Lectrosonics WME, WML Users Manual

INSTRUCTION MANUAL

WM

Watertight Transmitter and Remote Controls

With Digital Hybrid Wireless® Technology
US Patent 7,225,135

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Serial Number:

Purchase Date:

Rio Rancho, NM, USA
www.lectrosonics.com

WM

2

LECTROSONICS, INC.

Watertight Transmitter

Introduction

The WM transmitter is designed to resist damage when
used in wet or dusty conditions and also offer a compre­hensive feature set that makes it equally at home in film
and television production and on stage.

A solid machined aluminum housing with a corrosion re­sistant finish hosts dual battery compartments, a mois­ture sealed control panel with backlit LCD and enlarged
membrane switches. Recessed seats for the O-rings in
the battery caps and input jack allow the caps and mic
connector to be tightened securely without excessive
deformation of the O-rings.

The antenna is made of an extremely durable, multi­strand alloy that will withstand heavy abuse. It is mount­ed with a compression sealed strain relief that prevents
dust and moisture from entering the housing.

As the first stage in the signal processing chain, the
input preamp section includes very high quality, low
noise components with a wide range of gain adjust­ment in 1 dB increments and a DSP-controlled input
limiter. Dual color LEDs on the control panel accurately
indicate audio input level for precise gain adjustment.
Easily accessed screens on the LCD simplify setup and
adjustments.

Output power is adjustable to provide either extended
operating range or extended battery life as needed for
the application.

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 DSP-based design works with all Digital Hybrid
receivers, and is backward compatible for use with
Lectrosonics 200 Series, 100 Series, IFB receivers and
some other brands of analog wireless receivers.

Table of Contents

Introduction ........................................................................... 3

General Technical Description ............................................ 4

Servo Bias Input.................................................................. 4

No Pre-Emphasis/De-Emphasis ......................................... 4

Low Frequency Roll-Off ...................................................... 4

Input Limiter ........................................................................ 4

Signal Encoding and Pilot Tone .......................................... 5

Microprocessor Control ....................................................... 5

Compatibility Modes ............................................................ 5

Control Panel ...................................................................... 5

Wide-Band Deviation .......................................................... 5

Variable Power Output ........................................................ 5

Battery Operation ................................................................ 5

Frequency Blocks ................................................................ 5

Circulator/Isolator ................................................................ 5

Controls and Functions ....................................................... 6

LCD Screen ........................................................................ 6

Power LED .......................................................................... 6

Audio Input Jack .................................................................. 6

Battery Compartment and Thumb Screw ............................ 6

Modulation LEDs ................................................................. 6

AUDIO Button ..................................................................... 6

FREQ Button ....................................................................... 6

Up/Down Arrows ................................................................. 6

Antenna ............................................................................... 6

About Batteries ..................................................................... 7

Battery Compartments ......................................................... 7

Attaching and Removing the Microphone .......................... 7

Operating Instructions ......................................................... 8

Power Up and Boot Sequence ............................................ 8

Power Down ........................................................................ 8

Standby Mode ..................................................................... 8

Compatibility, Output Power, Bias Voltage (phantom power)

and LCD Backlight .............................................................. 8

Audio LF Roll-off and Gain .................................................. 9

Frequency Selection ........................................................... 10

Lock/Unlock Screens .......................................................... 10

Remote Control Enable/Disable and

Configuring Power Restore ................................................. 10

Preventing Corrosion ........................................................... 11

Optional RM Remote Control .............................................. 12

Powering the RM on and off ................................................ 12

Setup Screens .................................................................... 12

Operating Notes .................................................................. 13

RM Quick Reference ........................................................... 13

RM2 Remote Control ............................................................ 13

Troubleshooting .................................................................... 14

RM Troubleshooting ............................................................ 15

Accessories and Replacement Parts .................................. 16

Antenna Length by Block .................................................... 17

Specifications ...................................................................... 18

Service and Repair ............................................................... 20

Returning Units for Repair .................................................. 20

Consumer Alert for US Users - FCC Order DA 10-92

Most users do not need a license to operate this wireless microphone system. Nevertheless, operating this micro­phone system without a license is subject to certain restrictions: the system may not cause harmful interference; it
must operate at a low power level (not in excess of 50 milliwatts); and it has no protection from interference received
from any other device. Purchasers should also be aware that the FCC is currently evaluating use of wireless mi­crophone systems, and these rules are subject to change. For more information, call the FCC at 1-888- CALL-FCC
(TTY: 1-888-TELL-FCC) or visit the FCC’s wireless microphone website at www.fcc.gov/cgb/wirelessmicrophones.
To operate wireless microphone systems at power greater than 50mW, you must qualify as a Part 74 user and be
licensed. If you qualify and wish to apply for a license go to: http://www.fcc.gov/Forms/Form601/601.html

Rio Rancho, NM

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WM

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 output sound
systems, it 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.

+5V

5V

Regulator

4

+6V

Variable 1.8 - 4v

LECTROSONICS, INC.

Watertight 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 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

The transmitter operates with Lectrosonics Digital
Hybrid receivers and will yield the best performance
when doing so, however, due to the flexibility of digital
signal processing, the transmitter can also operate in
various compatibility modes for use with Lectrosonics
200 Series, Lectrosonics 100 Series, IFB and certain
non-Lectrosonics receivers. Contact the Lectrosonics
sales department for more information about non-Lec­trosonics receivers.

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.

Battery Operation

Switching power supplies convert battery voltages to
operate various circuit stages with maximum efficiency.

The firmware “remembers” the settings when the bat­teries are exhausted. After new batteries are installed,
a quick press of the AUDIO and FREQ buttons will turn
the power back on and return to the previous settings.
This is a unique behavior that takes place only when
the batteries fail during operation. If the unit is turned
off manually, a quick press of the buttons will turn it on
in the “standby” mode instead.

Because the battery caps make contact with the bat­tery before the cap is seated, the power does not turn
back on automatically. This allows both batteries to
be installed and the caps tightened before power is
restored.

Frequency Blocks

Lectrosonics established a “block” numbering system
years ago to organize the range of frequencies avail­able from the low end at 470.1 MHz band to the upper
end at 691.1 MHz. Each block includes 256 frequen­cies in 100 kHz steps, which is the maximum switching
range of the transmitters.

Circulator/Isolator

The RF output circuit includes a magnetically polar­ized ferrite called an isolator that blocks RF signals
entering the transmitter antenna from external sources
from traveling back into the final amplifier. This 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.

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.

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.

Rio Rancho, NM

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WM

Controls and Functions

Modulation

LEDs

LCD

Audio

Input Jack

PWR LED

AUDIO
Button

FREQ

Button

LCD Screen

The display is a highly visible backlit LCD with screens
for making all setup and level adjustments. The trans­mitter can be powered up with or without the RF output
turned on. With the RF output turned off, all adjust­ments can be made without creating interference for
other wireless systems in the vicinity.

For normal powering up and down, a countdown ap­pears in the LCD. The buttons must be held in for the
duration of the countdown, which helps to prevent ac­cidentally turning the transmitter on or off.

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.

A weak battery will sometimes cause the PWR LED
to glow green immediately after the unit is turned on,
but will soon discharge to the point where the LED will
turn red or the unit will turn off completely. When the
transmitter is in SLEEP mode, the LED blinks green
every few seconds.

Audio Input Jack

This is a threaded locking connector that accepts the
Lectrosonics watertight WP connector.

Battery Compartment and Thumb Screw

The large knurled thumbscrews are retain the batteries
and maintain solid battery contact. The lanyard keeps
the battery caps attached, but it can be removed if
desired using a 1/16 inch hex key (Allen wrench).

UP Arrow

Battery

Compartment

Caps

DOWN Arrow

Proper input gain adjustment is critical to ensure the
best audio quality. Two red/green LEDs will glow to ac­curately indicate modulation levels. The input circuitry
includes a wide range DSP-controlled limiter to prevent
distortion during high peak levels.

It is important to set the gain (audio level) high enough
to achieve full modulation during louder peaks in the
audio. The DSP-controlled limiter can handle peaks
over 30 dB 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. The -20 LED turns
red at 0 dB (full modulation).

Signal Level -20 LED -10 LED

Less than -20 dB Off Off

-20 dB to -10 dB

-10 dB to +0 dB

+0 dB to +10 dB Red Green

Greater than +10 db Red Red

Green Off

Green Green

AUDIO Button

The AUDIO button is used to display the gain and low
frequency roll-off settings. The UP and DOWN arrows
adjust the values. This 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 also 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. This but­ton is also used with the AUDIO button to enter standby
mode and to power the transmitter on or off.

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. Pressing both arrows simultaneously
enters the lock countdown. When an attempt is made
to change a setting while the control panel is locked,
a message will flash on the LCD as a reminder that
the unit is locked. Once locked, the buttons can only
be unlocked by removing the battery, or with the RM
remote control.

Antenna

The fixed whip antenna is constructed with a flexible,
woven, galvanized steel mesh cable.

Modulation LEDs

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LECTROSONICS, INC.

Watertight Transmitter

68

Voltage

Varies

About Batteries

The transmitter is powered by two AA batteries.
Lithium batteries are recommended for longest life,
which typically provides over 7.5 hours of operation at
room temperature with the output set to 250 mW. At 50
mW, the runtime is typically over 14 hours with lithium
batteries.

The PWR LED glows green when the battery is good.
The color changes to red at a mid-point of operating
life, and will continue to glow red until the battery gets
close to the end of its life. When the LED begins to
blink red, there are only a few minutes remaining.

The exact point at which the LED turns red will vary
with battery brand and condition, temperature and cur­rent drain. The LED is simply a reminder intended to
catch your attention, not an exact indicator of remain­ing time.

Green Red Blink

1.6

1.4

1.2

1.0
.8

Hours

24

Battery polarity is marked

on the rear cover

Battery Compartments

The battery compartments are a rugged, straight­forward design with a recessed entry that captures
the O-ring on the cap. The spring contact on the cap
maintains solid contact on the battery regardless of its
exact length.

The O-rings should be kept clean and dry, and coated
with petroleum jelly on a regular basis. See page 11 for
more information on preventing corrosion.

Attaching and Removing
the Microphone

The threaded WP watertight plug on the microphone
cable fits into a recessed jack on the top panel. The re­cess in the opening retains the O-ring when the plug is
tightened. The Lectrosonics M152WP lavaliere micro­phone is supplied with the WP plug already installed.
Other microphones can also be terminated with this
plug by following the instructions included with the WP
connector kits.

Rio Rancho, NM

Unscrew battery caps to

insert batteries

Treat O-ring with petroleum jelly before

connecting (see below)

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WM

Operating Instructions

Power Up and Boot Sequence

Simultaneously press and hold the AUDIO and FREQ
buttons until the startup count is completed. The
screen will display a count from 1 to 3 as the unit boots
up, then it switches to the Audio screen. As the unit
turns on, the Modulation LEDs and PWR LED all glow
red, then green, and then revert to normal operation.

The LCD displays a boot sequence which consists of
four screens ending with the audio screen similar to
this example:

 • Companyname: Lectro

 • Frequencyblock/FirmwareVer.: b21r1.1

 • Powerlevel: Pr100

 • Compatibilitymode: CP400

 • Audio(Inputgain): Aud22

Power Down

Simultaneously press and
hold the AUDIO and FREQ

buttons while observing that
the word “OFF” appears in the LCD along with a
counter. The screen will display a countdown from 3 to
1 and the unit will then turn 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

Quickly press both AUDIO

and FREQ buttons to enter

the “standby” mode. In this
mode the RF output is turned off so adjustments can
be made without interfering with other systems operat­ing in the same location. The LCD displays rf OFF to
remind you that the unit is not transmitting.

Use the AUDIO and FREQ buttons to access the vari­ous setup screens. When the adjustments are com­plete, press both the AUDIO and FREQ buttons briefly
to save the settings and turn the unit off.

Compatibility, Output Power, Bias Voltage
(phantom power) and LCD Backlight

Four different setup screens are accessed in a setup
mode that is accessed with a special button sequence.

 • CompatibilityMode

 • OutputPower

 • BiasVoltage(phantompower)

 • LCDBacklightSettings

Hold the UP arrow button and simultaneously press
the AUDIO and FREQ buttons. The compatibility setup
screen will appear. Each successive press of the
AUDIO button will step through the other three setup
screens.

Hold the UP

arrow button

Then press the AUDIO and FREQ

buttons at the same time

Note: The unit is automatically set to “standby” in
this setup mode, however, the rF OFF reminder
will not be displayed.

Compatibility Mode

In addition to its native Digital Hybrid mode, the trans­mitter will operate with Lectrosoncs 100 Series, 200
Series and IFB receivers, as well as several analog
receivers from other manufacturers.

From this screen, use the
UP and DOWN arrows to
select the desired mode.

 • CP 100: 100 Series mode

 • CP 200: 200 Series mode

 • CP 3: Mode 3 (contact the factory for details)

 • CP 400: 400 Series mode

 • CP IFB: IFB Series mode

 • CP 6: Mode 6 (contact the factory for details)

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LECTROSONICS, INC.