Sonifex HY02 DIGITAL, User Handbook Manual

  Page 1-6       Introduction & Installation 

 HY02 Digital TBU User's Guide

1.6.3.  Line Connect Switch 

 
This is the front panel button used to connect calls to and disconnect calls from the 

telephone line. It can be remoted by using the Remote Divert switch and the connection signal can be 
made permanent or momentary by adjusting jumper setting JP1.  

1.6.4.  Transmit and Receive Level Adjustment 

 
To the left of the LED bar graph meters are two holes which can be used to adjust the 

level of the transmitted and received signals. Inside the holes are a three way switch which can be 
adjusted by use of a small flat-blade screw-driver : 

1.6.4.1 Receive  Level 

The level of the input received by the unit depends on 

which of the three settings is selected. With the switch set to low, a -12dB 
signal received is output at 0dB. Selecting the Medium or High settings add 
+6dB and +12dB to the level respectively. Set the level so that the meter 
readings peak at the 0dB scale mark. 

The receive switch is set to Low by default. 
 

1.6.4.2  Transmit Level 

The level of the output sent by the unit depends on which 

of the three settings is selected. With the switch set to low,  -12dB is sent to 
the line for a reference 0dB input signal. For the Medium and High settings, 
-6dB and 0db respectively are sent to the line ( i.e. +6dB increase in level 
each time ). Use the Low setting for high level input ( where the LED bar 
graph is always going to the end of the meter ). Use the High setting for low 
level input ( where the bar graph meter never reaches the 0dB point ). 

The transmit switch is set to Medium by default. 

Setting 

Receive Level  

( ref 0dB output ) 

Transmit Level 

( ref 0db input ) 

High +12dB 

0dB 

6dB 

-6dB 

Low 0dB 

-12dB