Lectrosonics CR175 - Manual (Page 4)

CONTROLS AND FUNCTIONS - FRONT PANEL
MODULATION LEDs
Indicate the modulation (audio level) of the incoming signal, and can be used for proper adjustment of the
transmitter’s “MIC LEVEL” or “GAIN”. The -20 LED glows when the transmitter modulation is at a high enough level to
produce a good audio signal-to-noise ratio. It will normally flicker, or stay lit as you speak into the microphone. The
0dB lamp indicates a “peak,” showing that the transmitter modulation is at maximum. Constant lighting may indicate
that the audio gain in the transmitter may be set too high. It is normal and desirable that you see an occasional flicker
of the 0dB lamp in typical use.
OUTPUT CONTROL
Attenuates the audio output level of the receiver to match the input requirements of the equipment with which it is
used. The XLR output jack on the rear panel provides an audio output at microphone level for low impedance,
balanced inputs. At the extreme counter-clockwise position of the control knob, the output level of this XLR jack will
be 50dB at full modulation. In the fully clockwise position, the output level will be -20dB at full modulation. Intermedi­
ate settings are sometimes necessary due to the variations in different input compressors and ALC (automatic level
control) circuits on various VCR’s and audio inputs. The markings around the control knob are provided simply as
“memory markers;” they are not calibrated with reference to a specific output level.
OFF/ON POWER SWITCH
Turns the receiver power off and on.
POWER LED
Glows when the power switch is in the proper position and the battery is good, or when external 12 Volt DC power is
properly supplied. If this LED is very dim or does not light up when the switch is turned on, replace the battery or
check the connections from the external power source. The LED glows brightly to indicate a good battery and dims
as the battery voltage decreases.
The POWER LED is connected to a precision battery test circuit that continuously monitors battery voltage. The LED
is at full brightness with a new 9 volt alkaline battery. As the battery voltage drops during use, the LED brightness will
also decrease. After 4 to 5 hours, the battery voltage will be about 7 volts. The LED will be completely extinguished.
IMPORTANT!
When the battery voltage drops below 6 Volts, the power LED will remain off, but the other
3 LEDs will light up and a loud rush of audio noise will be heard as the squelch opens.
This condition is normal, and is easily remedied by replacing the battery.
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