Controls and functions, Input jack, Power on/off switch – Lectrosonics UM400a User Manual
Page 6: Power on led, Frequency select switches

UM400a
LECTROSONICS, INC.
6
Input Jack
The input on the UM400a accommodates virtually every
lavaliere, hand-held or shotgun microphone available.
Different line level signals can also be accommodated.
(See Wiring Hookups for Different Sources
.)
Power ON/OFF Switch
Turns the transmitter on and off. Even when the switch
is turned off or on abruptly, the pilot tone muting system
prevents “thumps” or transients from occurring.
Power On LED
The Power LED glows green when the battery is good
and the transmitter is turned on. The LED will glow
yellow/orange as the battery voltage drops and finally
glows red when there are about 30 minutes of operation
left (when using the recommended battery). The LED
blinks red when there are only a few minutes of life left.
Input Jack
Power ON/OFF Switch
AUDIO LEVEL Control
Modulation LEDs
ANTENNA Jack
Power LED
1.6. . . . . . . . 100K
Frequency Select Switches
0 1
2
3
4
5
6
7
8
9
A
B
C
D
E
F
0 1
2
3
4
5
6
7
8
9
A
B
C
D
E
F
Low Frequency Roll Off
Control
Controls and Functions
NOTE: While a NiMH battery provides long
operating time, it will give little or no warning
before it is depleted. If you use a NiMH battery in
the UM400a, we recommend trying a fully charged
battery in the unit, noting the length of time that it
will run the unit, and in the future use somewhat
less than that time to determine when the battery
needs to be replaced. Digital Hybrid receivers
include timers to accurate track battery usage.
A weak battery will sometimes light the Power LED to
the “good” green indication immediately after being put
in the unit, but will quickly discharge to the point where
the LED will go red or shut down (just like a flashlight
with “dead” batteries). If the lamp fails to light, the bat-
tery should be replaced.
Frequency Select Switches
Two 16-position rotary switches adjust the center
frequency of the carrier. The left-hand switch 1.6 MHz
steps and the right-hand switch makes 100K steps.