TB 9-6625-862-24
EQUIPMENT REQUIREMENTS
calibration procedure. This equipment is issued with Secondary Transfer Calibration
Standards Set AN/GSM-286, AN/GSM-287 or AN/GSM-705. 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
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.
Table 2. Minimum Specifications of Equipment Required
Common name
Minimum use specifications
Manufacturer and model
(part number)
AUDIO ANALYZER
Range: 35 Hz to 20 kHz
Boonton, Model 1121 (1121)
Distortion: < 1%
AUTOTRANSFORMER
Range: 105 to 125 V ac
Ridge, Model 9020A
Accuracy: 1%
(9020A)
FREQUENCY COUNTER
Range: 20 Hz to 21 kHz
Fluke, Model PM6681/656
(PM6681/656)
Accuracy: 0.5%
Range: 0.46 mV to 79 V
Fluke, Model 8840A/AF05
(AN/GSM-64D)
Accuracy: 0.29%
STEP ATTENUATOR
Range: 40 dB
Tech Laboratories, Model C8756
Voltage: 50 V
(MIS-35949)
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.
