SECTION I. IDENTIFICATION AND DESCRIPTION

Calibration Procedure For Rf Wattmeters Page Navigation
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TB 9-6625-1916-24

SECTION I

IDENTIFICATION AND DESCRIPTION

This bulletin provides instructions for the

1. Test Instrument Identification.

calibration of RF Wattmeters. 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.

This procedure covers the following high powered RF

a. Model Variations.

wattmeters known to exist in the Army (AN/URM-120, ME-82U, Sierra Models 164B; Bird

Models 4311 and 6835). However, this procedure can be used to calibrate any RF

wattmeter with a frequency range from 100 kHz to 1 GHz and a power range from 1 to 1000

watts.

b. Time and Technique. The time required for this calibration is approximately 1

hour, using the microwave technique.

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. This is a general procedure which provides calibration

within 5 percent of power levels under test up to 100 watts.

SECTION II

EQUIPMENT REQUIREMENTS

4. Equipment Required. Table 1 identifies the specific equipment to be used in this

calibration procedure. This equipment is issued with Secondary Transfer Standards Sets,

AN/GSM-286; AN/GSM-287; or AN/GSM-440 and Secondary Reference Calibration

Standards Set, NSN 4931-00-621-7878. Alternate items may be used by the calibrating

activity. The items selected must be verified to perform satisfactorily prior to use and must

bear evidence of current calibration. The equipment must meet or exceed the minimum use

specifications listed in table 1. The accuracies listed in table 1 provide a four-to-one ratio

between the standard and TI. Where the four-to-one ratio cannot be met, the actual

accuracy of the equipment selected is shown in parentheses.

5. Accessories Required. The accessories required for this calibration are common

usage accessories, issued as indicated in paragraph 4 above, and are not listed in this

calibration procedure. The following peculiar accessories are required for this calibration:

RF Power Amplifier, Ophir RF Inc., Model XRF733 and Termination N jack, dc to 4 GHz,

300 watts, Sierra, Model 160B-300 (10237502-2).