Lectrosonics UH200d - Manual (Page 5)

Frequency Agile Plug-on UHF Transmitter
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 UH200D is self-locking onto a standard microphone.
If severe noise is experienced when the microphone is moved
with respect to the UH200D, the cause is an unbalanced
condition between pins 2 and 3 of the microphone.
To Mic +5V / +15V / +42V
1 2
3
4.7uf
1uh
1uh
1uh
Preamp
1000
I
Input
Jack
Schematic
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 should light up in both the “PHTM” and “NO PHTM”
positions of the PWR switch.
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 4.5 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 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
These two 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, indicat­
ing that the signal level is being limited by the compressor.
Optimum signal-to-noise ratio is obtained when the limit LED
lights occasionally.
MIC LEVEL
This knob is 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)
Rio Rancho, NM – USA 5