SECTION II FUNCTIONAL OPERATION OF ELECTRONIC CIRCUITS

T.O. 31W2-4-206-2

TM 11-5805-622-14/1

SECTION II

FUNCTIONAL OPERATION OF ELECTRONIC CIRCUITS

4-18. ORDERWIRE EQUIPMENT.

alarm lamps may be deactivated by switched remov-

ing voltage from the alarm lamp circuit and connect-

4-19. Refer to Chapter 7, Circuit Diagrams, of this

ing alarm cut-off indicator lamp DS9.

manual to supplement the following.

4-26. VF INTERFACE MATCHING UNIT TF1791.

4-20. PILOT AMPLIFIER TF1772 (Figures 7-3 and

(Figure FO-7)

7-4)

4-27. The VF Interface Matching Unit permits ad-

4-21. The Pilot Amplifier TF1772 receives the syn-

justment of the VF Signal level in increments of 1,

chronization pilot signal (96 kHz) from the interface

2, 4, 8 and 16 dB in either the transmit or receive

circuitry in the Supergroup Miscellaneous Patch Bay.

direction. In the transmit direction the VF signal at

The signal is applied at pin 1 of the pilot amplifier

terminals 5 and 6 is attenuated by resistive networks

circuit card amplified and transmitted from pin 5.

consisting of resistors R1 through R20 to the level

The pilot signal is raised to a level of -34 dB across

desired for input to the Channel Modem and appears

at terminals 1 and 2. In the transmit direction the

75 ohms.

VF signal from the Channel Modem appears at termi-

4-22. SUPERGROUP AMPLIFIER TF1971.7 (Fig-

nals 13 and 14 of the interface unit. The signal is

ure FO-14)

amplified prior to adjustment to the required level by

the resistive network comprised of resistors R21

4-23. The Supergroup Amplifier TF1971.7 receives

through R40. Transistor Q1 serves to stabilize the

the 312 to 552 kHz Message Baseband Signal from the

4-28. CHANNEL MODEM TF3012.1a. (Figure FO-6)

4-29.

4-24. SUPERGROUP AMPLIFIER ALARM CIR-

CUITRY.

4-25.