Lectrosonics M175LS, M175 Data Sheet

M175/M175-LS

VHF Belt Pack Transmitters

TECHNICAL DATA

Feature Highlights

• Crystal controlled VHF frequencies

• Full 50 mW power output

• Uses input cable shield as antenna

• Wide range input limiter for low distortion
and maximum signal to noise ratio

• 43 dB range on input gain control

• LED battery status indicator

• Self-adjusting battery compartment
accommodates all makes of 9 volt
alkaline and lithium batteries

• Machined aluminum housing, panels and
rotating battery door

• Laser etched nomenclature

The M175 belt-pack transmitter is a VHF crystal con­trolled design for use with Lectrosonics 175 or 187 Series
receivers and the Long Ranger portable sound system.
The machined aluminum housing and spring-loaded belt
clip provide a rugged package well suited for professional
use. The M175 is a basic model with a single on-off
switch. The M175LS model includes a toggle switch that
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 extremelly 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 M175 provides 50 mW of output power and is
available on a wide range of VHF frequencies. The band
of frequencies between 169 and 172 MHz are low pow­ered allocations that can be used anywhere in the USA.
For television production, the M175 is also available on
VHF frequencies from 174 to 216 MHz, which covers TV
station broadcasts in the USA on channels 7 through 13.

The housing is contructed 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.

Rio Rancho, NM, USA
www.lectrosonics.com

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. The LS 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.

LECTROSONICS

M175

ON

PWR

OFF

+

MIC

LEVEL

–

MIC

AUDIO

OFF

ON

PWR

OFF

+

MIC

LEVEL

–

MIC

LECTROSONICS

M175-LS

The battery door rotates to open and close and
remains attached to the housing at all times.

Specifications

Operating frequencies: 150 to 216 MHz
RF Power Output: 50 mW
Deviation: ±15kHz
Spurious Radiation: 50dB below carrier
Frequency Stability: ±0.005%
Equivalent Input Noise: -123dB
Input Sensitivity: 8mV to 1.6V for full modulation
Input Compressor: Soft Compressor; 12dB range
Electret Bias: +5 Volt DC (positive bias)

581 Laser Road NE • Rio Rancho, NM 87124 USA • www.lectrosonics.com
[phone] • [phone] • fax [phone] • [e-mail]

Antenna: Input cord or microphone body
Input Jacks: Twist-lock micro for electret microphones
Battery Indicator: LED indicates battery condition
Battery Life: Approximately 15 hours
Controls: Power on/off slide switch

Recessed audio gain control
Mute on/off toggle switch (M175-LS only)

Size: 1.3 x 2.35 x 3.7 inches
Weight: 6.6 ozs with battery and microphone

September 1, 2005