6. INTERCOM TALK/LISTEN CIRCUIT.
The talk circuit starts at the handset
microphone element (Figure 8). When you key the handset and speak into the
microphone, this voice signal is changed into a corresponding electrical AC
signal. This AC signal is applied to pin D of J802 or J803, depending on
where the handset is connected, through the C-2298 to contact 2 of the A80
audio amplifier. The AC signal is amplified by the A80 and applied to pin K
of J801 and J804. (Trace this circuit on your system diagram.)
Talk circuit through C-2298 from J802 or J803.