my interest is peaked now.

C.Aymon wrote:
During the month of november 2004, a group of swiss radio-amateurs have the
unique opportunity to use the antenna system of Swiss Radio International in
Sottens. The call used for this special event is HE3RSI. Pictures of the
antennas are available here http://www.hb9mm.com/photos/Sottens2004

The antenna has been build in the in the beginning of the seventies. Today,
using powerfull computers and software, it would be very interesing to
modelize the antenna and check if the expected and measured gains and
patterns can be retrieved. For all of us who are interested in antennas
simulations, I post here the structure and the dimensions of the Sottens
antenna.

The antenna system consists of two antennas of the same structure. One
antenna (A) is for the band 9..15 Mhz and one (B) for 15..21 Mhz. Both
antennas are ''suspended'' on both sides of a reflector, please see the
pictures to have a better view of the situation.

Here is the antenna ''A'' structure (all dimensions in meters):

1) The antenna consists of 8 full-wave dipoles, each of length 19.7m

2) The 8 dipoles are organized in two identical groups of 4.

3) One group consists of 4 stacked dipoles, in a vertical plane. The lowest
dipole is at 22m above ground, then the second is 9.2m above the first, the
third is 11.40m above the second and the fourth is 9.2m above the third.

4) The two identical groups of 4 dipoles are put side by side in the same
vertical plane. The horizontal distance between the centers of the dipoles
of each group is 21.33m.

5) All dipole are center-fed in phase via (a system of) transmission lines
of the same length.

6) Each dipole is actually made of 3 parallel wires of 4.1mm diameter and
0.66m apart. The three wires of a dipole are in an horizontal plane.

7) The dipole groups are ''suspended'' in front of a reflector at a distance
of 7.4m of the reflector.

8) The reflector consists of (abt) 120 wires, of length (abt) 46m, stretched
between two towers of (abt) 63m heigh.

9) The whole system is rotatable and weights about 135 tons.

It would be interesting to have the gain and the pattern of the antenna on
all amateurs bands from 7Mhz to 28Mhz.

I am ready to (try to) answer to any question, or provide any missing
information.

To your keyboards

Best 73 de HB9DBC, Chris