RDL STTC1 Specifications

STICK-ON® SERIES

Model ST-TC1
Telephone System Coupler

ANYWHERE YOU NEED...

• To Simulate a Telco CO Line

• To Add Radio Control or Paging to KSU

• Contact Closure when Line is Selected

• Audio Input / Output from Telephone

Switching Unit

You Need The ST-TC1!

The ST-TC1 is part of the STICK-ON series from Radio Design Labs. The durable bottom adhesive
permits quick, permanent or removable mounting nearly anywhere or it may be used with RDL’s racking
accessories.

APPLICATION: The ST-TC1 is primarily intended to connect to an on-site telephone system switching
(KSU). Connections from the ST-TC1 go into the KSU as if the ST-TC1 was an incoming phone line.

When the KSU seizes the line to the ST-TC1, a relay contact closure is provided which can be used to
control a variety of equipment, such as a paging system or radio system. The closure is maintained as
long as the line is seized. A 600 Ω transformer-isolated audio feed is available for audio to or from the
telephone switching unit. The ST-TC1 will pass DTMF audio from a telephone keypad or other DTMF
generating device.

The ST-TC1 may be utilized to add paging zones or a radio system interface to a telephone system.
When any instrument in the telephone system picks up the line associated with the ST-TC1, the relay
closes to activate the radio or paging function, and the audio spoken into the handset appears at the
BAL-AUDIO terminals. The ST-TC1 can not be connected to a phone line that has ringer voltage
present.

The ST-TC1 can be used in conjunction with RDL’s ST-VOX1 modules to provide two-way
communication. The ST-VOX1 will provide the necessary push-to-talk function to key the two-way
communications systems.

RDL •• P.O. Box 1286 •• Carpinteria, CA., USA 93014 •• [phone] •• FAX [phone] •• http://www.rdlnet.com

STICK-ON® SERIES

Model ST-TC1
Telephone System Coupler

Installation/Operation

EN55103-1 E1-E5; EN55103-2 E1-E4

Typical Performance reflects product at publication time
exclusive of EMC data, if any, supplied with product.
Specifications are subject to change without notice.

Incoming

Lines from

Phone

Company

On-Site

Telephone

Switching

System

LINE 1
LINE 2
LINE 3
LINE 4

Balanced

Audio Input

or Output

LINE 5
LINE 6

Use the BAL AUDIO terminals

Connection

to Phone

Instruments

32

5

416

4 6

21 3

5

to either connect to the

line-level input or output of

audio devices such as a paging

system, radio, or a monitor.

In this example, selecting LINE 6 on any instrument

will activate the relay inside the ST-TC1 and will

make the BAL AUDIO connection available to that

instrument. If the BAL AUDIO terminals on the

ST-TC1 are connected to a paging input of an

amplifier system, then any phone instrument may

1 2

3

5

4

6

initiate an audio page by selecting LINE 6 and then

TYPICAL PERFORMANCE

Line Connection: Simulated telco central office line to feed telephone system.
Audio In/Out Impedance: 600 Ω balanced
Switching Contacts: Double-pole, Double-throw
Max. Switching Power: 60 W, 125 Vac
Max. Switching Voltage: 220 Vdc, 250 Vac
Max. Switching Current: 2 amp
Max. Carrying Current: 3 amp
Supply Input: 24 to 33 Vdc @ 50 mA, Ground-referenced
Dimensions: Height: 1.55 in 3.94 cm
Width: 3.00 in 7.62 cm

Depth: 0.65 in 1.65 cm
Note: Do not connect ST-TC1 directly to a telephone-company phone line, or any phone
line that has ringer voltage present.

TELEPHONE SYSTEM COUPLER

"LINE"

BAL

AUDIO

TO

PHONE

EQUIP

PWR

Use relay contacts to

trigger paging or radio

speaking.

system.

WARNING: Do NOT connect the

ST-TC1 directly to a
telephone-company phone line or
any phone line with ringer voltage

present.

TELEPHONE SYSTEM COUPLER

"LINE"

BAL

AUDIO

TO

PHONE

EQUIP

PWR

Use relay contacts to

trigger paging or radio

Balanced

Audio Input

or Output

In this example, The

ST-TC1's relay will

energize when the

taken off hook. The

relay will de-energize

when the handset is

DTMF audio can be
passed through the

connection from the

generating devices.

system.

phone handset is

returned to the

on-hook position.

BAL AUDIO

phone keypad or

other DTMF

891-0023H

Radio Design Labs Technical Support Centers

U.S.A. [phone], [phone]; Fax: [phone]

Europe [NH Amsterdam] (++31) 20-6238 983; Fax: (++31) 20-6225-287