Coaxial Cable - Kenwood TS-780 Instruction Manual

Adjustment (SWR)
Your antenna must be connected to a 50 ohms coaxial
cable, since the antenna impedance of the TS-780 is
5 0 Ohms. A l s o , t h e a n t e n n a m u s t b e a d j u s t e d t o
50 ohms impedance. This
pedance matthing.
Proper impedance matthing
ing SWR (VSWR: Voltage Standing Wave Ratio) using a
SWR meter. Ideal SWR is 1: 1.
The SWR meter s h o u l d b e c o n n e c t e d b e t w e e n t h e
antenna feeder and the antenna terminal at the rear of
the transceiver, whichever
that the reading of SWR meter varies somewhat depen-
ding on the location of connection because of the loss in
the antenna cable. This is particularly noticeable when
the antenna cable is more than 10 m long.
An antenna System which Shows
of less than 1 .5 will insure satisfactory transceive
Operation.

4-2. COAXIAL CABLE

For satisfactory transceive
must be used. When the transceiver is used for fixed sta-
tion Service, the coaxial cable becomes relatively long, so
low loss (large sized) coaxial cable of the shortest possible
Fig. 8
adjustment is called im-
is accomplished by check-
is more convenient. Note
a standing wave ratio
Operation, coaxial cable
Antenna feeder
ANT terminal
length should be used, as the loss of coaxial cable cannot
be neglected when operating in high frequency bands, par-
ticularly in 144 MHz or higher bands.
When the coaxial cable needs to be extended more than
10 m, use one of larger size such as RG8/U
W h a n S W R meter is c o n n e c t e d a s shown above. t h e actual
SWR at the antenna feeder is higher than 1.5 because of the
loss of the coaxial cable
Fig. 7 Adjustment of Antenna System
8. Antenna installation
1 Ground p l a n e
antenna
4-row
Stack (4 parallel
or UR67.
Coaxial cable
enna
horizontal
Tower