Lectrosonics FM870 - Manual (Page 11)

OPERATING INSTRUCTIONS
This section covers the initial adjustments to the FM870 and the companion transmitter that must be made
before the system is placed into operation:
1) Make sure the antenna is extended fully.
2) Connect the audio output cable as required. If you are connecting into a "house" sound system or
external audio or recording equipment, make those connections before turning on the power.
3) Turn both volume controls on the FM870 control panel to minimum (fully counter-clockwise).
4) Rotate the FM870 power/function switch to OPERATE. Verify that the POWER lamp lights.
5) Position yourself behind the FM870 (or sound system speakers) so that the sound from the speaker
output will be directed away from the microphone.
6) Plug your microphone into the transmitter. Rotate the plug clockwise to make sure the connection is
locked. Do not over-tighten the plug.
7) Turn the transmitter power on and verify that the red light on it lights. If the lamp is very dim or does
not light, replace the battery.
8) Observe that the RF lamp on the FM870 control panel is lighted. This verifies that the unit is receiving
a useable signal from the transmitter.
9) Position the microphone on your person in the same location it will be in during actual operation. The
microphone should ideally be within 6 to 10 inches from the mouth to minimize "feedback".
10) A small screwdriver is supplied with the transmitter. The screwdriver is used to adjust the audio gain
of the transmitter to match the microphone with your voice. The adjustment is made while observing
the MODULATION lamps on the FM870 control panel as shown in the figure on page 11.
11) Speak at the voice level you will be using during actual operation. While speaking, adjust the
transmitter gain until the -20 lamp is lighted or flickers and LIMIT lamp blinks only on the loudest
words. Raise and lower your voice while observing the lamps. The LIMIT lamp should only blink
occasionally.
12) You may now adjust the WIRELESS MIC VOLUME control to a level which will allow everyone in the
audience to hear clearly.
REMEMBER--the transmitter gain control is used only to adjust for proper MODULATION lamp indications.
DO NOT use it to adjust the output volume of the FM870. Different voices and different microphones will
usually require readjustment of the transmitter gain control, so check the adjustment frequently. If several
different people will be using the system and there is not time to make the adjustment for each individual,
adjust it for the loudest voice.
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