User's Manual

SRc5P and SRc Dual Receivers
LECTROSONICS, INC.
4
Digital Hybrid Wireless
®
The Lectrosonics Digital Hybrid Wireless
®
uses innova-
tive technology to combine the advantages of digital
audio with the advantages of analog RF transmission.
The result delivers the superior sound quality of a digital
system and the excellent range of an analog system.
A proprietary algorithm encodes the digital audio infor-
mation into an analog format which can be transmitted
in a robust manner over an analog FM wireless link. The
receiver employs state-of-the-art filters, RF amplifiers,
mixers and detector to capture the encoded signal and
a DSP recovers the original digital audio.
This digital/analog hybrid technique has some very
beneficial properties. Because the information being
transmitted is digitally encoded, immunity to noise is
much higher than what a compandor can offer. Because
the encoded audio is sent in analog format, spectral
and power efficiency and operating range are not com-
promised.
Under weak RF conditions, the received signal de-
grades gracefully, like an analog system, delivering
as much usable audio as possible at maximum range.
Since the audio is free of compandor artifacts, pumping
and breathing problems are also greatly reduced.
SRc
This is the basic receiver with audio outputs on the rear
panel only.
SRc5P
An additional audio output is provided next to the front
panel for use with cameras that have only one audio
input in the mounting slot. When the receiver is used
outside of a camera, this extra audio output can be
used to feed a recorder or IFB transmitter while the rear
panel audio outputs feed a mixer or camera.
Model Differences
Wideband Tuning Range
The increased congestion in the UHF television fre-
quency bands has driven the demand for extended tun-
ing ranges in wireless microphone equipment. The goal
is to be able to find empty places in the RF spectrum
where there is little or no interference. The logic behind
this thinking is valid except for the fact that a wideband
tuning range allows a greater amount of RF energy
from all sources to enter the receiver, This excessive
amount of RF energy can easily be enough to over-
whelm the receiver and shorten the operating range or
cause noise and dropouts.
To allow a wide tuning range and preserve the perfor-
mance of a narrowband receiver, the SRc Series design
employs tracking filters in the front-end section to block
RF energy above and below the tuned frequency. The
filter automatically adjusts to stay centered over the
operating frequency and significantly suppresses out of
band RF signals.
Tracking Filters Suppress Out-of-band Signals