Lectrosonics MM400C User manual

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Guide
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This guide is intended to assist with
initial setup and operation of your
Lectrosonics product.
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MM400C Transmitter
07 july10
U.S. Patent 7,225,135

LECTROSONICS, INC.2
Controls and Functions
Audio Input Jack
Designed for electret lavaliere microphones. Modest line level signals can also
be used.
Power ON/OFF and Mute Switch
Turns the transmitter on and off, or can be configured as an audio mute
switch.
Power LED
Indicates power status and battery strength.
Audio Level Control
The front panel Audio Level Control is used to adjust the incoming audio input
level for proper modulation.
Modulation LEDs
The two bicolor Modulation LEDs provide a visual indication of the input audio
signal level from the microphone.
Antenna
The flexible galvanized steel cable antenna supplied with the transmitter is
attached at the factory and is not removable by the user.
Frequency Select Switches
Two 16-position rotary switches adjust the operating frequency. The 1.6M is a
coarse adjustment and the 100K is the fine adjustment.
Belt Clip
The stainless steel wire belt clip may be removed for special applications by
simply pulling out one side to release the end of the clip.

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Audio Input Jack
Frequency Select
SwitchThumbscrew
and Cover Plate
Antenna
Battery
Compartment
Cap
Power ON/OFF and Mute
Switch (External Switch
Magnet Housing Assembly
Shown.)
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. Re-
move 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 BE-
FORE 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 each use (included with transmitter and O-ring replacement
kits). DO NOT USE ANYTHING OTHER THAN PURE PETROLEUM
JELLY. Silicone-based lubricants will dissolve the rubber. Failing to
lubricate the O-rings after each use will significantly shorten their life.

LECTROSONICS, INC.4
Operating Instructions
Selecting the Compatibility Mode
The MM400C can be used with Lectrosonics 400 Series Digital Hybrid, 200
Series analog, 100 Series analog and some non-Lectrosonics analog wireless
receivers. Contact the factory for details on the non-Lectrosonics models that
can be used. The transmitter must be set to the operating mode of the match-
ing receiver, which is done using the supplied screwdriver and a battery.
NOTE: The unit is supplied from the factory in Hybrid mode.
1) Ensure the battery is good.
2) Turn off the transmitter.
3) With a small screwdriver (included), set the Frequency Select Switches to
CC. (for Change, Change).
4) Power up the unit briefly – just long enough for the LED’s to light up and
then turn it off - about one second.
5) Change the Frequency Select Switches to one of the following settings:
• To set Lectrosonics 100 Series mode: 1,1
• To set Lectrosonics 200 Series mode: 2,2
• To set Mode 3*: 3,3
• To set Lectrosonics Hybrid mode: 4,4
• To set IFB mode: 5,5
• To set Mode 6*: 6,6
* contact the factory for details
6) Turn the unit on, wait a couple of seconds and turn off again.
7) Change the Frequency Select Switches to 0,0.
8) Turn on the transmitter to complete the operation.
The LEDS will blink to indicate the selected compatibility mode. Immediate-
ly after power up, all LEDS will blink together red, then green, followed
by the audio level LEDs (-20 and -10) blinking to indicate the mode.
The -20 and -10 LEDs will blink:
 •Oncefor100Seriesmode
 •Twotimesfor200Seriesmode
 •ThreetimesforMode3
 •Fourtimesfor400mode
 •FivetimesforIFBmode
 •SixtimesforMode6
At powerup the transmitter will confirm the current compatibility mode with
the number of blinks listed here. This setting will remain the same until
you reset it with the procedure listed above.

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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
Attaching a Microphone and Adjusting Gain
1) Ensure the battery is in good condition.
2) Insert the microphone plug into the input jack; be sure that the connector
is snug by tightening the threads.
3) Mute the associated receiver’s audio output.
4) Turn on the transmitter.
5) Position the microphone in the location you will use in actual operation.
While speaking or singing at the same voice level that will actually be
used, observe the Modulation LEDs. Adjust the AUDIO LEVEL control
until the –20 dB LED glows green with occasional red flickers and -10 dB
glows green. This will set the gain of your transmitter to between +0 dB
and +10 dB modulation.
(See chart at left.)
6) Once the gain
has been adjusted, the
audio system audio can
be turned on to make
level adjustments in the
main audio system.
NOTE: The transmitter Audio Level Control should not be used to
control the volume of your sound system or recorder levels. This
adjustment matches the input gain with the user’s voice level and
microphone positioning.
Operating Notes
If the audio level is too high — both LEDs will blink red frequently or glow a
steady red. This condition may reduce the dynamic range of the audio signal.
If the audio level is too low — neither LED will glow, or only the -20 LED will
glow green. This condition may cause hiss and noise in the audio.
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.

LECTROSONICS, INC.6
Frequency Select Switches
Two 16-position rotary switches adjust the center frequency of the carrier. The
1.6M is a coarse adjustment and the 100K is the fine adjustment.
Changing the Frequency
Locate the rotating watertight door on the bottom of the transmitter. Unscrew
the knob and pull the door outward, then swivel open to reveal two small
rotary switches. With the small screwdriver supplied with the kit, turn the left
switch to the first character in the two-digit Transmitter Frequency Switch Set-
ting code, then turn the right switch to the second character of the two-digit
code. For example: the frequency is 623.000, and the two-digit Setting code
is 56, thus the lefthand switch on your transmitter should be set to “5” and the
righthand switch to “6”.
Note: If you are using a receiver with a frequency scan function, find
a clear frequency with the receiver, then set the transmitter to the
frequency selected with the receiver. With Lectrosonics 400 Series
receivers, a front panel LCD character display will indicate the correct
transmitter switch settings as a two-character alphanumeric hex code
once a clear frequency has been located with the scan function (if the
receiver is so equipped).
Transmitter Frequency
Select Switches
012
3
4
5
6
7
8
9
A
B
C
D
EF012
3
4
5
6
7
8
9
A
B
C
D
EF
5 6

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Battery Installation
WARNING: Do not open battery compartment if unit is wet. Read
“Preventing Internal Corrosion” on page 3 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 us-
ing 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 warn-
ing. 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 Com-
partment Cover. The positive (+) bat-
tery 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.
Battery Compartment