Telex RTS SPK300L, User Manual

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Introduction
2
The Channel Selector Switch selects the channel on which the user will talk and listen. The headphone amplifier output
drives the user's headphones.
The Volume Control also feeds the speaker amplifier via the speaker switch and the speaker dim network.
The User Station Voltage Regulator takes power from channel 1, regardless of the channel selector switch setting (exception:
local power option units). The regulator not only supplies regulated power to the user station, but also prevents unwanted
interaction between the user station and theat intercom line which is supplying the power. Because the regulator takes power
from channel 1, channel 2 can be expanded into many channels by using a switch and, for each channel, a separate wire and a
termination network consisting of a 200 ohm resistor and a 10 microfarad capacitor in series. (See the Application Diagrams
in the TW Intercom Systems Technical Manual).
A TW System Power Supply terminates a line with 200 ohms.
Operational Controls
The SPK300L User Station has the following controls, described and shown in Section 3:
• Channel Select Switch
• Latching-action Microphone ON-OFF toggle switch.
• Momentary-action Microphone ON-OFF pushbutton switch.
• Speaker/Headphone Volume Control
• Call Switch /indicator
• Speaker ON/OFF switch
• Sidetone Adjustment
Connection, Inputs and Outputs
The SPK300L User Station has four input/output connectors:
• Dynamic Microphone type headset or handset
• Carbon Microphone type headset or handset
• Line Input (ties the station to the intercom line
• Loop/extension (allows another station to access the line through the first station. Also called loop-through.