Frequency Agile UHF Miniature Belt-Pack Transmitter MM400A DIGITAL HYBRID WIRELESSTM MINIATURE UHF BELT-PACK TRANSMITTER OPERATING INSTRUCTIONS LECTROSONICS, INC. Rio Rancho, NM www.lectrosonics.
MM400A The MM400 transmitter is FCC type accepted under Part 74: 536-608 MHz and 614-806 MHz 2 LECTROSONICS, INC.
Frequency Agile UHF Miniature Belt-Pack Transmitter Thank you for selecting the Lectrosonics MM400A miniature transmitter.
MM400A GENERAL TECHNICAL DESCRIPTION GENERAL The 400 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.
Frequency Agile UHF Miniature Belt-Pack Transmitter NO PRE-EMPHASIS/DE-EMPHASIS The signal to noise ratio of the 400 system is high enough to preclude the need for conventional preemphasis (HF boost) in the transmitter and de-emphasis (HF roll off) in the receiver.
MM400A CONTROLS AND FUNCTIONS AUDIO LEVEL ANTENNA MIC JACK MODULATION LEDs –10 –20 POWER POWER LED FREQUENCY SELECT SWITCH COVER PLATE BATTERY COMPARTMENT 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.
Frequency Agile UHF Miniature Belt-Pack Transmitter kit. (See WPMC-3 and WPMC-10 in Accessories Catalog.) ANTENNA A Switchcraft 850 connector can be used in an emer gency though it is not waterproof. AUDIO LEVEL Used to adjust the audio input level for the proper modulation. MODULATION LEDS The Modulation LEDs indicate the proper setting of the MIC LEVEL control. There are two bicolor modulation LEDs that can glow either red or green depending on the amount of gain applied.
MM400A BATTERY INSTALLATION 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.
Frequency Agile UHF Miniature Belt-Pack Transmitter OPERATING INSTRUCTIONS 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.
MM400A with the number of blinks listed in Step 1. The mode setting will remain the same until you reset it with the procedure listed above. ADJUSTING THE TRANSMITTER FREQUENCY If you are experiencing interference from another signal on your frequency, you may want to change the operat ing frequency of your system. The left switch (COARSE) changes the operating frequency by large increments and the right switch (FINE) changes it in small incre ments.
Frequency Agile UHF Miniature Belt-Pack Transmitter OPERATING NOTES 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. If the audio level is too high — both red LEDs will light frequently or stay lit. This condition may reduce the dynamic range of the audio signal.
MM400A 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 POSSIBLE CAUSE TRANSMITTER BATTERY LED OFF 1) Battery is inserted backwards. 2) Battery is dead. NO TRANSMITTER MODULATION LEDs 1) 2) 3) 4) RECEIVER RF LAMP OFF 1) 2) 3) 4) NO SOUND (OR LOW SOUND LEVEL), RECEIVER INDICATES PROPER AUDIO MODULATION Gain control turned all the way down.
Frequency Agile UHF Miniature Belt-Pack Transmitter SPECIFICATIONS AND FEATURES Operating frequencies: Block 21 Block 22 Block 23 Block 24 Block 25 Block 26 Block 27 Block 28 Block 29 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.
MM400A 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 out the intercon necting cords and then go through the TROUBLESHOOTING section in the 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.
LIMITEDONE ONE YEAR LIMITED YEARWARRANTY 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.
