Bird - The RF Experts
3171B and 3171B020, Dual Meter - Single Carrier, Wattcher RF Monitor

100 W to 250 kW, Dual Meter - Single Carrier RF Power Monitor

The 3171B High Speed Wattcher® RF Power Monitor/Alarm is a two channel power monitoring system for use in 50 ohm coaxial transmission lines. Adjustable set points allow user to preset maximum reflected and minimum forward power trip points. Activated audible/visual alarms indicate an erroneous condition present on the transmission line. Corrective action can then be followed to either protect transmission equipment or restore transmission line to operational characteristics.

This power monitoring capability is accomplished through the use of a dual port 50 ohm in sertion type line section. Each port must contain a standard Bird plug-in element. Usually elements with a ten to one ratio is recommended for the forward and reverse power levels. The Wattcher monitoring system also provides additional terminal connections for user specific applications.

3171B and 3171B020, Dual Meter - Single Carrier, Wattcher RF Monitor
product specifications:
Item No
Item Name
Dual Meter - Single Carrier, Wattcher® RF Monitor
Power Range
100 W to 250 kW using Bird® Plug-in Elements
Frequency Range
2 MHz - 1 GHz
Insertion VSWR
± 5% of full scale
Meter Scales
(FWD and RFL) 5, 10, 25 kW
Front Panel Buzzer, "Active" and "Trip" LEDs for forward/reflected
Response Time
25 µs max.
Activate Forward
73 µs to 50 ms nominal (adjustable) monitor delay
Front Panel Controls
Reset push-button, adjust FWD/RFL alarm levels screw
Rear Panel Features
DC FWD/RFL signal inputs, main and remote meter drive outputs, external 12-16 VDC supply input, alarm in/out, reset in/out, AC line voltage selector, fuse, IEC 320 AC receptacle.
TTL compatible +5 V logic. Outputs for remote meter
Includes (2) 25 ft. DC Cables
If length other than 25 ft. is desired, order two BNC (M) cables
AC Power
115/230 V, 50/60 Hz @ 56 mA max.
DC Power
12.7 to 16.0 VDC @ 400 mA max.
Gray Powder Coat
(W x H x D)
19" x 5-7/32" x 9-21/64"
483 x 133 x 237 mm
5 1/2 lbs. (2.5 kg)
Required Products
Line Section: 1-5/8", 3-1/8", 4-1/16, 6-1/8"
Two from Tables 1-5/8 AA, 3-1/8 AA, 4-1/16 AA, or 6-1/8 AA.
compatible devices:
Table 1-5/8AA - 30μA Standard
1-5/8" Standard Elements 30μA
Table 3-1/8AA - 30μA Standard
3-1/8" Line Section - Standard Elements 30μA
Table 4-1/16AA - 30μA Standard
4-1/16" Line Section - Standard Elements 30μA
Table 6-1/8AA - 30μA Standard
6-1/8" Line Section - Standard Elements 30μA
1-5/8" Thruline Line Section
1-5/8" Thruline Line Section
1-5/8" Thruline Line Section
3-1/8" Thruline Line Section
3-1/8" Thruline Line Section
3-1/8" Thruline Line Section
6-1/8" Thruline Line Section
6-1/8" Thruline Line Section
3170-058 Series
RF Coaxial Cables
3170-058 Series
RF Coaxial Cables
3170-058 Series
RF Coaxial Cables