TB 9-4931-427-24
IDENTIFICATION AND DESCRIPTION
1. Test Instrument Identification.
This bulletin provides instructions for the
calibration of Frequency Difference Meter, Tracor Model 527E and Hickok Model FDM
2100. The manufacturers' manuals were used as the 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. The Tracor Model 527E Frequency Difference Meter has a front
panel phase meter instead of the cathode ray tube used on the Hickok Model FDM 2100.
Information shown in parenthesis is for Hickok Model FDM 2100. Other variations among
models are described in text.
b. Time and Technique. The time required for this calibration is approximately 2
hours, using the dc and low frequency technique.
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) will follow the designated
adjustment. Report only those adjustments made and designated with (R).
3. Calibration Description. TI parameters and performance specifications which
pertain to these calibrations are listed in table 1.
Table 1. Calibration Description
Test instrument parameters
Performance specifications
Input
Frequency: 100 kHz to 5 MHz
Voltage: 0.5 to 10 V rms
Range: -10 to +10 parts in 107, 108, 109, 1010, or 1011
Frequency difference meter
5% of full scale
Accuracy:
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.
