PCB
The main PCB. The upper IC is the speech (anti-sidetone, etc) circuit, the lower one is the dialer. The upper switch is the handset gravity switch, the lower the earth recall button.
The tags at the top left are the handset connections (and for an extra earpiece). The terminal block below them carries the line connections. The dialer keypad plugs into the header to the right of the dialer IC.
PCB
The main PCB. The upper IC is the speech (anti-sidetone, etc) circuit, the lower one is the dialer. The upper switch is the handset gravity switch, the lower the earth recall button.
The tags at the top left are the handset connections (and for an extra earpiece). The terminal block below them carries the line connections. The dialer keypad plugs into the header to the right of the dialer IC.