Lectrosonics M185 - Manual (Page 7)

OPERATING INSTRUCTIONS
1) Insert the microphone plug into the input jack, aligning the pins; be sure that the connector locks in.
2) Turn the power switch to the "MUTE" position on the transmitter. The "MUTE" position allows
internal voltages to stabilize before audio signal paths are opened.
3) Position the microphone in the location you will use in actual operation.
4) Keeping the power switch in the "mute" position, speak as loudly as you expect you will in normal
system use. Rotate the MIC LEVEL knob so that the LEVEL LED flickers or stays lit as you speak.
The LIMIT LED should light up on loud "peaks." Occasional lighting of the LIMIT LED indicates proper
operation and optimum signal-to-noise ratio. Even when limiting is occurring, little or no distortion will
occur, due to the high linearity of the limiting circuitry in the M185. The input limiter will cleanly handle
peaks up to 20dB above full modulation.
5) Set up the receiver according to the receiver manual.
6) Move the switch to the "ON" position on the transmitter, verify that the modulation LEDs indicate
normally and adjust the volume of the sound system, or the record level of your recorder.
NOTE:
Do not use the MIC LEVEL control to control the volume of your sound system or the record
level on your recorder. This control should be set only as described in #4 above.
If the mic level is too high -- the LIMIT LED will light will light frequently or stay on. This condition may
cause distortion.
If the mic level is too low -- neither LED will light or the LEVEL LED will light dimly. This condition may
cause hiss and noise in the audio.
The LEVEL LED turns on at -10dB below full deviation. The LIMIT LED turns on at full deviation and
indicates that the input shunt compressor is operating. The input compressor operates over a full 20
dB range regardless of the gain control setting. The compressor uses a true absolute value circuit to
detect both positive and negative peaks. The attack time is 2 milliseconds and the release time is 80
milliseconds. Occasional limiting is desirable, indicating that the gain is correctly set and the transmitter
is being fully modulated.
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