TB 9-6625-1998-24
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 parenthesis.
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 accessory is required for this calibration: RF
Power Amplifier, Antenna Research Associated Inc., Model 757LC (757LC).
Table 2. Minimum Specifications of Equipment Required
Manufacturer and model
Common name
Minimum use specifications
(part number)
Boonton, Model 1121 (1121)
AUDIO ANALYZER
Frequency measurement:
Range: 19.6 Hz to 204 kHz
Accuracy: 0.25%
Distortion measurement:
Range: 20 Hz to 100 kHz
Capability: to 1 %
Agilent, Model 3458A (3458A)
Dc voltage:
Range: 46 to 52 V
Accuracy: 0.5%
Ac level measurement:
Range: 0.7 mV to 10.5 V
Frequency: 110 kHz
Accuracy: 1.25%
Biddle-Gray, Model 71-631
RESISTANCE STANDARD
Range: 1000
(7910328)
CALIBRATION PROCESS
6. Preliminary Instructions
a. The instructions outlined in paragraphs 6 and 7 are preparatory to the calibration
process. Personnel should become familiar with the entire bulletin before beginning the
calibration.
b. Items of equipment used in this procedure are referenced within the text by common
name as listed in table 2.
c. Unless otherwise specified, verify the results of each test and, whenever the test
requirement is not met, take corrective action before continuing with the calibration.
Adjustments required to calibrate the TI are included in this procedure. Additional
maintenance information is contained in TM 11-6625-683-14 for this TI.
d. When indications specified in paragraphs 8 through 11 are not within tolerance,
perform the power supply check prior to making adjustments. After adjustments are made,
repeat paragraphs 8 through 11. Do not perform power supply check if all other
parameters are within tolerance.
e. Unless otherwise specified, all controls and control settings refer to the TI.
