of force behind it so as always there should be no one hanging about the
base of the pole. Once the base is secured lay out the guys at 90 degrees
(two sets) as you woud for any mast then walk up.  Do NOT be tempted to
'support' it or pull it up using the un attached guys.  Walking it up keeps
all the stresses along a straight line, the pole will bend dramatically on
the way up but no harm will be done.
The other way to do it is to use a falling derrick arrangement (I thing
Bristol may use this?)
For me the golden rules are secure base, walk it up straight and to ensure
there are clamps at all the joints.  I suspect one of my sections slid
inside another during the storm a couple of years ago and then with slack
guys the pole just self destructed!
There are a couple of ways to set it up.  Hellically wind the wire round the
pole, slack twists will use up all the wire and does away with the need for
six feet or so coming away from the top of the pole.  Not sure what the
performance difference would be but suspect it may be very little.  I am
also unsure as to whether the use of the wire extension with the additional
guy wire securinging it to the ground could add unwelcome stresses to the
pole in adverse weather.  I have tried all the above and they have worked
well in portable situations.
There was some chat on the various user groups about using the pole to
support horizontal wires.  Generally this seems to be frowned upon as they
are designed not to have much horizontal strees once they are vertical (If
that makes any sense!!)
Although I am one of the few folk who have managed to destroy an 18m
SpiderBeam pole I think they are a great solution for LF antennas.  As such
a new one is on the shopping list for next years IOTA contest.
Good luck with the trip.
73
Jim,  MM0BQI



On 13 August 2011 19:59, Ian Pritchard <g3wvg at btinternet.com> wrote:

> Hi Chris ..
>
> If you're going to use a spiderbeam you may be intersted in this ...
>
> Some of the pictures in this link show the arrangement I used with my
> spiderbeam
> >>>>
>
> http://www.g3txf.com/dxtrip/MW5B/MW5B-10.html
> >>>>
>
> They are quite easy to erect single handed ...providing the ground is
> horizontal!  I made sure the geometry was correct for four way guying and
> then simply walked the mast vertical.
> The key to sucess is to allow the base to pivot 90 degrees without it
>  twisting. I made a simple short wooden "cage" to fit over the bottom of the
> spiderbeanm pole, this then swivels on a steel rod which passes through the
> top of a short piece of scaffold pole sriven into the ground.
>
> 73 Ian
>
>
> --- On Sat, 13/8/11, Chris Tran GM3WOJ <zl1ct1 at gm7v.com> wrote:
>
> > From: Chris Tran GM3WOJ <zl1ct1 at gm7v.com>
> > Subject: Re: [UK-CONTEST] GM1J EU92 IOTA Report
> > To: uk-contest at contesting.com
> > Date: Saturday, 13 August, 2011, 18:38
>  > Hello Jim et al
> >
> > Thanks for the interesting IOTA report and the 5 QSOs with
> > GM7V - being so
> > close to you makes working you difficult on some bands.
> >
> > A bit off-topic, but what is the recommended method - or
> > your experiences -
> > for erecting an 18m Spiderbeam pole ?  We've got one
> > for our upcoming
> > DXpedition but want to make sure there is no 'snap' sound
> > when we install
> > it.  I'm guessing the method may differ depending on
> > what wires etc the 18m
> > pole is supporting.
> >
> > This may be of interest to others on the reflector...
> >
> > 73
> > Chris
> > GM3WOJ
> >
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