Lectrosonics MM400b - Manual (Page 8)

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 connec­
tors.
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 remain­
ing 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 connec­
tors opened to allow any internal humidity to evapo­
rate. 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 PETRO­
LEUM 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 re­
moved.
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 Selec­
tion.) 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.
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.
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.
LECTROSONICS, INC. 8