I have a small
collection of information about old and modern military HF antennas
used over the World. Presently, two modern automobile HF antennas are described
at the article. The antennas are written “as it is,” i.e., I give
all information, that I have had. I know, the information is
not complete at all, but, nevertheless, the information is interesting
and it can help somebody to make own ‘car antennas.’
The basic types of military
antennas, which for a long time were used on communication cars, were construed during and before the World War II.
After WW-II researches for new antennas for communication cars
was renewed. Below we shall
consider two new type of car antennas
which have appeared in army after the World War-II still are in
use on modern communication car. There are magnet antennas and DDRR
antennas, that began to be used for communication cars (under
my information) rather recently - in the middle of 70s years of
the 20 century.
corner of the magnet antenna. Driven loop is coupled to the
transmitter with the help of a coaxial cable by characteristic
impedance of100 Ohm. The sizes of the army magnet antenna for
operation in 150 - 80 meters are exhibited in Figure 1b.
Mag Loop antennas of communication cars for 90 - 60 meters
Also magnet antennas are used for operation in HF range
of 90-60 meters. Such magnet antenna has smaller sizes as contrasted
to magnet antenna intended for operation in 150-90 meters. Magnet
antenna for 90-60 meters owing to its small sizes is installed
or above the roof of the cabin of communication
Loop antennas of communication cars for 150-80 meters
As usual a magnet antenna of the range is installed
on a communication car as it is shown in Figure 1. The magnet antenna ensures sure communication
in radius of 200 kms at the daylight time and up to 400 kilometers
at the night time.
Figure 1 Magnet antenna on a communication car
The magnet antenna at marching condition is installed
parallel to the car roof (see. Figure 1a) and does not hinder to ride the car
under low bridges or under trees in forests. The magnet antenna
stands in operating position with the help of an electric motor
or by operator hand. Figure 1b
shows the zenith magnet antenna in the operating position.
The magnet antenna (item 2, Figure 1b) is tuned in resonance on the operating
frequency with the help of variable capacitor (item 3, Figure 1b), which is weatherproofed by hermetic
box (item 4, Figure 1b).
The variable capacitor is turned with the help of an electric
motor. The magnet antenna is drove by a small loop (item 1, Figure
1b) that is installed in
car (see Figure 2) or at back edge of the car (see Figure 3).
At this installation of mag loop the roof of the car is free to
place other antennas or some more electronic equipment. The sizes
of the magnet antenna for operation in 90 - 60 meters are exhibited
in Figure 2 and Figure 3.
2 Magnet antenna
above the roof of the car cabin
3 Magnet antenna
on the back edge of the car
The magnet antennas
shown in Figures 1-3 usually are made of an aluminum bent
tube in 20- 40 millimeters in OD and 2-3 millimeters thick.
for 150 -90 meters is not intended for operation when a communication
car is moving. But Magnet antennas for 90 - 60 meters can be used
when a communication car is moving.