Stefan wrote (28th Dec):

> The wire is about 70m long and 30m above ground (average).
> I can measure C ~ 480 pF.
> The wire is out of stainless steel with 10mm diameter (or 12?).

Stefan wrote (2nd Jan):

> ant.jpg

Thanks.  From Google it looks like the wire length is 53m.

I put the significant buildings into LCnetgen and it
gives antenna capacitance 402pF with 12mm wire and
392pF with 10mm wire.  I've assumed those service rooms
on the roofs are 3m high.

I can't find a way to make 480pF.  Something wrong there.
Google shows the horizontal gap between builds = 42m.

As the model stands, effective height is 10.9m

When you resonate the antenna with a coil, do you find that
the resonant frequency agrees with 480pF antenna cap or are
the resonances higher than you expect?

--
Paul Nicholson