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.
MM400B 2 LECTROSONICS, INC.
Watertight Miniature UHF Belt-Pack Transmitter Thank you for selecting the Lectrosonics MM400B watertight miniature transmitter.
MM400B 4 LECTROSONICS, INC.
Watertight Miniature UHF Belt-Pack Transmitter Table of Contents General Technical Description .............................................................................................................................................................. 6 General ................................................................................................................................................................................................. 6 Digital Hybrid Wireless™ Technology* ..............
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.
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.
MM400B Controls and Functions Power ON/OFF Switch 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.
Watertight Miniature UHF Belt-Pack Transmitter Mic Jack Frequency Select Switches 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 (Lec trosonics P/N 21357) can be used in an emergency though it is not waterproof. (See Replacement Parts and Accessories.
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.
Watertight Miniature UHF Belt-Pack Transmitter Operating Instructions Switch settings to one of the following positions: 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).
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.
Watertight Miniature UHF Belt-Pack Transmitter Power Switch Function Selection Frequency Switch Cover Plate 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.
MM400B Replacing the Power Switch Magnet Housing Assembly Although the Power Switch’s Magnet Housing Assem bly 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.
Watertight Miniature UHF Belt-Pack Transmitter Microphone RF Bypassing 2 WIRE MIC Some mics require RF protection to keep the radio signal from affecting the capsule, even though the transmitter input circuitry is already RF bypassed. Preferred location for bypass capacitors 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.
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 rang
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 POSSIBLE CAUSE TRANSMITTER PWR LED OFF 1) Battery is inserted backwards. 2) Battery is dead. 3) Power ON/OFF switch configured to Normal Mode and is set to OFF.
MM400B 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: RF Power output: Pilot tone: Frequency stability: Deviation: Spurious radiation: Equivalent input noise: Input level: Input impedance: Input limiter: Gain control range: Modulation indicators: Low frequency roll-off: Controls: 537.600 - 563.100 563.200 - 588.700 588.800 - 607.900 and 614.100 - 614.300 614.400 - 639.900 640.000 - 665.500 665.
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 interconnect ing cables and then go through the Troubleshooting section in this manual.
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.
