SECTION III PRELIMINARY OPERATIONS - TB-9-6625-091-350006

TB 9-6625-091-35

SECTION III

PRELIMINARY OPERATIONS

6. Preliminary Instructions

a. The instructions outlined in this section 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 and item identification number as listed in tables 2 and 3. For the identification of

equipment referenced by item numbers prefixed with A, see table 2, and for prefix B, see

WARNING

HIGH VOLTAGE is used during the performance of this

calibration. DEATH ON CONTACT may result if personnel

fail to observe safety precautions.

7. Equipment Setup

a. Remove bottom and side covers from oscilloscope (A2).

b. Connect extension (B4) to TI and insert into vertical compartment of oscilloscope.

c. Energize equipment and allow at least 15 minutes for warm-up.

d. Turn TI VOLTS/CM switch to .05 and AC-DC switch to AC.

e. Using TI VERTICAL POSITION control, position trace on crt graticule centerline.

If trace cannot be positioned to centerline, set VERTICAL POSITION control to midrange

and adjust R6821 (fig. 1) until trace is positioned on crt graticule centerline.

f. Turn TI VARIABLE control throughout its range and observe that trace does not

move vertically. If necessary, adjust DC BAL control (front panel) until trace stabilizes.

g. Turn TI VARIABLE control to CALIBRATED.

SECTION IV

CALIBRATION PROCESS

NOTE

Unless otherwise specified, verify the results of each test and

take corrective action whenever the test requirement is not met

before continuing with the calibration.