TB 9-6625-2316-24
IDENTIFICATION AND DESCRIPTION
1. Test Instrument Identification.
This bulletin provides instructions for the
calibration of Telephone Cable Test Set (TCTS), AN/GTM-12. The manufacturer's manual
and TM 11-6625-3292-40 were used as prime data sources 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
hours, using the dc and low frequency and microwave techniques.
2. Forms, Records, and Reports
a. Forms, records, and reports required for calibration personnel at all levels are
prescribed by TB 750-25.
b. Adjustments to be reported are designated (R) at the end of the sentence in which
they appear. When adjustments are in tables, the (R) follows the designated adjustment.
Report only those adjustments made and designated with (R).
3. Calibration Description. TI parameters and performance specifications which
pertain to this calibration are listed in table 1.
Test instrument
parameters
Performance specifications
Range: <20 per 250 ft. of cable; maximum of <160
for 2000 ft.
Accuracy: 2.0%
A
Insulation
Range: >100 k
ccuracy: 2.0%
A
Range: >10 M
ccuracy: 3.0%
Crosstalk
Range: <-25 dB
Accuracy: 2.0%
EQUIPMENT REQUIREMENTS
4. Equipment Required. Table 2 identifies the specific equipment to be used in this
calibration procedure. This equipment is issued with Secondary Transfer Calibration
Standards Sets 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
exceed the minimum use specifications listed in table 2. The accuracies listed in table 2
provide a four-to-one ratio between the standard and TI.