TB 9-6625-2080-24
CALIBRATION PROCESS FOR FREQUENCY ELECTRONICS, MODEL FE2133A
AND VECTRON LABORATORIES, MODEL 244-4799
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
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 the manufacturer's manual for these TI's.
d. Unless otherwise specified, all controls and control settings refer to the TI.
HIGH VOLTAGE is used or exposed during the performance of
this calibration.
DEATH ON CONTACT may result if
personnel fail to observe safety precautions.
REDUCE
OUTPUT(S) to minimum after each step within the
performance check where applicable.
a. Place TI flat on level horizontal surface so that J1 is located above P1.
b. Connect dc power supply No. 1 positive output terminal to pin 3 of P1 on TI and
negative output terminal to pin 1 of P1 on TI. (For model FE2133A, connect a second lead
from negative output terminal to pin 6 of P1 on TI).
c. Adjust dc power supply No. 1 for a +28 Vdc output and allow at least 72 hours for TI
stabilization.
a. Performance Check
(1) Connect a 1 MHz output signal from time frequency workstation to REF INPUT
(2) Connect TI output jack to SIG INPUT of frequency difference meter.
(3) Remove protective bolt (on rear of TI) to gain access to adjustment and adjust
FREQUENCY ADJUST for minimum difference indication on frequency difference meter.
(4) Allow at least 24 hours for oscillator stabilization. Frequency difference meter
will not change more than 1 part in 109.