Lectrosonics Inc UM450V 사용자 설명서
UM450
LECTROSONICS, INC.
6
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5-Pin Input Jack Wiring for details.
Introduction
The 400 system uses 75 kHz wide deviation for an
extremely high signal to noise ratio. The switching
power supplies provide constant voltages to the trans-
mitter circuits from the beginning (9.3 Volts) to the end
(5.5 Volts) of battery life. The input amplifier uses an
ultra low noise op amp for quiet operation. It is gain
controlled with a wide range dual envelope input
compressor which cleanly limits input signal peaks over
30 dB above full modulation.
extremely high signal to noise ratio. The switching
power supplies provide constant voltages to the trans-
mitter circuits from the beginning (9.3 Volts) to the end
(5.5 Volts) of battery life. The input amplifier uses an
ultra low noise op amp for quiet operation. It is gain
controlled with a wide range dual envelope input
compressor which cleanly limits input signal peaks over
30 dB above full modulation.
Digital Hybrid Technology
All wireless links suffer from channel noise to some
degree, and all wireless microphone systems seek to
minimize the impact of that noise on the desired signal.
Conventional analog systems use compandors to
improve the signal to noise ratio, at the cost of subtle
artifacts (known as “pumping” and “breathing”). Wholly
digital systems defeat the noise by sending the audio
information in digital form, at the cost of some combina-
tion of power, bandwidth and resistance to interference.
degree, and all wireless microphone systems seek to
minimize the impact of that noise on the desired signal.
Conventional analog systems use compandors to
improve the signal to noise ratio, at the cost of subtle
artifacts (known as “pumping” and “breathing”). Wholly
digital systems defeat the noise by sending the audio
information in digital form, at the cost of some combina-
tion of power, bandwidth and resistance to interference.
The Lectrosonics Digital Hybrid system overcomes
channel noise in a dramatically new way, digitally
encoding the audio in the transmitter and decoding it in
the receiver, yet still sending the encoded information
via an analog FM wireless link. This proprietary algo-
rithm is not a digital implementation of an analog
channel noise in a dramatically new way, digitally
encoding the audio in the transmitter and decoding it in
the receiver, yet still sending the encoded information
via an analog FM wireless link. This proprietary algo-
rithm is not a digital implementation of an analog
UM450 Block Diagram
General Technical Description
compandor but a technique which can be accomplished
only in the digital domain, even though the inputs and
outputs are analog signals. (As of this writing, the
patent is still pending, so we cannot reveal detailed
information about the algorithm at this time.)
only in the digital domain, even though the inputs and
outputs are analog signals. (As of this writing, the
patent is still pending, so we cannot reveal detailed
information about the algorithm at this time.)
Channel noise still has an impact on received signal
quality and will eventually overwhelm the receiver. The
Digital Hybrid simply encodes the signal to use a noisy
channel as efficiently and robustly as possible, yielding
audio performance that rivals that of wholly digital
systems, without the power and bandwidth problems
inherent in digital transmission. As always, these
advantages come at a cost. The Digital Hybrid system
requires fairly intensive digital processing in both the
transmitter and the receiver. These processors cost
money, take up space and consume power. The Digital
Hybrid system also requires that the underlying RF link
be of excellent quality, with better frequency response
and distortion characteristics than that required by
conventional systems.
quality and will eventually overwhelm the receiver. The
Digital Hybrid simply encodes the signal to use a noisy
channel as efficiently and robustly as possible, yielding
audio performance that rivals that of wholly digital
systems, without the power and bandwidth problems
inherent in digital transmission. As always, these
advantages come at a cost. The Digital Hybrid system
requires fairly intensive digital processing in both the
transmitter and the receiver. These processors cost
money, take up space and consume power. The Digital
Hybrid system also requires that the underlying RF link
be of excellent quality, with better frequency response
and distortion characteristics than that required by
conventional systems.
Because it uses an analog FM link, the Digital Hybrid
enjoys all the benefits of conventional FM wireless
systems, such as excellent range, efficient use of RF
spectrum, and long battery life. However, unlike con-
ventional FM systems, the Digital Hybrid has done away
with the analog compandor and its artifacts.
enjoys all the benefits of conventional FM wireless
systems, such as excellent range, efficient use of RF
spectrum, and long battery life. However, unlike con-
ventional FM systems, the Digital Hybrid has done away
with the analog compandor and its artifacts.