Bird - The RF Experts

25-1000 MHz, 5-500W, Fixed Element RF Wattmeter

The Bird 4304A Wattmeter is an in-line sensor that measures RF power and load match in 50 Ohm coaxial transmission lines. It can be used with CW, AM, FM, and TV modulation, but not pulse modulation. It is supplied with a special broadband element with a frequency range of 25 to 1000 MHz. It can measure up to 500 W, depending on the frequency, and has a maximum VSWR of 1.07 with the standard “N” connectors. A range switch allows the full scale power to be reduced for greater accuracy.

The wattmeter is portable, with an included carrying strap. It has an aluminum housing and an easily removed back cover, with bumpers on the base and back that allow the meter to stand or lie flat. For additional protection, the microammeter is specially shock mounted. A screw on the lower front face of the meter is used to zero the pointer. Below the meter face, the RF line section protrudes slightly from the wattmeter housing with the element socket in the center

product specifications:
Item No
Item Name
Fixed 25-1000 MHz 5-500 Watt Element, Wattmeter
Power Range
5, 15, 50, 150, 500 W, with no scale limitations except power limited to 150 W from 800-1000 MHz
Frequency Range
25 MHz - 1.0 GHz
Insertion VSWR
25-521 MHz, 1.05 max. (with UHF female conn.)
512-1000 MHz, 1.07 max.
25-100 MHz, ± 7% of full scale, using correction charts.
100-512 MHz, ± 6 of full scale, no correction needed.
512-1000 MHz, ± 7% of full scale, no correction needed.
Insertion Loss
25-512 MHz, 0.10 dB max. (with UHF female conn._
512-1000 MHz range, 0.13 dB max.
QC Type (Female N normally supplied)
Light Gray Powder Coat
(H x W x D)
6-7/8" x 5-1/8" x 3-5/8", including connectors
175 x 130 x 92 mm
3 lbs. (1.4 kg)
(1) 4304A-1 Element supplied with unit
compatible devices:
4304A-1 Element
4304A-1 Element
Carrying Case - Portable Thruline®, Load, Signal Sampler, QC Connectors and 4 Elements
Carrying Case - Thruline® Wattmeter, 5 Elements and 1 Small Load
Carrying Case - 12 Plug-In Elements