Lectrosonics UCR411a User Manual
INSTRUCTION MANUAL
UCR411A
Digital Hybrid Wireless® Compact UHF Receiver
(US patent 7,225,135)
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Rio Rancho, NM, USA
www.lectrosonics.com
UCR411A
2
LECTROSONICS, INC.
UHF Digital Hybrid Wireless™ Receiver
Digital Hybrid Wireless
The Lectrosonics Digital Hybrid WirelessTM uses innovative technology to combine the new advantages of digital
audio with the classic advantages of analog RF transmission, thus delivering the superior sound quality of a digital system and the excellent range of an analog system.
A proprietary algorithm encodes the digital audio information 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 transmit-
®
ted is digitally encoded, immunity to noise is much higher
than a compandor can offer. Because the encoded audio
is sent in analog format, spectral and power efficiency
and operating range are not compromised.
Unlike traditional analog compandor systems, no artifacts are introduced under strong RF conditions.
Under weak RF conditions, the received signal degrades 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.
(*US Patent 7,225,135)
Rio Rancho, NM
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UCR411A
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LECTROSONICS, INC.
UHF Digital Hybrid Wireless™ Receiver
Table of Contents
Digital Hybrid Wireless
General Technical Description ..............................................................................................................................................................6
Compatibility Modes ..............................................................................................................................................................................6
Diversity Reception ...............................................................................................................................................................................6
RF Frequency Tracking Front-End and Mixer ........................................................................................................................................6
Microcontroller, PLL and VCO Circuits..................................................................................................................................................6
IF Amplifiers and SAW Filters ...............................................................................................................................................................7
Digital Pulse Counting Detector ............................................................................................................................................................7
DSP-Based Pilot Tone ...........................................................................................................................................................................7
Supersonic Noise-Based
Dynamic Filter and SmartSquelch
Smart Noise Reduction (SmartNR™) ....................................................................................................................................................7
Audio Output Level ................................................................................................................................................................................ 8
Test Tone ...............................................................................................................................................................................................8
Batteries ................................................................................................................................................................................................ 8
Power Supply ........................................................................................................................................................................................ 8
LCD Display ..........................................................................................................................................................................................8
Power Off ..............................................................................................................................................................................................8
Front Panel Controls and Functions .....................................................................................................................................................9
LCD Screen ..........................................................................................................................................................................................9
MENU Button ........................................................................................................................................................................................9
SELECT Up/Down Buttons ...................................................................................................................................................................9
Power ON/OFF Switch .......................................................................................................................................................................... 9
Rear Panel Features ...............................................................................................................................................................................9
XLR Audio Output Jack .........................................................................................................................................................................9
Power Input Jack ...................................................................................................................................................................................9
Main Window (LCD) .............................................................................................................................................................................. 10
Menu Selections from Main Window ...................................................................................................................................................11
Frequency Window..............................................................................................................................................................................11
Battery Level Window .........................................................................................................................................................................11
SETUP Window ..................................................................................................................................................................................12
LEVEL Setup Screen ..........................................................................................................................................................................12
TONE Setup Screen ...........................................................................................................................................................................12
TXBAT Setup Screen ..........................................................................................................................................................................12
PHASE Setup Screen .........................................................................................................................................................................12
SmartNR Setup Screen ......................................................................................................................................................................12
TUNING Setup Screen .......................................................................................................................................................................13
COMPAT Setup Screen .......................................................................................................................................................................13
Frequency Scan Mode .........................................................................................................................................................................14
Scan & VIEW WINDOW Elements ......................................................................................................................................................14
Fine VIEW WINDOW Elements ..........................................................................................................................................................14
Antenna Use and Placement ...............................................................................................................................................................15
Installation and Operating Instructions ..............................................................................................................................................16
Finding Clear Frequencies ..................................................................................................................................................................16
Locking and Unlocking the
UCR411A Front Panel Controls .......................................................................................................................................................... 17
Replacing the Batteries ........................................................................................................................................................................18
Antenna/Block Reference Table ..........................................................................................................................................................19
Pre-coordinated Frequencies ..............................................................................................................................................................20
Diagnostics ...........................................................................................................................................................................................21
Multi-channel System Checkout..........................................................................................................................................................21
Pilot Tone Bypass ................................................................................................................................................................................21
Replacement Parts and Accessories ..................................................................................................................................................22
Troubleshooting .................................................................................................................................................................................... 23
Specifications and Features ................................................................................................................................................................25
Service and Repair ...............................................................................................................................................................................26
Returning Units for Repair ..................................................................................................................................................................26
® ....................................................................................................................................................................................................................................................................................................3
™ ....................................................................................................................................................................................................................................................................7
Rio Rancho, NM
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UCR411A
General Technical Description
UCR411A Block Diagram
The UCR411A is a portable, high performance, tripleconversion, frequency synthesized, UHF receiver fully
compatible with all Lectrosonics 400 Series transmitters
(and some other transmitter types – see Compatibility
Modes for details). The RF performance is extremely
stable over a very wide temperature range, making the
UCR411A perfectly suited to the rough environmental
conditions found in the field. The proprietary audio processing includes a digital signal processor for very low
distortion and a superior signal-to-noise ratio.
The UCR411A front panel features a menu-driven LCD
graphic display and three control buttons to conveniently view and alter user settings. The main window,
for example, displays the pilot tone indicator, antenna
diversity phase, RF level, audio level, receiver battery
status and transmitter battery status. It is also possible
to bypass the pilot tone/squelch from the main display
window. Other windows display operating frequency,
audio output level, battery voltage and test tone status.
The frequency scan mode provides a spectrum analyzer for a graphical means of observing all signals “on the
air” within the frequency range of the receiver in order to
find operating frequencies that are free of interference.
Compatibility Modes
The UCR411A receiver was designed to operate with
Lectrosonics 400 Series transmitters and will yield the
best performance when doing so. Due to the flexibility
of digital signal processing, the UCR411A is also able
to operate with Lectrosonics 200 Series, Lectrosonics
100 Series, IFB Mode, as well as Modes 3 and 6, which
work with certain non-Lectrosonics transmitters.
Diversity Reception
The UCR411A technology with SMARTDiversity™ minimizes dropouts in situations where multi-path reflections can cause serious problems. The phase diversity
network and PIN diode RF switches are controlled by
the microprocessor using a sophisticated algorithm to
use both antennas simultaneously. This design keeps
the receiver compact enough for camera mounting or
shoulder bag applications, yet provides effective diversity reception.
RF Frequency Tracking Front-End and Mixer
The receiver is frequency agile and can be set to operate on any one of 256 frequencies within its tuning
range. To significantly reduce unwanted interference
and intermodulation problems, the UCR411A has a frequency selective front-end section that tracks and tunes
to the desired signal frequency and rejects or “tunes
out” unwanted interfering signals. The design consists
of four varactor tuned ceramic transmission line resonators controlled by the microprocessor to provide good
selectivity. The low noise high current RF amplifier was
designed with feedback regulation for stability and precise gain in order to handle stronger RF signals without
output overload. The first mixer is of new GaAs technology that has a very high third order intercept point. 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 receivers and transmitters commonly
used in field production “bag” systems.
Microcontroller, PLL and VCO Circuits
The 8-bit microcontroller is truly the “heart” of the
UCR411A receiver. It monitors user command inputs
from the front panel control buttons and numerous other
internal signals such as RF level, audio levels, pilot tone
levels and external/internal power voltages. Outputs
from the microcontroller drive the LCD display and
backlight, control the squelch and audio output attenuator, and operate the front-end tuning, the PLL/VCO
circuits and the antenna phase switch. The UCR411A
design and the advanced technology of the microprocessor control arguably set a new standard in wireless
microphone development.
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LECTROSONICS, INC.
UHF Digital Hybrid Wireless™ Receiver
IF Amplifiers and SAW Filters
The first IF low noise amplifier is controlled with feedback regulation and drives the first of two quartz SAW
(Surface Acoustical Wave) filters. The 244 MHz SAW
filters combine sharp tuning, constant group delay,
wide bandwidth and excellent temperature stability, far
superior to conventional LC filters. The 244 MHz first IF
signal is converted down to 10.7 MHz, filtered through
two ceramic filters for sharp selectivity, then converted
to 300 kHz.
Digital Pulse Counting Detector
The UCR411A receiver uses an elegantly simple, yet
highly effective digital pulse detector to demodulate
the FM signal, rather than a conventional quadrature
detector. This unusual design eliminates thermal drift,
improves AM rejection, and provides very low audio
distortion.
DSP-Based Pilot Tone
Note: This description applies only in 400 Series
mode. In 100 and 200 Series mode, and Mode 6,
only one pilot tone frequency is used on all channels,
emulating the original crystal-based system. In other
compatibility modes, no pilot tone is used.
The 400 Series system design uses a DSP-generated
ultrasonic pilot tone to control the receiver audio muting
(squelch). Brief delays when the associated 400 Series
transmitter is turned on or off, eliminate thumps, pops
or other transients that can occur when the power is
switched on or off. The pilot tone frequency is different
for each of the 256 frequencies in the tuning range of
a system (frequency block). This eliminates squelch
problems in multichannel systems where a pilot tone
signal can appear in the wrong receiver via intermodulation products. The DSP-generated pilot tone also
eliminates the need for fragile crystals, allowing the
receiver to survive shocks and mishandling much better
than older analog-based pilot tone systems.
Supersonic Noise-Based
Dynamic Filter and SmartSquelch
In addition to SmartNR, all 400 Series receivers are
equipped with a supersonic noise-based dynamic filter
and squelch system. The incoming audio is monitored for
energy above 22 kHz, besides the pilot tone. Excessive
high frequency energy indicates that the received signal
is too weak to achieve an acceptable signal-to-noise ratio.
Under marginal conditions, a variable lowpass filter is rolled
in dynamically, masking the noise while preserving as much
of the transmitted signal as possible. When the channel is
too noisy even for the filter, the audio is squelched.
This noise-based filter and squelch system replaces a
more or less equivalent system used for many years, which
based its operation on RF signal strength. Performance of
the two systems is virtually identical, but the noise-based
system requires no calibration and there is no better way to
track the signal-to-noise ratio than to measure it directly.
™
The UCR411A employs a sophisticated squelching system in an attempt to deliver the cleanest possible audio
during marginal conditions of reception. Any squelching
system faces inevitable trade-offs: squelch too much
and valuable audio information may be lost, squelch
too little and excessive noise may be heard; respond
too rapidly and the audio sounds “choppy,” respond too
sluggishly and syllables or entire words can be cut off.
The UCR411A combines several techniques to achieve
an optimal balance, removing distracting noise, without
the squelching action itself becoming a distraction. One
of these techniques involves waiting for a word or syllable to complete before squelching. Another technique
incorporates recent squelching history and recent signal
strength, adjusting squelching behavior dynamically for
the most serviceable result under variable conditions.
Using these and other techniques, the UCR411A can
deliver acceptable audio quality from otherwise unusable signals.
In the Pilot Tone Bypass mode, the squelch system is disabled. Received audio remains unmuted at all times with
this setting. (See Front Panel Controls and Functions.)
Smart Noise Reduction (SmartNR™)
Note: The SmartNR setting is user selectable
only in 400 Series mode. In other modes, noise
reduction is applied in such a way as to emulate
the original analog system as accurately as
possible and is not user adjustable.
The UCR411A has been meticulously designed using
the best available low noise components and techniques. Nonetheless, the wide dynamic range of digital
hybrid 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 microphone itself. (To put this in perspective, the noise generated by the recommended
4 k 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
UCR411A is equipped with a Smart Noise Reduction
algorithm, which removes hiss without sacrificing high
frequency response.
The Smart Noise Reduction algorithm works by attenuating only those portions of the audio signal that fit
a statistical profile for randomness or “electronic hiss”.
Because it isn’t simply a sophisticated variable low pass
filter as in Lectrosonics’ 195 and 200 Series designs,
much greater transparency is thus obtained. 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, no noise reduction is
performed and complete transparency is preserved. All
signals presented to the transmitter’s analog front end,
including any faint microphone hiss, will be faithfully reproduced at the receiver. When switched to NORMAL,
the factory default setting, enough noise reduction is
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UCR411A
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 applied 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 reduction 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 +5 dBu using
the front panel SEL Up and Down buttons.
Test Tone
To assist in matching the audio levels of equipment connected to the UCR411A, a 1 kHz audio test tone, adjustable from -50 to +5 dBu in 1 dB increments, is available
at the XLR connector. This tone is available through the
TONE display window.
Batteries
The UCR411A operates on two 9 Volt alkaline or LiPolymer rechargeable batteries.
NOTE: Do not use an alkaline and a LiPolymer
rechargeable in the same unit. Standard or “heavy
duty” batteries are not recommended.
Power Supply
The UCR411A may be operated from an external DC
power source (see Specifications and Features section
for allowed voltages.) The receiver has a built-in PolyFuse to protect the unit. This fuse automatically resets if
the power supply is disconnected for about 15 seconds.
The power section also has protection circuits that prevent damage to the receiver if a positive ground power
source is applied.
LCD Display
The display has four primary windows. Pressing the
Front Panel MENU button steps through each of these
windows.
If the battery gets low on either transmitter or receiver,
a message will interrupt the display every few seconds
and flash a low battery warning.
After power is turned off and back on again, the unit
defaults to the Main window and to the most recent
frequency, audio level, transmitter battery type and
other user settings. These settings are retained even if
the batteries are removed. After five minutes of no key
activity, the LCD backlight times out and reverts back to
last screen used when reactivated.
Power Up Sequence
The power up sequence consists of four messages that
appear automatically after the power is switched on.
1) UCR411A
BLK xx (xx is the frequency block number)
2) VERSION
R.R/A.A (R.R is the RF board firmware version,
A.A is the audio board firmware version)
3) COMPAT
XXX
Where “XXX” is one of the following:
NA 400 North American - Native 400 Series Digital Hybrid mode
NA 100 Lectrosonics 100 Series compatibility
NA 200 Lectrosonics 200 Series compatibility
NA M3 Compatible with certain non-Lectrosonics transmitters
NA IFB Compatible with all Lectrosonics IFB transmitters.
NA M6 Compatible with certain non-Lectrosonics transmitters
NA M7 Compatible with certain non-Lectrosonics transmitters
EU HBR European Union - Native 400 Series Digital Hybrid mode
EU 100 European Union - 100 Series compatibility
EU 200 European Union - 200 Series compatibility
EU M3 European Union - Compatible with certain
non-Lectrosonics transmitters
EU IFB European Union - Compatible with all Lectrosonics
IFB transmitters.
EU M6 European Union - Compatible with certain
non-Lectrosonics transmitters
EU M7 European Union - Compatible with certain
non-Lectrosonics transmitters
Note: NA M7 & EU M7 are only available with firmware
6.0 on the audio board.
4) TUNING
NORMAL Tune in single channel increments.
GRP x Tune in pre-coordinated intermod-free frequencies (x is A, B, C, D, U or V)
The Main Window appears after the introductory messages are displayed.
The UCR411A is fully operational during the power
up sequence and will immediately respond to button
pushes made before the automatic sequence is completed. If a valid transmitter signal is already present
when the receiver is turned on, the audio output will
typically be engaged somewhere in the middle of the
power-up sequence, following a brief delay to allow the
audio circuits to stabilize.
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LECTROSONICS, INC.
Front Panel Controls and Functions
UHF Digital Hybrid Wireless™ Receiver
LCD Screen
The LCD Screen is a graphics-type Liquid Crystal
Display that is used to monitor system operation and
configure the UCR411A.
MENU Button
The MENU button steps through the four primary windows and setup screens.
SELECT Up/Down Buttons
The SELECT Up/Down buttons are used to select various options within each display selection and to set the
operating frequency of the receiver.
Power ON/OFF Switch
The Power ON/OFF switch is used to apply battery or
external power to the unit.
Rear Panel Features
XLR Audio Output Jack
This is a standard XLR configuration with pin 2 “positive” with reference to hand-held and plug-on transmitters. With lavaliere microphones and belt-pack transmitters, however, phase will vary with different types of
microphones (2-wire vs. 3-wire for example). The audio
output is balanced but not floating, so an unbalanced
signal is available using pin 1 as ground and pin 2 as
signal, leaving pin 3 open.
SELECT Up Button MENU Button
SELECT Down Button
BATTERY DOOR
To open lift
this edge and
turn door
LCD Screen
Audio Output Jack
AUDIO
OUT
Power ON/OFF Switch
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3
10-18
VDC
Power Input Jack
The power input jack can accept 10-18 VDC - the
center pin is positive and sleeve is ground. The input
is diode protected to prevent damage if the power is
applied with reversed polarity, but the unit will not work
until the reversed polarity condition is fixed. The small
Velcro strip can be used as a strain relief and retainer
on the power cable to avoid accidental disconnection.
Attach the adhesive strip side to the side of the receiver
or mount with the opening end of the strip up - place the
cable in the strip and secure.
Rio Rancho, NM
Power Input Jack
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