TM 11-6625-2718-14&P
c. Disconnect the antenna cable from the
c. To determine the power dissipated in the
transmitter antenna (ANT) output jack (female
load, subtract the reflected power from the for-
B N C type). U s e Cable CG-409G/U to in-
ward power reading as follows:
terconnect the ANT output jack and the trans-
Watts (load) = Watts (forward) Watts
mitter connector.
(reflected).
d. C o n n e c t t h e a n t e n n a c a b l e t h a t w a s
Example: 8 watts (load) = 10 watts (for-
disconnected from the transmitter to the antenna
ward) -- 2 watts (reflected).
cable connector (female BNC type) at the bottom
d. The reflected power varies, depending on the
of the TS-2609A/U.
load. Where appreciable power is reflected, as
e. Energize the transmitter.
with a mismatched antenna, the subtraction of
reflected power is necessary to obtain radiated or
2-8. Types of Operation
dissipated power readings; however, this step
a. The TS-2609A/U provides different types of
may be unnecessary when the load is closely
information about the signal being transmitted.
matched to the transmitter because the reflected
The same installation setup is used for each type
power becomes negligible.
of operation.
NOTE
b. The following are the most usual types of
If the forward and reflected power
operation for the TS-2609A/U:
readings are alike, there is an opening in
(1) Determining load power (para 2-9).
the transmission line beyond the TS-
(2) Measuring and monitoring transmitter
2609A/U.
power (para 2-10).
( 3 ) Measuring and monitoring reflected
power (para 2-11).
Power
(4) Determining standing wave ratio (swr)
With the selector switch in the 100 FWD position,
t h e TS-2609A/U will continuously indicate
transmitter output. This mode of operation can be
used to detect intermittent transmitter troubles
WARNING
which will be indicated by inconsistent meter
T h e transmitter must be deenergized
indications.
before the TS-2609A/U is connected.
NOTE
W h e n the TS-2609A/U is connected to the
I f an antenna is not available, use
transmitter (para 2-7), the load power can be
Dummy Load, Electrical DA-75/U for
determined as follows:
the load.
100 FWD position and check the indication on the
meter 0 to 100 scale. If the transmitter rf output
Power
is less than 100 watts, as indicated by the meter,
With the selector switch in the 100 RFL position,
set and hold the selector switch in the 10 FWD
the TS-2609A/U will continuously indicate the
position to take the reading. The meter indication
power reflected from the load. Intermittent line or
is the forward power output of the transmitter.
antenna faults are indicated by inconsistent meter
When released, the selector switch automatically
indications.
returns to the 100 FWD position.
b. Position the selector switch in the 100 RFL
a. The TS-2609A/U is designed to provide
position and check the indication on the meter 0
forward and reflected power readings in watts. To
to 100 scale. If the meter indicates less than 10
convert these power readings to standing wave
watts reflected power, rotate and hold the selector
ratio (voltage swr) readings, use the graphs
switch in the 10 RFL position to take the reading.
provided in figures 2-3 and 2-4.
The meter indication is the reflected power. When
released, the switch automatically returns to the
100 RFL position.
