antenna was installed outside of my balcony in the second floor.
The antenna really served as Clothes Dryer so nobody knows about
its real application.
was fed through an ATU. Figure 2 shows schematic of the ATU. Schematic
of the ATU is close to a military ATU that used with such type
of antennas. Capacitors C1, C2 and C3 were air dielectric from
old tube receivers.
capacitors were 12- 495- pF each. All capacitors were installed
on isolation plates. Only stator plates were used in the capacitors
for connection to ATU. C1 was rotate through a plastic shaft.
Capacitors C2 and C3 were tied through isolation shaft that provided
its synchronous rotation.
L1 was tuned to resonance with the transmitting frequency. L1
has 20 turns Taps made from the hot end then from 15 and 10 turns
(from the cold end). The inductor was wound by copper wire in
1.2- mm diameter (17-AWG) on form in diameter of 50- mm, gap between
turn is 3.5- mm.
L2 helps match the ATU with transceiver output. The inductor has
5 turns of copper wire in diameter of 2.2- mm (11- AWG). The inductor
is wound in the center of L1. Taps
made from the hot end then from 4 and 3 turns (from the cold end).
With the ATU antenna could be tuned from 1.8 to 14.5- MHz.
I is possible tune the antenna up to 30- MHz if change L1 and
L2 to appropriative ones.