Sonifex HY02 DIGITAL, User Handbook Manual

  Page 1-2       Introduction & Installation 

 HY02 Digital TBU User's Guide

1.2.1. Manufacturer 

 
Sonifex Limited, 
61 Station Road,  
Irthlingborough, 
Northants,  
NN9 5QE 
United Kingdom 
 

1.2.2. Equipment Type 

 
HY02 

Digital

 telephone balance unit. 

1.2.3.  BABT Approval Number 

 
Apparatus power supply : NS/3619/123/L/601748 
 

1.2.4. Functions 

The HY02 Digital Telephone Balance Unit is suitable for use with the HY02 power 

supply for connection to B.T. exchange lines with a series connected telephone at the ‘Handset’ port.  
The hybrid unit is used as a four wire to two wire converter.  Incoming calls received at the handset 
may be diverted to the hybrid unit and produce a ‘telephone’ signal at the output of the unit.  0dB 
signals presented at the line input are transmitted to the telephone line only.  The HY02 Digital 
automatically balances the telephone line. 

1.2.5. Specified Systems 

 
The HY02 Digital is suitable for connection to any exchange line forming part of a 

Public Switched Telephone Network, PSTN, or a Relevant Branch system for PSTN lines or any 
extension.  This equipment is not suitable as an extension to a payphone. 

A definition of a Relevant Branch System for PSTN is given in BS6789 : Section 

6.1: 1986 clause 2.4 including the NOTE to that clause. 

1.2.6.  Ringer Equivalence Number 

 
The REN=1 marking on the rear of this equipment relates to the performance of the 

apparatus when used in combination with other items of apparatus. 

The REN indicates the maximum number of items that should be connected 

simultaneously to the line.  This equipment may be connected with series apparatus up to REN = 4 
maximum. 

1.2.7. Accessory Ports 

1.2.7.1  Barriered Ports 

 
The Handset series connection complies with BS6301. 
 

1.2.7.2  Accessory Ports 

a)   Line Input 

b)   Line Output 

 
This equipment is provided with a line cord and BT plug to BS6312 and is internally 

wired as specified in BS6305 1982.