achieved the amount of mismatch can be meas-
ured by measuring the amount of Standing
Waves that exist in the
coax
of the antenna feed
line. Measuring of the Standing Waves can be
accomplished by sampling the forward
power and the reflected
power and com-
paring them and then expressing this difference
as a ratio of reflected to forward power. At the
table 1 are some examples of amount power loss
for
a
Standing Wave Ratio.
3.
SWR and Power Measurement (Picture 1)
Do
not turn on the transmitter,
while the an-
tenna and test meter are disconnected.
To use this Standing Wave Ratio meter, it must
be connected in the antenna feet line. To do this,
a short length of coaxial cable is required
erably no longer than 2 feet.
With the transmitter off, disconnect the antenna
coax cable from the transmitter and
14
--
__ . . . . . . . . .
connect that coax cable to the jack of the SWR meter
marked with ANT.
Connect the short coax cable between the transmitter
and the TX-jack of the SWR meter.
If a long antenna coax cable is used and the antenna
should be matched, the measurement is more exact
if the short coax cable connected between the
na and the ANT jack at the SWR meter. Because
than has the antenna coax cable no influence for the
measurement.
Is the meter properly connected, select the
measuring area. For measuring of standard CB
transmitter with 4 Watt RF power, place the sli-
ding switch 1
OOW] to the 1 OW position.
Place the sliding switch
to the
FWD position.
During the transmitter is now switched on, set the
pointer with the knob
[CAL] to full scale de-
flection, [SET] mark on the meter.
15
