last summer I experimented and hung up of the antenna behind my
balcony at 1.5 meters from a wall. I have received a significant
improvement of the work of the antenna The antenna does very good
operation in the ether, better than others indoors antennas. It
gives low industrial noise and kills all TVI.
I. Grigorov. Antennas for radio amateurs. - Majkop, 1998.
at his shack
All amateurs know
if at a vertical antenna a top load it is used, the self –resonance
of the vertical antenna would be lower then a vertical without
the top load. How a top load does influence to antenna resonance?
At Reference 1 I found a very
interesting table having the data. I have proved the table with
MMANA, all okey, the
table gives very reliable data, so it is possible to use it at
many situations. Figure 1 shows different top loads. Data for
loaded effect for the top load is shown in Table 1 given at Reference 1.
K is coefficient: K = W/L, where W is a resonance wavelength
for the vertical antenna, L
is antenna length from the ground to the top load.
As it is seen, the “umbrella” top load (Figure 1e)
gives the most effect on the resonance of a vertical antenna. For example, if to use an umbrella load for
a vertical antenna in five meters height, the antenna quarter
wave fundamental resonance wavelength would be changed from 20
to 50 meters!
V. Technique of radio: Simple AM receivers. – Moscow, DMK-Press,