Lectrosonics M187 - Manual (Page 7)

Belt-Pack Transmitter
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 M187. The input limiter will cleanly handle peaks up to 35dB 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 distor­
tion.
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 35dB 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.
Rio Rancho, NM – USA 7