Topband: Ground radials problem - Tnks
er_araujo at yahoo.com
Mon Mar 4 23:55:49 EST 2013
Joe, John and Dean, many thanks for your answer and suggestions.
I need to add that fence wire used is iron and not aluminum and it was installed 2 years ago.
I still wonder if the huge difference in current distribution between the ground pipe and the radial before and after the rain is normal for 60 lying on the ground (now buried) radials or if it is a clear indication something is really wrong with my radials and I need to replace them (add another 60).
Many thanks........... Eddy.-
> ----- Original Message -----
> From: "Eduardo Araujo" <er_araujo at yahoo.com>
> To: topband at contesting.com
> Sent: Sunday, March 3, 2013 10:06:34 AM
> Subject: Topband: Ground radials problem
> Dear people, I experience a situation that confused me a
> little bit.
> I have a vertical with 60 fence wire buried radials 1/4 wave
> long plus a ground rod.
> Prior to the contest I decided to check the buried radials
> of my vertical. I have bundles ranging from 4 to 7 radials
> connected to a square ring around the base of the tower. I
> provided 20W input and measured the current entering each of
> the bundles which is a procedure I have done many times.
> To my big surprise there was little to no current entering
> most of them except one which also had a ground rod.
> This bundle took aprox 80% of the total current. Then I
> decided to measure the current entering the ground road and
> it was aprox 100% of the total for that bundle.
> This situation was the opposite I always had measured where
> the ground rod practically had insignificant current.
> 2 months had passed without any rain so I tried to spread
> some water around a radius of 4 meters but situation didn´t
> change dramatically but yes an small increase in all radials
> That night I thought a lot of possibilities but the
> strongest was that for some reason most of the radials had
> Next day we have 27mm of rain. Another surprise, everything
> back to normal. I had current in all bundles and almost
> nothing into the ground rod.
> Question 1: I expected that having 60 radials it should not
> matter if it rains or not. I expected to have a relative
> good shield of the ground and besides if the soil was so dry
> why the ground road was collecting so much current from it?
> Any guess what could be going on ?
> Question 2: Could it be possible that radials could have
> been eaten by the soil and I am having very short ones ?
> I am planning to add another 60 and for a reason of cooper
> cost I am planning to use what I think should be similar to
> what I read here many times as WD1. It is for exterior
> telephony drop consisting of a pair of 0.8 mm of stiff wire
> which looks like iron covered by cooper and both separated
> by 3mm of a very heavy plastic. I measured 13 ohms of DC
> resistance in 60 mts of wire.
> My plan is to split the 2 wires and use them as radials.
> Question 3: It is a good or a bad idea to use this kind of
> wire instead of fence wire?. Cooper will be the last option
> of course
> Many thanks in advance for your opinions.... Eddy, LU2DKT
> Topband Reflector
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