Be advised, that
minimum SWR and maximum of the radiation power do not match in the
EH- Antenna. If you would like to tune the antenna on to maximum
radiation power use to FSM (Field Strength Meter) at the tuning.
FSM should be placed far away from the antenna. However, 2- 3- meter
is enough for that.
When tune the antenna by
minimum SWR check the FSM. Find the compromising tuning when good
SWR match to the maxima reading of the FSM.
Off
course it is possible to use a MFJ- 259 (or something similar)
for tuning the EH- Antenna.
If
the EH-Antenna will be installed outdoor you should provide protection
of the antenna against atmospheric impact. The simple solution
is to place the antenna inside of a plastic tube diameter of 50-
mm. EH-Antenna should be installed along center line of the tube.
Resonance frequency of the antenna may be changed. To tune the
antenna in the resonance install at the upper end of the protection
tube a closed turn. The turn may be made of a strip of the copper
foil (the same as used at the cylinders) in width 8- 10 mm. By
changing location of the closed turn it is possible to tune the
EH- Antenna.
Attention! Tuning of the
EH- Antenna must be done at cold Antenna. You must remove RF power
from the antenna! Dangerous high voltage may be present on the
part of the antenna.
Practice of the EH- Antenna
For some reason I
cannot install the antenna outside. So I hang up the antenna at
the first floor of my apartment turn on transceiver and go ahead!
EH- Antenna was placed only near 2.5- 3- meter above the ground.
Figure 18 shows EH- Antenna inside of my apartment. Figure 19 shows view from the
window of my apartment. Table 1 shows some QSOs made with
the antenna. I called the stations. I do not work on CQ. Almost
all of stations replied to me from my first calling. My transceiver
had output RF power 50- Wtts.
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