Lectrosonics DCHT Users Manual
DCHT
Digital Transmitter
DCHT, DCHT/E01
INSTRUCTION MANUAL
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Purchase Date:
Rio Rancho, NM, USA
www.lectrosonics.com
DCHT, DCHT/E01
Table of Contents
Introduction ............................................................................ 2
DSP-controlled Input Limiter ................................................ 2
DCHT Block Diagram ........................................................... 3
Features and Functions ........................................................ 4
Optional Battery Eliminator .................................................. 4
Whip Antennas ..................................................................... 4
Battery Status LED Indicator ............................................... 5
Belt Clips .............................................................................. 5
IR (infrared) Port .................................................................. 5
Status LED ........................................................................... 5
Battery Installation ................................................................ 5
Powering On and Off ............................................................. 6
Powering On in Operating Mode .......................................... 6
Powering On in Standby Mode ............................................ 6
Powering Off ........................................................................ 6
Power Button Menu ............................................................... 6
Entering the Power Menu ..................................................... 6
LCD Menu Map ....................................................................... 7
Main Menu and Setup Screen Details .................................. 8
Entering the Main Menu ....................................................... 8
Main Window Indicators ...................................................... 8
Connecting the Signal Source ............................................. 8
Adjusting the Input Gain for Analog Inputs .......................... 8
Selecting Frequency ............................................................ 9
Selecting M2R Receiver Functions ...................................... 9
Selecting Programmable Switch Functions.......................... 10
Selecting the Low Frequency Roll-off .................................. 10
Selecting StMode (stereo mode) ......................................... 10
Selecting Input Type ............................................................. 10
Selecting Input Configuration ............................................... 10
Selecting Battery Type ......................................................... 11
BatTime ................................................................................ 11
Enable/Disable Remote Control Function ............................ 11
Setting Transmitter Output Power ........................................ 11
Locking/Unlocking Changes to Settings............................... 11
Restoring Default Settings ................................................... 11
Input Connections ................................................................ 12
Microphone Cable Termination
for Non-Lectrosonics Microphones .............................. 13
Wireless Designer Software ................................................ 14
Firmware Update Instructions .............................................. 14
Specifications ........................................................................ 14
Accessories ........................................................................... 16
Troubleshooting ..................................................................... 17
Service and Repair ................................................................ 18
Returning Units for Repair ................................................... 18
Introduction
The DCHT, DCHT/E01 transmitter is designed to work
with a companion receiver (such as the Lectrosonics
M2R, part of the Duet IEM system) as an audio relay
between an audio production bag or cart and a camera
or other audio device. The 6-pin input jack accepts two
mic or line level analog signals or AES digital signals
from external sources with a variety of adapter cables.
Analog inputs can be linked for the same gain when
used with a stereo source, or operate independently
with individual settings.
This third generation digital design features specially
developed, high efficiency digital circuitry for extended
operating time on two AA batteries. The transmitter can
tune in coarse or fine steps across the UHF television
band from 470.100 to 607.950 MHz (E01 frequency
range is 470.100 to 614.375 MHz), with a selectable
output power of 10, 25 or 50 mW.
Studio quality audio performance is assured by high
quality components in the preamp, wide range input
gain adjustment and DSP-controlled limiting. and
settings are included for any lavaliere microphone,
dynamic microphones and line level inputs. Input gain
is adjustable over a 51 dB range in 1 dB steps to allow
a precise match to the input signal level, to maximize
dynamic range and signal to noise ratio.
A separate switch is provided on the top panel that can
be configured as mute, power or bypass.
The housing is constructed of solid machined aluminum
for lasting ruggedness. The exterior is finished with an
ultra hard, dark electroless nickel finish called ebENi.
Firmware updates are made through a side panel micro
USB port.
DSP-controlled Input Limiter
The transmitter employs a DSP-controlled analog audio
limiter prior to the analog-to-digital converter. The limiter
has a range greater than 30 dB for excellent overload
protection. A dual release envelope makes the limiter
acoustically transparent while maintaining low distortion. It can be thought of as two limiters in series, connected as a fast attack and release limiter followed by
a slow attack and release limiter. The limiter recovers
quickly from brief transients, so that its action is hidden
from the listener, but recovers slowly from sustained
high levels to keep audio distortion low and preserve
short term dynamic changes in the audio level.
Canada ISED Notice
This device operates on a no-protection, no-interference basis. Should the user seek to obtain
protection from other radio services operating in the same TV bands, a radio licence is required.
For further details, consult Innovation, Science and Economic Development Canada’s document
Client Procedures Circular CPC-2-1-28, Voluntary Licensing of Licence-Exempt_Low-Power
Radio Apparatus in the TV bands.
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LECTROSONICS, INC.
DCHT, DCHT/E01 Block Diagram
Input
CHANNEL 1
Input
Preamp
Shunt
Limiter
Servo Bias
Supply
Gain
Adj
Bias Voltage
0, 2 or 3.6V
HI/Lo
Pass
Filter
Limiter Control
Converter
Audio
I2S
A-D
Jack
123456
Rate
Converter
CHANNEL 2 (analog/digital selectable)
Shunt
Limiter
Input
Preamp
Servo Bias
Supply
Gain
Adj
Limiter Control
Bias Voltage
0, 2 or 3.6V
HI/Lo
Pass
Filter
Audio
A-D
Converter
I2S
Digital Transmitter
DSP Clock
Oscillator
VCTCXO
36.864 MHz
Status Ready
PLL Ref
Phase Locked Loop
Microprocessor
Keypad
D-A Converter
I2S
Control
Baseband
Firmware
Update
Voltage Controlled
Oscillator
I + Q
Signals
(2) AA
Batteries
UART
Switching
Power
LED
Tricolor
IR Port
Power
Supply
Low
Pass
Filter
Low
pass
lters
USB
Jack
IQ Modulator
Buer
Final
Amplier
Filters
Rio Rancho, NM
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DCHT, DCHT/E01
Features and Functions
Battery
status LED
Enter menu/Select item
Return to
previous screen
Status Ready LED
Menu navigation
USB Port
Power/Power Menu
access
Programmable
function switch
Audio
input
jack
Bi-directional IR port
Modulation
indicators*
Antenna
port
Optional Battery Eliminator
The transmitter can be powered by external DC using
the optional LTBATELIM power supply adapter. The
battery door is replaced by the adapter with a simple
procedure. The adapter provides a locking coaxial connector and a variety of power cords and connectors are
available.
Whip Antennas
Because the transmitter tunes across such a
broad frequency range, it is best to use the appropriate antenna for maximum operation. Two
antennas are included with the transmitter, and
are shipped from the factory pre-cut and fully
assembled. Each antenna covers three blocks.
Refer to the chart below to determine which antenna matches the operating frequency you will
be using.
Frequency Cap
Block Range MHz Color Antenna
470 470.100 - 495.600 Black AMM19
19 486.400 - 511.900 Black AMM19
20 512.000 - 537.500 Black AMM19
21 537.600 - 563.100 Red AMM22
22 563.200 - 588.700 Red AMM22
23 588.800 - 607.950 Red AMM22
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LECTROSONICS, INC.
Digital Transmitter
Battery Status LED Indicator
The Power/Function LED on the top panel will mirror
the keypad LED unless the programmable switch is set
to Mute, and the switch is turned on.
Alkaline, lithium or rechargeable batteries can be used
to power the transmitter. The type of batteries in use are
selectable in a menu on the LCD.
When alkaline or lithium batteries are being used, the
LED labeled BATT on the keypad glows green when the
batteries are good. The color changes to red at a mid-
point of the runtime. When the LED begins to blink red,
there will be only a few minutes of operation remaining.
The exact point at which the LEDs turn red will vary
with battery brand and condition, temperature and
power consumption. The LEDs are intended to simply
catch your attention, not to be an exact indicator of
remaining time.
A weak battery will sometimes cause the Power LED to
glow green immediately after the transmitter is turned
on, but it will soon discharge to the point where it will
turn red or the unit will turn off completely.
Rechargeable batteries give little or no warning when
they are depleted. If you wish to use these batteries
in the transmitter, the most accurate way to determine
runtime status is by testing the time provided by a par-
ticular battery brand and type, then using the BatTime
function to determine remaining runtime.
NOTE: Refer to the Main Menu and Setup section
for BatTime details.
Belt Clips
The wire belt clip may be removed by pulling the ends
out of the holes in the sides of the case. Be sure to
have a firm grip to avoid scratching the surface of the
housing.
An optional spring-loaded, hinged belt clip (model num-
ber BCSLEBN) is also available. This clip is attached by
removing the plastic hole cap on the back of the hous-
ing and mounting the clip with the supplied screw.
IR (infrared) Port
The IR port is available on the top of the transmitter for
quick setup using a receiver with this function available.
IR Sync will transfer the settings for frequency from the
receiver to the transmitter.
Status LED
Blue LED indicates ready status.
Battery Installation
The transmitter is powered by two AA batteries. Lithium
batteries are recommended for longest life.
The battery status circuitry compensates for the difference in voltage drop between alkaline and lithium batteries across their usable life, so it’s important to select
the correct battery type in the menu.
Because rechargeable batteries run down quite abruptly, using the Power LED to verify battery status will not
be reliable. However, it is possible to track battery status
using the battery timer function available in the receiver.
Push outward on the battery compartment door and lift
it to open.
Slide door outward,
then lift up to open
Insert the batteries according to the markings on the
back of the housing.
If the batteries are inserted incorrectly, the door will
close but the unit will not operate.
The battery contacts can be cleaned with alcohol and
a cotton swab, or a clean pencil eraser. Be sure not
to leave any remnants of the cotton swab or eraser
crumbs inside the compartment.
Spring contacts
Rio Rancho, NM
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DCHT, DCHT/E01
Powering On and Off
Powering On in Operating Mode
Press and hold the Power Button for several seconds
until a counter on the LCD progresses from 1 through 3.
When you release the button, the unit will be operational with the RF output turned on and the Main Window
displayed.
Hold
DCHT
for
Rf On
...3
V1.43
/0.42
Powering On in Standby Mode
A brief press of the power button , and releasing it
before the counter has reached 3, will turn the unit on
with the RF output turned off. In this Standby Mode the
menus can be browsed to make settings and adjustments without the risk of interfering with other wireless
systems nearby.
Hold
for
Rf On
...1
After settings and adjustments are made, press the
power button again to turn the unit off.
Release Power
Button before
the counter
reaches 3 to
enter Standby
Mode
Powering Off
Powering
O . . .
1
again before the countdown is completed, the unit will
remain turned on and the LCD will return to the same
screen or menu that was displayed previously.
To turn the unit off, hold the Power
Button in and wait for the countdown, or use the programmable
switch (if it is configured for this
function).
If the power button is released, or the
top panel switch is turned back on
DCHT
MUTE
470.100
-40
-20
RF indicator blinks
DCHT
470.100
-40
-20
+0
Power Button Menu
Entering the Power Menu
When the unit is turned on and the Main Window is displayed, press the power button to open a menu with
various setting and functions. Use the and arrow
buttons to highlight menu items. Then press MENU/SEL
to execute the item or enter a setup screen. The following options are available:
• Resume - returns to the previous mode and screen
• Pwr Off - turns the unit off irrevocably. Press either
the power button
off. If the Programmable Switch has been set to
+0
control the power, a message will be displayed
prompting you to use the switch to turn the power
off.
Resume
Pwr Off
Rf On?
AutoOn?
• Rf On? - enters a screen to enable the operating or
standby modes
• AutoOn? - If external power or batteries fail while
the unit is transmitting, the unit will automatically
turn back on after power is restored or fresh batteries are installed. This function is enabled by selecting Yes in the menu options. It does not work when
the transmitter is in the Standby mode.
• Backlit - adjusts the duration of the LCD back light
to 30 seconds, 5 minutes, or to remain on
• LED Off - enters a screen with options to turn the
control panel LEDs on or off
• About - displays model number and firmware
version
or MENU/SEL to turn the unit
Use
ProgSw
to power
off.
Message appears
if ProgSw is set to
control power
NOTE: If the programmable switch is in the OFF
position, power can still be turned on with the
power button.
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LECTROSONICS, INC.
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