Lectronics DBu, Инструкция по эксплуатации

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Digital Belt-Pack Transmitter
Rio Rancho, NM 3
DBu, DBu/E01 Block Diagram
Filters
Keypad
3V
Battery
Oscillator
VCTXO
I2S
I2S
Voltage Controlled
Oscillator
Final
Amplifier Control
PLL Ref
Phase Locked Loop
System Cloc
k
Switching
Power
Supply
Microprocessor
D-A Convert-
er
A-D
Converter
Shunt
Limiter
Limiter Control
Gain
Adj
HI/Lo
Pass
Filter
Input
Preamp
5 Pin
Jack
0, 2 or 4V
I + Q
Baseband
Signals
Low
pass
filters
IQ Modulator
Audio
Firmware
Update
Key Received
Blue LED
Low
Pass
Filter
Buffer
36.864 mHz
2-way
IR Port
FPGA
-
.
4
5
5
+5V
Servo Bias
Supply
UART
USB
Jack
Security Key
Servo Bias
Voltage
DBu Transmitter
Consumer Alert for US Users - FCC Order DA 10-92
Most users do not need a license to operate this wireless microphone system. Nevertheless, operating this microphone system
without a license is subject to certain restrictions: the system may not cause harmful interference; it must operate at a low power
level (not in excess of 50 milliwatts); and it has no protection from interference received from any other device. Purchasers should
also be aware that the FCC is currently evaluating use of wireless microphone systems, and these rules are subject to change.
For more information, call the FCC at 1-888- CALL-FCC (TTY: 1-888-TELL-FCC) or visit the FCC’s wireless microphone website at
www.fcc.gov/cgb/wirelessmicrophones. To operate wireless microphone systems at power greater than 50mW, you must qualify
as a Part 74 user and be licensed. If you qualify and wish to apply for a license go to: http://www.fcc.gov/Forms/Form601/601.
html
Servo Bias Input and Wiring
The DBu, DBu/E01 input preamp is a unique design that
delivers audible improvements over conventional trans-
mitter inputs, is easier to use and much harder to over-
load. It is not necessary to introduce pads on some mics
to prevent overload of the input stage, divide the bias
voltage down for some low voltage mics, or reduce the
limiter range at minimum gain settings.
Two different microphone wiring schemes are available
to simplify and standardize the configuration. Simplified
2-wire and 3-wire configurations provide several arrange-
ments designed for use only with servo bias inputs to
take full advantage of the preamp circuitry. Other wiring
schemes are compatible with Servo Bias and conven-
tional inputs.
A line level input wiring provides an extended frequency
response with an LF roll-off at 35 Hz for use with instru-
ments and line level signal sources.
DSP-controlled Input Limiter
The transmitter employs a digitally-controlled analog
audio limiter prior to the analog-to-digital converter.
The limiter has a range greater than 30 dB for excellent
overload protection. A dual release envelope makes the
limiter acoustically transparent while maintaining low
distortion. It can be thought of as two limiters in series,
connected as a fast attack and release limiter followed
by a slow attack and release limiter. The limiter recovers
quickly from brief transients, so that its action is hidden
from the listener, but recovers slowly from sustained high
levels to keep audio distortion low and preserve short
term dynamic changes in the audio.