TB 9-6625-2076-35
(2) Connect TI COMP (rear) to CH2 INPUT on oscilloscope, and synthesizer/level
generator OUTPUT 50 Ω to CH1 INPUT of oscilloscope.
(3) Enter a frequency of 108.000 MHz into TI and press TONE SELECT 9960 FM
only (30 Hz VAR OFF) pushbutton.
(4) Adjust oscilloscope CH2 VOLT/DIV VARIABLE control for a 4-division vertical
deflection on crt.
controls for a 4-division horizontal deflection on CH 1 of oscilloscope crt.
(6) The crt will display a 4-division square pattern with a slowly oscillating circle or
ellipse inside the square pattern as shown in figure 2.
Figure 2. Typical FM
Deviation Oscilloscope Display (Zero Beat Method).
NOTE
A slight drift is acceptable.
(9) Subtract frequency recorded in (7) above from frequency measured in (8) above
and divide the difference by 2. The quotient will be between 478 and 482 Hz.
b. Adjustments. No adjustments can be made.
9