User guide

Calibration Checks

Seup Test

Note: This test determines if the wattmeter needs recalibration:

1. The following equipment is required, connected in series with the Bird

4304A (Refer to Figure 9).

• RF source

• Low pass filter

• Reference, known accurate, wattmeter

• 50Ω load

• Cables

Note: Keep all connections as short as possible to minimize mis-

match and insertion losses.

2. Set the RF source to produce a signal with power in the upper one-third of

the scale for each power range.

3. Compare the reading on the Bird 4304A with the reference wattmeter.

Note: If the unit is outside the stated accuracy range, return it to a

Bird Service Center for calibration.

Figure 9 Calibration Check Setup

Calibrating a Bird Element 4304A-1

Required Equipment

• RF source capable of 100W from 25 MHz to 1000 MHz

• RF source capable of 500 W at 405 MHz

• Power standard

• Model 4304A Wattmeter

150

500

Low Pass

Filter

4304A

RF Source

50 Load

Reference

Wattmeter