Dchr Digital 2-Channel Receiver; Smart Tuning (Smarttune™); Encryption; Rf Front-End With Tracking Filter - Lectrosonics DCHR Instruction Manual

DCHR Digital Stereo/Mono Receiver
The DCHR Digital Receiver is engineered to work along-
side the DCHT transmitter to form the Digital Camera
Hop system. The receiver is also compatible with the
M2T unencrypted encrypted digital stereo transmitters,
and the D2 Series mono digital transmitters, including
the DBu, DHu, DBSM, DSSM, and DPR-A. Designed to
be camera mountable and battery powered, the receiver
is ideal for location sound and televised sports, along
with many other applications. The DCHR employs ad-
vanced antenna diversity switching during digital packet
headers for seamless audio. The receiver tunes across a
wide UHF frequency range.
The DCHR has a single audio output jack that can be
configured as 2 independent balanced, adjustable mic/
line level outputs or as a single 2 channel AES3 digital
output.
The headphone monitor output is fed from a high-qual-
ity stereo amplifier with power available to drive even
inefficient headphones or earphones to sufficient levels
for noisy environments. An intuitive interface and high
resolution LCD on the unit provide users with a quick
read on the status of the system.
The DCHR also employs 2-way IR sync, so settings
from the receiver can be sent to a transmitter. This
way, frequency planning and coordination can be done
quickly and confidently with on-site RF information.
Smart Tuning (SmartTune™)
A major problem facing wireless users is finding clear
operating frequencies, especially in RF saturated en-
vironments. SmartTune™ overcomes this problem by
automatically scanning all the frequencies available in
the unit, and tuning to the frequency with the lowest RF
interference, significantly reducing setup time.

Encryption

The DCHR provides AES 256-bit, CTR mode encryp-
tion. When transmitting audio, there are situations where
privacy is essential, such as during professional sporting
events. High entropy encryption keys are first created
by the DCHR. The key is then synced with an encryption
capable transmitter/receiver via the IR port. The audio
will be encrypted and can only be decoded and heard if
both the transmitter and the DCHR have the matching
key. Four key management policies are available.
Rio Rancho, NM

RF Front-End with Tracking Filter

A wide tuning range is helpful in finding clear frequen-
cies for operation, however, it also allows a greater
range of interfering signals to enter the receiver. The
UHF frequency band, where almost all wireless micro-
phone systems operate, is heavily populated by high
power TV transmissions. The TV signals are immensely
more powerful than a wireless microphone or portable
transmitter signal and will enter the receiver even when
they are on significantly different frequencies than the
wireless system. This powerful energy appears as noise
to the receiver, and has the same effect as the noise
that occurs with extreme operating range of the wire-
less system (noise bursts and dropouts). To alleviate this
interference, high-quality front-end filters are needed in
the receiver to suppress RF energy below and above the
operating frequency.
The DCHR receiver employs a selective frequency,
tracking filter in the front-end section (the first circuit
stage following the antenna). As the operating frequency
is changed, the filters re-tune into six different "zones"
depending on the selected carrier frequency.
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470 MHz
In the front-end circuitry, a tuned filter is followed by an
amplifier and then another filter to provide the selec-
tivity needed to suppress interference, yet provide a
wide tuning range and retain the sensitivity needed for
extended operating range.
Digital Camera Hop Receiver
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614 MHz
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