TM 11-6625-622-40
into the forward power wattmeter circuit. Sim-
longer of equal magnitude and in phase, so that a
ilarly, capacitors C4, C9, and C10, and rf choke
resultant dc voltage is produced at diode CR2.
L2 keep stray rf out of the reverse power watt-
The dc voltage is applied to the RF OUTPUT
meter circuit.
meter circuits to provide an indication of rf re-
flected power on the transmission line. Resistors
c. The WATTS REFLECTED FORWARD
R3 and R4 are of equal value, as are resistors
switch connects the desired directional coupler
output to the wattmeter. The wattmeter indicates
R5 and R6. Their values are selected by the
the rf power on the line.
manufacturer to calibrate the meter. Resistors R3
and R4 calibrate the 2,000-watt ranges, and re-
sistors R5 and R6 calibrate the 200-watt ranges.
after passing through transformer T1, is con-
Capacitors C3, C7, and C8, and rf choke L1 pro-
nected from J17 to the top panel DIR WM RF
vide filtering action to keep stray rf from getting
OUT J10 connector.
2-5
