PTC 405

The PTC-405 is a lightweight two wire telephone (housed in a polyurethane impregnated case for extra protection) and is compatible with all types of exchange and in conjunction with the PTC-404 and PTC-414. However, unlike the PTC-414 this does not feature a key pad tone generator.
Power Supply
The PTC-405 is powered by 3 x 1.5V primary cells ("D size" batteries), giving an overall potential difference of 4.5V. This composes the internal power supply. However, the phone can also draw power from the external exchange or central battery banks.
Slide Switch Positions
The sliding selection switch features three different positions:
- CB (Central Battery) - The phone will take its power from either the exchange or from a central battery bank.
- LB (Local Battery) - The phone is powered by the internal power supply
- Ring (Ring Position) - Enables the internal magneto to produce a ring pulse to call other phones.