[Lf] [Fwd: LF: Ant Questions]

[Andre Kesteloot]

Martyn Kinder wrote:

> Hi all,
>
> I'm about to put up a 136kHz Antenna and have a couple of questions.
>
> I don't have much space in the garden, approx 20m from the apex of the
> roof to a 20m high poplar tree in the opposite corner. I am considering
> an offset 'T' with a multi-wire top.
>
> I am assuming (within practical limits) that as much capacitance as
> possible in the antenna is beneficial. It will resonate with lower
> inductance and therefore lower resistive losses.
>
> The RSGB LF experimenters h/b (p52) suggests that 2 wires separated by
> 100mm will provide 39% increase in capacitance. Is it safe to assume
> that putting multiple wires up at 100mm will provide a compound
> percentage increase? I am considering 6 wires at 100mm separation. Are
> there any better solutions - I have neighbours I wish to remain on
> speaking terms with...
>
> What effect does height have on the antenna? I can fairly safely get the
> antenna up to 10m above ground level without too much difficulty. Will
> there be any significant benefit to raising the tree end of the antenna
> to say 15m.
>
> I will probably feed the aerial at about 5m from the house with two
> coils, one at ground level and a second 2 litre coke bottle sized coil
> at the junction between the vertical and the capacitive top.
>
> Sorry for the newbie type questions. Getting this right first time is
> important, neither the tree nor the apex of the house are particularly
> easy to get at and I don't want to do it too many times...
>
> 73,
>
> Martyn G0CZD