Sound Power Phone System

Capacitors in a Handset

1

Capacitors in a headset

2

One blocks dc and other provides for power factor correction

Open circuit will affect what?

Only the station with the open

Short circuit will affect what?

The entire circuit

The transmitter and receiver units on all sound powered phones are what?

Hermetically sealed / not repairable

What do you never use on a phone circuit to test it?

A megger

Loss of sensitivity is what?

Weakening of the transmission

Caused by Partial ground or moisture in the elements

The normal resistances of sound powered transmitter and receiver units

Transmitter - 10 ohms

Receiver - 62 ohms

What circuit is designated casualty communication circuit?

Circuit X40J

Minimum Resistance to ground?

50k ohms

String circuits

Consists of a series of telephone station jack boxes connected in parallel to a common line

Switchbox circuits

Originate from a sound powered switchbox