Lectrosonics R400a User Manual
R400A
UHF Diversity Receiver
Also part of IS400 and TM400 Systems
(Includes IFB Mode)
INSTRUCTION MANUAL
Featuring
Digital Hybrid Wireless® Technology
(US Patent 7,225,135)
Fill in for your records:
Serial Number:
Purchase Date:
Rio Rancho, NM, USA
www.lectrosonics.com
R400A
2
LECTROSONICS, INC.
UHF Wireless Diversity Receiver
Table of Contents
Introduction .............................................................................................................................................................................................4
Digital Hybrid Wireless
Diversity Reception ...............................................................................................................................................................................4
RF Front-End and Mixer ........................................................................................................................................................................ 4
IF Amplifiers and SAW Filters ...............................................................................................................................................................4
Digital Pulse Counting Detector ............................................................................................................................................................5
Frequency Tuning Groups .....................................................................................................................................................................5
Microprocessor, PLL and VCO Circuits.................................................................................................................................................5
Digital Signal Processor ........................................................................................................................................................................5
Smart Tuning (SmartTune
Compatibility Modes ..............................................................................................................................................................................5
DSP-Based Pilot Tone ...........................................................................................................................................................................5
Smart Squelch
™
Smart Noise Reduction (SmartNR
RF-Controlled Digital Noise Filter .........................................................................................................................................................6
Balanced and Unbalanced Audio Outputs ............................................................................................................................................6
LCD Screen ..........................................................................................................................................................................................6
Power Supply ........................................................................................................................................................................................ 6
Initial Setup .............................................................................................................................................................................................7
Front Panel Controls and Functions .....................................................................................................................................................8
LCD Screen ..........................................................................................................................................................................................8
POWER/PREV Menu Button ................................................................................................................................................................8
MENU Control .......................................................................................................................................................................................8
Balanced Audio Output .........................................................................................................................................................................8
Unbalanced Audio Output .....................................................................................................................................................................8
Power Input Jack ...................................................................................................................................................................................8
Main Antenna and Diversity Antenna Inputs .........................................................................................................................................8
Rear Panel Features ...............................................................................................................................................................................8
Antenna Use and Placement .................................................................................................................................................................9
R400A Menu Options ...........................................................................................................................................................................10
R400A Menu Map ...............................................................................................................................................................................10
Main Screen Display ...........................................................................................................................................................................10
Menu Functions ..................................................................................................................................................................................11
SetUpRx ..........................................................................................................................................................................................11
Freq .................................................................................................................................................................................................11
Level-B ............................................................................................................................................................................................11
Level-U ............................................................................................................................................................................................11
Tuning ..............................................................................................................................................................................................11
Compat ............................................................................................................................................................................................11
Tone-B .............................................................................................................................................................................................11
Tone-U .............................................................................................................................................................................................11
PilotBP .............................................................................................................................................................................................12
Phase-B ...........................................................................................................................................................................................12
Phase-U ..........................................................................................................................................................................................12
TxBatt ..............................................................................................................................................................................................12
SmartNR .........................................................................................................................................................................................12
Back ................................................................................................................................................................................................13
LockSet ...........................................................................................................................................................................................13
SmartTune
™
.....................................................................................................................................................................................13
Scan ................................................................................................................................................................................................13
Pre-Coordinated Frequencies .............................................................................................................................................................14
Compatible Frequency Table ............................................................................................................................................................... 14
Compatibility Diagram .........................................................................................................................................................................15
Using SmartTune
Programming User Groups .................................................................................................................................................................17
Adding User Group Frequencies .....................................................................................................................................................17
Deleting User Group Frequencies ...................................................................................................................................................17
Call Lectrosonics .................................................................................................................................................................................17
Troubleshooting ....................................................................................................................................................................................18
Replacement Parts and Accessories ..................................................................................................................................................20
Service and Repair ...............................................................................................................................................................................21
Returning Units for Repair ..................................................................................................................................................................21
Specifications and Features ................................................................................................................................................................22
®
........................................................................................................................................................................4
™
) ..................................................................................................................................................................5
....................................................................................................................................................................................5
™
and the Scan Function .........................................................................................................................................16
™
) ....................................................................................................................................................6
Rio Rancho, NM
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R400A
Introduction
The R400A is a high performance, triple-conversion,
frequency synthesized UHF receiver fully compatible
with all Lectrosonics 400 Series Digital Hybrid Wire-
®
transmitters, 200 Series and 100 Series analog
less
transmitters and Lectrosonics IFB transmitters, plus
some analog transmitters from other manufacturers
(call Lectrosonics for details). The R400A features 256
user selectable frequencies and its proprietary audio
processing includes a digital signal processor (DSP) for
very low distortion, a superior signal to noise ratio and
two independent audio outputs, one balanced and one
unbalanced.
The receiver features a menu-driven LCD graphic display, a push-button POWER/PREV MENU control and
a dual function (push/rotate) PUSH FOR MENU/ROTATE TO SELECT control (hereafter called the MENU
control) as a convenient means of viewing and altering
user settings.
The MENU control provides simple and intuitive access
to change and adjust settings and operating levels.
Pushing the MENU control from the Main Window enters the Top Menu which displays a choice of five submenu options: SetUpRx, LockSet, SmartTune™, Scan
and Exit. Rotating the MENU control either highlights
a menu option or sets a parameter. Pushing the MENU
control either selects the highlighted menu option or
enters (or reenters) a menu.
Digital Hybrid Wireless
Lectrosonics Digital Hybrid Wireless® (US Patent
7,225,135) uses innovative technology to combine the
new advantages of digital audio with the classic advantages of analog RF transmission. The result is 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
the latest filters, RF amplifiers, mixers and detector to
capture the encoded signal and a DSP (Digital Signal
Processor) 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 a compandor-based system can offer
and no artifacts are introduced under strong RF conditions, and spectral and power efficiency and operating
range are not compromised.
Diversity Reception
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.
RF Front-End and Mixer
The R400A 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 R400A’s front-end is tuned to
the desired frequency band and rejects or “tunes out”
unwanted out-of-band signals. Two tuned
HI-Q ceramic transmission line resonators prior to a low
noise, high current RF amplifier provide good selectivity.
A robust RF amplifier and LC bandbass filter provide
added insurance against strong RF interference. The
overall design ensures stability, selectivity and precise
gain in order to handle strong RF signals without input
overload.
IF Amplifiers and SAW Filters
The first IF low noise amplifier is controlled with feedback regulation and drives a quartz SAW (Surface
Acoustical Wave) filter. The 244 MHz SAW filter combines sharp tuning, constant group delay, wide bandwidth and excellent temperature stability, far superior to
conventional LC filters. The second mixer converts the
244 MHz first IF signal down to 10.7 MHz. The second
IF is filtered through two ceramic filters for sharp selectivity, then itself is converted down to 300 kHz and fed
to the Digital Pulse Counting Detector.
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LECTROSONICS, INC.
UHF Wireless Diversity Receiver
Digital Pulse Counting Detector
The R400A 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.
The output from the Digital Pulse Counter is an analog
signal containing the digital audio information. This signal is fed through a low pass filter to an A-D Converter
in the Digital Signal Processing section.
Frequency Tuning Groups
The R400A provides four “factory set” compatible
frequency groups (A through D) and two user programmable frequency groups (U and V).
The factory groups have been selected to avoid intermodulation problems. Each group includes eight
channels.
The user programmable frequency groups can have up
to 16 frequencies per group.
Microprocessor,
PLL and VCO Circuits
An 8-bit microprocessor 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 power voltage. The microprocessor
also drives the LCD display, controls the squelch and
audio output attenuator, and operates the PLL/VCO
circuits and the antenna phase switch.
Digital Signal Processor
The DSP reconstructs the original digitized audio from
the A-D Converter and detects the ultrasonic Pilot Tone.
The DSP also incorporates an RF-controlled digital
noise filter (in addition to SmartNR™). This RF sensitive
variable frequency filter reduces high frequency response under extremely weak RF conditions. The filter
does nothing until the RF signal strength drops below
3uV, at which point it begins to roll off high frequencies.
Usable audio remains unaffected, but noise-ups or “hits”
occurring near the fringe of reception sound much less
harsh.
The reconstructed original analog audio signal is then
sent to the audio output section.
Smart Tuning (SmartTune™)
A major problem facing wireless users is finding clear
operating frequencies, especially in RF saturated environments. SmartTune™ overcomes this problem by automatically scaning all the frequencies available in the
receiver’s frequency block and tuning the receiver to the
frequency with the lowest RF interference, significantly
reducing setup time.
Compatibility Modes
The R400A receiver was designed to operate with
Lectrosonics 400 Series transmitters and will yield the
best performance when doing so. However, due to the
flexibility of digital signal processing, the R400A is also
able to operate with Lectrosonics 200 Series, 100 Series and IFB transmitters, and certain non-Lectrosonics
transmitters in special compatibility modes. (Contact
the Lectrosonics Sales Department for a complete list
of compatible transmitters.)
DSP-Based Pilot Tone
The 400 Series system design uses a DSP generated
ultrasonic pilot tone from the transmitter to control the
receiver audio muting (squelch). If the Pilot Tone is enabled, a Pilot Tone Detect signal generated by the DSP
automatically controls the receiver’s squelch. Built-in
brief delays are also incorporated to eliminate the
thumps, pops or other transients that can occur when
the transmitter is turned 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. Using the
DSP to detect the 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.
Note: The above description applies only in 400
Series mode. In other modes requiring pilot tones,
only one pilot tone frequency is used
on all channels.
Smart Squelch
The R400A 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 R400A 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 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 R400A 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.
™
Rio Rancho, NM
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R400A
Smart Noise Reduction (SmartNR™)
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 mic preamp,
or the (usually) greater noise from the microphone itself.
(To put this in perspective, the noise generated by the
recommended 4 k Ohm 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 R400A 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.”
SmartNR™ offers significantly increased transparency
over the sophisticated variable low pass filters used
in previous designs. Desired high frequency signals
having some coherence such as speech sibilance and
tones are not affected.
The Smart Noise Reduction algorithm has three modes,
selectable from a user setup screen: Off, Normal and
Full.
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.
NORMAL (factory default) - Enough noise reduction is 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.
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.
Noise-Controlled Digital Filter
In addition to SmartNR™, the R400A contains a supersonic noise-sensitive variable frequency filter, which reduces high frequency response under extremely weak
RF conditions. This filter does nothing until the level of
supersonic noise present in the received audio exceeds
a predetermined threshold at which point it begins to
roll off high frequencies. Usable audio remains unaffected, but noise-ups or “hits” occurring near the fringe
of reception sound much less harsh.
Balanced and Unbalanced
Audio Outputs
The R400A offers two audio outputs for the ultimate in
flexibility: Balanced (XLR) and Unbalanced Line Out/
Monitor (1/4-inch jack.) Both outputs operate independently and are controlled by their own digital attenuator.
LCD Screen
The LCD screen is used in conjunction with the MENU
control to change and control the operational settings,
and also provide a visual feedback of overall system
operation. (See R400A MENU SELECTIONS.)
Power Supply
The R400A is operated from an external DC power
source with a range of +8 VDC to +18 VDC, up to 0.20
amperes (200 milliamps) maximum. The receiver has
a built-in Poly-Fuse to protect the unit. If a problem
occurs that trips this fuse, it will reset after the power
supply is disconnected for about 15 seconds. The
power input section also has built-in protection circuits
that prevent damage to the receiver if a positive ground
power source is applied.
Note: The R400A requires external DC power and
has no provisions for internal batteries.
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.
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LECTROSONICS, INC.
Initial Setup
1. Connect the power cord from the power supply to
the Power Input Jack.
2. Attach the antennas or antenna cables to the MAIN
ANT and DIV ANT BNC connectors.
3. Press the POWER/PREV MENU button to turn on
the unit on. Check to see that the LCD displays the
three-screen Power Up Sequence:
Lectrosonics
R400A VXX where VXX is the current firmware
version installed
Block XX where XX is the frequency tuning range
block number
After the Power Up Sequence is displayed, the
Main Window appears and the R400A is ready for
operation.
4. Ensure the receiver and transmitter are set to
the same Compatibility Mode, then locate a clear
operating frequency (see Frequency Coordination.)
Then set the Transmitter Frequency Select Switches to match the receiver’s operating frequency.
(See R400A Menu Options.)
5. Turn the transmitter on and verify that an RF signal
is indicated on the LCD.
6. Connect an audio cable to the appropriate audio
output jack. Because the audio outputs operate independently, external equipment can be connected
to either, or both output jacks.
7. Locate a clear operating frequency. The easiest
method is to use SmartTune™ and then set the
transmitter frequency indicated on the display.
Note: For more detailed instructions, see “Using
SmartTune™ and the Scan Function” on page 16.
8. Refer to the associated transmitter operating instructions and adjust the transmitter gain.
Warning: This is perhaps the most important
step in the setup procedure.
In general, adjust the transmitter gain so that the
voice peaks will cause the audio modulation level
indicators on both the receiver and transmitter to
show full modulation on the loudest peak audio
levels. Normal levels should cause the R400A’s
audio level bar to fluctuate fully resulting in the best
possible signal to noise ratio for the system.
Note: A common mistake is to use the transmitter
audio gain control to set the overall audio level
of the entire system. The transmitter gain
control is not a volume control and must be set
independently of the overall system audio level.
The transmitter gain control is only used to set the
proper modulation of the transmitter. It is used to
UHF Wireless Diversity Receiver
POWER/
PREV MENU
Button
Main
Antenna Input
match the transmitter to the type of microphone
and the sound levels that will be present at that
microphone. We encourage users to either
disconnect the rest of the sound system or turn the
sound system gain to minimum to prevent either
feedback or overload as the transmitter gain is
set. Only after the transmitter gain control is set
should the gain of the rest of the audio system be
adjusted to achieve the desired sound or signal
levels.
Unbalanced
Audio Output
Audio OutputPower Input Jack
MENU ControlLCD Screen
Diversity
Antenna Input
Balanced
9. Use the Level or Tone menus to adjust the audio
output levels to match the required input level of
any connected devices (camera, mixer, recorder,
etc.). The adjustment range is from -50 dBu to +5
dBu in 1 dBu steps for the balanced output and -55
dBu to +0 dBu in 1 dBu steps for the unbalanced
output.
Note: The test tone output is especially useful for
an exact level match. With the test tone running,
adjust for the maximum desired peak level using
the metering on the connected device.
10. If desired, access the LockSet menu to lock the
R400A front panel controls to prevent inadvertently
modifying the receiver settings during operation.
Rio Rancho, NM
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R400A
Front Panel Controls and Functions
LCD Screen
The LCD Screen is used to monitor system operation
and display information while configuring the R400A.
(See R400A Menu Options.)
POWER/PREV Menu Button
Dual function control providing a POWER On/Off
function and a return to previous menu function. If the
receiver is turned off, momentarily pressing this button
turns the receiver on. If the receiver is already turned
on, pressing this button causes the LCD to display the
previous menu. Pressing and holding the button for at
least two seconds turns the unit off.
MENU Control
The dual function MENU control is used to access
menus and change receiver settings. Push the control
to enter the TopMenu, or activate the selected menu option. Rotate the control to either select a menu option
or to set an operating parameter.
POWER/
PREV MENU
Button
MENU ControlLCD Screen
Rear Panel Features
Balanced Audio Output
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. An unbalanced signal is available using Pin 1 as ground, Pin 2 as signal
and leaving Pin 3 open.
Unbalanced Audio Output
This is a standard 1/4-inch phone jack with the center
pin positive and the sleeve connected to ground. This
jack provides unbalanced line-level audio output.
Power Input Jack
The power input jack accepts +8 VDC to +18 VDC
(center pin is positive and sleeve is ground). The input
is diode protected to prevent damage if the power is applied with reversed polarity, and it will keep the unit from
operating until the condition is fixed.
Main Antenna and Diversity Antenna Inputs
The MAIN ANT and DIV ANT inputs are both 50 Ohm,
BNC connectors. In single antenna configurations,
the antenna is connected to the MAIN ANT jack. (See
Antenna Use and Placement.)
Main
Antenna Input
Unbalanced
Audio Output
Power Input Jack
Diversity
Antenna Input
Balanced
Audio Output
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LECTROSONICS, INC.
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