Bird - The RF Experts

Single Meter - Single Element, Panel-Mount RF Wattmeter

4521, RF Wattmeter is a single element socket and single meter unit. It's designed for power measurement in CW and FM systems that employ 50-Ohm cable or 7/8" EIA transmission lines. All models include a precision line section and either one or two 3-scale analog which give full-scale direct readings from 100 mW to 10 kW.

The rack panel fits standard 19-inch equipment racks. Plug-In Elements, the same used in the Bird model 43, are sold separately. Depending on the element selected , the 4521 will cover frequencies from 0.45 to 2700 MHz. Measurement accuracy is ±5% of full scale. Forward and reflected power are measured by rotating the element.

product specifications:
Item No
Item Name
Single Meter- Single Element, Panel-Mount Wattmeter
Power Range
100 mW to 10 kW using Bird® Plug-in Elements
Frequency Range
450 kHz to 1.0 GHz (depending on element)
Insertion VSWR
with N Connectors 1.05 max. to 1000 MHz
± 5% of full scale
QC Type - N (F) normally supplied
Gray Powder Coat
(W x H x D)
19 in x 5.22 in x 1.69 in
(483 mm x 133 mm x 43 mm)
3.5 lbs. (1.6 kg)
Quoted accuracy only when used with other Bird® Products. Applies only when coupling is less than 30 dB
compatible devices:
Table 1 - Standard Elements
7/8" Line Section - Standard Elements
Table 2 - Low Power Elements
7/8" Line Section - Low Power Elements
Table 3 - High Frequency Elements
7/8" Line Section - High-Frequency Elements, Entire Table ±8% FS
Table 4 - Low Frequency Elements
7/8" Line Section - Low Frequency Elements
Table 6 - Milliwatt Elements
7/8" Line Section - Milliwatt Elements