17th. Sept. 2007/ 4.6.08
Loop with magnetic loop. The diameter of the magnetic loop is only 1/10
bis 1/100 of the wavelength!
On September 15th I performed an
interesting comparison with a horizontal loop antenna.
This happened during a shortly planned demonstration during the day of
the open door in the military barracks
of the communication troops in Emmental.
In addition to the planned operational demonstration of the antenna, we
could make a signal comparison between
the RoomCap antenna and the station HB4FF.
HB4FF could use the best HF antenna of the barracks there.
The operating stations on 40m SSB
had the following technical data:
Station HB4FF :
Transmitter: Yaesu FT-1000
Power: 100 Watt PEP
Antenna: Horizontal wire loop over the
Hight above ground = 9m
Wire length of loop = 80m
Feeding: Automatic Tuner SG-230 in feeding
point of loop with SWR 1:1
Low loss 50 Ohm coax cable to transmitter.
Station HB9ABX/m :
Transmitter: Kenwood TS-50S
Power: 100 Watt PEP
Antenna: RoomCap with 1.5m
radiator length without top capacity
mounted on the car as seen
in the picture:
In the foreground HB9ABX/m with the white RoomCap antenna.
The loop antenna over the field in front of the group of trees.
In front of the left tree of the group one sees the left pole of the
loop, in front of the most
right tree one sees the right pole, and in the center front the pole
with the feeding point.
The back poles are nearly invisible.
10:00 MEZ: OM2AD, Erwin in Slovac Republic (Malacky)
Report for HB4FF: 5 8 bis 9
Report for HB9ABX: 5 9
10:50 MEZ: TM2RCW, Jean-Mark in Bordeaux, France
Report for HB4FF: 5
Report for HB9ABX: 5 9+20db
Jean-Mark emphasized: HB9ABX is good 10 db
stronger than HB4FF
Here you see the explication and demonstration of the antenna to the
followed by the QSOs.
The following HAMs participated in this demonstration:
HB9CVB (thanks for the pictures!)
And afterwards we received a fine dinner offered by the military camp.
Here follow two links about the horizontal wire loop antenna
by the recognized expert L.B.Cebik, W4RNL (SK April 2008):
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On May 20th, 2008 a large test was
conducted, that confirmed the results obtained
in this test. Here is the large Test.