Lectrosonics DCR822-A1B1 Instruction Manual page 5

The DCR822 digital 2-channel receiver is the true suc-
cessor to the venerable UCR411a - a dual-channel pack-
age in the same size - and represents state-of-the-art RF
performance with Vector Diversity (an advanced type of
true diversity) and extremely robust front-end architec-
ture, bringing the highest level of RF and audio perfor-
mance to field and location production.
Extremely high Third Order Intercept (IP3) performance of
+15 dBm, 24-bit/48 kHz audio performance, and AES-
256 CTR mode encryption ensure that professionals in
all audio disciplines have the tools needed to get the job
done, even in extremely tough environments. On-board
recording in .WAV (BWF) format via microSDHC card give
this receiver unique possibilities for different workflows.
Compatibility Modes
The DCR822 receiver was designed to operate with
Lectrosonics digital transmitters from the D2, DCH and
M2 series. The receiver is also backward compatible
with Digital Hybrid Wireless® transmitters including those
with NA Hybrid, NU Hybrid, JA HYBRID and EU Hybrid
modes.
Encryption
The DCR822 receiver features AES 256-bit, CTR mode
encryption, with 4 different key policies available.
Vector Diversity Reception
The DCR822 technology with Lectrosonics Vector Di-
versity (an advanced version of true diversity) minimizes
dropouts in situations where multi-path reflections can
cause serious problems. Traditional true diversity or ratio
diversity methods work well for FM and Hybrid systems
but fall short of the ideal for today's digital receivers. The
DCR822's Vector Diversity subsystem delivers clean,
artifact-free performance by combining the two receiver
signals via a unique phase-matching system for maxi-
mum RF signal to noise.
RF Frequency Tracking Front-End and
Mixer
In addition to the extremely high IP3 capability of the
receiver, to significantly reduce unwanted interference
and intermodulation problems, the DCR822 has a fre-
quency selective front-end section that tracks and tunes
to the desired signal frequency and rejects unwanted
interfering signals. The low noise, high current RF ampli-
fier was designed with feedback regulation for stability
and precise gain in order to handle stronger RF signals
without output overload. This produces a robust front-
end that is as selective as fixed single frequency designs
and is suitable for use in close proximity to other receiv-
ers and transmitters commonly used in field production
bag systems.
Smart Noise Reduction (SmartNR
The DCR822 has been meticulously designed using the
best available low noise components and techniques.
Nonetheless, the wide dynamic range of digital and
Rio Rancho, NM
Hybrid transmission technology, combined with flat
response to 20 kHz, makes it possible to hear the -120
dBV noise floor in the transmitter's mic preamp, or the
(usually) greater noise from the lav microphone itself.
(To put this in perspective, the noise generated by the
recommended 4k bias resistor of many electret lavaliere
mics is –119 dBV and the noise level of the microphone's
electronics is much higher.) In order to reduce this noise
and thus increase the effective dynamic range of the
system, the DCR822 is equipped with a selectable Smart
Noise Reduction algorithm, which removes hiss without
sacrificing high frequency response.
The Smart Noise Reduction algorithm works by attenuat-
ing only those portions of the audio signal that fit a statis-
tical profile for randomness or "electronic hiss." Desired
high frequency signals having some coherence such as
speech sibilance and tones are not affected.
The Smart Noise Reduction algorithm has three modes
- OFF/NORMAL/FULL - selectable from a user setup
screen. When switched OFF (the default setting for
digital compat modes) no noise reduction is performed
and complete transparency is preserved. All signals
presented to the transmitter's front end, including any
faint microphone hiss, will be faithfully reproduced at
the receiver. When switched to NORMAL, (the factory
default setting for Hybrid modes) enough noise reduc-
tion is applied to remove most of the hiss from the mic
preamp and some of the hiss from lavaliere microphones.
The noise reduction benefit is dramatic in this position,
yet the degree of transparency maintained is exceptional.
When switched to FULL, enough noise reduction is ap-
plied to remove most of the hiss from nearly any signal
source of reasonable quality, assuming levels are set
properly at the transmitter. This additional noise reduc-
tion comes at the cost of some transparency for low-
level room noise, yet the algorithm remains undetectable
under most circumstances.
Audio Output Level
A setup screen is provided for adjusting the audio output
level in 1 dB increments from -50 to +7 dBu using the
front panel MENU/SEL, UP, and DOWN buttons.
Test Tone
To assist in matching the audio levels of equipment con-
nected to the DCR822, a 1 kHz audio test tone, adjustable
from -50 to +7 dBu in 1 dB increments, is available at the
outputs. If using AES3 outputs, the level is fixed and can-
not be adjusted.
Batteries
The DCR822 can operate on four disposable, 1.5VDC AA
Lithium batteries (recommended). Alkaline is not advised.
Power Supply
The DCR822 may also be operated from an external DC
)
™
power source (see Specifications & Features section for
allowed voltages.) The receiver has a built-in Poly-Fuse
for protection. This fuse automatically resets if the power
supply is disconnected for about 15 sec. The power sec-
Dual Channel Digital Receiver
5