TB 9-6625-187-24
IDENTIFICATION AND DESCRIPTION
This bulletin provides instructions for the
1. Test Instrument Identification.
calibration of RF Directional Thruline Wattmeter, Bird, Model 4304A with broadband
element 4304A-1. The manufacturer's manual was used as the prime data source in
compiling these instructions. The equipment being calibrated will be referred to as the TI
(test instrument) throughout this bulletin.
a. Model Variations. None.
b. Time and Technique. The time required for this calibration is approximately 4
microwave frequency techniques.
2. Forms, Records, and Reports. Forms, records, and reports required for calibration
personnel at all levels are prescribed by TB 750-25.
3. Calibration Description. TI parameters and performance specifications which
pertain to this calibration are listed in table 1.
Table 1. Calibration Description.
Test Instrument parameters
Wattmeter mainframe 4304A
Performance specifications
Power Range
Frequency range
Switch settings
5
25 MHz 1 GHz
15
25 MHz 1 GHz
50
25 MHz 1 GHz
150 1
25 MHz 1 GHz
1
500
25 MHz 800 MHz
Plug-in element 4304A-1
Frequency range: 25 MHz to 1 GHz
Power range: 0 to 500 watts 1
25 MHz to 100 MHz 2
7% FS with correction factor 2
Accuracy:
100 MHz to 512 MHz
6% FS
512 MHz to 1 GHz
7% FS
Not calibrated above 100 watts.
1
For frequencies below 100 MHz, a correction factor must be applied to the reading.
2
NOTE
The correction table is located on the back cover plate of the TI.
Multiply the measured power reading on the TI meter by the
correction factor to determine the actual power.
