Figure 2-19. 10-kHz oscillator circuit, simplified schematic diagram

TM 11-6625-467-34

collector of Q5 and causes sustained circuit oscilla-

2-24. 10 kHz Oscillator

tions. The L and C parts in the collector circuit of Q5

are resonant at 10 kHz and cause the circuit to oscil-

The 10-kHz oscillator circuit is composed of three

late at that frequency. The emitter follower circuit

transistors and associated circuits that produce a

of transistor Q7 receives its input from the collector

10-kHz sine wave output. Transistors Q5 and Q6

circuit of Q6. Emitter follower Q7 current-amplifies

form a tuned amplifier/feedback circuit that oscil-

the 10-kHz signal and provides a low impedance

l a t e s at a frequency of 10-kHz. Capacitor C13

10-kHz circuit output. Resistors R11 and R12 form a

couples the 10 kHz signal from the collector of Q5 to

voltage divider that provides a low-amplitude cir-

the base of Q6. The circuit of transistor Q6 is a split-

cuit output at the junction of the two resistors.

load phase inserter. The feedback circuit composed

of resistor R6 and capacitor C14 couples the signal

2-25. 500-kHz Frequency-Modulated

from the emitter of Q6 back to the emitter of Q5.

Oscillator

The signal at the emitter of a phase splitter is not

phase inverted; therefore, the feedback signal pres-

The 500-kHz fm oscillator produces a 500-kHz fre-

ent at the emitter of Q5 reinforces the signal at the

NOTES:

1. UNLESS OTHERWISE INDICATED:

ALL RESISTANCE VALUES ARE IN OHMS

ALL CAPACITANCE VALUES ARE IN MI CROMICROFARADS

ALL INDUCTANCE VALUES ARE IN HENRIES

2. COMPONENT LOCATED ON CHASSIS

3. COMBINATION OF C10, C11, AND C12 IN PARALLEL

4. PARTIAL REFERENCE DESIGNATIONS ARE SHOWN;

FOR COMPLETE DESIGNATION PREFIX WITH UNIT NUMBER

OR SUBASSEMBLY DESIGNATION A3

INDICATES EQUIPMENT MARKING

Figure 2-19. 10-kHz oscillator circuit, simplified schematic diagram

2-60