Lectrosonics SMQV20A User Manual
INSTRUCTION MANUAL
SMV Series
Super Miniature Variable Power Transmitters
With Digital Hybrid Wireless® Technology
US Patent 7,225,135
SMQV Dual Battery Model
SMV Single Battery Model
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Purchase Date:
Rio Rancho, NM, USA
www.lectrosonics.com
SMV Series
Introduction
The SM Series variable power transmitters are the
product of many years of engineering and experience in
professional audio markets. The unique design provides
several distinct features for professional applications:
• Selectable output power to maximize battery life or
operating range as needed
• Superb, compandor-free audio quality
• Ultra-lightweight, corrosion resistant housing
• Water resistant seals for use in damp environments
• Programmable compatibility modes for use with a
wide variety of different receivers
The Digital Hybrid Wireless® design (US Patent
7,225,135) combines 24-bit digital audio with analog
FM resulting in a system that has the same operating
range as analog systems, the same spectral efficiency
as analog systems, the same long battery life as analog
systems, plus the excellent audio fidelity typical of pure
digital systems.
The SM Series transmitters feature the unique servo
bias input circuitry with a standard TA5M type input jack
for use with electret lavaliere mics, dynamic mics, or
line level signals. A water resistant control panel with
LCD, membrane switches and multi-color LEDs make
input gain adjustments, frequency and compatibility
mode selection quick and accurate, without having to
view the receiver. The battery compartment accepts
AA lithium or rechargeable batteries. The housings are
machined from solid aluminum blocks to provide an
extremely lightweight and rugged package. A special
non-corrosive finish resists salt water exposure and
perspiration in extreme environments.
These ETSI compliant transmitters work with Digital
Hybrid receivers in the Nu Hybrid mode, with Lectrosonics IFB receivers, and in a special Mode 3 for use
with receivers from another manufacturer.
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LECTROSONICS, INC.
Super-Minature Belt Pack Transmitter
Table of Contents
Introduction .............................................................................................................................................................................................2
General Technical Description ..............................................................................................................................................................4
Controls and Functions .........................................................................................................................................................................6
LCD Screen ..........................................................................................................................................................................................6
Power LED ............................................................................................................................................................................................ 6
Power LED Off Feature .........................................................................................................................................................................6
Audio Input Jack ....................................................................................................................................................................................6
Modulation LEDs ...................................................................................................................................................................................6
AUDIO Button .......................................................................................................................................................................................6
FREQ Button .........................................................................................................................................................................................6
Up/Down Arrows ...................................................................................................................................................................................6
Battery and Battery Eliminator Installation .......................................................................................................................................... 7
Attaching and Removing the Microphone ............................................................................................................................................7
Operating Instructions ...........................................................................................................................................................................8
Power Up and Boot Sequence .............................................................................................................................................................. 8
Power Down ..........................................................................................................................................................................................8
Standby Mode .......................................................................................................................................................................................8
LCD Backlight Settings .........................................................................................................................................................................8
Selecting the Compatibility Mode
and Output Power .................................................................................................................................................................................8
Audio Screen ........................................................................................................................................................................................9
Frequency Screen .................................................................................................................................................................................9
Lock/Unlock Screen ..............................................................................................................................................................................9
Remote Control Operation ....................................................................................................................................................................9
Configuring for Power Restore ............................................................................................................................................................10
Setting Transmitter Operating Frequency ............................................................................................................................................10
Set Up in 100 kHz Mode .....................................................................................................................................................................10
Set Up in 25 kHz Mode .......................................................................................................................................................................10
Adjusting Audio Level (Gain) ............................................................................................................................................................... 10
Locking or Unlocking the Controls ......................................................................................................................................................11
5-Pin Input Jack Wiring ........................................................................................................................................................................11
Line Level Signals ...............................................................................................................................................................................12
Installing the Connector: .....................................................................................................................................................................12
Microphone RF Bypassing ..................................................................................................................................................................12
Microphone Cable Termination
for Non-Lectrosonics Microphones .............................................................................................................................................13
Wiring Hookups for Different Sources ...............................................................................................................................................14
Silver Paste on SM Series Transmitter Thumbscrews .......................................................................................................................15
LectroRM ...............................................................................................................................................................................................16
Straight Whip Antennas .......................................................................................................................................................................17
Accessories for single battery models: ..............................................................................................................................................18
Accessories for dual battery models: .................................................................................................................................................18
Accessories for Both Models ..............................................................................................................................................................19
Troubleshooting ....................................................................................................................................................................................20
Specifications and Features ................................................................................................................................................................22
Service and Repair ...............................................................................................................................................................................23
Returning Units for Repair ..................................................................................................................................................................23
Rio Rancho, NM
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SMV Series
General Technical Description
Servo Bias Input
The voltage and current requirements of the wide variety of electret microphones used in professional applications has caused confusion and compromises in the
wiring needed for wireless transmitters. To address this
problem, the unique Servo Bias input circuit provides an
automatically regulated voltage over a very wide range
of current for compatibility with all microphones.
Digital Hybrid Wireless® Technology
All wireless links suffer from channel noise to some degree, and all wireless microphone systems seek to minimize the impact of that noise on the desired signal. Conventional analog systems use compandors for enhanced
dynamic range, at the cost of subtle artifacts (typically
“pumping” and “breathing”). Wholly digital systems defeat
the noise by sending the audio information in digital form,
at the cost of some combination of power, bandwidth and
resistance to interference.
Digital Hybrid systems overcome channel noise in a
dramatically new way, digitally encoding the audio in the
transmitter and decoding it in the receiver, yet still sending the encoded information via an analog FM wireless
link. This proprietary algorithm is not a digital implementation of an analog compandor but a technique that
can be accomplished only in the digital domain, even
though the inputs and outputs are analog.
Because it uses an analog FM link, the Digital Hybrid
system enjoys all the benefits of conventional FM wireless systems and it does away with the analog compandor and its artifacts.
No Pre-Emphasis/De-Emphasis
The Digital Hybrid design results in a signal-to-noise ratio
high enough to preclude the need for conventional preemphasis (HF boost) in the transmitter and de-emphasis
(HF roll off) in the receiver. This eliminates the potential
for distortion of signals with abundant high-frequency
information.
Low Frequency Roll-Off
The low frequency roll-off can be set for a 3 dB down
point at 35, 50, 70, 100, 120 and 150 Hz to control subsonic and very low frequency audio content in the audio. The actual roll-off frequency will vary slightly depending upon the low frequency response of the microphone.
Excessive low frequency content can drive the transmitter into limiting, or in the case of high level sound systems, can even cause damage to loudspeaker systems.
The roll-off is normally adjusted by ear while listening
as the system is operating.
Input Limiter
A DSP-controlled analog audio limiter is employed before the A-D converter. The limiter has a range of more
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, a fast attack and release limiter
followed by a slow attack and release limiter. The limiter
recovers quickly from brief transients, with no audible
side effects, and also recovers slowly from sustained
high levels to keep audio distortion low while preserving
short term dynamics.
X1
11.289 MHz
+5V
5V
Regulator
+6V
X2
12.000 MHz
Variable 1.8 - 4v
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LECTROSONICS, INC.
Super-Minature Belt Pack Transmitter
Signal Encoding and Pilot Tone
In addition to controlling the limiter, the DSP also encodes the digitized audio from the A/D converter and
adds an ultrasonic pilot tone to control the squelch in
the receiver. A pilot tone squelch system provides a reliable method of keeping a receiver output muted (audio
mute) even in the presence of significant interference.
When the system is operating in the Nu Hybrid mode, a
different pilot tone frequency is generated for each carrier frequency to prevent inadvertent squelch problems
in multi-channel sytems.
Microprocessor Control
A microprocessor monitors user command inputs from
the control panel buttons and numerous other internal
signals. It works intimately with the DSP to ensure the
audio is encoded according to the selected Compatibility Mode and that the correct pilot tone is added to the
encoded signal.
Compatibility Modes
SM Series ETSI compliant transmitters are designed to
operate with Lectrosonics Digital Hybrid receivers in Nu
Hybrid Mode and will yield the best performance when
doing so. However, due to the flexibility of digital signal
processing, the transmitters can also operate with Lectrosonics IFB receivers and in a special Mode 3 for use
with receivers from another manufacturer. Contact the
factory for details on this special mode.
Variable Power Output
This advanced feature allows the operator to optimize
the transmitter for maximum battery life, or for maximum
operating range. Power output is selected using the
LCD in a setup mode while the RF output of the transmitter is turned off.
Battery Options and Operating Time
Switching power supplies convert regulated battery voltages to operate various circuit stages with maximum
efficiency.
The firmware “remembers” the power status when a
battery fails, so the transmitter will be turned on automatically when the battery is replaced and the previous
settings will be enabled.
Circulator/Isolator
The RF output circuit includes a one way circulator/isolator using a magnetically polarized ferrite. This device
greatly reduces RF intermodulation produced when
multiple transmitters are used in close proximity to one
another (several feet apart). The isolator also provides
additional RF output stage protection against static
shock.
Control Panel
The control panel includes four membrane switches and
an LCD screen to adjust the operational settings. Multicolor LEDs are used to indicate audio signal levels for
accurate gain adjustment and for battery status.
Wide-Band Deviation
±75 kHz deviation improves the signal to noise ratio and
audio dynamic range of a wireless system dramatically,
compared to other designs that use ±30 kHz to 40 kHz
deviation. Wide deviation combined with a high powered
transmitters makes a significant improvement in signal
to noise ratio and operating range.
Rio Rancho, NM
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SMV Series
2468
Hours
Voltage
Varies
Controls and Functions
Modulation
LEDs
Battery
Compartment
Cover Plate
Battery
Compartment
Thumb Screw
PWR LED
AUDIO Button FREQ Button
LCD Screen
The LCD is a numeric-type Liquid Crystal Display with
screens for adjusting power, frequency, audio level and
low frequency audio roll-off. The transmitter can be
powered up with or without the RF output turned on. A
countdown appears in the LCD when powering on and
off, allowing the transmitter to be turned on without RF
for adjustments, and to prevent accidentally turning it off
with momentary button presses.
Power LED
The PWR LED glows green when the battery is good.
The color changes to red when there is about 30 minutes of operation left with the recommended lithium battery. When the LED begins to blink red, there are only a
few minutes of life.
The exact point at which the LED turns red will vary
with battery brand and condition, temperature and current drain. The LED is intended to simply catch your
attention, not to be an exact indicator of remaining time.
Green Red Blink
1.6
1.4
1.2
1.0
.8
A weak battery will sometimes cause the PWR LED to
glow green immediately after the transmitter is turned
on, but will soon discharge to the point where the LED
will turn red or the unit will turn off completely.
Power LED Off Feature
In normal operating mode, the DOWN and UP Arrow
buttons may be used to turn the PWR LED indicators off and on. This setting does not persist through a
power cycle nor does it affect the LCD backlight.
LCD
UP Arrow
Antenna
Jack
Audio
Input Jack
DOWN Arrow
Audio Input Jack
The Servo Bias input circuitry accommodates virtually
every lavaliere, handheld or shotgun microphone available, plus line level signals.
Battery Compartment and Thumb Screw
The large knurled thumbscrew is used to release or
secure the Battery Compartment Cover Plate.
Modulation LEDs
Proper input gain adjustment is critical to ensure the
best audio quality. Two bicolor LEDs will glow either red
or green to accurately indicate modulation levels. The
input circuitry includes a wide range DSP controlled
limiter to prevent distortion at high input levels.
It is important to set the gain (audio level) high enough
to achieve full modulation during louder peaks in the
audio. The limiter can handle over 30 dB of level above
full modulation, so with an optimum setting, the LEDs
will flash red during use. If the LEDs never flash red, the
gain is too low. In the table below, +0 dB indicates full
modulation.
Signal Level -20 LED -10 LED
Less than -20 dB Off Off
-20 dB to -10 dB Green Off
-10 dB to +0 dB Green Green
+0 dB to +10 dB Red Green
Greater than +10 db Red Red
AUDIO Button
The AUDIO button is used to display the audio level and
low frequency roll-off settings. The UP and DOWN arrows adjust the values.
The AUDIO button is also used with the FREQ button to
enter standby mode and to power the transmitter on or off.
FREQ Button
The FREQ Button displays the selected operating
frequency and toggles the LCD between displaying
the actual operating frequency in MHz and a two-digit
hexadecimal number that corresponds to the equivalent
Lectrosonics Frequency Switch Setting.
Up/Down Arrows
The Up and Down arrow buttons are used to select the
values on the various setup screens and to lock out the
control panel.
Antenna
The transmitter uses a whip antenna with a flexible woven, galvanized steel mesh cable and a standard SMA
connector.
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LECTROSONICS, INC.
Super-Minature Belt Pack Transmitter
Battery and Battery
Eliminator Installation
Note: Standard zinc-carbon batteries marked
“heavy-duty” or “long-lasting” are not adequate.
The battery status circuitry is designed for the voltage
drop over the life of lithium batteries.
To install new batteries:
1. Turn the Battery Cover Plate Thumbscrew counterclockwise a few turns until the door will rotate.
2. Insert the new batteries into the housing. The posi-
tive (+) battery terminal goes into the transmitter first.
3. Align the Battery Cover Plate and tighten the Battery Cover Plate Thumbscrew.
Two battery
compartments
(SMQV)
Gore-Tex®
covered vent
Do Not
Cover Vent
Polarity
engraved into
housing
Attaching and Removing
the Microphone
The flexible sleeve over the 5-pin plug on the microphone helps prevent dust and moisture from getting into
the input jack. The flange around the rim of the connector on the transmitter helps retain the sleeve after it is
installed and
The following procedure simplifies the attachment and
removal of the microphone to assure the sleeve is
seated securely.
Align the pins on the plug and jack and insert the connector.
1
Pinch and
squeeze the
sleeve on this end
2
to work it down
over the flange.
If the sleeve is pulled
down and covering the
connector, squeeze the
end of the sleeve so you
can feel the connector
inside and press it into
the jack until it latches.
Pinch and squeeze the
sleeve near the flange
and work it down with a
kneading motion over
the flange all the way
around until it stays in
place flush with the
housing. Pull on the
connector to make sure
it is firmly latched.
NOTE: Refer to the
previous section entitled
Configuring for Power
Restore
To install the battery eliminator, loosen the
thumbscrew completely and remove the battery
door. Insert the battery eliminator and tighten the
thumbscrew.
Install plastic cap
on dual battery
model to cover
the open battery
compartment.
Gore - Tex Registered trademark of W. L. Gore and Associates
Rio Rancho, NM
3
Release button
To remove the connector, pull the sleeve back
to expose the black
release button. Press the
button to unlatch the
plug.
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SMV Series
Operating Instructions
Power Up and Boot Sequence
1) Ensure that good batteries are installed in the unit.
2) Simultaneously press and hold the AUDIO and
FREQ buttons until the Power On Boot Sequence is
initiated.
The count will progress from 1
through 3 and the unit will then
power up with the RF output
turned on. During this turn on sequence, the
modulation and power LEDs all glow red, then
green, and then revert to normal operation.
The LCD displays a bootup sequence which con-
sists of four screens:
Company Name: Lectro
Frequency Block (bXX) and
Firmware Version (rX.X): b21r1.1 (typ)
Power Level Pr 250
Compatibility Mode: CP 400 (typ)
Audio: Aud 12 (typ)
Power Down
LCD Backlight Settings
The LCD backlight can be set to turn off after either 5
minutes or 30 seconds, or stay on continuously.
Hold the UP arrow in while powering up the unit to enter
the setup screen. Press the AUDIO button repeatedly
to step through the setup items to reach the backlight
settings screen. Use the UP or DOWN arrow button to
select the desired setting.
Selecting Step Size mode
Hold the UP arrow in while powering up the unit to enter
the setup screen. Press the AUDIO button repeatedly
to step through the setup items to reach the Step Size
Mode screen. Use the UP or DOWN arrow button to
select the desired setting.
Initial Power Off
Timer Screen
1) Simultaneously press and hold the AUDIO and
FREQ buttons while observing that the word “Off”
appears in the LCD along with a counter.
2) When the counter reaches “0”, the unit turns off.
Note: If the AUDIO and FREQ buttons are
released before the LCD goes blank at the end of
the countdown, the unit will not turn off. Instead, it
will stay energized and the display will return to the
previous screen.
Standby Mode
With the power turned off,
pressing the AUDIO and
FREQ buttons briefly places
Standby Screen
turned off so all setup adjustments can be made
without interfering with other systems operating in the
same location. The screen displays “rf OFF” to remind
the user that the unit is not transmitting.
While the unit is in the standby mode, access the setup
screens using the AUDIO and FREQ buttons and make
adjustments using the Up and Down arrows.
the unit in Standby Mode. In
this mode the RF output is
Selecting the Compatibility Mode
and Output Power
The transmitter will work with
Digital Hybrid receivers in the
IFB compatibility mode
Power setting
Note: The unit automatically enters the Standby
Mode when selecting compatibility.
1) Set the receiver’s audio controls to minimum.
2) From a power off condition, hold down the Up
arrow, then simultaneously press the AUDIO and
FREQ buttons.
3) Press either AUDIO or FREQ button to select the
compatibility screen and use the Up and Down arrows to select the desired mode.
The following Compatibility Modes are available:
• Mode 3 (contact the factory for details): CP 3
• Nu Hybrid: CP Nu
• IFB Series mode: CP IFB
4) Press either AUDIO or FREQ button to select the
power setting screen and use the Up and Down
down arrows to select the desired level of power.
5) Simultaneously press the AUDIO and FREQ buttons to exit this mode and turn off the power.
Nu Hybrid mode, Lectrosonics
IFB receivers and in a special
Mode 3 for use with receivers
from another manufacturer.
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LECTROSONICS, INC.
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