Lectrosonics UH100 - Manual (Page 4)

CONTROLS AND FUNCTIONS
The UH100 may be used with a wide variety of microphones.
The 3-pin XLR connector on the UH100 allows the transmitter to
be used with any dynamic microphone, as well as many two wire
positive bias lavalier systems (such as those systems supplied
by Lectrosonics).
INPUT JACK
Standard 3-pin Switchcraft XLR type. Pin 2 is signal, pin 3 is a
floating signal ground, and pin 1 is case ground (see schematic
below). The UH100 is self-locking onto a standard microphone.
The XLR connector is permanently bonded to the metal collar,
and is not normally replaceable. The electret bias is 5 Volts at
1mA or less. The bias is connected in a “phantom” manner and
will not interfere with any standard balanced microphone. If
severe noise is experienced when the microphone is moved
with respect to the UH100, the cause is an unbalanced
condition between pins 2 and 3 of the microphone.
To Mic
Preamp
1uh
1 2
3
1uh
1uh
1K 100
+5V
100uf
Input Jack Schematic
POWER SWITCH
Turns the battery power on and off.
POWER ON/OFF LED
Glows brightly when battery is good. A weak or dim LED means
that the battery is weak, and has about an hour of operation left.
If the LED fails to light, the battery should be replaced.
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 5 hours the battery voltage will be about 7 Volts. The LED
will be completely extinguished. Since the internal circuits are
all tightly regulated and the RF output stage has a separate
discrete regulator, the transmitter will continue to operate to a
TOP VIEW CONTROL PANEL
LIMIT LED
LEVEL LED
O N
O F F
L E V E L
BATTERY
POWER
LED
battery voltage of 6.5 Volts. From 6.5 Volts to 6 Volts, the
transmitter will still operate, but with degraded performance.
Please note that a weak battery will sometimes light the POWER
LED immediately after turn on, but soon will discharge to the
point where the LED will extinguish.
The combination of an accurate battery condition indicator and
regulation of all internal circuits guarantees much longer battery
life, as well as consistent performance versus battery life.
MODULATION LEDS: Indicate the proper setting of the MIC
LEVEL control.
LEVEL LED: Flickers or glows most of the time if the audio
volume is adequate for normal operation.
LIMIT LED: Lights up when the audio volume is high, indicating
that the signal level is being limited by the compressor. Opti­
mum signal-to-noise ratio is obtained when the limit LED lights
occasionally.
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.
FREQUENCY ADJUST
These two rotary switches adjust the center frequency of the
carrier. The 1.6M is a coarse adjustment and the 100K is the fine
adjustment. Each transmitter is factory aligned at the center of
its operating range. The default position of the frequency select
switches is in the center of the transmitter’s range.
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
Frequency select switches, default position (8,8)
4