Lectrosonics FM870 - Manual (Page 6)

M170 SERIES TRANSMITTERS
Standard FM-AV4 systems include an M170 belt-pack transmitter which is designed to be used with a
lavalier or headset microphone. The optional M170-XLR transmitter (see page 6) is similar to the M170
but is equipped with two microphone connectors - a locking micro jack for lavalier or headset microphones
and an XLR connector for use with standard low impedance hand held microphones. If you have one of
the other optional Lectrosonics transmitters, consult the supplied manual for that transmitter for the
description and operating instructions.
The POWER ON/OFF switch, located on the side opposite the belt clip, turns the power on and off. The
switch should be left in the OFF position when the transmitter is not in use. The red LED above the on/off
switch indicates the condition of the battery. As long as this LED glows, even dimly, the battery is sufficient
to operate the transmitter.
The GAIN ADJUSTMENT matches the audio gain of the transmitter to different microphones, individual
voices, and other inputs. (see item 10 and 11 on page 10 in the section on OPERATING INSTRUCTIONS).
This adjustment is extremely important.
The BATTERY ACCESS THUMB SCREW is turned counterclockwise to remove the side cover to replace
the battery. The battery will only fit in one way. Observe the battery contact pad before inserting the
battery. The positive contact is the smaller one and fits into the compartment closest to the bottom of the
transmitter. Insert the battery contact end first, then push down the other end for a snug fit. To remove
the battery, push the exposed bottom edge of the battery with your fingernails toward the contacts and lift
it up and out.
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