Lectrosonics M175-LS VHF Belt Pack Transmitters with Mute Switch, 171.045 MHz Operating Frequency

The Lectrosonics M175LS Belt Pack Transmitters with 171.045 MHz operating frequency provides noiseless muting of the audio, while leaving the transmitter carrier turned on, which is often desirable when used with the Long Ranger sound system. The audio input section includes a high quality, low noise preamp with a wide range input limiter to prevent distortion during loud peaks in the audio. A wide range input gain control accommodates essentially any lavalier or headset microphone that use an electret capsule. High output dynamic microphones and modest line level signals can also be used.

Noise and hiss is reduced to very low levels with a type of noise reduction called a "compandor." The compandor processing is idealized for human voice to keep distortion at extremely low levels. The transmitter operates on a standard 9 volt alkaline or lithium battery. Battery status is indicated by the varying brightness of an LED on the control panel. The battery door rotates to open and close and remains attached to the housing at all times. Self adjusting battery contacts and firm pressure applied by the door assure reliable contact with any known 9 volt battery.

The housing is constructed of extruded and machined aluminum with durable powder coated and anodized finishes. Control panel nomenclature is laser etched into the finish for lasting ruggedness in the field. The control panels on the transmitters are straightforward layouts and easy to use, even at first glance. Power is turned on and off with a rugged slide switch, mounted in a position that easy to reach, yet at a low enough profile to prevent accidental operation. This model includes a bat handle toggle switch for audio muting that can be operated without having to view the transmitter, even under clothing. The input gain is adjusted with a recessed pot using a screwdrive supplied with the transmitter. Once set to match a particular user's voice and microphone, this control needs no regular adjustment, so it is recessed below the panel surface to prevent accidental adjustment.