MAGNETIC LOOP WITH CAPACITIVE LOAD
FOR 30-10M
A light and portable Magnetic Loop Antenna
with improved Bandwidth and Performance
(Page [and Antennas!] under construction!)
I built this antenna according to a design by Gerhard, HB9ADF (Patent pending).
Equilateral Triangle Loop, Aluminium Profile 8 x 1mm, 1m side length,
suspended between two 3m Wires (20m Band) about 1.8m above Ground.
The ends of the suspension wires have to be folded back and twisted or shortened for 15, 12 and 10m.
75 pF Tuning Capacitor
Coupling loop with no galvanic connection to the magnetic loop
VSWR Curve, note 2:1 Bandwidth of 100kHz!
I made my first QSO with this antenna with Bernd, HA/DL3NAN/M on 14.252 SSB, 30W, true 59 on both sides.
The 2:1 bandwidth would increase with better adjustment of the coupling loop to a VSWR near 1:1 (in the above diagram 1.56:1).
The loop without the capacitive load of the two suspension wires has a bandwith of less than 30kHz and the capacitor is arching at less than 5W!
The capacitive loads can be placed in the plane of the loop, as above, or in any direction, anywhere at the periphery of the loop.
Capacitive loads near the capacitor,
2 aluminium rods 6mm x 1.5 m each, 90� to the plane of the loop
...and that's how the antenna looks like, suspended under the roof of my terrace
The first QRP QSO (FT-817 from batteries, 2W) with this antenna was with Tom, EA6AEU on 14.266 SSB, 55 for me, 59 for him.
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