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TH3
Digital Telephone Hybrid
OPERATING INSTRUCTIONS
and trouble-shooting guide
LECTROSONICS, INC.
Rio Rancho, NM
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INTRODUCTION
Lectrosonics is proud to offer the TH3, our third generation digital hybrid. The TH3
interfaces with a standard telephone line to add teleconferencing capability to any
sound system. Sophisticated featues, fast setup, easy operation, high sound quality
and low cost make the TH3 an ideal choice for board rooms, conference rooms, talk
radio and countless other applications.
Product Highlights
• DTMF dialing capability
• Simultaneous 2-wire/4-wire bridging for 3-site conferencing
• Three-way echo elimination with patented algorithm
• Level meters for easy setup
• Privacy mode can mute transmit only, receive only, or both
• AGC enhances volume of weak signals
• Wired remote control interface
• Serial interface for integration with control systems
• Front panel switches may be disabled for secure installation
• Tape recorder output with relay for automatic recording
• Automatic telephone answer and disconnect
• Compatible with third-party echo cancellers
TABLE OF CONTENTS
INTRODUCTION.................................................................................................. 2
FRONT PANEL..................................................................................................... 3
REAR PANEL ....................................................................................................... 4
BRIEF TECHNICAL DESCRIPTION ................................................................... 5
TH3 WIRING GUIDE............................................................................................ 6
BASIC OPERATION.............................................................................................9
LEVEL SETTING PROCEDURE ....................................................................... 10
TH3 SOFTWARE CONTROL PANEL ................................................................ 11
SERIAL PORT HARDWARE AND SOFTWARE ............................................... 15
LecNet SERIAL PORT PROTOCOL.................................................................. 16
ACCESSORIES.................................................................................................. 22
GLOSSARY OF TH3 CONCEPTS..................................................................... 22
SPECIFICATIONS..............................................................................................23
TROUBLESHOOTING .......................................................................................24
FCC N OTI C E S ................................................................................................... 25
SERVICE AND REPA IR ..................................................................................... 27
RETURNING UNITS FOR REPAIR................................................................... 27
WARRANTY ......................................................................................... Back cover
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Digital Telephone Hybrid
FRONT PANEL
LECTROSONICS, INC.
RIO RANCHO, NM U.S.A.
TX
LEVEL
TELEPHONE
RX
LEVEL
CODEC
RX
LEVELTXTRIM
LecNet
ANTI-ECHO
LecNet
ANTI-ECHO
RX
LEVEL
The TX LEVEL control is used to set the proper amount of local signal, with the aid of the TX LEVEL meter.
The TELEPHONE RX LEVEL control is used to set the proper telephone receive level, with the aid of the RX LEVEL
meter.
The CODEC RX LEVEL control is used to set the proper codec receive level, with the aid of the RX LEVEL meter.
The CODEC TX TRIM control adjusts the level supplied to the CODEC OUT plug on the rear panel, accommodating
level requirements of the codec.
The LecNet ANTI-ECHO control adjusts the amount of echo reduction applied to a Lectrosonics automatic micro-
phone mixer (e.g. AM8 or AM16) via the LecNet expansion port.
DIGITAL HYBRID
TX
LEVEL
The LecNet ANTI-ECHO, RX LEVEL and TX LEVEL meters aid in setting system audio levels optimally.
The TELEPHONE and CODEC interfaces include the following b uttons and indicators.
TELEPHONE CODEC
CONNECT
PRIVACY
UP
RECEIVE
VOLUME
DOWN
CONNECT
PRIVACY
RECEIVE
VOLUME
UP
DOWN
SWITCHES
DISABLED
POWER
The CONNECT button initiates or terminates a connection. The CONNECT led indicates an active connection. The
telephone connect led flashes when the telephone line is ringing.
The PRIVACY button mutes either the transmit signal, the received signal, or both, depending on the interface’s
current privacy mode. When the privacy feature is engaged, the PRIVACY led flashes to indicate the current privacy
mode, then glows steadily. Pr ivacy may be disengaged by pressing the button again. For detailed information about
privacy modes, please refer to the Privacy Feature topic in the chapter on BASIC OPERATION.
The RECEIVE VOLUME buttons permit fine control of the receive volume during normal operation. Each button
press alters the receive gain by 1 dB, and the control offers a range of -12 dB to +6dB (19 settings). The default
setting of 0 dB may be restored by pressing both volume buttons simultaneously.
The SWITCHES DISABLED led indicates that the interface buttons on the front panel have been disabled at the
installer’s option. The wired remote controls and serial commands will operate normally.
The POWER switch turns the TH3 on and off. The POWER led serves as a power status indicator.
Rio Rancho, NM – USA
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REAR PANEL
PWR
IN
(CH40)
20 VAC
EXPANSION
OUT
IN
LecNet
(RS232)
REMOTE CONTROLS
TELEPHONE
CODEC
The PWR IN jack must be attached to an appropriate power source, such as the included CH40 wall transformer.
The EXPANSION OUT and EXPANSION IN jacks are used to attach the TH3 to other LecNet equipment (e.g. AM8
or AM16 mixers).
The LecNet (RS232) jack may be connected to the serial port of a personal computer for configuration and testing.
The REMOTE CONTROLS connectors may be wired to switches and leds for wired remote control of the TH3’s
interface functions (connect, privacy, volume up and volume down). A pinout of the remote control ports is provided
in the SPECIFICATIONS chapter.
AUX
IN OUT
+
–
SUPPLEMENTARY
ECHO CANCELLER
RECORD OUT
OUTPUT
LEVEL
+
–
FINE
LEVEL
RELAY
COARSE
LEVEL
+
–
LINE
MIC
RX INSERT
+–+
OUTIN OUTIN
TX INSERT
+
+
–
–
–
CODEC
+–+
OUTIN
–
TELEPHONE
LINESET
The AUX interface provides line level, balanced or unbalanced main input and output from the TH3. Any signal
imposed at AUX IN is transmitted to all connected interfaces, and any signal received from connected interfaces is
available at AUX OUT, with as little of the transmitted signal as possible. The OUTPUT LEVEL control may be used
to match the TH3’s AUX OUT signal with the level requirements of any attached equipment.
The RECORD OUT interface contains a mix of transmitted and received signals, suitable for recording all parties in
a conversation. The signal may be used balanced or unbalanced. The COARSE LEVEL switch and FINE LEVEL
control easily accommodate the most common level requirements. When used as an unbalanced output, ground the
negative output to ensure proper operation of the COARSE LEVEL switch. The relay contacts are closed when a
connection is active, and open otherwise.
The SUPPLEMENTARY ECHO CANCELLER jacks may be used to connect an external echo canceller for addi-
tional acoustic echo cancellation. Balanced operation is recommended, though unbalanced operation is possible.
The CODEC jack provides line level, balanced or unbalanced input and output connections to an external four wire
codec, as is commonly used in video conferencing applications. The CODEC RX LEVEL and CODEC TX TRIM front
panel controls may be used to accommodate a wide range of audio levels, including the industry standard levels, -10
dBV and +4dBu.
The TELEPHONE SET jack may be connected to an external telephone device. The device is connected to the
telephone line only when the TH3 telephone interface is not connected. A standard telephone set, attached to this
jack, may be used for dialing where DTMF dialing from the TH3 via the serial port is not practical or convenient.
The TELEPHONE LINE jack connects to a standard telephone line.
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Digital Telephone Hybrid
BRIEF TECHNICAL DESCRIPTION
The TH3 provides a high-quality, flexible and powerful interface to a telephone line, a 4-wire video codec, or both
simultaneously with bridging. Each interface offers basic controls to connect, invoke privacy (selective mute), and
perform fine adjustments to the receive volume. The basic controls are available from the front panel, the wired
remote controls, and via the serial port. Using the serial port, additional features may be controlled, such as echo
suppression settings, telephone receive AGC, auto answer and auto disconnect, DTMF dialing and specialized signal
routing.
PHONE
INTERFACE
CODEC
INTERFACE
AUX PORT
EXPANSION
PORTS
MAIN IN
MIX- IN
MAIN OUT
LINE ECHO
CANCEL
"CODEC TX TRIM"
"CODEC RX L E V E L "
"OUTPUT LEVEL"
"TELEPHONE
RX LEVEL"
ECHO
SUPPRESSION
(SOFT)
"MAIN IN"
"MIX MINUS IN "
(SOFT)
AGC
ECHO
SUPPRESSION
(SOFT)
"AUX INPUT"
"EXPANSION PORT"
"RX LEVEL"
RX BUS
TX BUS
"TX LEVEL"
"TX LEVEL"
MIX- OUT
SIG IN
SIG OUT
SIG TOTAL
log
"MAIN OUT"
"MIX MINUS O UT"
"LECNET ANTI-ECHO"
TH3 Block Diagram
Rio Rancho, NM – USA
"LECNET ANTI-ECHO"
"FINE LEVEL"
"COARSE LEVEL"
LINE/MIC
SWITCH
RECORD
OUT
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TH3 WIRING GUIDE
Following are example wiring diagrams for various types of installations.
Example 1: AM8 MIXER
In this example, the TH3 is connected to an AM8 mixer,
and both local and remote signals are amplified. The
single LecNet cable passes signals both to and from the
AM8.
PWR
(CH40)
20 VAC
PWR
(CH40)
20 VAC
IN
EXPANSION
IN
M
S
A
S
L
T
A
E
V
R
E
OUT
EXPANSION
OUT
IN
LecNet
(RS232)
IN
LecNet
(RS232)
Switch in MASTE R position
Sound Reinforcement Amplifier
REMOTE CONTROLS
TELEPHONE
LECTROSONICS, INC.
REMOTE LEVEL
CONTROL
MAIN OUT
+ –
CODEC
CH8 IN
1 2 3 4
INPUT
TH3
+
–
AM8
DIR
OUT
PWR
(CH40)
20 VAC
PWR
(CH40)
20 VAC
EXPANSION
IN
IN
M
A
S
L
S
T
A
V
E
R
E
OUT
EXPANSION
OUT
IN
LecNet
(RS232)
IN
LecNet
(RS232)
Switch in MASTE R position
Sound Reinforcement Amplifier
REMOTE CONTROLS
TELEPHONE CODEC
LECTROSONICS, INC.
REMOTE LEVEL
CONTROL
MAIN OUT
+ –
CH8 IN
1 2 3 4
INPUT
+
–
AM8
AUX
OUTPUT
IN OUT
LEVEL
+
+
–
–
TH3
Example 2: AM8 MIXER, NO LOCAL
DIR
OUT
SOUND REINFORCEMENT
In this example, the TH3 is connected to an
AM8 mixer, and only the remote signals from
the TH3 are amplified. The single LecNet
cable passes signals both to and from the
AM8.
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Digital Telephone Hybrid
PWR
(CH40)
20 VAC
PWR
(CH40)
20 VAC
EXPANSION
IN
IN
M
A
S
S
L
A
T
E
V
R
E
OUT
EXPANSION
OUT
IN
LecNet
(RS232)
IN
LecNet
(RS232)
Switch in SLAVE position
PWR
IN
EXPANSION
(CH40)
20 VAC
M
S
A
S
L
A
T
E
V
R
E
IN
OUT
LecNet
(RS232)
Switch in MASTE R position
Sound Reinforcement Amplifier
REMOTE CONTROLS
TELEPHONE
LECTROSONICS, INC.
REMOTE LEVEL
CONTROL
MAIN OUT
+ –
LECTROSONICS, INC.
REMOTE LEVEL
CONTROL
MAIN OUT
+ –
CODEC
CH8 IN
1 2 3 4
CH8 IN
1 2 3 4
INPUT
+
–
AM8
+
–
AM8
DIR
OUT
DIR
OUT
AUX
IN OUT
+
–
OUTPUT
LEVEL
+
–
TH3
Example 3: TWO AM8 MIXERS
In this example, the TH3 is connected to a
pair of AM8 mixers. Both local and remote
signals are amplified. The single LecNet
cable passes signals both to and from the
AM8.
Note the interconnection of the mixers, with
the last mixer in the chain set as the master.
This technique may be used to add mixers to
any of the other examples.
Example 4: AM16 MIXER
In this example, the TH3 is connected to an
AM16 mixer. Due to the flexibility of the
PWR
(CH40)
20 VAC
EXPANSION
IN
IN
OUT
LecNet
(RS232)
REMOTE CONTROLS
TELEPHONE
CODEC
AUX
IN OUT
+
–
+
–
AM16, the same wiring configuration may be
used whether or not local sound reinforcement is required. The single LecNet cable
ON
LecNet
(RS232)
AUDIO EXPANSIO
AUDIO EXPANSIO
LINE
1 10 9
C
UTPUTS
0dB GAIN (LINE) +30dB GAIN (ELECTRET) +50dB GAIN (DYNAMIC)
GAIN
6
5
65
+––+
GAIN
4
LINE OUTPUTS
43
3
21
43658710 9
+––++––++––++––+
GAIN
21
2
1
+––+
passes signals both to and from the AM16.
In the AM16 software setup, Misc Settings
tab, be sure the Expansion In port is linked
to the NOM bus associated with the microphones (usually NOM 1). This ensures that
the LecNet anti-echo feature will work
PWR
IN
EXPANSION
(PS60)
M
OUT IN
S
A
S
L
16.5 VAC
T
A
E
V
E
R
PHANTOM POWER
16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1
MADE IN U.S.A.
OFF
correctly.
Sound Reinforcement Amplifier
INPUT
AM16 NOM settings
The Matrix Setup tab must assign “Exp In”
to the amplified output, so the remote signals can be heard. The matrix may be further manipulated to route the
microphone signals to the amplifier, or not, as desired.
OUTPUT
LEVEL
TH3
+––+
+––+
AM16
AM16 Matrix Settings
Rio Rancho, NM – USA
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Example 5: NON-LECTROSONICS MIXER
In this example, the TH3 is connected to a third-party
mixer, and both local and remote signals are amplified.
REMOTE CONTROLS
TELEPHONE
CODEC
AUX
IN OUT
+
–
LEVEL
FINE
LEVEL
RELAY
COARSE
LEVEL
+
–
LINE
MIC
OUTPUT
+
–
RECORD OUT
TH3
Note that the combined local and remote signal is
derived from the record out jack on the TH3. This is
valid and completely functional, but with this configuration the TH3 must be powered on in order for the local
microphones to be audible through the sound reinforcement system.
The LecNet anti-echo feature of the TH3 will not work
without a Lectrosonics mixer.
Microphone Mixer
OUTPUT
Sound Reinforcement Amplifier
INPUT
Example 6: NON-LECTR OSONICS MIXER,
NO LOCAL SOUND REINFORCEMENT
In this example, the TH3 is connected to a third par ty
mixer, and only remote signals are amplified.
The LecNet anti-echo feature of the TH3 will not work
without a Lectrosonics mixer.
8
REMOTE CONTROLS
TELEPHONE CODEC
IN OUT
Microphone Mixer
Sound Reinforcement Amplifier
AUX
+
–+–
OUTPUT
LEVEL
FINE
LEVEL
RECORD OUT
RELAY
+
OUTPUT
INPUT
–
COARSE
LEVEL
MIC
TH3
LINE
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Digital Telephone Hybrid
BASIC OPERATION
This chapter describes the TH3’s most essential user functions. The word “interface” is used here to distinguish
between the controls associated with the telephone (“telephone interface”) and those associated with the 4-wire
codec (“codec interface”).
Placing a T elephone Call
Telephone calls may be initiated from the TH3’s front panel, from a wired remote control, or from a PC or control
system connected via the TH3’s serial port. The TH3’s DTMF dialer may be used only from a PC or control system.
The simplest way to place a call is to attach a standard telephone to the Telephone Set jack. Dial the call with the
telephone, then press the CONNECT button for the telephone interface. When the TH3 connects, it automatically
disconnects the telephone set from the line. The CONNECT led will turn on and remain illuminated for the duration
of the call.
If the TH3 does not remain connected, please refer to the TROUBLESHOOTING chapter.
For information about using the TH3 software control panel to dial a call, please refer to the chapter on the TH3
SOFTWARE CONTROL PANEL.
Answering a Telephone Call
Upon receipt of an incoming call, the CONNECT led flashes and, optionally, a beeping sound is sent to the audio
outputs to indicate a ringing condition. By default, the TH3 will not answer telephone calls automatically. To manually
answer an incoming telephone call, press the CONNECT button for the telephone interface on either the front panel,
the wired remote control, or the TH3 software control panel. The CONNECT led will turn on and remain illuminated
for the duration of the call.
If the TH3 does not remain connected after answering, please refer to the Troubleshooting chapter.
For information about answering the phone from the TH3 software control panel or configuring the TH3 to answer
incoming calls automatically, please refer to the chapter on the TH3 Software Control Panel.
Ending a Telephone Call
The CONNECT button acts as a toggle. Pressing it while a call is in progress will disconnect the call.
The TH3 offers an automatic disconnect feature which is disabled by default. On telephone networks supporting this
feature, the TH3 can automatically disconnect when the other party disconnects. This feature is not compatible with
some PBX systems and the call waiting feature on some telephone networks. Please refer to the TH3 SOFTWARE
CONTROL PANEL chapter for information on enabling automatic disconnect.
Using the 4-wire Codec
The codec interface works nearly identically to the telephone interface, except that it is simpler. The codec interface
requires no dialing, and no automatic answer or automatic disconnect features are offered.
To connect or disconnect, simply press the codec CONNECT button on either the front panel, the wired remote, or
the TH3 software control panel.
Rio Rancho, NM – USA
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Privacy Feature
The PRIVACY buttons mute the respective interface’s transmit signal, receive signal, or both, depending on the
interface’s current privacy mode. As the privacy feature is engaged, the PRIVACY led flashes a confirmation to
indicate the current privacy mode, then glows steadily. The privacy modes and confirmation flashes are listed in the
following table.
Privacy mode Privacy led confirmation
Mute TX only 1 flash
Mute RX only 2 flashes
Mute TX and RX 3 flashes
Each interface’s current privacy mode may be selected from the front panel or wired remote control via special
button combinations. To select a specific privacy mode, simply hold down one or more RECEIVE VOLUME buttons
while pressing the PRIVACY button. The privacy mode is selected according to the following table. The privacy led
flashes to confirm the selected mode.
Button Combination Privacy Mode Privacy led confirmation
UP+PRIV A CY Mute TX only 1 flash
DOWN+PRIVACY Mute RX only 2 flashes
UP+DOWN+PRIVACY Mute TX and RX 3 flashes
Each interface has its own privacy mode. The selected privacy modes persist when the TH3 is powered off.
Adjusting the Receive Volume
When the TH3 is installed, all levels are adjusted for good performance. Sometimes, in the course of a conversation,
it is desirable to make small changes to the receive volume to compensate for varying conditions. For this purpose,
the TH3 offers RECEIVE VOLUME up and down buttons on the front panel and the wired remote. The software
control panel offers a slider that performs the same function.
The receive volume up and down buttons provide a range from -12 dB to +6 dB in 1 dB steps (for a total of 19
possible settings). The default setting is +0 dB. The receive volume may be reset to +0 dB directly by pressing the
up and down volume buttons together.
Each interface has its own receive volume. The selected receive volume settings persist when the TH3 is powered
off.
If you find you are constantly adjusting the telephone receive volume, you may wish to consider increasing the Rx
AGC setting. Refer to the chapter on the TH3 SOFTWARE CONTROL PANEL for more information on the AGC
feature.
LEVEL SETTING PROCEDURE
In order to obtain the best performance from the TH3, it is necessary to set all audio levels properly. Thanks to the
built-in metering, the procedure is simple.
1. TX LEVEL
Have someone speak normally into a local microphone and adjust the TX LEVEL control so that the red led on the
TX LEVEL meter lights only occasionally.
If more than one local microphone is installed, please verify that all microphone levels are approximately equal,
applying any necessary corrections at the mixer.
2. TELEPHONE RX LEVEL
If the telephone line interface portion of the TH3 will be used, it is necessary to set the TELEPHONE RX LEVEL
control.
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Digital Telephone Hybrid
Establish a telephone call (the BASIC OPERATION chapter tells how to do this), preferably to an actual person,
group or location to which this TH3 will typically connect. If this is not possible, a call may be placed to a recorded
message service.
Press both TELEPHONE RECEIVE VOLUME buttons simultaneously to reset the user telephone receive volume to
its default setting (0 dB).
Adjust the TELEPHONE RX LEVEL control so that the red led on the RX LEVEL meter lights only occasionally. An
active telephone connection will also be required for step 4, below, so you might not want to disconnect just yet.
Note: It is common for the dial tone and other signaling tones to be louder than nor mal speech levels. Particularly if
the receive AGC is not used, the dial tone may read off the scale of the RX LEVEL meter when the TELEPHONE RX
LEVEL is set correctly for speech. This is normal and does not require a reduction in the level setting.
3. CODEC RX LEVEL, CODEC TX LEVEL
If the four wire codec interface portion of the TH3 will be used, it is necessary to set the CODEC RX LEVEL and
CODEC TX LEVEL controls.
Establish a connection using the four wire codec (the BASIC OPERATION chapter tells how to do this).
Press both CODEC RECEIVE VOLUME buttons simultaneously to reset the user codec receive volume to its default
setting (0 dB).
Adjust the CODEC RX LEVEL control so that the red led on the RX LEVEL meter lights only occasionally. Adjust the
CODEC TX TRIM control for proper level as required by the codec. If the codec provides no level indication, in most
cases setting the CODEC TX TRIM approximately the same as the CODEC RX LEVEL control will suffice.
4. LecNet ANTI-ECHO [with Lectrosonics Mixers only]
If your installation uses a Lectrosonics mixer which is connected via the TH3’s LecNet Expansion Out jack, use this
procedure to set the LecNet ANTI-ECHO control.
With a connection established (either telephone or codec), have someone speak normally into a local microphone
and take note of the behavior of the LecNet ANTI-ECHO meter. Next, have the remote party speak, and adjust the
LecNet ANTI-ECHO control until the deflection of the LecNet ANTI-ECHO meter is approximately equal to that
caused by the local signal.
Note: Exactly where to set the LecNet ANTI-ECHO control is largely a matter of preference. If it is set too low, the
remote party may hear objectionable echoes immediately after speaking. If it is set too high, local speakers may
have difficulty interrupting the remote speaker. In most cases, setting the control for equal meter deflection, as
above, yields excellent results.
TH3 SOFTWARE CONTROL PANEL
Some of the TH3’s more advanced features may be accessed only via the serial port. A convenient software “control
panel” for the TH3 is included in the LecNet Master Pro software package. The TH3 software may be run alone as a
demonstration of the TH3’s features, or via LecNet Master Pro for live control of a TH3. The TH3 software control
panel permits easy access to all TH3 features, as described below.
Installing the Software
To install LecNet Master Pro, insert the LecNet Master Pro disk and run SETUP.EXE from the disk.
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Starting the Control Panel Software
To start the TH3 software control panel, it is first necessary to run LecNet Master Pro. If LecNet Master Pro does not
immediately detect the TH3, check to make sure that the LecNet PC cable is connected from the PC’s COM port to
the TH3. Check also that LecNet Master Pro is accessing the correct COM port. Once the TH3 is proper ly detected,
the TH3 software control panel can be started by choosing Select Device from LecNet Master Pro’s Devices menu.
The Main Window
The main window provides access to most TH3 features, some of which are duplicated on the front panel and wired
remote controls.
The title bar of the main window includes the word “Demonstration” when the software control panel was invoked
directly, as a demonstration of the TH3’s features and control panel operation. When the software control panel is or
has been actively connected to a TH3, as when invoked via LecNet Master Pro, the TH3’s LecNet device address
appears in the title bar. This is especially useful if more than one TH3 is being configured simultaneously.
In the upper right-hand corner of the window is the LecNet Status frame, which indicates whether the serial link to
the TH3 is currently active. A status of on means the TH3 is connected, the control panel is active, and the settings
shown correspond with the TH3’s current configuration. [Note: The connection will be active only when the TH3
software control panel application is active.]
Below the status frame is the Tone Pad, which may be used to generate DTMF dialing tones. If you prefer to type in
a number to be dialed automatically, see the Dial... command under the TH3 menu.
The two largest frames in the main window are the Telephone and Codec frames, which control the TH3’s tele-
phone and codec interfaces. Each frame is equipped with connect and privacy buttons and indicators, which
duplicate the corresponding front panel controls. The privacy indicator does not flash the current privacy mode, as it
does on the front panel, however the current privacy mode is displayed, and may be selected via the radio buttons.
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Digital Telephone Hybrid
The receive volume is implemented as a slider but it selects the receive volume in the same way that the front panel
buttons do, with a range of -12 to +6 dB in 1 dB steps (a total of 19 positions).
The Echo Suppression sliders choose the amount of echo suppression applied to each interface. Echo suppression refers to the dynamic trade-off of gain between the transmit and receive paths during conversation. Echo
suppression reduces echo and feedback problems, but too much may interfere with the ability of parties to interrupt
each other naturally. Echo suppression may be set from 12 dB to 24 dB. The default setting, 18 dB, yields satisfactory results in most cases.
The Rx AGC slider enables an optional AGC (“Automatic Gain Control”) in the telephone receiver. Up to 12 dB of
AGC is available (in 3 dB increments). AGC tends to equalize disparate volume levels, so that poor connections
sound as loud as good connections, and gentle speakers sound as loud as aggressive speakers. The trade-off is
that AGC brings with it a corresponding increase in background noise level. The default setting is 0 dB of AGC,
which is ideal when line conditions remain predictable and favorable. Under variable line conditions, where it is
frequently necessary to adjust the receive volume for comfortable listening, AGC is recommended. The proper
setting to use must be determined experimentally.
The Answer On Ring checkbox controls the TH3’s automatic telephone answering feature. If the box is unchecked,
the TH3 will not answer the phone. If the box is checked, the TH3 will count rings and answer on the ring number
specified. If the Auto Disconnect box is checked, the TH3 monitors the line for a “calling party control” signal. This
signal is sent by some central offices when the other party disconnects. This feature might not work reliably if “call
waiting” is in use, or if the TH3 is connected to a PBX or other line simulator. The Audible Ring Chime checkbox
permits a beeping noise to be sent to the audio outputs when the telephone line is ringing.
The Misc. frame contains controls to disable the TH3’s front panel switches (for physical security of the installation),
and to adjust the TH3’s dialing speed. When the front panel switches are disabled, the recessed level adjustment
controls still function, and all remote controls will continue to operate. The dialing speed parameter is provided only
to accommodate unusually fast or slow telephone switches. The default setting of 4 is nearly always adequate.
The LecNet menu may be used to explicitly activate and deactivate the LecNet serial connection. Generally these commands are not used explicitly, as LecNet Master Pro automatically
establishes the connection, and the TH3 control panel automatically suspends or closes the
connection as needed for sharing with other software. If the TH3 control panel is run directly
instead of via LecNet Master Pro, the LecNet On command may be used to switch from demonstration mode and actively connect a TH3. The Exit command quits the TH3 control panel
software. A confirmation is required if the LecNet connection is currently active.
The TH3 menu is used to access some special features of the TH3. The Dial...
command invokes the Dial Telephone Call window. The Signal Routing... com-
mand invokes the TH3 Signal Routing window . The Factory Settings... command
reverts the connected TH3 to the default factory settings. A confirmation is
required, and the LecNet address of the TH3 is not affected.
The Dial Telephone Call Window
The Dial Telephone Call window accepts a telephone number for
automatic dialing.
A maximum of 16 digits may be dialed. If the telephone interface
is not already connected, it will be connected prior to dialing.
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The TH3 Signal Routing Windo w
The TH3 Signal Routing window permits the TH3’s
internal signal routing to be modified for unusual
applications.
The default settings are as shown, with all inputs
and outputs enabled, and the supplementary echo
canceller inserts bypassed. Most applications do
not require any change to these settings.
Unchecking AUX Input mutes the TH3’s AUX IN
port. AUX OUT continues to function normally,
and the TH3’s other inputs are unaffected.
Unchecking Expansion Port prevents the TH3 from accepting input signals from any expansion port source. The
checkboxes below (Main In and Mix Minus In) offer individual muting of the expansion port inputs.
Unchecking Main Out or Mix Minus Out prevents the TH3’s output from reaching the indicated expansion port
destinations.
Checking Use External Canceller enables the Supplementary Echo Canceller inserts on the rear panel. If no
external echo canceller is connected, the signal paths will be incomplete and the TH3 will not function.
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Digital Telephone Hybrid
SERIAL PORT HARDWARE AND SOFTWARE
Serial Port Hard ware Connection
The serial port on the TH3 is a minimal RS-232 implementation. The figure shows the wiring diagram to accommodate interconnection with either a 9- or a 25-pin serial port on a PC or other serial device.
S
R
T
Tip
Ring
Sleeve
Tip
Ring
Sleeve
LecNet Device to PC
3.5MM
Stereo Plug
Wiring Diagram, 9 Pin D-Sub
LecNet Device Transmit
LecNet Device Receive
Gnd
LecNet Port
Wiring Diagram, 25 Pin D-Sub
LecNet Device Transmit
LecNet Device Receive
Gnd
LecNet Port
9 or 25 Pin Female
D-Subminiature
CD
N/C
RX
TX
DTR
Gnd
DSR
RTS
CTS
N/C
Chassis Gnd
RI
RX
TX
Sig Gnd
RTS
CTS
DSR
DTR
1
2
3
4
5
6
7
8
9
3
2
7
1
4
5
6
20
Host
Serial
Port
(PC)
Host
Serial
Port
(PC)
LecNet Device to AMX or Crestron
S
R
T
Tip
Ring
Sleeve
3.5MM
Stereo Plug
LecNet Device Transmit
LecNet Device Receive
Gnd
LecNet Port
D-Subminiature
N/C
N/C
N/C
N/C
N/C
N/C
9 Pin Female
1
RXD
TXD
Gnd
2
3
4
5
6
7
8
9
AMX
or
Crestron
Port
AMX Programming Notes
If you are using an AMX system to control your LecNet
equipment, you’ll want to purchase the Lectrosonics
PT3 Protocol Translator. The PT3 connects between
the AMX bus and any LecNet equipment. With the
PT3, the LecNet equipment looks just like native AMX
equipment. The PT3 is the fastest and most productive way to control LecNet devices with an AMX
system.
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LecNet SERIAL PORT PROTOCOL
All LecNet devices use a modification of the typical one-to-one connection between two RS-232 compatible devices.
LecNet devices have both an RS-232 transmitter and receiver section. The transmitter section is “tri-stated”, or
placed in a high impedance mode, until the particular device is addressed. To facilitate the simple parallel connection
of multiple devices on a single RS-232 port, an addressing scheme is employed to route commands from the host to
the proper LecNet device. When a device receives its address from the host computer, it temporarily turns on its RS232 transmitter long enough to send whatever data is requested by the host. In this way, multiple devices may drive a
single transmit signal back to the host, because only the addressed device will turn on its transmitter.
Valid address values are 128-254 (80 hex-FE hex). Because a LecNet device will interpret any single data byte
whose value is greater than 127 as an address, single byte data (as opposed to addresses) sent from the host must
be in the range of 0-127. If a data value needs to be sent from the host that exceeds 127, the host must format two
bytes of output such that the first byte is the lower 7 bits of the 8 bit value, and the second byte is 1 if the MSB of the
data byte is 1, or 0 if the MSB of the data byte is 0.
All interchange of commands and data with any LecNet device is done numerically rather than ASCII. The only
exception to this is the return data on the Get Device Name command (see command description below). Each
LecNet command must be preceded by the address of the device to be controlled. If a device with the requested
address exists on the system, it will respond by sending a 0 (0 hex, not ASCII) back to the host. Thus, each interchange with a LecNet device follows this pattern:
1) Host sends device address as a single byte.
2) Host receives byte of 0 hex from the LecNet device as acknowledgment.
3) Host sends command (1 byte) to the LecNet device.
4) Host and LecNet device exchange data based on particular command sent.
Note that some LecNet commands cause LecNet devices to return an additional acknowledgment byte of data to
confirm the end of a transaction. This is most typical of commands that cause the LecNet device to be busy for more
than a few milliseconds processing the command. The additional acknowledgment byte lets the host know that the
LecNet device is no longer busy and can receive more commands. If a command does return an additional acknowledgment byte, this will be explicitly stated in the command description.
As an example of a specific interchange between a host and a TH3, the following general procedure would be used
to get a name string back from the TH3.
Set up the communications parameters of the device which will be the host. The correct parameters for all LecNet
devices are 9600 baud, no parity, 8 data bits, 1 stop bit. This need only be done once when the host is initialized.
1) Host sends the device address of the TH3 (133 or 85 hex, by default).
2) Host receives byte of 0 hex from the TH3 as acknowledgment.
3) Host sends command 1 hex (1 byte) to the TH3 to get the name data.
4) The TH3 sends to the host 4 bytes. The first byte is 3 hex, which is the number of bytes in the TH3’s name string.
The TH3 will then send the ASCII characters “T”, “H”, and “3” to the host.
The following section is a listing of available TH3 commands. The word “Host” in the command descriptions means
the IBM PC or compatible, AMX controller, or Crestron controller to which the TH3 is connected. All numbers are
decimal unless otherwise specified.
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Digital Telephone Hybrid
General Device Commands
Get Device Name - Causes the TH3 to send its “name” string back. The first data byte is the length of the name
string, and the rest of the data bytes are the device name.
Host sends command - 1
Host receives data bytes: Byte 1 is the length of the name string (3 for the TH3), bytes 2 thru 4 are the ASCII values
for “TH3”.
Set Device Address - Changes the TH3’s device address. The new setting persists when the TH3 is powered off.
Even when the TH3 is restored to factory settings, the device address is not changed.
Host sends command - 2
Host sends 1 byte representing the new device address, 128-254.
Restore Factory Settings - Causes the TH3 to revert to its original factory settings. All settings are affected with the
exception of the LecNet device address. This may be changed only by issuing the Set Device Address
command, above.
Host sends command - 3
Get Firmware Version - Causes the TH3 to send to the host the version number of the current firmware (times ten).
For example, Version 1.0 software would be returned as byte value 10 (decimal).
Host sends command - 25
Host receives data byte: firmware version.
Basic Operation Commands
Set Phone Connect - Causes the TH3 to connect or disconnect the telephone interface.
Host sends command - 30
Host sends byte: 0 to disconnect, 1 to connect
Get Phone Connect - Retrieves connect status of telephone interface.
Host sends command - 31
Host receives data byte: 0 if disconnected, 1 if connected
Set Phone Privacy - Engages or disengages telephone privacy feature. This command has no effect if the
telephone interface is not connected.
Host sends command - 32
Host sends byte: 0 to disengage privacy feature, 1 to engage
Get Phone Privacy - Retrieves privacy status of telephone interface.
Host sends command - 33
Host receives data byte: 0 if disengaged, 1 if engaged
Set Codec Connect - Causes the TH3 to connect or disconnect the codec interface.
Host sends command - 34
Host sends byte: 0 to disconnect, 1 to connect
Get Codec Connect - Retrieves connect status of codec interface.
Host sends command - 35
Host receives data byte: 0 if disconnected, 1 if connected
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Set Codec Privacy - Engages or disengages codec privacy feature. This command has no effect if the codec
interface is not connected.
Host sends command - 36
Host sends byte: 0 to disengage privacy feature, 1 to engage
Get Codec Privacy - Retrieves privacy status of codec interface.
Host sends command - 37
Host receives data byte: 0 if disengaged, 1 if engaged
DTMF T one Commands
Send DTMF Tone - Causes the TH3 to dial a single DTMF digit. The telephone connect status is not affected, and
the tone is generated regardless of telephone connect status.
Host sends command - 40
Host sends ASCII byte representing DTMF tone
Valid values are the ASCII numerals 0-9 and the characters A-D, * and #.
Dial Telephone Number - Causes the TH3 to dial a telephone call whose number is supplied as a string. The
telephone interface is automatically connected, if necessary, before dialing begins.
Host sends command - 41
Host sends ASCII string representing telephone number
Valid values are the ASCII numerals 0-9 and the characters A-D, * and #. A comma may be used to insert a
one second delay. The ! character may be used to generate a “flash” signal. Any unrecognized character is
ignored (i.e. dashes and parentheses are acceptable). The string must be terminated by a carriage return
(decimal 13). The string’s length must not exceed 16 characters plus the carriage return.
Setup Commands
Set Panel Disable - Disables or enables the front panel switches on the TH3.
Host sends command - 50
Host sends byte: 0 to enable panel, 1 to disable
Get Panel Disable - Retrieves the enabled or disabled status of the TH3 front panel switches.
Host sends command - 51
Host receives data byte: 0 for enabled, 1 for disabled
Set Dial Speed - Determines the TH3’s DTMF tone duration and automatic dialing speed.
Host sends command - 52
Host sends byte in range 1-10: 1 is the fastest, 10 is the slowest, 4 is the default speed.
Get Dial Speed - Retrieves the current dialing speed.
Host sends command - 53
Host receives data byte in range 1-10: 1 is the fastest, 10 is the slowest, 4 is the default speed.
Set Auto Disconnect - Turns the TH3’s automatic disconnect feature on or off.
Host sends command - 54
Host sends byte: 0 to disable the feature, 1 to enable it
Get Auto Disconnect - Retrieves the status of the TH3’s automatic disconnect feature.
Host sends command - 55
Host receives data byte: 0 if the feature is disabled, 1 if it is enabled
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Digital Telephone Hybrid
Set Auto Answer - Configures the TH3’s automatic telephone answering feature.
Host sends command - 56
Host sends byte: 0 to disable the feature, 1-10 to specify a ring count on which to answer the telephone.
Get Auto Answer - Retrieves the current status of the TH3’s automatic telephone answering feature.
Host sends command - 57
Host receives data byte: 0 if disabled, 1-10 specifies ring count on which TH3 answers.
Set Phone Rx AGC - Configures the telephone receive AGC.
Host sends command - 58
Host sends byte: 0: AGC off, 1: 3 dB, 2: 6 dB, 3: 9 dB, 4: 12 dB
Get Phone Rx AGC - Retrieves the current configuration of the telephone receive AGC.
Host sends command - 59
Host receives data byte: 0: AGC off, 1: 3 dB, 2: 6 dB, 3: 9 dB, 4: 12 dB
Set Expansion Input Routing - Controls TH3 expansion port input signal routing.
Host sends command - 60
Host sends byte: 0: both exp inputs off, 1: mix minus input on, 2: main input on, 3: both exp inputs on
Get Expansion Input Routing - Retrieves the current TH3 expansion port input signal routing.
Host sends command - 61
Host receives data byte: 0: both exp inputs off, 1: mix minus input on, 2: main input on, 3: both exp inputs on
Set Expansion Output Routing - Controls TH3 expansion port output signal routing.
Host sends command - 62
Host sends byte: 0: both exp outputs off, 1: mix minus output on, 2: main output on, 3: both exp outputs on
Get Expansion Output Routing - Retrieves the current TH3 expansion port output signal routing.
Host sends command - 63
Host receives data byte: 0: both exp outputs off, 1: mix minus output on, 2: main output on, 3: both exp
outputs on
Set Input Signal Routing - Controls TH3 input signal routing.
Host sends command - 64
Host sends byte: 0: all inputs off, 1: expansion port inputs on (refer to Set Expansion Input Routing command, above), 2: aux input on, 3: expansion port and aux inputs on
Get Input Signal Routing - Retrieves TH3 input signal routing.
Host sends command - 65
Host receives data byte: 0: all inputs off, 1: expansion port inputs on (refer to Set Expansion Input Routing
command), 2: aux input on, 3: expansion port and aux inputs on
Set Supplementary Canceller Insert - Enables or disables supplementary echo canceller inserts.
Host sends command - 66
Host sends byte: 0 to bypass insert, 1 to enable insert
Get Supplementary Canceller Insert - Retrieves status of echo canceller inserts.
Host sends command - 67
Host receives data byte: 0 if insert is bypassed, 1 if insert is enabled
Set Audible Ring Chime - Enables or disables the audible ring chime feature.
Host sends command - 68
Host sends byte: 0 to disable the feature, 1 to enable it
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Get Audible Ring Chime - Retrieves status of audible ring chime feature.
Host sends command - 69
Host receives data byte: 0 if feature is disabled, 1 if enabled
Set Phone Echo Suppression - Selects amount of echo suppression applied to telephone interface.
Host sends command - 70
Host sends byte in range 36-72: 36 represents 12 dB of suppression, 72 represents 24 dB of suppression.
Any amount in between may be selected for continuous adjustment between 12 and 24 dB in 1/3 dB increments.
Get Phone Echo Suppression - Retrieves amount of echo suppression applied to telephone interface.
Host sends command - 71
Host receives data byte: 36 represents 12 dB of suppression, 72 represents 24 dB of suppression. Any
amount in between may be selected for continuous adjustment between 12 and 24 dB in 1/3 dB increments.
Set Phone Rx Atten - Performs fine adjustment of telephone receive volume.
Host sends command - 72
Host sends byte in range 0-54, 126 or 127: 0 represents +6 dB, 18 represents 0 dB, 54 represents -12 dB.
All values in between 0 and 54 are valid, representing 1/3 dB increments. A value of 126 causes the receive
volume to decrease 1 dB. A value of 127 causes the receive volume to increase 1 dB.
Get Phone Rx Atten - Retrieves current fine adjustment of telephone receive volume.
Host sends command - 73
Host receives byte in range 0-54: 0 represents +6 dB, 18 represents 0 dB, 54 represents -12 dB. All values
in between are valid, representing 1/3 dB increments.
Set Phone Privacy Mode - Selects privacy mode for telephone interface.
Host sends command - 74
Host sends byte: 1: mute tx only, 2: mute rx only, 3: mute both
Get Phone Privacy Mode - Retrieves privacy mode for telephone interface.
Host sends command - 75
Host receives data byte: 1: mute tx only, 2: mu te rx only, 3: mute both
Set Codec Echo Suppression - Selects amount of echo suppression applied to codec interface.
Host sends command - 80
Host sends byte in range 36-72: 36 represents 12 dB of suppression, 72 represents 24 dB of suppression.
Any amount in between may be selected for continuous adjustment between 12 and 24 dB in 1/3 dB increments.
Get Codec Echo Suppression - Retrieves amount of echo suppression applied to codec interface.
Host sends command - 81
Host receives data byte: 36 represents 12 dB of suppression, 72 represents 24 dB of suppression. Any
amount in between may be selected for continuous adjustment between 12 and 24 dB in 1/3 dB increments.
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Set Codec Rx Atten - Perfor ms fine adjustment of codec receive volume.
Host sends command - 82
Host sends byte in range 0-54, 126 or 127: 0 represents +6 dB, 18 represents 0 dB, 54 represents -12 dB.
All values in between 0 and 54 are valid, representing 1/3 dB increments. A value of 126 causes the receive
volume to decrease 1 dB. A value of 127 causes the receive volume to increase 1 dB.
Get Codec Rx Atten - Retrieves current fine adjustment of codec receive volume.
Host sends command - 83
Host receives byte in range 0-54: 0 represents +6 dB, 18 represents 0 dB, 54 represents -12 dB. All values
in between are valid, representing 1/3 dB increments.
Set Codec Privacy Mode - Selects privacy mode for codec interface.
Host sends command - 84
Host sends byte: 1: mute tx only, 2: mute rx only, 3: mute both
Get Codec Privacy Mode - Retrieves pr ivacy mode for codec interface.
Digital Telephone Hybrid
Host sends command - 85
Host receives data byte: 1: mute tx only, 2: mute rx only, 3: mute both
Monitoring Commands
The following commands are intended for convenient fast monitoring of TH3 status from control systems.
Get Quick Settings - Retrieves information about current TH3 status that may change at any time.
Host sends command - 100
Host receives 3 data bytes:
Byte 1: connect status, privacy status and privacy mode for both interfaces, expressed as a bitmap.
The low order nibble contains telephone information, and the upper nibble contains codec information. Within each nibble, bit 0 (the LSB) is the connect status, bit 1 is the privacy status, and bits 2
and 3 contain the privacy mode.
Byte 2: telephone receive attenuation (see Get Phone Rx Atten, above)
Byte 3: codec receive attenuation (see Get Codec Rx Atten, above)
Get Full Settings - Retrieves information about current TH3 status that does not change asynchronously (except
signal routing information).
Host sends command - 101
Host receives 4 data bytes:
Byte 1: telephone echo suppression (see Get Phone Echo Suppression, above)
Byte 2: codec echo suppression (see Get Codec Echo Suppression, above)
Byte 3: upper nibble: dial speed (see Get Dial Speed), lower nibble: auto answer setting (see Get
Auto Answ er).
Byte 4: bit 4-7 (upper nibble) rx agc setting (see Get Phone Rx AGC, above), bit 2 audible ring
chime status, bit 1 auto disconnect enable status, bit 0 (LSB) panel switch disable status
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ACCESSORIES
Standard
21552 15 ft. telephone cable with RJ-11 connectors
21553 9-pin male D-sub connector
21554 Shell for 9-pin D-sub connector
21551 12" mini-DIN LecNet expansion cable
21529 9-pin D-sub to stereo mini plug LecNet PC cable
40024 CH-40 wall transformer
LNETWIN LecNet software
M-TH3 TH3 instruction manual
35679 mini straight slot screwdriver
21580 5-pin depluggable terminal block
Optional
RCW-TEL wall plate remote control unit
RCW-DESK table top remote control unit
21592 24" mini-DIN LecNet expansion cable
GLOSSARY OF TH3 CONCEPTS
AGC
Automatic Gain Control. As used in the TH3, a circuit that compresses telephone receive volume levels, so that
weaker signals sound almost as loud as stronger ones. The trade-off is that background noise levels are also
increased in proportion to the AGC setting.
Bridging
Bridging refers to the interconnection of two otherwise separate interfaces. The TH3 not only has the ability to
communicate via telephone and to communicate via the 4-wire codec interface simultaneously, it has the ability to
bridge
the interfaces, such that codec signals are retransmitted over the telephone and vice versa.
Echo Suppression
A process whereby the gains of the transmit and receive paths are altered during a conversation, so that the path
that is least active receives the least gain. This has the effect of reducing both feedback and acoustic echo. The TH3
uses a patented echo suppression algorithm for smooth, transparent operation.
Hybrid
A device that converts a two-wire interface (e.g. the telephone network) to a four-wire interface, by isolating the
transmit and receive paths. The TH3 is a hybrid, with many special features.
Interface
As used in this manual, “interface” is used to distinguish groups of controls associated with the telephone and the 4wire codec. (e.g. “Press the CONNECT button for the telephone interface.”)
LecNet Anti-Echo
This is a special echo reduction feature available only when the TH3 is used with a Lectrosonics mixer. It allows the
TH3’s receive signal to participate in the automatic microphone mixing algorithm, so that the local microphones
receive less gain while the remote party is speaking.
Line Echo Canceller
The portion of a hybrid that removes as much as possible of the reflected transmitted signal from the receive path.
The job of the line echo canceller is made difficult by the highly variable conditions encountered on telephone lines.
The TH3 uses a specialized DSP chip for this purpose.
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Digital Telephone Hybrid
Privacy Modes
The privacy switch on the TH3 can do three different things, based on the interface’s current privacy mode. The
three modes are, “mute tx only”, “mute rx only”, and “mute tx and rx”.
Supplementary Echo Canceller
The term “supplementary echo canceller” refers to any third-party acoustic echo canceller. Such a device may be
used to supplement the existing echo cancelling abilities of the TH3. Typically, an additional 5 dB of echo cancellation may be achieved. In installations where very large amounts of microphone gain are required, a supplementary
echo canceller might significantly improve system performance.
SPECIFICATIONS
Technical Specifications
Power Input 300 mA (10W max.) at 20VAC
Expansion Jacks LecNet compatible, 8-pin mini-DIN, max. level +18dBu
RS-232 Port LecNet compatible, stereo mini phone jack, 9600 baud, 8 bits, no parity, 1 stop bit
Wired Remote Controls DB9F connector (see next section for pinout); max. LED current per pin 7mA
Aux 5-pin depluggable terminal block connector; electronically balanced output; nom. output
Record Out 5-pin depluggable terminal block connector; electronically balanced output; max. mic level
Supplementary Echo Canceller two 5-pin depluggable terminal block connectors; electronically balanced outputs; nom.
Codec Interface 5-pin depluggable terminal block connector; electronically balanced output; nom. output
Telephone Interface RJ11 modular connectors; compliant with FCC Part 68; impedance 600 ohms; auto answer
range -10 dBu to +4 dBu; max. output level +10 dBu; output impedance 200 ohms
balanced, 100 ohms unbalanced; nom. input range -10 dBu to +4 dBu; max. input level +10
dBu; input impedance 20K ohms balanced, 10K ohms unbalanced
-20dBu; max. line level +4dBu; nom. impedance 600 ohms balanced, 300 ohms
unbalanced; tape relay max. current 0.25A;
levels +4 dBu; input impedance 20K ohms balanced, 10K ohms unbalanced; output
impedance 200 ohms balanced, 100 ohms unbalanced
range -10 dBu to +4 dBu; max. output level +10 dBu; output impedance 200 ohms
balanced, 100 ohms unbalanced; nom. input range -10 dBu to +4 dBu; max. input level +10
dBu; input impedance 20K ohms balanced, 10K ohms unbalanced; echo suppression 12 dB
to 24 dB in 1 dB steps; user receive volume -12dB to +6dB in 1 dB steps
on ring count 1-10 if enabled; disconnect on calling party control signal if enabled; echo
suppression 12 dB to 24 dB in 1 dB steps; frequency response 300 Hz to 3500 Hz, +- 3dB;
THD (250 Hz to 3.3 KHz) less than .2%; user receive volume -12dB to +6dB in 1 dB steps
Physical Characteristics
Weight 4 lb.
Dimensions 19" wide x 1.75" high x 8" deep
Pinout for Wired Remote Controls
(specifications subject to change without notice)
54321
9876
Rio Rancho, NM – USA
VOLUME DOWN
VOLUME UP
PRIVACY
CONNECT
PRIVACY LED
CONNECT LED
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TROUBLESHOOTING
The following are general guidelines and initial suggestions. If a problem persists, please refer to the section,
SERVICE AND REPAIR.
Telephone interface won’t stay
connected.
Software control panel spontaneously disconnects from LecNet
I can hear the remote parties on both
the telephone and codec interfaces,
but they are having trouble hearing
each other.
The TH3 appears to connect but I’m
not getting any sound.
I have trouble interrupting the other
party, or the other party has trouble
interrupting me.
The automatic disconnect feature is disconnecting the line inappropriately.
Ensure that the telephone line is connected to the telephone line jack and
not the telephone set jack. Ensure that the line is live by connecting a
telephone to the telephone set jack and getting a dial tone. If you are
connecting via a PBX or have call waiting enabled, it may be necessary to
disable the automatic disconnect feature via the software control panel.
All LecNet software must share the serial port so that multiple software
control panels may be operated simultaneously. The TH3 software will
close the serial port temporarily whenever the software is minimized or
inactive. It will reconnect when reactivated.
It is possible to set receive levels too low and then compensate with more
amplification. You will hear the remote parties but they will not hear each
other properly. Also, the echo suppression will not work optimally in this
situation. To correct, use the meters to set the receive levels of both the
telephone and codec interfaces, as described in the LEVEL SETTING
PROCEDURE.
Verify that privacy is not engaged (privacy led is off), and the interface is
connected (connect led is on). Make sure the potentiometers on the front
panel are not turned all the way down. Check all interconnects and mixer
settings. If the telephone interface is to be used, verify that an external
telephone, connected to the telephone set jack, is able to raise a dial tone
when the TH3 telephone interface is not connected. If the meters are
moving, check f or problems with the local sound reinforcement system.
With the software control panel, verify that the supplementary echo canceller inserts are not active and that all inputs and outputs are enabled. If all
else fails, try restoring the TH3 to factory settings, as described at the end
of this section.
This problem occurs when the transmit and receive levels are not set
equitably, or when the LecNet anti-echo adjustment is set incorrectly.
Repeat the steps in the LEVEL SETTING PROCEDURE to correct.
The TH3 works fine, but I am very
aware of the dynamic gain adjustments as the other party speaks. I
find it somewhat distracting.
The front panel switches don’t work.
[Factory Reset Procedure] My TH3 is
not working and I am unable to gain
access to a PC right now.
24
When the TH3 is set up optimally, the echo suppression and LecNet antiecho operation is fairly subtle. It is possible that your ears are exceptionally
well conditioned to detect the effects, so you are not comfortable with the
default settings. It is also possible that the TH3 could be adjusted for better
performance. Repeat the LEVEL SETTING PROCEDURE to make sure
that all levels are set correctly. If operation does not improve, try a smaller
amount of echo suppression from the software control panel, or try reducing the LecNet anti-echo setting on the front panel.
If the “switches disabled” led is on, the front panel switches have been
disabled. They can be enabled again using the software control panel or by
restoring factory settings, as described at the end of this section.
The TH3 may be reset to its factory default settings by holding down both
codec receive volume buttons as the power is turned on. The TH3’s LecNet
address remains unchanged, but all other settings revert to their defaults.
This will work even if the front panel switches had been disabled previously.
The switches will no longer be disabled after this procedure.
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Digital Telephone Hybrid
FCC PART 68 COMPLIANCE
This equipment complies with Part 68 of the FCC rules. On the rear panel of this
equipment is a label that contains, among other information, the FCC registration number and ringer equivalence number (REN) for this equipment. If requested, this information must be provided to the telephone company.
This equipment uses the following USOC jacks: RJ11C.
The REN is used to determine the quantity of devices which may be connected
to the telephone line. Excessive REN on the telephone line may result in the
devices not ringing in response to an incoming call. In most, but not all areas,
the sum of the RENs should not exceed five (5.0). To be certain of the number of
devices that may be connected to the line, as determined by the total REN,
contact the telephone company to determine the maximum REN for the calling
area.
If this equipment causes harm to the telephone network, the telephone company
will notify you in advance that temporary discontinuance of service may be
required. If advance notice isn’t practical, the telephone company will notify the
customer as soon as possible. Also, you will be advised of your rights to file a
complaint with the FCC if you believe it is necessary.
The telephone company may make changes in its facilities, equipment, operations, or procedures that could affect the operation of the equipment. If this
happens, the telephone company will provide advance notice in order for you to
make the necessary modifications in order to maintain uninterrupted service.
If trouble is experienced with this equipment, please contact Lectrosonics, Inc. at
(800) 821-1121 for repair and/or warranty information. If the trouble is causing
harm to the telephone network, the telephone company may request you
remove the equipment from the network until the problem is resolved.
The following repairs can be done by the customer: No user serviceable parts
inside.
This equipment cannot be used on telephone company-provided coin service.
Connection to Party Line Service is subject to state tariffs.
FCC PART 15 COMPLIANCE
This equipment has been tested and found to comply with the limits for a class B
digital device, pursuant to Part 15 of the FCC Rules. These limits are designed
to provide reasonable protection against harmful interference in a residential
installation. This equipment generates, uses and can radiate radio frequency
energy and, if not installed and used in accordance with the instructions, may
cause harmful interference to radio communications. If this equipment does
cause harmful interference to radio or television reception, which can be determined by turning the equipment off and on, the user is encouraged to try to
correct the interference by one or more of the following measures:
• Reorient or relocate the receiving antenna.
• Increase the separation between the equipment and receiver.
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Digital Telephone Hybrid
SERVICE AND REPAIR
If your system malfunctions, you should attempt to correct or isolate the trouble before concluding that the equipment
needs repair. Make sure you have followed the setup procedure and operating instructions. Check out the interconnecting cords and then go through the TROUBLE SHOOTING section in the manual
We strongly recommend that you do not try to repair the equipment yourself and do not have the local repair shop
attempt anything other than the simplest repair. If the repair is more complicated than a broken wire or loose connection, send the unit to the factory for repair and service. Don’t attempt to adjust any controls inside the units.
Once set at the factory, the various controls and trimmers do not drift with age or vibration and never require readjustment. There are no adjustments inside that will make a malfunctioning unit start working.
LECTROSONICS’ ser vice department is equipped and staffed to quickly repair your equipment. In warranty repairs
are made at no charge in accordance with the terms of the warranty. Out of warranty repairs are charged at a
modest flat rate plus parts and shipping. Since it takes almost as much time and effort to determine what is wrong
as it does to make the repair, there is a charge for an exact quotation. We will be happy to quote approximate
charges by phone for out of warranty repairs.
RETURNING UNITS FOR REPAIR
You will save yourself time and trouble if you will follow the steps below:
A. DO NOT return equipment to the factory for repair without first contacting us by letter or by phone. We need to
know the nature of the problem, the model number and the serial number of the equipment. We also need a phone
number where you can be reached 8 am to 4 pm (Mountain Standard Time).
B. After receiving your request, we will issue you a return authorization number (R.A.). This number will help speed
your repair through our receiving and repair departments. The return authorization number must be clearly shown
on the
C. Pack the equipment carefully and ship to us, shipping costs prepaid. If necessary, we can provide you with the
proper packing materials. UPS is usually the best way to ship the units. Heavy units should be “double-boxed” for
safe transport.
D. We also strongly recommend that you insure the equipment, since we cannot be responsible for loss of or damage
to equipment that you ship. Of course, we insure the equipment when we ship it back to you.
Mailing address: Shipping address: Telephones:
Lectrosonics, Inc. Lectrosonics, Inc. Regular: (505) 892-4501
PO Box 15900 581 Laser Rd. Toll Free (800) 821-1121
Rio Rancho, NM 87174 Rio Rancho, NM 87124 FAX: (505) 892-6243
USA USA
World Wide Web: http://www.lectrosonics.com Email: sales@lectrosonics.com
outside of the shipping container.
Rio Rancho, NM – USA
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LIMITED ONE YEAR WARRANTY
LIMITED ONE YEAR WARRANTY
The equipment is warranted for one year from date of purchase against defects in
materials or workmanship provided it was purchased from an authorized dealer. This
warranty does not cover equipment which has been abused or damaged by careless
handling or shipping. This warranty does not apply to used or demonstrator equipment.
Should any defect develop, Lectrosonics, Inc. will, at our option, repair or replace any
defective parts without charge for either parts or labor. If Lectrosonics, Inc. cannot
correct the defect in your equipment, it will be replaced at no charge with a similar new
item. Lectrosonics, Inc. will pay for the cost of returning your equipment to you.
This warranty applies only to items returned to Lectrosonics, Inc., shipping costs
prepaid, within one year from the date of purchase.
This Limited Warranty is governed by th e la w s of th e S ta te o f N e w Mexico. It states the
entire liablility of Lectrosonics Inc. and the entire remedy of the purchaser for any
breach of warra n ty a s o u tlin e d a b o ve . NEITHER LECTROSONICS, INC. NOR
ANYONE INVOLVED IN THE PRODUCTION OR DELIVERY OF THE EQUIPMENT
SHALL BE LIABLE FOR ANY INDIRECT, SPECIAL, PUNITIVE, CONSEQUENTIAL,
OR INCIDENTAL DAMAGES ARISING OUT OF THE USE OR INABILITY TO USE
THIS EQUIPMENT EVEN IF LECTROSONICS, INC. HAS BEEN ADVISED OF THE
POSSIBILITY OF SUCH DAMAGES. IN NO EVENT SHALL THE LIABILITY OF
LECTROSONICS, INC. EXCEED THE PURCHASE PRICE OF ANY DEFECTIVE
EQUIPMENT.
This warranty gives you specific legal rights. You may have additional legal rights
which vary from state to state.
LECTROSONICS, INC.
581 LASER ROAD
RIO RANCHO, NM 87124 USA
January 17, 2001
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