Lectrosonics H187 User manual

Quick
Start
Guide
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This guide is intended to assist with
initial setup and operation of your
Lectrosonics product.
For a detailed user manual, down‑
load the most current
version at:
www.lectrosonics.com/manuals
Narrowband Plug-OnTransmiter
H187
06 jun10
U.S. Patent 7,225,135

LECTROSONICS, INC.2
Controls and Functions
Power LED
Modulation LEDs Input Jack
Battery Door
AUDIO LEVEL Control

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Input Jack
Standard 3‑pin Switchcraft XLR type. The H187 is self‑locking onto a stan‑
dard microphone.
Power/Mute Switch
Turns the battery power on and off. The center position is an “audio mute”
which should be used when setting the MIC LEVEL control.
When turning the transmitter on, pause for a moment in the “mute”
position. This will prevent a turn‑on surge from occurring (a “thump”
sound).
Power LED
Indicates power status and battery strength. A weak or dim LED means that
the battery is weak, and has about an hour of operation left.
Audio Level Control
The front panel AUDIO LEVEL Control is used to adjust the incoming audio
input level for proper modulation.
Modulation LEDs
The two bicolor Modulation LEDs provide a visual indication of the input audio
signal level from the microphone.
Level LED
Flickers or glows all the time if the audio volume is adequate for normal op‑
eration.
Limit LED
Lights up when the audio volume is high, indicating that the signal level is be‑
ing limited by the compressor.
Mic Level
Used to adjust the audio input volume for the proper modulation level.
Rotate knob until the LEVEL LED flickers when there is an input signal.
The LIMIT LED should light occasionally.

LECTROSONICS, INC.4
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.
TO AT TACH
TO REMOVE
Hold the
transmitter
case with the
microphone
pointed
upward.
Rotate the
collar in the
direction
shown.
Pull on mic to ensure it is locked.
Press firmly, listen for click.
Depress collar fully.
Click!
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.
POWER
ON/OFF
LED
Top View
MODULATION LEDS
-10 -20
5) Move switches to “ON” position on both the transmitter 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.

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Operating Notes
If the mic level is too high — the LIMIT LED 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 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 compromised 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 being fully modulated.

LECTROSONICS, INC.6
Battery Replacement
The H187 transmitter is powered by a standard alkaline of Li Polymer rechar‑
gable 9 Volt battery. It is important that you use ONLY these battery types for
longest life. Standard zinc‑carbon batteries marked “heavy duty” or “long‑
lasting” are not adequate. They will provide only about 4 hours of operation.
Similarly, nicad rechargeable batteries only give 4 hours of operation, and
will also run down quite abruptly. Alkaline batteries provide about 14 hours of
operation.
To open the battery compartment, press outward on the cover door in the
direction of the arrow as shown in the drawing. Only slight, sliding pressure is
needed to open and close the battery door.
Swing the door open and take note of the polarity marked inside showing the
location of the positive (+) and negative (‑) terminals. Insert the battery and
close the cover by pressing in and across, reversing the opening procedure
outlined above. Note that the battery door will NOT close if the battery is
inserted incorrectly, since the terminals will hit a protective polarity barrier.

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