Lectrosonics REFUM - Manual

REFUM/REFSWITCH
TECHNICAL DATA
Referee Transmitter and Switch
• Externally switched “no pop” audio muting
• Digital Hybrid Wireless™
(U.S. Patent 7,225,135)
• Compatible with older Lectrosonics
analog receivers
• 256 synthesized UHF frequencies and
100 mW output power
• Adjustable low frequency roll-off
• Rugged machined aluminum construction
A Complete System Includes:
• REFUM transmitter
• REFSWITCH external mute with
Interface cable
• M152 or other electret microphone
Digital Hybrid Wireless TM is a revolutionary new
design that combines digital audio with an analog
FM radio link to provide outstanding audio qual­
ity and the extended operating range of the finest
analog wireless systems. The design eliminates the
audio companding process.
The design overcomes channel noise in a dramati­
cally 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 algorithm is not a
digital implementation of an analog compandor. In­
stead, it is a technique which can be accomplished
only in the digital domain, even though the audio
inputs and outputs are analog signals.
US Patent No. 7,225,135
The referee transmitter offers sports officials the latest
digital/analog hybrid technology in a convenient, weather-
resistant package. Using the REFSWITCH external belt-
pack switch assembly, the audio in the REFUM transmit­
ter can be muted or engaged, without pops or clicks in the
audio.
A 5-pin input jack provides taps for low impedance
dynamic mics, electret lavalier mics (positive or nega­
tive bias) and a pin designated for audio muting using
an external switch. Input gain is adjustable over a 43 dB
range to perfectly match the audio input level for optimum
modulation, minimum distortion and maximum signal to
noise ratio. Input levels are accurately indicated by two
LEDs on the control panel.
The input is gain controlled with a wide range dual enve­
lope input limiter, which cleanly limits input signal peaks
over 30 dB above full modulation. Along with the Digital
Hybrid Wireless™ audio path, the RF transmission is an
aggressively optimized FM system with +/- 75 kHz wide
deviation for a high signal to noise ratio. The overall sys­
tem delivers full bandwidth audio frequency response up
to 20 kHz plus excellent operating range and resistance
to interference.
The REFUM is powered by a single 9 V battery and
provides a full 100 mW output for extended operating
range. The housing and belt-clip are machined aluminum,
powder coated and laser engraved for ruggedness and
legibility.
Rio Rancho, NM, USA
www.lectrosonics.com