Lectrosonics UCR411A-21, UCR411A-22, UCR411A-20, UCR411A-19, UCR411A-25 User manual

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INSTRUCTION MANUAL
UCR411A
Digital Hybrid Wireless® Compact UHF Receiver
(US patent 7,225,135)
Serial Number:
Purchase Date:
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
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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.
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Power Input Jack
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