Operating Instructions - Lectrosonics H187 Instruction Manual

H187

Operating Instructions

1) Insert the H187 into the selected microphone.
Listen for the "click" that indicates the H187 has
locked on to the microphone. Pull on the mic to
insure proper locking has occurred.
2) Turn the power switch to the "MUTE" position on
both the transmitter and the receiver. The "MUTE"
position allows internal voltages to stabilize before
audio signal paths are opened.
3) Hold the microphone as you will when you will be
using it.
4) Speak as loudly as you expect to speak 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 (about 10-
15% of the time) indicates proper operation and
optimum signal-to-noise ratio. Even when the
transmitter is limiting, little distortion is produced
because of the high linearity of the gain control
circuit in the H187.
5) Move switches to "ON" position on both the trans-
mitter and the receiver and adjust the volume of the
sound system.
NOTE: The MIC LEVEL control should not be
used to control the volume of your sound system.
This is accomplished using the level control on the
receiver, or a level control on the mixing console.
Press firmly, listen for click.
Depress collor fully.
Pull on mic to insure locking.
6
TO ATTACH
If the mic level is too high — the LIMIT LED 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 will
cause hiss and noise. You may experience severe
reduction in apparent range if the modulation level is
too low. It may sound as if you are getting dropouts.
What is actually happening is that you are hitting your
noise floor because the S/N ratio has been compro-
mised by the low modulation.
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 fully modulated.
TO REMOVE
Hold the transmitter
case and rotate the
collar in the direction
shown. Do this over
a soft surface as the
microphone may pop
off suddenly.
LECTROSONICS, INC.