Lectrosonics WM User manual

Quick
Start
Guide
Fill in for your records:
Serial Number:
Purchase Date:
This guide is intended to assist with
initial setup and operation of your
Lectrosonics product.
For a complete instruction manual,
visit and download at:
www.lectrosonics.com/US
Watertight Transmitter
WM
Digital Hybrid Wireless®
U.S. Patent 7,225,135
Updated for firmware v2.6
13 November 2017

LECTROSONICS, INC.2
Battery Compartment
Caps
Audio
Input Jack
AUDIO Button
LCD
FREQ Button
Modulation
LEDs
PWR LED
UP Arrow
DOWN
Arrow
Controls and Functions
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 interfer-
ence 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.
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. An
alkaline battery will have about 20 minutes of life left. When the LED begins to blink red,
there are only a few minutes of life.
Note: A NiMH rechargeable battery will give little or no warning when it is depleted. If you wish to use
NiMH batteries, we recommend trying fully charged batteries in the unit and using the battery timer feature
available in most receivers to determine the available operating time.
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 con-
nector.
Battery Compartments and Thumb Screws
The large knurled thumbscrews 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).
Modulation LEDs
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. Full modulation is indicated when the -20 LED first turns red.
With an optimum setting, the -20 LED will flicker red during operation. If the LEDs never
flash red, the gain is too low.
Power LED

www.lectrosonics.com 3
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 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 made of a flexible, woven, galvanized steel mesh cable.

LECTROSONICS, INC.4
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 of the manual online for more
information on preventing corrosion.
•
•
•
•
•
DO NOT COVER
VENT HOLES
Battery polarity is marked
on the rear cover
Unscrew battery caps to
insert batteries
Do not cover
vent holes
Attaching and Removing the Microphone
Treat O-ring with petroleum
jelly before connecting
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.

www.lectrosonics.com 5
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.: b25r2.4
•Power level: Pr 100
•Compatibility mode: CP 400
•Audio (Input gain): Aud 22
Power Down
Press and hold the AUDIO and FREQ buttons while observing
that the word “OFF” appears in the LCD. 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 stay energized and the display will
return to the previous screen.
Standby Mode
Quickly press both AUDIO and FREQ buttons to enter the “stand-
by” mode. In this mode the RF output is turned off so adjust-
ments 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 the AUDIO and FREQ buttons together to save the
settings and turn the unit off.
Lock/Unlock the Keypad
The control panel buttons can be locked out to avoid inadvertent changes in the settings
or turning the unit off unintentionally. Simultaneously pressing and holding both the UP
and DOWN arrow buttons during normal operation starts a countdown timer.
The timer starts at three and counts down to zero. When the timer reaches zero, the
transmitter’s controls are locked.
With the controls locked, the AUDIO and FREQ buttons can still be used to display cur-
rent settings. Any attempt to change a setting by pressing either the Up or Down arrow
button will result in an on-screen Loc reminder that the controls are locked.
Once the transmitter is locked, it cannot be unlocked or powered off using the buttons.
The only ways to unlock a locked transmitter are to remove the batteries or unlock it via
the RM remote control.

LECTROSONICS, INC.6
UP Arrow Settings
With the unit turned off, hold the UP arrow button and simultaneously press the AUDIO
and FREQ buttons. Each successive press of the AUDIO button will step through the
setup screens.
• Compatibility Mode
• Input Type
• RF Power Output
• LCD Backlight
• Frequency Step Size
Use the UP and DOWN arrow buttons to scroll through the options. The selected op-
tions will automatically be stored when the power is turned off. Press both the AUDIO
and FREQ buttons to exit the menu and turn the power off.
Note: The unit is automatically set to “standby” in this setup mode; with rF
OFF not displayed.
Compatibility Mode
•CP 400: 400 Series (Digital Hybrid) mode
•CP IFb: IFB Series mode
•CP 6: Mode 6 (contact the factory for details)
•CP 100: 100 Series mode
•CP 200: 200 Series mode
•CP 3: Mode 3 (contact the factory for details)
Input Type
•LInE: Bias turned off; line level impedance
•PH oFF: Bias turned off for dynamic mics
•PH 2: Bias at 2 volts for electret mics
•PH 4: Bias at 4 volts for electret mics
The correct bias is specified by the microphone manufacturer. 4 volts is typical for most
electret lavaliere microphones. 2 volts is preferred by some mic manufacturers such as
Countryman for the very small B6 and E6 models.
RF Power Output
•Pr 50 50 mW for maximum battery life
•Pr 100 100 mW is an intermediate setting
•Pr 250 250 mW for maximum operating range
LCD Backlight
•bl 5 Stay on for five minutes
•bl 30 Stay on for 30 seconds
•bl on Stay on continuously
Frequency Step Size
This menu item allows frequencies to be selected in either 25 kHz or 100 kHz incre-
ments. If the desired frequency ends in .025, .050 or .075 MHz, the 25 kHz step size
must be selected.
•Stp 100 Frequency steps in 100kHz increments
•Stp 25 Frequency steps in 25 kHz increments

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DOWN Arrow Settings
Hold the DOWN arrow button and simultaneously press the AUDIO and FREQ buttons.
Each successive press of the AUDIO button will step through the setup screens.
• Remote Control
• Auto Power Restore
• Audio Mute
Use the UP and DOWN arrow buttons to scroll through the options. The selected op-
tions will automatically be stored when the power is turned off. Press both the AUDIO
and FREQ buttons to exit the menu and turn the power off.
Remote Control
This setting enables the transmitter to respond to audio “dweedle” tones from an app
operating on a mobile device. Use the UP and DOWN arrow buttons to enable or dis-
able the remote function.
•rc on Enables the remote function
•rc oFF Disables the remote function
If a remote control signal is detected but the function is turned off, the message rc
oFF will be displayed briefly on the transmitter’s LCD to confirm that a valid signal was
received, but that the transmitter is not configured to respond to it.
Auto Power Restore
This setting determines how the transmitter is powered up again after the batteries have
become exhausted in normal operation.
When this function is turned on, the unit will power up to normal operation with a brief
press of the AUDIO and FREQ buttons after the batteries have been replaced.
When this function is turned off, the AUDIO and FREQ buttons need to be held in for
the completion of the count to turn the unit back on for normal operation.
This is a unique behavior that takes place only when the batteries fail during opera-
tion. If the unit is turned off manually, a quick press of the buttons will turn it on in the
“standby” mode instead.
The firmware is written this way because the battery caps make contact with the bat-
tery before the cap is seated, and the fact that there are two separate battery caps to
tighten. This allows both batteries to be installed and the caps tightened before power
is restored. It also makes turning the unit back on easier when wearing gloves since the
buttons do not need to be held in.
•PbAc 1 Turns power restore ON
•PbAc 0 Turns power restore OFF
Audio Mute
Beginning with firmware v2.6 on the US version, the AUDIO button can be configured to
work as a mute button by turning this setting on. A quick press of the AUDIO button will
then mute the audio and a message will appear on the LCD confirming that the audio is
muted. Another quick press turns the audio back on.
•At on Enables the audio mute function
•At oFF Disables the audio mute function
During operation, the LCD will continuously display the state of audio muting as a
reminder, showing the audio as ON or OFF.
The AUDIO button will still work to set Input Gain by pressing and holding it in for a few
seconds, however, if the audio is muted, no sound will be heard during the adjustment.
If the transmitter is in “standby,” the Low Frequency Roll-off can be adjusted whether
or not the audio mute function is enabled. When the audio mute function is enabled
and the unit is turned on and transmitting, only the audio level (input gain) can be
adjusted by holding the AUDIO button in for a few seconds.

LECTROSONICS, INC.8
AUDIO Button Settings
Low Frequency Roll-off
It is possible that the low frequency roll-off point could affect the
gain setting, so it’s generally good practice to make this
adjustment before adjusting the input gain. Press and hold the
AUDIO button with LF (XX) on the screen while selecting the desired roll-off frequency
with the UP and DOWN arrows.
• LF 35 35 Hz
• LF 50 50 Hz
• LF 70 70 Hz
• LF 100 100 Hz
• LF 120 120 Hz
• LF 150 150 Hz
The roll-off is often adjusted by ear while monitoring the audio.
Input Gain
The audio input level (input gain) can be adjusted with the unit in
the “standby” mode or while powered up in normal operation. The
modulation LEDs on the control panel indicate the audio level
and limiter activity. The maximum signal to noise ratio is achieved at full modulation,
when the -20 LED first turns red. This gain adjustment matches the transmitter gain with
the microphone’s output level, the user’s voice level and the position of the microphone.
This gain setting should not be used to control the volume of your sound system or
recorder levels.
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
Note: Different voices will usually require different gain settings, so check this
adjustment as each new person uses the system. If several different people will
be using the transmitter and there is not time to make the adjustment for each
individual, adjust it for the loudest voice.
Warning: If the wireless system is connected to a live sound system, turn
the sound system level down first to avoid severe feedback.
1) Position the microphone in the location where it will be used in actual operation.
2) Place the transmitter in the “standby” mode or turn it on for normal use.
3) While speaking or singing into the microphone at the same voice level that will be
used, observe the LEDs on the control panel. Hold the AUDIO button and press
the UP or DOWN arrow buttons to adjust the gain until the -20 LED flickers red on
louder peaks. This LED turns red at the instant full modulation takes place and the
very onset of limiting. The red color does not indicate overload or clipping.
If the unit was set up in “standby” mode, it will be necessary to turn the transmitter off,
then power it up again in normal operation so the RF output will be on. Then the other
components in the sound or recording system can be adjusted.

www.lectrosonics.com 9
FREQ Button Settings
The frequency can be displayed either in MHz or as a two-digit hexadecimal number
and it can be set when the unit is in “standby” or when the transmitter is powered up in
the normal operating mode.
MHz Hex Code
The hexadecimal numbering system is unique to Lectrosonics where two alphanumeric
characters correspond to the left and right switch settings on earlier analog transmitters
that had mechanical rotary switches to adjust frequency.
• Press the FREQ button repeatedly to toggle between either the MHz screen or the
Hex Code screen.
• While holding the FREQ button, use the UP or DOWN arrow buttons to move the
operating frequency up or down from the current setting.
The two-digit hex code is easier to remember, which can be handy when setting up a
multi-channel system.
Preventing Corrosion
Whenever the transmitter has been exposed to moisture or perspiration, follow the
instructions below to minimize the risk of corrosion.
IMPORTANT: Dry the unit before removing the microphone connector
and/or battery caps
If the transmitter has been exposed to salt water, rinse it with fresh water and then dry
the exterior of the transmitter thoroughly with a clean paper towel or cloth. Remove all
moisture around the battery caps and microphone cable connector.
After removing the battery caps and microphone connector, wipe off any residual mois-
ture around the battery compartment and microphone jack openings and on the battery
caps and microphone connector.
The O-rings should be coated with Vaseline®or an equivalent petroleum jelly* before
each use to ensure the seals are watertight.
IMPORTANT: Do not use anything other than pure petroleum jelly to
lubricate the O-rings. Silicon-based lubricants will dissolvel the O-rings.
Store the unit with no batteries installed, battery caps removed and the microphone
disconnected to allow any buildup of humidity and moisture to evaporate.
*Vaseline is a registered trademark of Conopco, Inc.

LECTROSONICS, INC.10
Re-conditioning (drying out) the caps
and desiccant beads
An easy way to heat the doors is to use a coffee mug warmer, which typically costs
about $10. The surface temperature of about 220 degrees (F) will dry the doors and
desiccant, but it will not disturb any light lubricant (like the Vaseline petroleum provided
with the WM) that is on the O-ring seals.
It is also possible to use the mug warmer to dry out the doors without removing them
from the case as shown below. Do not place the transmitter on this heated surface.
Lay it to one side as shown.
The mug warmer used for testing consumed 17 watts, so it could even be used on a
sound cart AC supply without being a huge drain on the batteries.
The color of the desiccant beads can be observed by shining a pen light on one edge of
the battery cap to illuminate the desiccant. Ideally, they will be an amber/orange color at
room temperature.

www.lectrosonics.com 11
Replacement O-rings
Model ORINGKIT/WM Includes replacement O-rings for battery caps and microphone
plug with WM style connector, and petroleum jelly pouch.
Separate parts:
P/N 35877 O-ring; .433” ID x .623” OD
P/N 35750 O-ring; .312” ID x .437” OD
P/N 32408 petroleum jelly pouch; 5 grams
Replacement battery caps
Early WM transmitters had standard battery caps. Later design included compartments
inside the caps containing moisture absorbing desiccant beads. A kit model WM-
DESIKIT is available that includes two replacement battery caps, O-rings, lanyards, a
center thumbscrew and allen wrench.
The desiccant beads are silica gel grade 52, manufactured by a US Company named
ADCOA under part number SG52002. Large containers can be purchased from
ADCOA, and small quantities are available from Lectrosonics. Contact Lectrosonics or
search online for adcoa.net for details.
To replace the
beads, remove the
retaining screw
and vented cover
with a Phillips
head screwdriver

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. or an authorized
dealer, shipping costs prepaid, within one year from the date of purchase.
This Limited Warranty is governed by the laws of the State of New Mexico. It states the
entire liablility of Lectrosonics Inc. and the entire remedy of the purchaser for any
breach of warranty as outlined above. 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.