20. MODULATION CIRCUIT.
a. Signal to J-3513/U. At the commander's or crew member's C-2298 J802
audio connector (handset keyed and speaking into the mike) the voice is
changed into an AC signal and applied to pin D of the audio connector
(Figure 65). The signal is then applied to the A80 module, amplified and
passed through the MONITOR switch (set to ALL, A, or B). It passes to pin K
J801/J804 through the CX-4723 and the AM-1780. There the signal is applied
to relay (K503 commander, K502 crew member), then to J501 pin U, through the
CX-4723 to the J-3513 J7 pin U.
(Trace these circuits on your system
Modulation circuit from the C-2298.