Figure 2. Adjustment locations

Calibration Procedure For Test Oscillator, Model 654A Page Navigation
6

TB 9-6625-1947-24

(7) Alternately adjust S2C2 (fig. 2) and S2C8 (fig. 2) until frequency counter

indicates 10.2 kHz and multimeter indicates between -340 mV and -360 mV (R).

Figure 2. Adjustment locations - top view.

(8) Rotate FREQUENCY dial fully cw. Frequency counter will indicate between

965 Hz and 970 Hz.

(9) Set FREQUENCY dial for a 1 kHz indication on frequency counter. If dial does

not indicate 1, perform (a) through (c) as listed below:

(a) Remove FREQUENCY dial knob and loosen the four retaining screws.

(b) Slip FREQUENCY dial until 1 is aligned with reference marker.

Tighten retaining screws and install FREQUENCY dial knob (R).

(c)

(10) Set FREQUENCY dial to 10.

(11) Readjust S2C2 (fig. 2) and S2C8 (fig. 2) alternately until frequency counter

indicates 10 kHz and multimeter indicates -350 mV (R).

(12) Set FREQUENCY RANGE switch to X1M and FREQUENCY dial to 10.

(13) Adjust S2C6 (fig. 2) and S2Cl2 (fig. 2) for a frequency counter reading between

10.1 MHz and 10.2 MHz, and A2TP2 (fig. 1) for multimeter reading between -0.38 V and

-0.40 V (R).