Lectrosonics MM400a


Lectrosonics MM400a


The Lectrosonics MM400a is a water resistant belt pack transmitter

The Digital Hybrid Wireless design combines 24-bit digital audio with analog FM techniques to provide the operating range of the finest analog wireless systems and the audio quality of a pure digital system. The 100 mW RF output power extends operating range, and DSP controlled, dual-envelope limiter cleanly handles input peaks to allow higher gain settings. 

Available with the VT500 water resistant lav mic. 

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  • RF Carrier Frequency Range: Block 26 (665.600 - 691.100 MHz) 
  • 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. (in 400 Series Mode)
  • Spurious radiation: 60 dB below carrier
  • Equivalent input noise: –118 dBV, A-weighted
  • Input level: Nominal 2 mV to 300 mV, before limiting. Greater than 1.5V maximum, with limiting.
  • Input impedance: 2 kOhm Input limiter: Soft limiter, >30 dB range
  • Gain control range: 43 dB; semi-log rotary control
  • Modulation indicators: Dual bicolor LEDs indicate modulation of –20, -10, 0, +10 dB referenced to full modulation.
  • Low frequency roll-off: –12 dB/octave; 70 Hz
  • Controls: Front panel knob adjusts audio gain. Rotary switches on bottom panel adjust transmitter frequency.
  • Audio Frequency Response: 70 Hz to 20 kHz, +/-1dB (The audio is deliberately rolled off at 70 Hz using a 12 dB/octave filter. This filter cannot be disabled.)
  • Signal to Noise Ratio (dB): (overall system, 400 Series mode) SmartNR No Limiting W/ Limiting OFF 103.5 108.5 NORMAL 107.0 111.5 FULL 108.5 113.0 (Note: The dual envelope “soft” limiter provides exceptionally good handling of transients using variable attack and release time constants. The gradual onset of limiting in the design begins below full modulation, which reduces the measured figure for SNR without limiting by 4.5 dB)
  • Total Harmonic Distortion: 0.2% typical (400 Series mode)
  • Audio Input Jack: 2.5 mm Microjack (matches Switchcraft 850 Microplug)
  • Antenna: Detachable, flexible bronze wire supplied. 50 Ohm port allows connection to test equipment.
  • Battery: 1.5 Volt AA lithium recommended
  • Battery Life: 2 hours (alkaline); 4.5 hours (lithium); NiMH: 3.5 hours Weight: 3.6 ozs. (102 grams) with lithium battery, no antenna
  • Overall Dimensions: 3.03 x 2 x 0.69 inches (not including microphone or antenna)