User's Manual

2
The MM400 transmitter is FCC type accepted under Part 74: 536-608 MHz and 614-806 MHz
WARNING! TO PREVENT INTERNAL CORROSION!
If the transmitter is wet (either due to immersion or high levels of perspiration),
BEFORE opening any covers or connectors, 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. THIS IS IMPORTANT! DO NOT CLOSE ANY COVER OR CONNECTOR
BEFORE MAKING CERTAIN THERE IS NO MOISTURE IN OR NEAR THE
OPENING. After use, it is important to store the transmitter in a dry place with all
access doors and connectors opened to allow any internal humidity to evaporate.
Specifically, open the battery door, the frequency 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.
TABLE OF CONTENTS
WARNING! TO PREVENT INTERNAL CORROSION! ................................ 2
INTRODUCTION ................................................................................................... 3
GENERAL TECHNICAL DESCRIPTION .............................................................. 3
Temporary Placeholder ......................................................................................... 4
CONTROLS AND FUNCTIONS ............................................................................ 6
BATTERY INSTALLATION .................................................................................... 7
OPERATING INSTRUCTIONS .............................................................................. 8
OPERATING NOTES ............................................................................................ 8
ADJUSTING THE TRANSMITTER FREQUENCY ............................................... 8
MICROPHONE RF Bypassing ............................................................................. 9
TROUBLESHOOTING........................................................................................... 9
SPECIFICATIONS AND FEATURES ................................................................. 10
SERVICE AND REPAIR...................................................................................... 11
RETURNING UNITS FOR REPAIR .................................................................... 12
WARRANTY .......................................................................................... Back cover