Telex 38109-977 manual Belt Pack Headset User Station Functional Description

Table 2.2 Intercom connector wiring by various manufacturers.

Clear-Com

Pin #	Function
1	Common for Audio, Power, &
	Shield
2	DC power: 30 volts nominal
3	Unbalanced Audio
Audiocom

Pin #	Function
1	Common for Audio, Power, &
	Shield
2	Audio + DC Power
3	Audio + DC Power
RTS TW

Pin #	Function
1	Common for Audio, Power &
	Shield
2	Channel 1 Audio + DC Power
3	Channel 2 Audio

The wireless systems usually include an interface to the wired systems. Principal manufacturers include Telex Communications, Vega (now part of Clear-Com), and HME. We will go into further detail on wireless systems in a later chapter of this manual.

Wired intercoms are mostly of the distributed amplifier kind. The distributed amplifier is built into a User Station. User stations come in various packages and are of three kinds: headset, speaker-microphone, or both. The various packages include a belt pack (worn on the users belt, and of the headset kind), console mount (headset or speaker-microphone), rack mount (headset or speaker-microphone), desk mount (portable speaker station), wall mount (headset or speaker-microphone), and console/rack mount Master Station/Main Station (details later). The distributed amplifier concept allows each user to adjust his/hers own listening level. The user station also includes a microphone amplifier, a line amplifier/buffer, volume control(s), talk switch(es). Some user stations also may have a Call light, status indicators, and a channel selector. The microphone may be in the headset, fastened to or plugged into a speaker station, in a handset, or in a push-to-talk hand held unit.

Belt Pack Headset User Station Functional Description

A typical single channel belt pack headset user station has the following connectors: Intercom Line (XLR-3) and a Headset Connector (XLR-4).

The station has the following controls:

Microphone ON/OFF (sometimes called a TALK switch), and a headset Volume Control. It may also have a Call Lamp and a Call Lamp Send button. Examples of this station are an RTS™ BP318 single channel belt pack, or an Audiocom® BP1002, or a Clear-Com®RS- 501.

A typical two channel headset belt pack user station adds a channel selector switch to the above. Examples RTS™BP351, Clear-Com®RS-502, Audiocom® BP2002

C h a p t e r 2 - I n t r o d u c t i o n t o P a r t y - L i n e I n t e r c o m S y s t e m s 11