Sonifex DHY-03 Instruction Manual

Digital Telephone Hybrid
User Handbook

bDHY-03 User Handbook
This handbook is for use with the following products :
DHY-03 Automatic digital TBU, free standing
DHY-03S Automatic digital TBU, 19”rack mounted
DHY-03T Twin automatic digital TBU, 19” rack mounted
DHY-03EC Automatic digital TBU, eurocard
©Sonifex Ltd, 2008 - 2010
All Rights Reserved
Revision 1.08, February 2010
Sonifex Ltd, 61, Station Road, Irthlingborough,
Northants, NN9 5QE, England.
Tel: [phone]
Fax: [phone]
Email: [email protected].uk
Website: http://www.sonifex.co.uk
Information in this document is subject to change without notice and does not represent a commitment on the part of the
vendor. Sonifex Ltd shall not be liable for any loss or damage whatsoever arising from the use of information or any error
contained in this manual.
No part of this manual may be reproduced or transmitted in any form or by any means, electronic or mechanical, including
photocopying, recording, information storage and retrieval systems, for any purpose other than the purchaser’s personal
use, without the express written permission of Sonifex Ltd. Unless otherwise noted, all names of companies, products
and persons contained herein are part of a completely ctitious adaptation and are designed solely to document the use of
Sonifex product.
DHY-03 USER HANDBOOK
DHY-03 USER HANDBOOK

DHY-03 User Handbook c
CONTENTS
CONTENTS
Contents
Warranty i
Warranty and Liability i
Unpacking the DHY-03 iii
Returning the Warranty Card iii
Safety Information iv
Safety of Mains Operated Equipment iv
Voltage Setting Checks iv
Fuse Rating iv
Power Cable and Connection v
Opening the DHY-03 v
Power For DHY-03EC v
Ordering the Correct Mains Lead vi
Installation Information vi
Atmosphere vi
Electromagnetic Radiation vi
WEEE & RoHS Directives - Sonifex Statement vii
Reporting Faults viii
1 Introduction 1
What is a Telephone Hybrid ? 2
Available Formats 2
Model DHY-03 Automatic digital TBU 3
Model DHY-03S Automatic digital TBU 3
Model DHY-03T Twin automatic digital TBU 3
Model DHY-03EC Eurocard automatic digital TBU 3
Connecting the DHY-03 TBU 4
Using the DHY-03 5
First Use 5
Using the DHY-03 with the Broadcast Bionics PhoneBox 5
Using the DHY-03 with Internal Telephone Exchanges 5
Receiving a Call 6
Integrated Ringing Detector – Auto Answer 6
Making a Call 6
Call Established 7
Level Setting 7
DTMF Detection 7
Integrated Disconnect Detector – Auto Disconnect 7
Conference Calls 7
Using the Conference Port as a Record Output 8
2 Conguration & Controls - DHY-03, DHY-03S, DHY-03T 9
Front Panel Controls 9
Power LED Indicator 9
Line Connect Button 9
Gain Switches 9
LED Bargraphs 9
Status & Operating Mode Information 10
Reset Button 11
Rear Panel Controls 11
Adjusting the Microphone Gain Level 11
Mic/Line Input Select Switch 11
Conguration Settings Switches 11

dDHY-03 User Handbook
CONTENTS
CONTENTS
Noise Gate Select - SW1 {ON} 12
Ducking Enable - SW2 {ON} 12
Auto Disconnect Enable - SW3 {ON} 12
Ring Detector (Auto Answer) Enable - SW4 {ON} 12
Acoustic Cancellation Enable – SW6 {OFF} 13
Network Cancellation Enable – SW7 {ON} 13
Country Set on Power Up – SW8 {OFF} 13
Remotes 13
RS232 Serial Port 13
DHY-03 Internal Controls & Adjustments 14
Conguration & Controls - DHY-03EC 15
Controls 15
Power LED Indicator 15
Gain Jumpers 15
Tricolour LED Level Indicators 15
Status & Operating Mode Information 16
Reset Button 16
Conguration Settings Switches 16
Noise Gate Select - SW1 {ON} 17
Ducking Enable - SW2 {ON} 17
Auto Disconnect Enable - SW3 {ON} 17
Ring Detector (Auto Answer) Enable - SW4 {ON} 17
Acoustic Cancellation Enable – SW6 {OFF} 17
Network Cancellation Enable – SW7 {ON} 17
Country Set on Power Up – SW8 {OFF} 17
Momentary Latching Function -SW9 {OFF} 18
Debug Function - SW10 {OFF} 18
Remotes 18
RS232 Serial Port 18
Jumper and Select Switcher Functions 18
Country Code Selection 19
Hybrid Technical Description 21
Electrical Interface 21
Impedance Matching 22
Echo Cancellation 22
Calibration of DHY-03 Hybrid 22
Calibration of Telephone Interface 23
Calibration of Network Cancellation Coecients 23
Acoustic Cancellation 23
Updating Firmware 23
3 Serial Port Control 24
DHY-03 Serial Connection 24
Normal Mode 24
Setting Mode 24
Bootstrap Mode 24
SCI Software 24
Serial Interface Commands & Responses 24
Normal Mode Commands 24
Setting Mode Commands 25
Bootstrap Mode Commands 25
Status Request Responses 25
Error Messages 26
DHY-03 Serial Parameters 26
Parameter Numbers – Function and Value 26
Extended Parameter Description 28
Calibration Register – parameter 3 28

DHY-03 User Handbook e
CONTENTS
CONTENTS
Telephone Interface Meter Select – parameters 7 28
Disconnect Type – parameters 25,50,75,100,125,150,175 29
Telephone Interface Hybrid Pointer – parameters 26,51,76,101,126,151,176 29
Telephone Interface Register 16 - parameters 28,53,78,103,128,153,178 29
Telephone Interface Register 17 - parameters 29,54,79,104,129,154,179 29
Telephone Interface Register 18 - parameters 30,55,80,105,130,155,180 30
Telephone Interface Register 22 - parameters 31,56,81,106,131,156,181 30
Telephone Interface Register 23 - parameters 32,57,82,107,132,157,182 30
Telephone Interface Register 24 - parameters 33,58,83,108,133,158,183 31
Telephone Interface Register 26 - parameters 34,59,84,109,134,159,184 31
Telephone Interface Register 30 - parameters 35,60,85,110,135,160,185 31
AC Impedance Setting 32
Telephone Interface Register 31 - parameters 36,61,86,111,136,161,186 32
Telephone Interface Register 59 - parameters 37,62,87,112,137,162,187 32
Telephone Interface Adaptation Dierential – parameters 43,68,93,118,143,168,193 33
Telephone Interface Adaptation Response – parameters 44,69,94,119,144,169,194 33
Miscellaneous Register – parameters 45, 70, 95, 120, 145, 170 & 195 33
Disconnect Tones – parameters 200,208,216,224,232,240 34
Cadence Pattern 1 – parameters 201,209,217,225,233,241 34
Success Time/Cadence Pattern 2 – parameters 202,210,218,226,234,242 34
Cycles for Transform – parameters 203,211,219,227,235,243 34
Coecient for Tone 1 – parameters 204,212,220,228,236,244 34
Coecient for Tone 2 – parameters 205,213,221,229,237,245 34
Threshold Level – parameters 206,214,222,230,238,246 34
4 Technical Specication 35
DHY-03 Connection Details 35
Line Output 35
Mic/Line Input 35
Remotes 36
RS232 Serial Port 36
Telephone Handset 37
Telephone Line 37
Telephone Connections 37
Conference Audio/Record Output 37
Mains Input 37
Protective Earth Terminal 37
DHY-03EC I/O Connector 38
Technical Specication 39
Physical Specication 39
Accessories 40
Divert Relay Function 40
Approvals Information 40

fDHY-03 User Handbook
FIGURES
FIGURES
Figures
Table A : Packing List. iii
Table B : Power Connections. v
Table C : Mains Lead Table. vi
Figure 1-1 : DHY-03 Front & Rear. 3
Figure 1-2 : DHY-03S Front & Rear. 3
Figure 1-3 : DHY-03T Front & Rear. 3
Figure 1-4 : DHY-03EC View From Above. 3
Figure 1-5 : DHY-03 User Connections. 4
Figure 1-6 : Audio Paths for Conference Call. 8
Figure 1-7 : Conference Port Cable Connections. 8
Figure 2-1 : Front Panel Controls. 9
Figure 2-2 : Rear Panel Controls. 11
Figure 2-3 : Conguration Settings Switches. 12
Figure 2-4 : Rear Panel Controls. 13
Figure 2-5 : PCB Layout. 14
Figure 2-6 : DHY-03EC Controls. 15
Figure 2-7 : DHY-03EC Conguration Settings Switches. 16
Figure 2-8 : DHY-03EC Diagram. 18
Table 2-1 : Supported Disconnect Tone Details by Country. 21
Table 2-2 : Calibration Parameter Settings. 22
Table 3-1 : Meter Select Parameter Values. 28
Table 3-2 : Disconnect Type Parameter Values. 29
Table 3-3 : Telephone Interface Register 16. 29
Table 3-4 : Telephone Interface Register 17. 29
Table 3-5 : Telephone Interface Register 18. 30
Table 3-6 : Telephone Interface Register 22. 30
Table 3-7 : Telephone Interface Register 23. 30
Table 3-8 : Telephone Interface Register 23 - RTO Values. 30
Table 3-9 : Telephone Interface Register 23 – RCC Values. 30
Table 3-10 : Telephone Interface Register 24. 31
Table 3-11 : Telephone Interface Register 26. 31
Table 3-12 : Telephone Interface Register 30. 31
Table 3-13 : Telephone Interface Register 30 - AC Impedance settings. 32
Table 3-14 : Telephone Interface Register 31. 32
Table 3-15 : Telephone Interface Register 59. 32
Table 3-16 : Adaptation Dierential Parameter Values. 33
Table 3-17 : Adaptation Response Parameter Values. 33
Table 3-18 : Table of Disconnect Tone Values. 33
Figure 4-1 : DHY-03 Rear Panel Connections. 35
Table 4-1 : Technical Specication. 39
Table 4-2 : Physical Specication. 39
Table 4-3 : Accessories. 40

DHY-03 User Handbook i
Warranty
Warranty and Liability
Important: the purchaser is advised to read this clause
(a) The Company agrees to repair or (at its discretion) replace Goods which are found to
be defective (fair wear and tear excepted) and which are returned to the Company
within 12 months of the date of despatch provided that each of the following
are satised:
(i) notication of any defect is given to the Company immediately upon its
becoming apparent to the Purchaser;
(ii) the Goods have only been operated under normal operating conditions and
have only been subject to normal use (and in particular the Goods must have
been correctly connected and must not have been subject to high voltage or
to ionising radiation and must not have been used contrary to the Company’s
technical recommendations);
(iii) the Goods are returned to the Company’s premises at the Purchaser’s expense;
(iv) any Goods or parts of Goods replaced shall become the property of
the Company;
(v) no work whatsoever (other than normal and proper maintenance) has been
carried out to the Goods or any part of the Goods without the Company’s prior
written consent;
(vi) the defect has not arisen from a design made, furnished or specied by
the Purchaser;
(vii) the Goods have been assembled or incorporated into other goods only in
accordance with any instructions issued by the Company;
(viii) the defect has not arisen from a design modied by the Purchaser;
(ix) the defect has not arisen from an item manufactured by a person other than
the Company.
In respect of any item manufactured by a person other than the Company, the Purchaser
shall only be entitled to the benet of any warranty or guarantee provided by such
manufacturer to the Company.
(b) In respect of computer software supplied by the Company the Company does not
warrant that the use of the software will be uninterrupted or error free.
(c) The Company accepts liability:
WARRANTY
WARRANTY

ii DHY-03 User Handbook
(i) for death or personal injury to the extent that it results from the negligence of
the Company, its employees (whilst in the course of their employment) or its
agents (in the course of the agency);
(ii) for any breach by the Company of any statutory undertaking as to title, quiet
possession and freedom from encumbrance.
(d) Subject to conditions (a) and (c) from the time of despatch of the Goods from the
Company’s premises the Purchaser shall be responsible for any defect in the Goods
or loss, damage, nuisance or interference whatsoever consequential economic or
otherwise or wastage of material resulting from or caused by or to the Goods. In
particular the Company shall not be liable for any loss of prots or other economic
losses. The Company accordingly excludes all liability for
the same.
(e) At the request and expense of the Purchaser the Company will test the Goods to
ascertain performance levels and provide a report of the results of that test. The
report will be accurate at the time of the test, to the best of the belief and knowledge
of the Company, and the Company accepts no liability in respect of its accuracy
beyond that set out in Condition (a).
(f) Subject to Condition (e) no representation, condition, warranty or other term, express
or implied (by statute or otherwise) is given by the Company that the Goods are of
any particular quality or standard or will enable the Purchaser to attain any particular
performance or result, or will be suitable for any particular purpose or use under
specic conditions or will provide any particular capacity, notwithstanding that the
requirement for such performance, result or capacity or that such particular purpose
or conditions may have been known (or ought to have been known) to the Company,
its employees or agents.
(g) (i) To the extent that the Company is held legally liable to the Purchaser for any
single breach of contract, tort, representation or other act or default, the
Company’s liability for the same shall not exceed the Price of the Goods.
(ii) The restriction of liability in Condition (g)(i) shall not apply to any liability
accepted by the Seller in Condition (c).
(h) Where the Goods are sold under a consumer transaction (as dened by the Consumer
Transactions (Restrictions on Statements) Order 1976) the statutory rights of the
Purchaser are not aected by these Conditions of Sale.
WARRANTY
WARRANTY

DHY-03 User Handbook iii
Unpacking the DHY-03
The DHY-03 is shipped with the following equipment. Please check your packaging to
ensure that you have all of the items below. If anything is missing, please contact the
supplier of your equipment immediately.
Item Quantity Quantity Quantity
DHY-03 & DHY-03S DHY-03T DHY-03EC
DHY-03 automatic telephone hybrid 1 2 1
Telephone line lead (RJ11 to RJ11) 1 2 -
Telephone line lead (RJ11 to BT plug) 1 2 -
Telephone line lead adapter
(BT socket to RJ11 plug) 1 2 -
IEC Mains lead tted with moulded
mains plug 1 2 -
Handbook and warranty card 1 1 1
Table A : Packing List.
Each DHY-03 is shipped in protective packaging and should be inspected for damage before
use. Where an item is found to have transit damage, notify the carrier immediately with all
the relevant details of the shipment. Packing materials should be kept for inspection and
also for if the product needs to be returned.
Returning the Warranty Card
In order to register the date of purchase so that we can keep you informed of any design
improvements or modications, it is important to complete the warranty registration
document that is enclosed and return it to Sonifex Ltd in the UK, or register online at
www.sonifex.co.uk/register
For your own records you should write down the serial number (which can be found on the
rear of the DHY-03 or on the connector on the DHY-03EC.
Serial Number ………………………………………
WARRANTY
WARRANTY

iv DHY-03 User Handbook
Safety Information
Safety of Mains Operated Equipment
This equipment has been designed to meet the safety regulations currently advised
in the country of purchase and it conforms to the safety regulations specied by
use of the CE Mark.
Warning : There are no user serviceable parts inside the equipment. If you should ever
need to look inside the unit, always disconnect the mains supply before removing the
equipment covers.
Warning: The DHY-03 line socket should only be connected with apparatus
complying with BS6301, and the connection to the network must not be hard wired
Interconnection directly or indirectly with equipment ports marked in accordance with
BS6301 to unmarked ports may produce hazardous conditions on the network and
advice should be obtained from a competent engineer before such a connection is made.
Warning: This apparatus must be earthed by means of the earth connector on the rear
panel, and the connection to the telecommunications network should be removed
before disconnecting the earth. Disconnection of this earth connection may render the
equipment unsafe, with a consequential possible electrical shock hazard from exposed
metallic parts.
Warning: The barriered ports ‘LINE’and ‘HANDSET’ must not be connected directly
or indirectly to the un-barriered ports, ‘MIC/LINE INPUT’, ‘OUTPUT’, ‘CONFERENCING’,
‘REMOTES’ or ‘RS-232’.
Voltage Setting Checks
The integral power supply is designed to accept a universal input of 85 to 264 VAC mains
input voltage. The safety specication of your DHY-03 complies with local requirements and
must be earthed through the mains connector.
Fuse Rating
The DHY-03 is supplied with a single fuse in the live conducting path of the mains power
input. For reasons of safety it is important that the correct rating and type of fuse is
used. Incorrectly rated fuses could present a possible re hazard, under equipment fault
conditions. The fuse rating for DHY-03 is:
230 or 115 V operation - 1A 5 x 20mm SB
The active fuse is tted on the outside rear panel of the unit.
SAFETY INFORMATION
SAFETY INFORMATION

DHY-03 User Handbook v
Power Cable and Connection
An IEC power connector is supplied with the DHY-03 which has a moulded plug attached
– this is a legal requirement. If no moulded plug has been supplied with your DHY-03, please
contact your supplier, because an IEC connector is always supplied from the Sonifex factory.
If for any reason, you need to use the DHY-03 with a dierent power cable, you should use
the following wiring guidelines
Wire Colour Connection
Green, or green and yellow Earth (E)
Blue, or Black Neutral (N)
Brown, or Red Live (L)
Table B : Power Connections.
Connect the equipment in accordance with the connection details and before applying
power to the unit, check that the machine has the correct operating voltage for your mains
power supply.
Important Note : The terminal marked on the rear panel must be earthed.
Opening the DHY-03
If you need to get inside the unit to make conguration adjustments, simply remove the 4
screws in the corners of the rear panel. The rear panel and main PCB will slide backwards out
of the metal chassis.
Warning : The power must be switched o at the supply or the power lead must be
disconnected before attempting to open the unit. Removal of the cover can expose
dangerous voltages.
Warning : The telephone line plug should be disconnected from the telecommunications
network exchange line before removing the equipment covers.
Power For DHY-03EC
The DHY-03EC requires an extended DC supply of 5V or 15V (jumper selectable). This supply
should be isolated.
SAFETY INFORMATION
SAFETY INFORMATION

vi DHY-03 User Handbook
Ordering the Correct Mains Lead
When ordering a TBU from Sonifex, it is helpful if you can specify your required operating
voltage and mains lead. After the product code add:
UK, for 230V, UK 3 pin to IEC lead
EC, for 230V, European Schuko 2 pin to IEC lead
US, for 115V, 3 pin to IEC lead
AU for 230V, Australasian 3 pin to IEC lead
Table C : Mains Lead Table.
E.g. order DHY-03S UK for a UK IEC lead to be supplied.
Installation Information
Atmosphere
The units should be installed in an area that is not subject to excessive temperature
variation (<0°C, >50°C), moisture, dust or vibration.
Electromagnetic Radiation
The cover is connected to earth by means of the xing screws. It is essential to maintain
this earth ground connection to ensure a safe operating environment and provide
electromagnetic shielding.
SAFETY INFORMATION
SAFETY INFORMATION

DHY-03 User Handbook vii
WEEE & RoHS Directives - Sonifex Statement
The Waste Electrical and Electronic Equipment (WEEE) Directive was agreed on
13 February 2003, along with the related Directive 2002/95/EC on Restrictions
of the use of certain Hazardous Substances in electrical and electronic
equipment (RoHS).
The Waste Electrical and Electronic Equipment Directive (WEEE) aims to minimise the
impacts of electrical and electronic equipment on the environment during their life times
and when they become waste. It applies to a huge spectrum of products. It encourages
and sets criteria for the collection, treatment, recycling and recovery of waste electrical and
electronic equipment. All products manufactured by Sonifex Ltd have the WEEE directive
label placed on the case. It gives a contact for individuals who are unsure about the correct
procedure when the product has reached its “end of use”.
Sonifex Ltd will be happy to give you information about local organisations that can
reprocess the products, or alternatively all products that have reached “end of use”can be
returned to Sonifex and will be reprocessed correctly free of charge.
Sonifex Ltd has phased out the use of certain hazardous substances identied in the
European Union’s Restriction of Hazardous Substances (RoHS) directive. The RoHS directive
limits the use of certain hazardous substances currently used in EEE manufacture, including
lead, mercury, cadmium, hexavalent chromium, and halide-containing compounds PBB
(polybrominated biphenyl) and PBDE (polybrominated diphenyl ether). Elimination of these
substances will result in more environmentally friendly recycling of electronic equipment.
For the products which Sonifex manufacture, the main area where products were aected
was in the use of lead for manufacturing and assembling electronics circuit boards.
Sonifex Ltd practices lead-free (LF) manufacturing processes. LF solder is used on the
surface-mount PCB manufacturing processes and for hand soldering. The printed circuit
boards (PCBs) used are either gold plated, or immersion tin plated, both of which use no
lead. Historically the PCBs were hot air solder levelled (HASL) PCBs which used tin/lead
based solder.
The manufacturing processes include the assembly of purchased components from various
sources. Product is oered as RoHS compliant, or LF, only after sucient evidence is received
from the component manufacturers that their components are RoHS compliant. Sonifex
Ltd relies solely on the distributor, or manufacturer, of the components for identication of
RoHS compliance. Thus whilst every eort is made to ensure compliance, Sonifex Ltd makes
no warranty, or certication, or declaration of compliance concerning said components.
Sonifex Ltd denes“Lead Free” as pertaining to any product, which has been manufactured
by Sonifex Ltd using components which have been declared by the manufacturers as
“Lead Free”. All statements by Sonifex Ltd of RoHS compliance are based on component
manufacturer documentation.
SAFETY INFORMATION
SAFETY INFORMATION

viii DHY-03 User Handbook
Reporting Faults
Although this Sonifex product is manufactured to the highest standards, it is possible that
minor faults may appear in the equipment over its normal lifetime. If you nd any problems
with the DHY-03, please contact your Sonifex distributor, or contact Sonifex directly at the
following address, or fax with a copy of this completed sheet :
To : From:
Sonifex Ltd, Name
61, Station Road, Position
Irthlingborough, Company
Northants. Address
NN9 5QE, UK
Tel : [phone] Tel
Fax : [phone] Fax
Email : [email protected].uk Email
For the Serial No. of your machine, see the
back panel of the DHY-03 unit.
DHY-03 Serial No.
Please describe the error in as much detail as possible (for example what you were doing
when the problem occurred, what actually happened, etc)
Description of DHY-03 Error
Also, if you have any suggestions for additions or upgrades to the DHY-03 unit , we would
like to hear what they are :
Additions that I Would Like to See
REPORTING FAULTS
REPORTING FAULTS

DHY-03 User Handbook 1
1 Introduction
The DHY-03 is a high quality digital telephone hybrid, which is suitable for most general
telephony applications and is often used in radio and TV stations, bingo halls and dealing
oors. The digital DHY-03 telephone hybrid is the replacement for the DHY-02, which for
many years has set the standard as an excellent value, high quality telephone hybrid. The
DHY-03 can be used for any application where a clean telephone signal is required and the
line is not subject to excessive delay. The DHY-03 retains many of the features of the DHY-02
and adds some additional ones. Some of the features of the DHY-03 include:
.Fully automatic - adapts to varying line conditions and has automatic signal limiting.
.Fully adaptive echo cancellation to 127msec - default is 24msec.
.75dB typical line balance rejection oering superb performance and crystal
clear audio.
.Front panel input and output gain controls (jumpers on DHY-03EC).
.Front panel LED metering of receive and send signals.
.Built-in conferencing for 2 hybrids, so that a single telco channel on a mixing desk can
receive 2 calls (unavailable on DHY-03EC).
.Integrated ring detector - automatic call answering after a pre-determined number
of rings.
.Automatic call disconnection. Fitted with K-break, line polarity reversal and dial tone
disconnect detection, dened by the country selection.
.Automatic ducking facility allows the talent to‘shout-down’, or talk over, a caller by
reducing the gain of the caller’s signal if it goes above a certain level.
.Local and remote line hold switching - calls can be remotely switched through a
mixing console.
.Line hold/release button to control line hold circuit, illuminates to indicate the status
of the line and ashes to show ring status.
.DTMF tone recognition allowing a opto-isolated GPI output to be made on receipt of
selected DTMF tones, e.g. for starting a studio automation recorder automatically to
record a remote telephone interview.
.International operation with built-in congurable settings for each country. Country
selection allows the unit to provide line impedance and a simulation circuit to match
the country.
.RS232 serial port for remote control of the TBU, DTMF tone dialling and rmware
upgrades to add new country settings.
INTRODUCTION
INTRODUCTION 1

2DHY-03 User Handbook
.Remote port distributes the remote line connect switch and tally output, a
momentary/latch selector and the DTMF detect output.
.The remote line connect switch can be either momentary or latching in its action.
.Balanced mic/line input - 10k balanced input selectable for 0dBu clean feed line, or
microphone level with adjustable gain (line input only on DHY-03EC).
.Divert relay (for new units, see page 40).
.Balanced output - 0dBu low impedance balanced output, with output gain settings.
.Record output - the conferencing output can be set via a jumper to give a mix
of the caller and mic/line input signals for recording both sides of the telephone
conversation (unavailable on DHY-03EC).
.Line limiter, bandpass lter and output noise gate with preset threshold providing low
distortion audio.
.Built in universal power supply between 90V AC and 250V AC, 47-63Hz, IEC
mains input (external DC required by DHY-03EC).
.ETSI approval compliant with European PTT specications.
What is a Telephone Hybrid ?
Telephone hybrids (or telephone balance units, TBUs) provide the interface between
professional audio equipment and the public telephone network. They provide protection
for your equipment and the public telephone lines, allowing for varying line signals and line
conditions. Automatically cancelling out the unwanted signal they also facilitate two-way
communication down a single telephone line, converting the two-wire telephone signal to a
four-wire send and return signal to be linked to a studio mixer, for example.
The hybrid has a telephone line connection and separate terminals for audio input and
output from a broadcast mixer, or other professional audio source.
A large proportion of Sonifex hybrids are used in radio and television broadcasting
applications for allowing external callers to be connected to the studio mixing console.
Most of the other units are supplied to communication operations for allowing extremely
eective conversion between four-wire audio circuits and standard telephone lines.
Built to a very high specication, the DHY-03 is simple to install and automatically adapts to
line conditions and programme content.
Available Formats
The DHY-03 digital telephone hybrids are available in four dierent formats. Three modules
have their own approved, integrated power supply and the DHY-03EC requires an external
DC supply:
INTRODUCTION
INTRODUCTION
1

DHY-03 User Handbook 3
Model DHY-03 Automatic digital TBU
Figure 1-1 : DHY-03 Front & Rear.
Model DHY-03S Automatic digital TBU
Figure 1-2 : DHY-03S Front & Rear.
Model DHY-03T Twin automatic digital TBU
Figure 1-3 : DHY-03T Front & Rear.
INTRODUCTION
INTRODUCTION 1
Model DHY-03EC Eurocard
automatic digital TBU
Figure 1-4 : DHY-03EC View From Above.

4DHY-03 User Handbook
Connecting the DHY-03 TBU
Connect the earth and mains power connections as per the information given in the
Warranty and Safety Information sections of the handbook. The hybrid unit should be
connected with reference to Figure 1-5.
The telephone line socket is connected to the telephone network using the RJ11 to RJ11
cable provided. An adaptor is provided to connect to a standard BT socket.
A simple telephone handset can be used to take and make calls when plugged into the
equipment handset connector. An adapter is provided if the handset is tted with a BT plug
as standard.
A remote switch may be connected at the Remotes socket in order to control the line
connect button from say, the telco channel of a mixing desk.
Connect the output from the mixing desk“clean-feed” to the mic/line input of the DHY-03,
with the mic/line input select switch set to “line”. A clean-feed is a signal produced by a telco
module on a mixer which is used as the output to be fed back to a caller on a telephone
line. The cleanfeed is a sum of all the other signals which constitute the programme output,
except for the caller’s audio (this is so that the caller doesn’t hear him/herself in the
ear-piece). A cleanfeed signal will generally be of a better quality than a mix-minus signal.
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Figure 1-5 : DHY-03 User Connections.
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The characteristics of the mic/line input are determined by the state of the mic/line
conguration selection switch. It is a balanced bridging input and in line mode will accept
normal signals at 0dBu peaking to +8dBu from a sound mixer clean feed. In mic mode,
available on all units except DHY-03EC, the unit will accept 200 Ω microphone level signals
with a maximum gain of 74dB. It is suitable for a wide range of microphones and the
available gain is 74dB to 40dB, which can be adjusted by the mic level pre-set mounted

DHY-03 User Handbook 5
on the rear panel. The input circuitry to the DHY-03 has a very eective limiter, which will
prevent high level overloading problems. Ideally, the maximum input level should not
exceed +12dBu. This limiter is used for both line and mic input modes.
Connect the output of the DHY-03 to the tele input of the mixing console. The output
connection will deliver a balanced/oating low impedance signal of 0dBm from the
telephone line. The output of the digital hybrid unit is normally 0dBu from a balanced
source of 50 Ω or less across the useful bandwidth of the equipment. The bandwidth is
restricted by the line conditions between 250 Hz and 4 kHz. The output stage is capable
of driving into 600 Ω loads at up to +8dBu. Termination of the output is not necessary
however and direct connection can be made into the mixer telephone return channel.
The output stage has a 3-way gain switch control, mounted on the front panel (level to
line), which may be set to give 0dB signals at the output. In addition an output noise gate
operates when the telephone signal is below the noise gate threshold control. This noise
gate reduces the output gain by 34dB under no signal conditions eliminating the aects of
telephone line cross talk.
Isolation of better than 75dB is created between the input and output connectors when the
hybrid unit is functioning on an exchange line.
Note: The earth bond at the screw terminal must be connected to a technical earth to
ensure the safe operation of the equipment under all line conditions.
Using the DHY-03
First Use
Before using the DHY-03 you should ensure that it is connected as gure 1-5 and that the
unit is setup for the correct line conditions.
1. With the unit powered o set the dipswitches of the SETTINGS on the rear panel to
the appropriate country specication (see Table 2-1).
2. Ensure that dipswitch 8 is also set on and then power up the unit. During the power
up cycle the new country code should be reected in the top row of LEDs, on the
front panel.
3. Now return the dipswitches to their default condition – switches 1,2 & 6 on, with
switches 3 & 4 also on if you wish to use automatic call handling. The unit should now
be ready to make & receive calls.
Using the DHY-03 with the Broadcast Bionics PhoneBox
The DHY-03 telephone hybrids can be simply congured to operate with the Avaya
telephone switch used in the Broadcast Bionics PhoneBox system. Follow the procedure
for“First Use“ and in section 1, select Country code number 119 (see page 21). This will
congure the hybrid to operate correctly with the Avaya switch.
Using the DHY-03 with Internal Telephone Exchanges
The DHY-03 can be congured to operate with internal exchanges, such as the Avaya
exchange - contact [email protected].uk with details of the exchange and we
should be able to program the unit to those particular settings, using one of the User Set
country codes (see page 19). Typically, most modern exchanges connect to the outside
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6DHY-03 User Handbook
world via digital lines - in this case there is no network echo and switch 7 should
be turned o.
Receiving a Call
With the equipment connected as in Figure 1-5 calls may be received and detected by the
ringer in the telephone handset. To receive the call, lift the handset and establish contact
with the caller. The call may be diverted to the telephone hybrid by pressing either the
front panel mounted line connect button or by means of the remote connect switch (if
connected).
Note : The DHY-03EC and later DHY-03 units (see page 40) have an integrated divert
relay that will automatically disconnect the handset when the unit handles the calls. For
early DHY-03 units (see page 40), at this point, the telephone handset must be replaced,
otherwise the line will be double terminated resulting in poorer performance. For early
units, order the accessory DHY-03RLY in order to have a divert relay to automatically
disconnect the handset.
Alternatively, the incoming calls can be answered manually from the line connect button or
the remote line connect switch or automatically by enabling the integrated ringing detector
(settings SW4 On). Ringing tone will illuminate the line connect button. The line connect
button lamp is o in the non-connected mode and illuminated in the connected mode.
It is recommended that the auto-disconnect feature be used when the ringing detector
is enabled.
Note : The remote lamp tally mimics the front panel line connect button lamp, i.e.
it ashes when ringing and is on when the line is held.
The hybrid unit will now behave as a 4-wire to 2-wire converter with signal inputs at the
mic/line input connector and telephone signal output at the output connector.
The call may be cleared by re-pressing the line connect button or by means of the remote
divert switch. The call can also be cleared automatically by enabling the auto-disconnect
feature, or via the serial port CLR: command
With both auto-answer and auto-disconnect in use, call handling can be completely
automatic in operation (settings SW3 & SW4 On).
The DHY-03EC has a on-board line connect switch and LED to indicate it’s function.
Normally the line connect function is performed through the remote line connect input.
Integrated Ringing Detector – Auto Answer
Ringing detectors can be used when you need to answer a call automatically, for instance,
if a journalist les a report to a tape recorder over a telephone line, the call can be picked up
after a set number of rings by the ringing detector. The DHY-03 has a built in ring detector
that is enabled by setting SW4 on the rear panel.
Making a Call
To initiate a call, lift the handset and dial the required telephone number. When the call
has been established, press the line connect button and the call will be handed over to
the telephone hybrid unit. At this point, for early DHY-03 units (see page 40) the telephone
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