1-8. BLOCK DIAGRAM PRESENTATION. (CONT)
SIDETONE GATE CIRCUIT
The sidetone circuit provides current for the receive amplifier after the latch circuit is energized. With the digit keysender, it also
provides proper voice and digit side tones.
The latch circuit energizes the seize oscillator when the handset is lifted from the cradle. It also energizes the receive amplifier and
sidetone gate circuit needed to establish a voice and sidetone path after the seize acknowledge signal is received from a switching
facility. It also stops the seize oscillator after a seize acknowledge signal is received.
1-9. OPERATIONAL MODES AND CONTROLS.
The digit keysender contains digit keys 0 through 9 and the letters R and C. Key C sets up conferencing capabilities in three modes:
All members of the conference number are automatically called at the same time.
Key C and the numbers of each conference number are pressed on the digit keys one at a time.
Each person of the conference presses Key C and an agreed upon number on the digit keys at an agreed upon time to speak in
Key R, when used with the digit keys, can set up priority and precedence calls. Priority and precedence rating allows the caller to break
into calls of a lower precedence level or priority rating.