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Pattern Width, half power points
Gain over single vertical
Side attenuation
Rear attenuation
Impedance
Directional Characteristics
VSWR: Exceptionally low SWR is present with a phased array. If phasing lines are
correctly measured and the terminal impedance of each antenna is very close to 50 Ohms:
Typical SWR: Broadside 1.2:1, Endfire 1.4:1, Cardioid 1.2:1.
The 1/4 and 1/2 wave transformers, identified as L3, L4 and L5 are calculated from the
lowing formula:
1/4 wave
EXAMPLE:
1/4 wave at 7200 KHz = 246000 / 7200 = 34.16
P A R T 2 - M U L T I - B A N D O P E R A T I O N
M U L T I - B A N D I N G
Multi-banding is easily accomplished by
choice spacing two identical verticals. (refer
to charts A,B, and C and associated Figures 1
through 5) Switchable 1/4 wave length and 1/2
wave length phasing cables must be employed
for each band. These cables can be placed in
the station in any suitable fashion along with a
manual
switching
system.
E L E C T R I C A L S P E C IFICATIONS:
Two Phased Verticals
Uni-directional
P H A S I N G L I N E S :
246000 x vel.
f
frequency (in KHz)
1/4 wave = 25.62
ft.
arrangement
or
relay
120 degrees
4.5 dB
20 dB
30 dB
50 Ohms
vel. factor - reg. coax.
RADIATION PATTERN:
Consideration must be given to the fact that 1/2
wave spacing (optional) is ideal for phasing.
When multi-banding with close and wide spac-
ing, compromise radiation patterns must be
expected. In most cases a choice spacing serves
3 bands most effectively with good directional
characteristics, added gain and low angle per-
formance.
Three Phased Verticals
60 degrees
4.5 dB
20 dB
30 dB
50 Ohms
Uni-directional
0.66
34.16
x.75
25.62
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