INSTRUCTION MANUAL
MM400B
Watertight Miniature UHF Belt-Pack Transmitter
Featuring Digital Hybrid Wireless™ Technology
Fill in for your records:
Serial Number:
Purchase Date:
Rio Rancho, NM, USA
www.lectrosonics.com
MM400B
LECTROSONICS, INC. 2
Watertight Miniature UHF Belt-Pack Transmitter
Thank you for selecting the Lectrosonics MM400B
watertight miniature transmitter. The unique design
provides several distinct features for professional
applications:
• Outstanding RF operating range
• Superb audio quality
• Ultra-lightweight, corrosion resistant housing
• Watertight seals for use in wet environments
• Programmable emulation modes for maximum
versatility
The Digital Hybrid Wireless
™
design (US Patent Pending) combines 24-bit digital audio with analog FM
techniques to provide the operating range of the finest
analog wireless systems and the audio quality of a pure
digital system. The 100 mW RF output power extends
operating range, and the DSP controlled, dual-envelope
limiter cleanly handles input peaks to allow higher gain
settings. This combination maximizes operating range
and the signal to noise ratio of the system.
The input provides 6 VDC bias voltage for use with
modern electret lavaliere microphones. Multi-color
LEDs are provided to make input gain adjustments
quick and accurate, without having to view the receiver.
The battery compartment accepts AA alkaline, lithium
or NiMH batteries, and a detachable antenna ¼ wavelength flexible cable connects to a watertight 50 Ohm
SMA port on the transmitter.
The MM400B is machined from a solid aluminum block
to provide the lightweight, rugged package needed in
extreme environments without compromising functionality. Input jacks and controls are O-ring sealed for
watertight protection in wet environments. A special
noncorrosive finish (same as is used on NASA space
vehicles) resists salt water exposure and perspiration in
extreme environments.
The DSP-based design offers backward compatibility
with a handful of earlier analog designs, such as the
Lectrosonics 100 and 200 Series receivers, and other
brands of analog wireless receivers. Compatibility
Modes are easily selected with a sequence of frequency switch settings and cycling the unit’s power.
Only the MM400B transmitter is covered in this manual.
Companion receivers are covered in separate manuals.
Rio Rancho, NM 3
MM400B
LECTROSONICS, INC. 4
Watertight Miniature UHF Belt-Pack Transmitter
Table of Contents
General Technical Description ..............................................................................................................................................................6
General ................................................................................................................................................................................................. 6
Digital Hybrid Wireless™ Technology* ................................................................................................................................................. 6
Low Frequency Roll-Off ........................................................................................................................................................................ 6
Input Limiter .......................................................................................................................................................................................... 7
Digital Signal Processor ....................................................................................................................................................................... 7
Microprocessor, PLL and VCO Circuits ................................................................................................................................................7
Compatibility Modes .............................................................................................................................................................................7
Pilot Tone Squelch ................................................................................................................................................................................7
Wide-Band Deviation ............................................................................................................................................................................ 7
Magnetic Power ON/OFF Switch .......................................................................................................................................................... 7
Battery Life ........................................................................................................................................................................................... 7
Frequency Agility .................................................................................................................................................................................. 7
Circulator/Isolator ................................................................................................................................................................................. 7
Controls and Functions .........................................................................................................................................................................8
Preventing Internal Corrosion ............................................................................................................................................................... 8
Power ON/OFF Switch ......................................................................................................................................................................... 8
Power LED ............................................................................................................................................................................................ 8
Mic Jack................................................................................................................................................................................................9
Audio Level ...........................................................................................................................................................................................9
Modulation LEDs ..................................................................................................................................................................................9
Frequency Select Switches ..................................................................................................................................................................9
Antenna ................................................................................................................................................................................................9
The Belt Clip .......................................................................................................................................................................................10
Battery Installation ..............................................................................................................................................................................10
Operating Instructions ........................................................................................................................................................................11
Selecting the Compatibility Mode .......................................................................................................................................................11
Adjusting Transmitter Frequency ........................................................................................................................................................ 11
Attaching a Microphone and Adjusting Audio Levels ......................................................................................................................... 12
Power Switch Function Selection ....................................................................................................................................................... 13
Determine Power Switch Function Mode ........................................................................................................................................ 13
Changing Power Switch Function ................................................................................................................................................... 13
Replacing the Power Switch Magnet Housing Assembly ................................................................................................................14
Microphone RF Bypassing .................................................................................................................................................................. 15
Replacement Parts and Accessories .................................................................................................................................................16
UHF Transmitter Antenna Specifications ............................................................................................................................................ 16
Troubleshooting ...................................................................................................................................................................................17
Specifications and Features ............................................................................................................................................................... 18
Service and Repair ...............................................................................................................................................................................19
Returning Units for Repair ..................................................................................................................................................................19
Rio Rancho, NM 5
MM400B
General Technical Description
General
The 400 Series (or Digital Hybrid Wireless™) system
uses 75 kHz wide deviation for an extremely high signal
to noise ratio. The switching power supplies provide
constant voltages to the transmitter circuits from the
beginning (1.5 Volts) to the end (0.85 Volts) of battery
life. The input amplifier uses an ultra low noise op amp
for quiet operation. It is gain controlled with a wide
range dual envelope input compressor which cleanly
limits input signal peaks over 30 dB above full modulation.
Note: The terms 400 Series and Digital Hybrid
Wireless™ describe the same product line are
interchangeable.
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
(known as “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.
The Lectrosonics Digital Hybrid Wireless™ system
overcomes 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 which can be
accomplished only in the digital domain, even though
the inputs and outputs are analog signals.
Because it uses an analog FM link, Digital Hybrid
Wireless™ enjoys all the benefits of conventional FM
wireless systems, such as excellent range, efficient use
of RF spectrum, and resistance to interference. However, unlike conventional FM systems, the Digital Hybrid
has done away with the analog compandor and its
artifacts.
Low Frequency Roll-Off
A 12 dB per octave low frequency roll-off is provided in
the audio section, with the -3 dB point at 70 Hz. The
actual roll-off frequency will vary somewhat according
to the low frequency response of the mic capsule being
used.
The low frequency roll-off is used to remove subsonic
(or very low frequency) audio, such as that produced by
air conditioning systems or automobile traffic, from the
audio signal. Excessive low frequency content in the
audio input can cause a variety of audio problems
including driving the transmitter into limiting. For
example, in sound reinforcement systems, as one
instance, excessive low frequency content can cause
excessive power amplifier drain or even damage to
loudspeaker systems.
+6V Bias Supply
(see Input Jack Wiring for details)
Mic
Jack
(Fits Switchcraft
plug #850.)
Hi/Lo
Pass
Filter
Bicolor
Modulation
LEDs
*US Patent Pending
Shunt
Limiter
Phase Locked Loop
4MHz
Reference
Input
Amp
Audio
Level
Freq
Switches
Audio
Microprocessor
A-D
Converter
11001001
Digital Signal Processor
D-A
Converter
11001001
Vol tage
Controlled
Oscillator
Encoded
Audio and
Pilot Tone
Magnetic
Power On/Off
Switch
MM400B
Block Diagram
Switching
Powe r
Supply
1.5V
AA
Lithium
50
Ohm
Isolator
LECTROSONICS, INC. 6
Bicolor
Powe r
LED
+3.3v
+3v
+1.8v
+6v
-3v
Watertight Miniature UHF Belt-Pack Transmitter
Input Limiter
The MM400B transmitters employ a digitally-controlled
analog audio limiter just before the analog-to-digital
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, 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 both keep
audio distortion low and preserve short term dynamic
changes.
Two bicolor LEDs indicate limiter activity. (See
ing Instructions, Adjusting Audio Levels
speaking, some limiting is desirable in normal operation
to improve the signal to noise ratio of the system. The
limiting action is not audible and does not create
distortion.
Operat-
.) Generally
Digital Signal Processor
The DSP constructs the original digitized audio from the
A-D Converter , adds an ultrasonic Pilot Tone to control
the receiver's squelch (only in 400 Series and 200
Series Compatibility Mode with the Pilot Tone enabled –
Pilot Tone Squelch
see
defined Compatibility Mode.
), and implements the user
Microprocessor, PLL and VCO Circuits
An 8-bit microprocessor monitors user command inputs
and numerous other internal signals. It also drives the
Modulation LEDs, controls the Pilot Tone and operates
the PLL/VCO circuits.
Compatibility Modes
The MM400B transmitter was designed to compatible
with Lectrosonics 400 Series receivers and will yield the
best performance when doing so. However, due to the
flexibility of digital signal processing, the MM400B is
also able to operate with Lectrosonics 200 Series,
Lectrosonics 100 Series, IFB and certain nonLectrosonics analog receivers in special compatibility
modes. (Contact the Lectrosonics Sales Department
for a complete list of compatible transmitters.)
Pilot Tone Squelch
The 400 Series wireless system uses an ultrasonic tone
between 25 and 32 kHz to operate the receiver squelch.
The pilot tone squelch system keeps the receiver muted
until it receives the pilot tone from the matching transmitter, even if a strong RF signal is present on the
carrier frequency of the system. The “pilot tone”
frequency is different for each of the 256 available
carrier frequencies to prevent the pilot tone from being
transferred to the wrong receiver via an intermodulation
product.
Wide-Band Deviation
A ±75 kHz deviation improves the capture ratio, signal
to noise ratio and AM rejection of a wireless system
dramatically, compared to other designs that use 30
kHz to 40 kHz deviation. This combined with a full 100
mW of power output makes a significant improvement
in signal to noise ratio and maximum operating range.
Magnetic Power ON/OFF Switch
A magnetic power switch is used to control the application of power to the MM400B circuits and as an audio
mute switch. The function of this switch can be set by
the user. (See
ON/OFF Switch
When the Power ON/OFF switch is configured as a
power switch, the ON/OFF positions are used in the
conventional manner, i.e., ON turns the transmitter on,
and OFF turns it off.
When the Power ON/OFF switch is configured as an
audio mute switch, placing the switch in the OFF
position mutes the audio. Placing the switch in the ON
position turns on the audio.
Controls and Functions, Magnetic Power
.)
Battery Life
Switching power supplies throughout the design allow
over 6 hours of operation using a single AA lithium
battery. (An alkaline AA battery will provide about 1.75
hours and a 2200 mAh NiMH AA battery will provide
about 4 hours of operating time) The battery contacts
are spring loaded in order to prevent “rattle” as the unit
is handled.
Frequency Agility
The transmitter section uses a synthesized, frequency
selectable main oscillator. The frequency is extremely
stable over a wide temperature range and over time.
Two 16-position rotary switches, located on the under a
waterproof cover on the bottom of the unit, provide 256
frequencies in 100 kHz steps over a 25.5 MHz range.
This alleviates carrier interference problems, a definite
problem in mobile or traveling applications.
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 within a few feet of
each other. It also provides additional RF output stage
protection but is rarely seen in a wireless microphone
transmitter due to its high cost.
Rio Rancho, NM 7
MM400B
Controls and Functions
Modulation and
Power LEDs
Antenna
Power ON/OFF Switch
(External Switch Magnet
Housing Assembly Shown.)
Battery
Compartment
Cap
Frequency Select
SwitchThumbscrew
and Cover Plate
Audio Level Control
Microphone Jack
Preventing Internal Corrosion
It is very important that you properly dry the transmitter
when it becomes wet due to immersion or high levels of
perspiration BEFORE opening any covers or connectors. Follow the procedure below for best results:
1. Carefully blot the transmitter dry with a clean paper
towel or cloth. Remove all moisture. After opening
any connector or cover, carefully blot up any remaining moisture that may have remained around the seal.
IMPORTANT! DO NOT CLOSE ANY COVER OR
CONNECTOR BEFORE MAKING CERTAIN THERE
IS NO MOISTURE IN OR NEAR THE OPENING.
2. After use, it is important to store the transmitter in a
dry place with all access compartments and connectors opened to allow any internal humidity to evaporate. Specifically, open the Battery Compartment,
the Frequency Switch Cover Plate and fully unscrew
and remove the microphone connector before
storing. Do not store wet and do not store sealed.
If moisture is sealed inside the unit it has nowhere to
go other than to chemically react with and destroy
components and the printed circuit board.
3. Lubricate all rubber O-rings with petroleum jelly
(such as Vaseline) after eash use (included with
transmitter and O-ring replacement kits). DO NOT
USE ANYTHING OTHER THAN PURE PETROLEUM JELLY. Silicone-based lubricants will dis-
solve the rubber. Failing to lubricate the O-rings
after each use will significantly shorten their life.
Power ON/OFF Switch
A waterproof, magnet Power ON/OFF switch is located
on the unit’s side panel. The switch actually consists of
two components. A magnetically actuated internal
component and a magnet housing assembly. The
switch is designed so that the unit will still operate if the
Switch Magnet Housing Assembly is missing or removed.
The function of the Power ON/OFF Switch can also be
changed so it operates as an audio mute switch. (See
Operating Instructions, Power Switch Function Selection
.) These functions are illustrated in the chart below:
Power Switch Position
Function ON OFF
Normal, or Applies Power Turns Unit Off
Power Mode to Unit
Audio Mute Turns On Audio Mutes Audio
Mode
If the MM400B Power ON/OFF Switch has been
configured for Audio Mute Mode, it is still possible to
turn off the transmitter without removing the battery.
This is done by placing the switch in the ON position,
then toggling the switch between the ON and OFF
position three times in less than five seconds, i.e., ON
(Starting Position)-OFF-ON-OFF-ON-OFF.
The user-selected configuration of the Power ON/OFF
switch is stored in memory and persists until
reconfigured by the user.
Power LED
The PWR LED provides an indication of the battery’s
condition. 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 left in the battery.
The PWR LED blinks red for a short period when the
transmitter is configured for Normal Mode and the
Power ON/OFF switch is set to OFF. At the end of the
power off sequence, then PWR LED extinguishes.
A weak battery will sometimes cause the PWR LED to
glow green immediately after being put in the unit, but
will soon discharge to the point where the LED will blink
red or shut off completely.
Note: A NiMH battery gives little or no warning
when it is depleted. If you use NiMH batteries in
the MM400B, we recommend trying fully charged
batteries first, noting the length of time that the
batteries will run the unit, then plan for somewhat
less time to determine when the battery needs to
be replaced. Some Lectrosonics receivers have
timers for use with these batteries.
LECTROSONICS, INC. 8
Watertight Miniature UHF Belt-Pack Transmitter
Mic Jack
The Mic Jack is a 2.5 mm microplug that is wired to
accommodate two-wire positive bias lavalieres. While
the M152-WP (waterproof) is specifically designed for
the MM400B, other two-wire lavaliere microphones can
be adapted to the MM440B using the WPMC-3 or
WPMC-10 kits. A Switchcraft 850 connector (Lectrosonics P/N 21357) can be used in an emergency
though it is not waterproof. (See Replacement Parts
and Accessories.)
The equivalent input circuit wiring for the Mic Jack is
shown below:
Mic
Jack
2k
FB
330pF 330pF
FB
100
2k
30uF
2k
2.2nF
6V Mic Bias
To Mic Amp
Audio Level
The Audio Level Control is used to adjust the audio
input level from the microphone for proper modulation
of the output signal from the transmitter.
Frequency Select Switches
Two 16-position rotary Frequency Select Switches are
used to select the operating frequency, for setting
Compatiblity Modes and for configuring the Power ON/
OFF switch.
The switches are accessed by loosening the retaining
screw holding the cover plate, lifting the cover away
from the housing and rotating it to expose the switches.
For setting the operating frequency, the left switch
(1.6MHz) adjusts the operating frequency up or down in
1.6 MHz increments. The right switch (100kHz) adjusts
the frequency up or down in 100 kHz increments. (See
Operating Instructions, Adjusting the Transmitter
Frequency
.)
A sequence of Frequency Select Switch settings and
Power ON/OFF toggles are used to set Compatibility
Modes and for configuring the Power ON/OFF switch.
Operating Instructions, Setting Compatibility
(See
and
Modes
Frequency Switch
Cover Plate
Power Switch Function Selection
.)
Frequency Switch Cover Plate
Retaining Screw
Battery Compartment
Modulation LEDs
The two bicolor Modulation LEDs provide a visual
indication of the audio signal level input from the
microphone. These LEDs can glow either red or green
to indicate modulation levels as shown in the following
chart.
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
When the Power ON/OFF Switch is configured for Audio
Mute Mode, the -10 Modulat ion LED is also used to
indicate if the transmitter is in an audio muted, or an
unmuted condition. In Audio Mute Mode, if the Power
ON/OFF switch is set to OFF, the transmitter remains
powered up; however, the audio is muted and the -10
Modulation LED blinks green.
If the Power ON/OFF switch is set to ON and the switch
is configured for Audio Mute Mode, -10 and -20 LEDs
operate normally to indicate audio level.
0
1
F
2
E
3
D
C
4
5
B
6
A
9
7
8
1.6M
Frequency Select Switches
F
E
D
C
B
A
9
100K
0
1
2
3
4
5
6
7
8
Battery
Compartment Cap
Antenna
The flexible steel cable antenna supplied with the
transmitter is cut to 1/4 wavelength of the center of the
frequency block (the frequency range) of the transmitter.
It is mounted with an SMA connector. The SMA connector is a 50 Ohm RF port which can also be connected directly to test equipment.
Replacement antennas are available in pre-cut lengths
for specific frequency blocks, or as a kit with instructions to cut the antenna for any frequency block. (See
Replacement Parts and Accessories
.)
Rio Rancho, NM 9
MM400B
The Belt Clip
The belt clip may be removed for special applications
by gently spreading the spring wire clip and pulling the
ends out of the holes in the case. The clip can be
installed in either the up or down position so that when
the transmitter is worn, the antenna can be pointing up
or down. Replacement belt clips are available. (See
Replacement Parts and Accessories
.)
Battery Installation
Stainless Steel Belt Clip
Battery Compartment
WARNING: Do not open battery compartment if
unit is wet. Read “Preventing Internal
Corrosion” on page 8 before proceeding.
The transmitter is powered by a standard lithium, NiMH
or alkaline AA 1.5 volt battery. The battery status
circuitry is designed for the voltage drop over the life of
lithium batteries. While NiMH rechargeable batteries
will work, they run down quite abruptly. Because of this,
using the PWR LED to verify battery status not reliable
with NiMH batteries. It is possible to track battery status
using the Battery Timer function available in a number
of Lectrosonics receivers. (Refer to your receiver
manual to determine if this function is available.)
Alkaline batteries provide about 1.75 hours of operation
with some warning. Lithium batteries can be used to
provide over 6 hours of operation and provide about 30
minutes of warning as the LED turns red.
Note: Standard zinc-carbon batteries marked
“heavy-duty” or “long-lasting” are not adequate.
To access the battery compartment, unscrew and
remove the Battery Compartment Cover. Take note of
the polarity marked on the battery case showing the
location of the positive (+) and negative (-) terminals.
The positive (+) battery terminal goes into the transmitter first. Screw the Battery Compartment Cover back
into the transmitter body. If the battery is inserted
incorrectly, the cover will not screw in easily and the unit
will not work.
LECTROSONICS, INC. 10
Operating Instructions
Watertight Miniature UHF Belt-Pack Transmitter
Selecting the Compatibility Mode
All Digital Hybrid receivers are capable of working with
Lectrosonics MM400B transmitter, and by setting the
proper Compatibility Mode, the unit will also work with
200 Series and 100 Series analog receivers, plus some
other brands (contact the factory for details). In order to
operate properly, the transmitter must be set to the
operating mode of the matching receiver, which is
easily done using a small screwdriver and a battery.
The following procedure assumes that the Power ON/
OFF switch is configured for Normal Mode. If it has
been configured for Audio Mute Mode, see
Switch Function Selection
to change the configuration
to Normal Mode.
Note: The unit comes from the factory in the Digital
Hybrid mode.
1) Set the audio controls for the corresponding
receiver to minimum.
Power
Switch settings to one of the following positions:
• 100 Series mode: 1,1
• 200 Series mode: 2,2
• Mode 3: 3,3
• 400 Series mode: 4,4
• IFB Series mode: 5,5
7) Power up the unit briefly – just long enough to
watch the LED’s glow and then turn the transmitter
Off.
8) Set the Frequency Select Switches to 0,0.
9) Turn on the transmitter and observe the Modulation
LEDs to verify the compatibility mode for the unit
has changed.
NOTE: Each time the transmitter is turned on, the
Modulation LEDs will confirm the current
operating mode with the number of blinks listed in
Step 2. The mode setting will not change until
reset with the procedure listed above.
2) Install a good battery in the transmitter. Move the
Power Switch to ON and observe the Modulation
Frequency Switch Cover Plate
LEDs to determine the current Compatibility Mode.
The –20 and –10 LEDs will blink simultaneously:
• Once for 100 Series mode
• Two times for 200 Series mode
• Three times for “Other” receivers
• Four times for 400 Series mode
• Five times for IFB Series mode
3) Move the Power Switch to the OFF position.
Loosen the Frequency Switch Cover Plate
4)
Retaining Screen and rotate the cover to
expose the Frequency Select Switches.
With a small screwdriver (included with
your unit), set the Frequency Select
Switches to CC. (for Change, Change).
5)
Power up the unit briefly – just long
0
1
F
2
E
3
D
C
4
5
B
6
A
9
7
8
1.6M 100K
Frequency Select Switches
0
1
F
2
E
3
D
C
4
5
B
6
A
9
7
8
enough to watch the LED’s glow and
then turn the transmitter Off.
6)
Change the Frequency Select
Adjusting Transmitter Frequency
If you are experiencing interference from another signal
on your operating frequency, you may need to change
the operating frequency of your system. This is done
through two Frequency Select Switches located under
Modulation LEDs
POWER LED
the Frequency Switch Cover Plate on the bottom of the
transmitter case.
The left switch is for coarse frequency adjustment, and
it increments the operating frequency in 1.6 MHz steps.
The right switch is for fine frequency adjustment and it
increments the operating frequency in 100 kHz steps. If
you are using a 200 Series or 400 Series receiver, it is
suggested to use the built in frequency spectrum
scanning function on the associated receiver to find a
clear channel. Turn the transmitter off and leave the
receiver turned on. Scan across the frequency band to
find a frequency where little or no RF activity is displayed. Set both the transmitter and the receiver to this
Power ON/OFF
Switch
Rio Rancho, NM 11
new frequency. Turn on the transmitter to ensure the
RF signal is strongly indicated at the receiver.
MM400B
NOTE: All 400 Series (and a number of earlier
receivers) offer a front panel LCDs that indicate
the correct transmitter switch settings when
locating clear channels. Use the scanning
functions on these receivers to find a clear
channel, then switch both the receiver and
transmitter to the Frequency Select Switch settings
indicated in the receiver’s display.
If you are using a 100 Series receiver, turn off the
transmitter and observe the RF LED on the front panel
of the UCR100 receiver. If it flickers, or glows red, then
adjust the UCR100’s Frequency Select Switches up or
down in 100 kHz increments until the RF LED extinguishes. Set the MM400B transmitter’s Frequency
Select Switches to the same settings. Turn on the
transmitter and observe that the RF LED on the receiver glows brightly.
Attaching a Microphone and
Adjusting Audio Levels
The front panel Modulation LEDs indicate limiter activity.
(See chart.) Since the distortion introduced by the
limiter is minimal and full modulation is assured, occasional forays into the red by the -10 LED is acceptable.
1) Install a fresh battery.
2) Insert the watertight microphone plug into the Mic
Jack and screw it in snugly.
NOTE: Different voices will usually require different
settings of the Audio Level Control, 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.
7) Once the MM400B’s audio gain has been set, the
remaining components of the audio system can be
energized and adjusted.
WARNING:The AUDIO LEVEL control should
not be used to control the volume of your
sound system or recorder levels. This gain
adjustment matches the transmitter gain with
the user’s voice level and microphone
positioning.
Modulation
LEDs
WARNING: Do not overtighten as this will
distort the “O-ring” and allow moisture to enter
the unit.
3) Mute the main sound system and rotate the Audio
Level Control on the MM400B to maximum counterclockwise (Off).
4) Set the Power ON/OFF switch to the ON position.
5) Position the microphone in the location where it will
be used during in actual operation.
6) Observe the MM400B Modulation LEDS while
speaking or singing into the microphone at the
same voice level that will be used during the
program. Gradually rotate the Audio Level
Control control clockwise until both LEDs glow
green with the -20 dB occasional blinking red.
This indicates full modulation and is the
optimum setting for the transmitter’s gain.
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
POWER
LED
Power On/Off
Switch
Microphone Jack
Antenna
Connector
Audio
Level
Control
LECTROSONICS, INC. 12
Watertight Miniature UHF Belt-Pack Transmitter
Power Switch Function Selection
The Power ON/OFF Switch can also be used as an
audio mute switch. When used as an audio mute
switch, the power switch causes the transmitter’s audio
to be muted when the Power ON/OFF switch is placed
in the OFF position. The -10 Modulation LED blinks
green to indicate that the transmitter is in Audio Mute
Mode.
Function On Off
Normal, or Applies Power Turns Unit Off
Power Mode to Unit
Audio Mute Turns On Audio Mutes Audio
Mode
In Audio Mute Mode, the transmitter can still be turned
off by toggling the Power ON/OFF switch rapidly. Turn
the Power Switch ON then OFF three times (ending in
the OFF position) within five seconds to initiate the
power off sequence. The sequence is ON-OFF-ONOFF-ON-OFF.
Determine Power Switch Function Mode
1) If the transmitter is turned off, set the Power Switch
ON and observe the Modulation LEDs.
2) After the power up sequence completes, place the
POWER ON/OFF switch in the OFF position and
observe the -10 Modulation LED.
3) If the PWR LED glows and the -10 Modulation LED
blinks green, the Power Switch is in Audio Mute
Mode. If the LEDs extinguish, the Power Switch is
in Normal or Power Mode.
Power Switch Position
Frequency Switch Cover Plate
1.6M 100K
Frequency Select Switches
Changing Power Switch Function
1) Ensure the Power ON/OFF switch is in the OFF
position.
2) Loosen the Frequency Switch Cover Plate Retaining Screw, pull it away from the transmitter body,
then rotate it to expose the Frequency Select
Switches.
3) With a small screwdriver (included with your unit),
set the Frequency Select Switches to F,F.
4) Rapidly toggle the Power ON/OFF switch to ON
then back to OFF.
5) Change the Frequency Select Switch settings to the
following position:
Normal Mode: 1,1
Audio Mute Mode: 2,2.
5) Rapidly toggle the Power ON/OFF switch to ON
then back to OFF.
6) Set the Frequency Select Switches to 0,0.
7) Rapidly toggle the Power ON/OFF switch to ON
then back to OFF.
8) Turn on the transmitter. After the powerup sequence has completed, set the Power ON/OFF
Switch to OFF and observe the -10 Modulation LED
and the PWR LED.
If the Power ON/OFF switch is configured for
Normal Mode, the -10 Modulation LED will go out
and the PWR LED will blink red for a short period
then go out indicating the transmitter has shut
down.
If the Power ON/OFF switch is configured for
Audio Mute Mode, the PWR LED continues to
monitor battery condition while the -10
Modulation LED blinks green.
Rio Rancho, NM 13
MM400B
Replacing the Power Switch Magnet Housing Assembly
Although the Power Switch’s Magnet Housing Assembly is designed to provide years of rugged use it may
become inadvertently damaged or lost. Use the
following procedure to install a new Magnet Housing
Assembly.
1) If necessary, use a nonmetallic tool such as an
“orange stick” to remove the damaged Magnet
Housing Assembly and clean any debris from the
Magnet Housing Assembly slot. Apply a small
amount of petroleum jelly or white lithium grease to
the area before inserting the new magnet assembly.
Warning: If you must use something metallic,
as illustrated in the example, use extreme
caution not to scratch the finish. Breaching the
finish may cause corrosion of the metal
housing.
2) Notice that the Magnet Housing Assembly Slot has
a wide spot in the middle. Place the new Magnet
Housing Assembly in the slot so that one tab is in a
small groove in one side of the slot.
3) Use a nonmetallic implement to snap the other side
of the Magnet Housing Assembly into the slot.
4) Ensure a good battery is installed, then slide the
new Power ON/OFF Switch to ON to verify that it is
working properly.
Magnet Housing
Assembly
Magnet Housing
Assembly Slot
LECTROSONICS, INC. 14
Microphone RF Bypassing
Watertight Miniature UHF Belt-Pack Transmitter
Some mics require RF protection to keep the radio
signal from affecting the capsule, even though the
transmitter input circuitry is already RF bypassed.
If the mic is wired as directed, and you are having
difficulty with level, high noise, or poor frequency
response; RF is likely to be the cause.
The best RF protection is accomplished by installing RF
bypass capacitors at the mic capsule. If this is not
possible, or if you are still having problems, capacitors
can be installed on the mic wires inside the TA5F
connector housing.
Install the capacitors as follows: Use 330 pF capacitors.
Capacitors are available from Lectrosonics. Please
specify the part number for the desired lead style.
2 WIRE MIC
Preferred location for bypass capacitors
SHIELD
AUDI O
CAPSULE
MICROPHONE
CONNECTOR
Alternate location for bypass capacitors
Leaded capacitors: P/N 15117
Leadless capacitors: P/N SCC330P
All Lectrosonics lavaliere mics are already bypassed
and do not need any additional capacitors installed for
proper operation.
Rio Rancho, NM 15
MM400B
Replacement Parts and Accessories
Part/Model # Description
26486 Replacement wire belt clip
AMM (xx) Replacement whip antenna,
specify frequency block (xx)
21357 Non-watertight audio input plug
WPMC-3 Watertight plug kit - 3 pieces
WMPC-10 Watertight plug kit - 10 pieces
P1201-1 Switch Magnet Housing Assembly
UHF Transmitter Antenna Specifications
All Lectrosonic UHF transmitter antennas follow the
color code specifications in the chart below to identify
operating frequency block range. (The frequency block
range is engraved on the ouside housing for each
individual transmitter.)
If a situation exists whereby the antenna is defective
and the antenna cap is missing, refer to the following
chart to determine the correct replacement antenna.
FREQUENCY CAP
BLOCK RANGE COLOR
20 512.000 - 537.500 Black
21 537.600 - 563.100 Brown
22 563.200 - 588.700 Red
23 588.800 - 614.300 Orange
24 614.400 - 639.900 Yellow
25 640.000 - 665.500 Green
26 665.600 - 691.100 Blue
27 691.200 - 716.700 Violet (Pink)
28 716.800 - 742.300 Grey
29 742.400 - 767.900 White
30 768.000 - 793.500 Black-w/Label
31 793.600 - 819.100 Black-w/Label
32 819.200 - 844.700 Black-w/Label
33 844.800 - 865.000 Black-w/Label
ANTENNA
WHIP LENGTH
4.98"
4.74"
4.48"
4.24”
4.01"
3.81"
3.62"
3.46"
3.31"
3.18"
3.08"
2.99”
2.92”
2.87”
Note: Blocks 30 through 33 are labeled with the
frequency block number.
16 LECTROSONICS, INC.
Watertight Miniature UHF Belt-Pack Transmitter
Troubleshooting
Before going through the following chart, be sure that you have a good battery in the transmitter. It is important that
you follow these steps in the sequence listed.
SYMPTOM
TRANSMITTER PWR LED OFF
NO TRANSMITTER MODULATION LEDs
-10 MODULATION LED IS BLINKING
GREEN AND RECEIVER HAS NO AUDIO
RECEIVER INDICATES NO RF
NO SOUND (OR LOW SOUND LEVEL),
RECEIVER INDICATES PROPER AUDIO
MODULATION
POSSIBLE CAUSE
1) Battery is inserted backwards.
2) Battery is dead.
3) Power ON/OFF switch configured to Normal Mode and is
set to OFF.
1) Verify Transmitter PWR LED is glowing.
2) Gain control turned all the way down.
3) Mic capsule is damaged or malfunctioning.
4) Mic cable damaged or mis-wired.
1) Power ON/OFF Switch is configured for Audio Mute Mode and
the switch is in the OFF, or mute position. (See
Functions
1) Transmitter not turned on.
2) Transmitter battery is dead.
3) Transmitter antenna missing or defective.
4) Receiver antenna missing or improperly positioned.
5) Transmitter and receiver not on same frequency.
Check switches/display on transmitter and receiver.
6) Operating range is too great.
1) Receiver output level set too low.
2) Receiver output is disconnected; cable is defective or connectors
not wired correctly.
3) Sound system or recorder input is turned down.
4) Receiver/Transmitter compatibility mode mismatched.
5) Transmitter audio muted.
.)
Controls and
DISTORTED SOUND
HISS AND NOISE -- AUDIBLE DROPOUTS
EXCESSIVE FEEDBACK
Rio Rancho, NM 17
1) Transmitter gain (audio level) is far too high. Check Modulation
LEDs on transmitter and receiver as it is being used. (See
Operating Instructions, Attaching a Microphone and Adjusting
Audio Levels
2) Receiver output may be mismatched with the sound system or
recorder input. Adjust output level on receiver to the correct level
for the recorder, mixer or sound system.
3) Excessive wind noise or breath “pops.” Reposition microphone
and/or use a larger windscreen.
4) Transmitter is not set to same frequency as receiver. Check that
frequency select switches on receiver and transmitter match.
5) Receiver/Transmitter compatibility mode mismatched.
1) Transmitter gain (audio level) far too low.
2) Receiver antenna missing or obstructed.
3) Transmitter antenna missing.
4) Operating range too great. Check RF level on receiver indicator.
1) Transmitter gain (audio level) too high. Check gain adjustment
and/or reduce receiver output level.
2) Transmitter too close to speaker system.
3) Mic is too far from user’s mouth.
.)
MM400B
Specifications and Features
Operating frequencies:
Block 21 537.600 - 563.100
Block 22 563.200 - 588.700
Block 23 588.800 - 607.900 and 614.100 - 614.300
Block 24 614.400 - 639.900
Block 25 640.000 - 665.500
Block 26 665.600 - 691.100
Block 27 691.200 - 716.700
Block 28 716.800 - 742.300
Block 29 742.400 - 767.900
Frequency selection: 256 frequencies in 100 kHz steps
RF Power output: 100 mW (nominal)
Pilot tone: 25 to 32 kHz; 5 kHz deviation
(in 400 Series Mode)
Frequency stability: ± 0.002%
Deviation: ± 75 kHz max. (in 400 Series Mode)
Spurious radiation: 60 dB below carrier
Equivalent input noise: –118 dBV, A-weighted
Input level: Nominal 2 mV to 300 mV, before limiting.
Greater than 1.5V maximum, with limiting.
Input impedance: 2 kOhm
Input limiter: Soft limiter, >30 dB range
Gain control range: 43 dB; semi-log rotary control
Modulation indicators: Dual bicolor LEDs indicate modulation of
–20, -10, 0, +10 dB referenced to full
modulation.
Low frequency roll-off: –12 dB/octave; 70 Hz
Controls: Front panel knob adjusts audio gain.
Audio Frequency Response: 80 Hz to 20 kHz, +/-1dB, -3 dB @ 70 Hz
Signal to Noise Ratio (dB):
(overall system, 400 Series mode)
Note: The dual envelope “soft”
limiter provides exceptionally good
handling of transients using variable
attack and release time constants. Once activated, the limiter compresses 30+ dB of
transmitter input range into 4.5 dB of receiver output range, thus reducing the measured
figure for SNR without limiting by 4.5 dB
Total Harmonic Distortion: 0.2% typical (400 Series mode)
Audio Input Jack: 2.5 mm Microjack (matches Switchcraft 850
Antenna: Detachable, flexible galvanized steel
Battery: 1.5 Volt AA lithium recommended
Battery Life: 1.75 hours (alkaline); over 6 hours (lithium);
Weight: 3.6 ozs. (102 grams) with lithium battery,
Overall Dimensions: 3.03 x 2 x 0.69 inches (not including
Rotary switches on bottom panel adjust
transmitter frequency.
(The audio is deliberately rolled off at 70 Hz
using a 12 dB/octave filter. This filter cannot
be disabled.)
SmartNR No Limiting w/Limiting
OFF 103.5 108.0
NORMAL 107.0 111.5
FULL 108.5 113.0
Microplug)
with SMA connector. (50 Ohm antenna port
also allows connection to test equipment.)
3.5 hours (2200 mAhr) NiMH
no antenna
microphone or antenna)
Emission Designator: 180KF3E
Specifications subject to change without notice.
The FCC requires that the following statement be
included in this manual:
This device complies with FCC radiation exposure limits
as set forth for an uncontrolled environment. This device
should be installed and operated so that its antenna(s)
are not co-located or operating in conjunction with any
other antenna or transmitter.
LECTROSONICS, INC. 18
Watertight Miniature UHF Belt-Pack Transmitter
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 the interconnecting cables and then go through the Troubleshooting section in this 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’ Service 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
For timely service, please 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 A.M. to 4 P.M. (U.S. 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 outside of the shipping container.
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 dam-
age to equipment that you ship. Of course, we insure the equipment when we ship it back to you.
Mailing address: Shipping address: Telephone:
Lectrosonics, Inc. Lectrosonics, Inc. (505) 892-4501
PO Box 15900 581 Laser Rd. (800) 821-1121 Toll-free
Rio Rancho, NM 87174 Rio Rancho, NM 87124 (505) 892-6243 Fax
USA USA
Web: E-mail:
www.lectrosonics.com sales@lectrosonics.com
Rio Rancho, NM 19
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.
581 Laser Road NE • Rio Rancho, NM 87124 USA • www.lectrosonics.com
(505) 892-4501 • (800) 821-1121 • fax (505) 892-6243 • sales@lectrosonics.com
June 28, 2006
Loading...