[Lf] LF: Leaves]

[Andre' Kesteloot]

Dave wrote:

> Dear all.
>
> Whilst in GM this last week I noticed that I couldn't get the 3A antenna
> current I got when I was last up there, in early spring. I supposed the
> reason to be the amout of leaves on the trees which totally surround ( and
> support!) the antenna.
> I went in search of the elusive extra 200mA by raising the antenna and
> adding more top wire up to the new higher support. Although the top was then
> about 3mtrs higher at  the centre point and another 6mtrs of wire had been
> added, there was no increse in current.
> I added a few more earth wires, again a waste of time...
> I assume the higher top made an improvement as, the same current into a
> higher antenna is better but I couldn't test this.
>
> I then went for a drive to the coast with a 2.5mtr whip via a tuned pre-amp
> feeding the Alinco DX70 which was tuned to DCF39 on 138.8.
> I kept an eye on the S meter and noted the following.
> Best signal was in open, flat, coutryside.
> Trees by the roadside made a big difference (worse).
> Being beside a freshwater loch (lake) appeared to make no difference.
> A bridge over the estuary was pretty good.
> Being near the sea was no better unless you were VERY near.
>
> No surprises there then.....
> I wonder if I had used a magnetic receive antenna, (loop or rod) whether it
> would have been so affected by the trees? If not, would a TX loop be better
> where there are a lot of trees?
>
> Dave G3YXM.