Sam Hallas' Website
With the circuit board out of the way the way the cradle rest actuator works is revealed.
The spring fits against a notch in the earpiece lever. The rocking lever in the middle connects to the microphone button and the earpiece lever. A cunning piece of mechanics.
The ends of the spring unclip from the case moulding allowing the spring to drop flat against the cover. The rocking lever in the centre can be pulled from its clips. The microphone button is then free to be removed. The earpiece lever slides out through the earpiece moulding.
The key tops have a locating groove at the top of each key top so they will only fit the right way up. Notice the difference in the contact side of the recall button (at the top) on the keypad mat. The other buttons have carbon pads to connect with the printed circuit tracks. The recall button operates a small plastic insert attached to the recall switch and has no carbon pad.
There are very few piece parts in the entire case assembly which is a tribute to the economy of the design.
The circuitry for the tone caller is entirely on the circuit board. The visible part (left) is simply a transducer. It snaps into the base moulding, but is quite difficult to remove. A semicircular bump ensures it fits in the correct orientation.