Lectrosonics M170XLR - Manual (Page 3)

GENERAL DESCRIPTION
The M170 Series transmitter is offered in five versions. The standard model is the M170. The
M170-LS, M170-XLR, M170-BGO, and the M170-CTM are modifications of the standard M170.
The M170 and M170-LS transmitters use the microphone cord for the antenna. The M170-XLR uses
the hand-held microphone for the antenna. This feature eliminates the need for the "dangling wire"
antenna found on many transmitters. The walnut body of the M170-CTM is securely attached to a
machined aluminum plate which serves as the antenna ground plane and as mass to absorb vibration.
The M170 Series transmitters use a crystal controlled oscillator and temperature compensation circuitry
to ensure that the transmitter does not drift over time or with age.
To suppress audible noise, a "compandor" noise reduction circuit is used which is compatible with all
Lectrosonics 170 series or 185 series receivers. In addition, the input limiting circuit will absorb 12 dB
of overload without distortion. The audio circuitry is extremely quiet, with low distortion for natural
reproduction of either voice or music. The wide input adjustment range of M170 Series transmitters
allows the use of virtually any microphone on the market and with line level inputs such as tape
recorders or musical instruments.
The M170 Series transmitters operate from a replaceable standard 9 Volt alkaline battery. A precision
battery test circuit continuously monitors the battery voltage. A highly visible LED glows as long as the
battery voltage is high enough to operate the transmitter. A 9 Volt alkaline battery will provide up to 15
hours of operation.
The electret microphone input jack provides 5 Volts DC positive bias for all Lectrosonics electret
microphones. Many other electret microphones may be adapted to the M170 Series by making simple
wiring changes in the microphone connector.
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