Lectrosonics UT700 User Manual

700 Series

Encrypted Digital UHF Wireless System

INSTRUCTION MANUAL

Includes:

UDR700
UM700
UT700

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Serial Number:

Purchase Date:

Rio Rancho, NM, USA
www.lectrosonics.com

UDR700 / UM700 / UT700

Table of Contents

Introduction ............................................................................................................................................................................................5

Overall System Design .........................................................................................................................................................................5

UDR700 Block Diagram .................................................................................................................................................................... 5

UDR700 Encrypted Digital Receiver .................................................................................................................................................... 5

Rota-Versity™ Reception ..................................................................................................................................................................5

RF Section ........................................................................................................................................................................................5

Digital Demodulator .......................................................................................................................................................................... 6

Digital Signal Processing ..................................................................................................................................................................6

Audio Output .....................................................................................................................................................................................6

UM700 Block Diagram..........................................................................................................................................................................6

Encrypted Digital Transmitters ..............................................................................................................................................................6

DSP-Cntrolled Dual Envelope Analog Limiter...................................................................................................................................6

Digital Signal Processing and Modulation ........................................................................................................................................7

Transmitter RF Output Section..........................................................................................................................................................7

Long Battery Life ............................................................................................................................................................................... 7

UT700 Block Diagram .......................................................................................................................................................................... 7

Frequency Agility .............................................................................................................................................................................. 7

Antenna ............................................................................................................................................................................................7

UT700 Microphone Element .............................................................................................................................................................7

Comparing Diversity Reception and Rota-Versity™ ........................................................................................................................... 8

SmartDiversity™ ............................................................................................................................................................................... 8

Rota-Versity™ ...................................................................................................................................................................................8

The 700 Series Encryption System ...................................................................................................................................................... 9

Level 1 ..................................................................................................................................................................................................9

Level 2 ..................................................................................................................................................................................................9

Level 3 ..................................................................................................................................................................................................9

UDR700 Controls and Functions ........................................................................................................................................................11

UDR700 Front Panel ..........................................................................................................................................................................11

RF Level Indicator ...........................................................................................................................................................................11

Transmitter Audio Level...................................................................................................................................................................11

Information and Status Display ....................................................................................................................................................... 11

Menu Button....................................................................................................................................................................................11

Select Up/Down Buttons .................................................................................................................................................................11

Rota-Versity™ Switch .....................................................................................................................................................................11

Antenna Phase Combining Indicator .............................................................................................................................................. 11

Power Switch ..................................................................................................................................................................................11

Security Jack .................................................................................................................................................................................. 11

Audio Monitor Level ........................................................................................................................................................................11

Audio Monitor Jack ......................................................................................................................................................................... 11

UDR700 Rear Panel ...........................................................................................................................................................................12

AC Power Supply ............................................................................................................................................................................12

EXT Power Connector ....................................................................................................................................................................12

Analog Audio Output Control ..........................................................................................................................................................12

GND/LIFT Switch ............................................................................................................................................................................ 12

Phase 0/180 ....................................................................................................................................................................................12

Digital Audio Output - AES-3id........................................................................................................................................................12

Antenna Jacks ................................................................................................................................................................................12

UDR700 Iinformation and Status Display Menus and Functions........................................................................................................12

Power Up Sequence ....................................................................................................................................................................... 12

Enabling and Disabling the Buttons ................................................................................................................................................ 12

Menu Interface....................................................................................................................................................................................13

Main Tuning Menu .............................................................................................................................................................................. 13

TV Tuning Menu .................................................................................................................................................................................. 13

Group Tuning Menu ............................................................................................................................................................................ 13

AES Output Menu...............................................................................................................................................................................13

Security Menu ....................................................................................................................................................................................13

Key Generation Menu .........................................................................................................................................................................13

LECTROSONICS, INC. 2

Encrypted Digital Wireless System

UM700 Controls and Functions ..........................................................................................................................................................14

Input Jack ...........................................................................................................................................................................................14

Power On/Off Switch .......................................................................................................................................................................... 14

Power LED .......................................................................................................................................................................................... 14

Frequency Select Switches ................................................................................................................................................................14

Audio Level Control ............................................................................................................................................................................14

Modulation LEDs ................................................................................................................................................................................14

Antenna ..............................................................................................................................................................................................14

Adjustable Low Frequency Roll-Off Control ........................................................................................................................................ 15

The Belt Clip .......................................................................................................................................................................................15

UM700 Battery Installation ................................................................................................................................................................. 15

UT700 Controls and Functions ...........................................................................................................................................................16

Power On/Off Switch .......................................................................................................................................................................... 16

Power LED .......................................................................................................................................................................................... 16

Hiding the Power LED ........................................................................................................................................................................16

Encryption Key Link ............................................................................................................................................................................ 16

Frequency Select Switches ................................................................................................................................................................16

Modulation LEDs ................................................................................................................................................................................17

Audio Level Control ............................................................................................................................................................................17

Locked Mode ...................................................................................................................................................................................... 17

UT700 Battery Installation ..................................................................................................................................................................17

System Installation and Operating Instructions ............................................................................................................................... 19

System Setup .....................................................................................................................................................................................19

Changing the Security Level...............................................................................................................................................................22

Setting the Encryption Key .................................................................................................................................................................22

Protecting the Encryption Key ............................................................................................................................................................23

UT700 Vari-Mic™ Controls .................................................................................................................................................................23

Bass / Mid / Treble (LO / MID / HI) .................................................................................................................................................. 23

Preamp Level Control .........................................................................................................................................................................24

Bass Filter ..........................................................................................................................................................................................24

5-Pin Input Jack Wiring (UM700) ........................................................................................................................................................24

RF Bypassing (UM700) ......................................................................................................................................................................25

Line Level Signals (UM700) ............................................................................................................................................................... 25

Encryption Key Cables .......................................................................................................................................................................25

Troubleshooting ...................................................................................................................................................................................27

Power Problems .................................................................................................................................................................................27

UDR700 ..........................................................................................................................................................................................27

UM700 ............................................................................................................................................................................................ 27

UT700 .............................................................................................................................................................................................27

RF Problems.......................................................................................................................................................................................27

Audio Problems ..................................................................................................................................................................................28

Specifications .......................................................................................................................................................................................30

Overall System................................................................................................................................................................................30

UDR700 Digital Receiver ................................................................................................................................................................ 30

UM700 Digital Transmitter ...............................................................................................................................................................30

UT700 Digital Transmitter ................................................................................................................................................................ 30

Replacement Parts and Accessories .................................................................................................................................................32

Service and Repair ............................................................................................................................................................................... 33

Returning Units for Repair ..................................................................................................................................................................33

Microphone Cord Termination ............................................................................................................................................................34

Rio Rancho, NM 3

UDR700 / UM700 / UT700

LECTROSONICS, INC. 4

Introduction

X

The 700 Series encrypted digital wireless microphone
system uses a digital audio chain and an encrypted
digital RF communications link for excellent sound
quality and data security. The applications for this
system include high-end motion picture, studio and
stage, and boardrooms, courtrooms and conference
rooms where security is a concern. While these
applications are very different from one another, this
single system is able to provide significant benefits in all
of these areas of operation.

Overall System Design

The 700 Series system uses state-of-the-art techniques
to offer superb audio quality and formidable security.
Audio is sampled at 44.1 kHz using a 24-bit A/D con­verter in the transmitter. (For perspective, a CD uses
the same sample rate, but only 16 bits per sample.)
High-entropy encoding, cryptographically secure
encryption, efficient modulation/demodulation,
decryption and decoding all take place in the digital
domain, using highly optimized proprietary techniques.
If digital audio output is desired, there is no need to
convert back to analog at all; otherwise, the first and
only conversion back to analog occurs at the receiver’s
output.

In the transmitter, the audio first passes through a DSP­controlled, dual-envelope analog limiter to prevent
distortion from occurring on high level peaks. The audio
is then digitized and fed to a DSP. The DSP uses a
proprietary audio encoding scheme to lower the bit rate
and provide the high entropy required for secure
encryption. The bit stream is then encrypted, appor­tioned into packets, and sent over the air using a
proprietary digital modulation technique.

In the receiver, the digital baseband signal is demodu­lated to recover the original bit clock and data stream.

Encrypted Digital Wireless System

The DSP separates out the packet headers and de­crypts the audio data. The audio data is then decoded
to recover the original audio signal present in the
transmitter.

UDR700 Encrypted Digital Receiver

Rota-Versity™ Reception

The UDR700 receiver uses a proprietary technique to
implement a unique and very effective type of diversity
reception called Rota-Versity

Rota-versity is a microprocessor controlled antenna
phase matching technique. The UDR700 uses a four
way phase shifter to combine the power of the two
antennas in any of four phase angles, 90 degrees apart.
Hundreds of times per second, all of the four phase
angles are tried. The angle offering the best reception
is always used for the audio data. The result is that the
diversity system “tracks” the phase shifts between the
two antennas, keeping phase cancellation loss under 1
dB at all times. Multi-path dropouts are minimized and
operating range is maximized by using both antennas,
in phase, at all times.

RF Section

The RF section of the UDR700 is a traditional dual­conversion superheterodyne receiver. Once the
antenna power is combined, the RF signal is passed
through dual tracking filters. These 7 MHz bandpass
filters are centered on the operating frequency as it is
tuned through the 25.6 MHz frequency block for excel­lent selectivity and interference rejection. The first
tracking filter is followed by a GaAs FET attenuator that
applies from 2 to 32 dB of attenuation to provide very
high overload protection. The amount of attenuation is
controlled by the RSSI (Received Signal Strength
Indicator) feedback from the second IF.

TM

.

UDR700 Block Diagram

Input

Input

Bandpass

Bandpass

Filter

Filter

Input

Bandpass

Filter

AES-3id

Jack

Headphone

Out

LR

Phase

Out

Reverse

2

3

1

Rio Rancho, NM 5

RF
Amp

Antenna

Kill Switch

A/B/Rot.

RF
Amp

Attenuator

Switch

600

4-Way
Phase

Combiner

0/90/180/270

Audio

Amp

Tracking

Filter

AES3

Transmitter

Anti-aliasing

Filter

FET

Attenuator

D/A

Converter

RF
Amp

RSSI

Tracking

Filter

Oscillator

Microprocessor

Microprocessor

1st

Mixer

1st

Local

Display

& Buttons

244

MHz

Decode

Dual
SAW

Filters

2nd

Mixer

2nd

Local

Oscillator

Digital Signal

Processor

Decrypt

Integrated Circuit

10.7
MHz

Quadrature

Detector

RSSI

Digital

Demodulator

UDR700 / UM700 / UT700

The 244 MHz from the first IF is reduced to the second
IF of 10.7 MHz, and is then fed to the Quadrature
Detector. The first mixer is a GaAs MMIC device with a
rated IP3 (third order intercept) of +24 dBm to minimize
undesired IM products. Because the signal is digital,
thermal drift in the detector has little effect on the
signal’s content, unlike an analog receiver.

Digital Demodulator

The digital demodulator consists of a PLL clock recov­ery circuit and a bit slicer. The recovered bit clock and
data stream are fed to the DSP. In addition, the recov­ered bit clock is used to derive the timings for the
receiver’s digital audio circuits, so the receiver audio is
synchronous with the transmitter audio, sample for
sample.

Digital Signal Processing

The DSP uses the packet headers as a timing refer­ence to recover the digital audio data. The data is then
decrypted and decoded to recover the original digitized
audio samples. Additionally, the packet headers also
contain transmitter battery status information, which is
extracted by the DSP.

Audio Output

The digital audio samples are sent to the AES-3id
transmitter for digital audio output, and to the D/A
converter for conversion to analog. The converter
output is filtered and amplified, and then fed to a
transformer, attenuator and XLR jack. The analog
output is also sent to a separate headphone amplifier
on the UCR700 front panel for monitoring purposes.
The signal at the headphone output is taken just ahead
of the output transformer, so it provides the same audio
quality as the XLR output and can also be used as a
second output or recorder feed.

UM700 Block Diagram

Mic

Jack

1
2
3
4
5

+3.3V Bias
Supply

Encryption
Key Link

Bicolor

Modulation

LEDs

Hi/Lo
Pass
Filter

Input
Amp

LF

Rolloff

Shunt
Limiter

Freq

Switches

Audio

Audio
Level

Microprocessor

A-D

Converter

11001001

Dual

Envelope

Limiter

Digital Signal Processor

Encode

Encrypt

The main audio output amplifier is set for maximum
gain. This output passes through a passive attenuator
and phase switch on its way to the rear panel Audio
Output XLR jack. The passive attenuator reduces the
audio level in calibrated 5 dB steps, ensuring the signal­to-noise ratio of the receiver remains the same at all
output levels selected by the rear panel control.

Encrypted Digital Transmitters

Two encrypted digital transmitters are offered, a belt
pack unit and a hand held unit. Although their physical
packages differ, internally, they are essentially the
same. The major difference is the microphone input
jack in the UM700 and the VariMic
hand held transmitter.

The microphone input jack used in the UM700 is
configured so that virtually every lavaliere, hand-held or
shotgun mic can be used, regardless of whether they
use positive or negative bias. (See UM700 Controls
and Functions and 5-Pin Input Jack Wiring.)

The UT700 uses a built in microphone element. (See
UT700 Microphone Element.)

DSP-Cntrolled Dual Envelope Analog Limiter

In order to make the best use of the high quality A/D
converter, microphone audio is limited in the analog
domain first, before being sampled. The DSP controls
this process, but because the limiting is done in the
analog domain, levels near the converter’s maximum
may be used without fear of clipping. (The limiter has a
range of more than 30 dB for excellent overload protec­tion.)

The limiter has a fast attack, but different release
characteristics, depending on the nature of the signal
that drove the input into limiting. Brief transients result
in a fast decay, to avoid “pumping” effects, while sus­tained loud signals result in a slower decay, to keep
distortion to a minimum. The result is a transparent­sounding limiter with excellent low distortion character­istics.

Switching

Power

9V

Battery

Supply

Bicolor
Power
LED

+3.3v
+1.8v
+9v

-3v

™

used in the UT700

Phase

Locked

Loop

Voltage

Controlled

Oscillator

Digital

Modulator

RF

Amp

50

Isolator

LECTROSONICS, INC. 6

Encrypted Digital Wireless System

Digital Signal Processing and Modulation

The preamplified and limited audio signal is converted
to digital using a 24-bit A/D converter and fed to the
DSP. Within the DSP, the audio is encoded to reduce
the bit rate and increase entropy in the data stream
prior to encryption. The data stream is then encrypted
and apportioned into packets, delimited by packet
headers. The complete bit stream is modulated onto
the carrier using a modified pi/4 DQPSK (differential
quadrature phase shift keying) method. This modula­tion method makes efficient use of the RF spectrum
and is easy to demodulate reliably.

Transmitter RF Output Section

Intermodulation (IM) is a problem that occurs in the final
amplifier stages of conventional transmitters when the
transmitters are within a few feet of each other. This
can create serious problems in multichannel wireless
systems when an IM signal falls in the same range as
the carriers, IF frequencies, local oscillator or image
frequencies of the systems being operated. The
UM700 and UT700 eliminate this problem by passing
the modulated radio signal through a circular isolator
before it enters the antenna. The circular isolator
functions like a “one-way check valve,” allowing the RF
signal to pass through to the antenna, but not allowing
spurious RF to pass back into the transmitter amplifier
stage. This provides excellent stability and eliminates
IM in the output stage of the transmitter.

Long Battery Life

The use of highly efficient circuits and switching power
supplies throughout the design allow over 4 hours of
operation using a single 9 volt alkaline battery. (A 9 V
lithium battery will provide over 7.5 hours of operation.)
The battery compartment is a unique mechanical
design which automatically adjusts to fit any brand of 9
volt battery, and the battery contacts are spring loaded
to prevent “rattle” as the unit is handled.

UT700 Block Diagram

Mic

Element

Preamp

Level

Encryption
Key Link

Bicolor

Modulation

LEDs

Preamp

Tone

Input

Amp

LF

Rolloff

Shunt
Limiter

Freq

Switches

Audio

Audio
Level

Microprocessor

A-D

Converter

11001001

Dual

Envelope

Limiter

Digital Signal Processor

Encode Encrypt

Frequency Agility

700 Series wireless systems are currently available in
four different “blocks” of 256 frequencies each, from

562.200 to 665.500 MHz.

Note: Frequencies between 608.000 MHz to

614.000 MHz are reserved and not available for
commercial use.

Each of these blocks is preset at the factory and
provides 256 selectable frequencies in 100 kHz steps
over a 25.6 MHz bandwidth. This wide variety of
selectable frequencies alleviates carrier interference
problems in mobile or traveling applications. Two 16­position rotary switches are used to select the fre­quency.

The transmitter section uses a synthesized, frequency
selectable main oscillator. The frequency is extremely
stable over a wide temperature range and over time.

Antenna

At UHF, where wavelengths and antennas are shorter
than at VHF, a resonant length wire is preferred over
using the microphone cable as the antenna. The
antenna on the UM700 is a flexible 1/4 wavelength
insulated galvanized steel cable, detachable via an
SMA connector. The impedance of this connector is 50
Ohms.

The UT700 has a dipole antenna incorporated into the
circuit board.

UT700 Microphone Element

The UT700 includes the Lectrosonics VariMicTM mic
element. The VariMic
electret) microphone that is adapted for the unique
circumstances of wireless microphones. It offers
excellent dynamic range while minimizing handling
noise and low frequency noise (rumble or wind).

In the VariMic

TM

increases the usable dynamic range 12 dB and greatly
reduces distortion, just as if the FET were being

Switching

9V

Battery

Power
Supply

TM

is a cardioid condenser (back

, an unusual pumped source FET circuit

+3.3v
+1.8v
+9v

-3v

Bicolor
Power
LED

Phase

Locked

Loop

Rio Rancho, NM 7

Voltage

Controlled

Oscillator

Digital

Modulator

RF

Amp

50

Isolator

UDR700 / UM700 / UT700

ROTA-VERSITY™ DIGITAL

PHASE CORRELATION

0

270

90

MICROPROCESSOR

RECEIVER

180

PHASE CORRECTED

COMBINING

supplied with 48 Volts. A unique 16-position sensitivity
control at the element itself can also adjust the sensitiv­ity over a 15 dB range. This is in addition to the normal
gain control in the wireless microphone. The result is
the widest dynamic range of any condenser mic in a
wireless microphone.

TM

The VariMic

has a three-point damped rubber suspen­sion to reduce high frequency handling noise and a
generous sized windscreen to keep wind noise and
breath pops away from the microphone.

Comparing Diversity Reception and Rota-Versity

The UDR700’s new approach to diversity reception is a
vast improvement over traditional designs. Traditional
analog diversity reception designs employed techniques
ranging from simple antenna and audio signal switching
using one or two receivers, to dual-receiver ratio
combining systems. In the digital realm, even more
advanced techniques are possible to analyze and
correct antenna phase.

A popular phrase, “true diversity,” arose in defense of
dual-receiver audio switching diversity designs versus
very low cost receivers that simply had two antennas
mounted on a single unit. Diversity reception can be
implemented by mixing or selecting the audio from two
separate receivers, or by various antenna combining
techniques ahead of the receiver. In reality, all receiver
designs can aptly be called “true diversity” if they make
use of two or more antennas that are receiving diverse
(uncorrelated) signals.

Two diversity designs found in use today include Audio
Switching Diversity and Ratio Diversity. Both offer some
improvement in
audio reception,
but with a
significant
increase in
equipment costs
because of the
need for two
receivers.
SmartDiversity
from
Lectrosonics is
different.

8

™

SmartDiversity

AUDIO SWITCHING

DIVERSITY

RECEIVER A

SWITCH

AUDIO
OUTPUT

™

RECEIVER A

RECEIVER AUDIO OUTPUT

SELECTED BY RF LEVEL

RATIO DIVERSITY

AUDIO COMBINING

RECEIVER A

AUDIO

PANNING

CIRCUIT

RECEIVER A

RECEIVER AUDIO OUTPUTS
MIXED IN OptiBlend™ RATIO
CONTROLLED BY RF LEVEL

AUDIO
OUTPUT

SmartDiversity™ is a microprocessor controlled tech­nique that automatically analyzes audio content and RF
levels to determine optimum timing for the switching
activity. Active analog antenna phase switching tech­niques use both antennas at the same time, with 180
degree phase switching to help keep the received
signals in phase and minimize dropouts. When the
overall RF signal strength quickly drops, the phase of
one antenna is switched 180 degrees. If the switch
increases the RF
level, it will remain
latched in that
position until the
RF level quickly
drops again. Both
antennas are used
at the same time,
so overall operating
range is also
improved.

Rota-Versity

Rota-Versity™ is only possible in the digital realm. Rota-

TM

Versity
output of two antennas in any of four phase angles,
each 90 degrees apart, regardless of RF levels. Hun­dreds of times per second, all of the phase angles are
explored, with the angle offering the best reception
used for the audio data. The result is the diversity
system “tracks” the phase shift between the two anten­nas to ensure that they always add to one another (they
are always less than 90 degrees out of phase). Multi­path dropouts are minimized and operating range is
maximized by using both antennas simultaneously.
Because it times
phase switches
to happen only
during digital
packet headers
where no audio
is being con­veyed, Rota-

™

versity
transparent and
cost effective .

is also

™

ANTENNA PHASE

SWITCHING

MICROPROCESSOR

RECEIVER

180 DEGREE PHASE

SWITCHING

™

uses a four-way phase shifter to combine the

LECTROSONICS, INC.

The 700 Series Encryption System

Encrypted Digital Wireless System

To guard against eavesdropping, the encryption in the 700
Series digital wireless system makes use of several
processes and a unique key setup procedure to provide a
high level of entropy and thus maximum security. A 128­bit key is used to create a formidable barrier against brute
force attacks attempting to break the encryption code.
The result is 340 trillion, trillion, trillion possible key
combinations.

The audio signal entering the transmitter first passes
through a DSP controlled, dual-envelope limiter that cleanly
limit signal peaks up to 30 dB above full modulation. The
signal is then converted to 24-bit digital audio, with sampling
at 44.1 kHz. The resulting bit stream is then digitally
compressed to meet the bandwidth requirements for the
radio output, encrypted and then transmitted over the air.

The encryption key setup procedure involves a cable
connection between the transmitter and receiver. Once
connected, the receiver maybe placed into the key
generation mode and the operator is prompted to make
several button pushes on the front panel of the receiver.
These button pushes capture the instanteneous value of a
fast, free running, 16-bit timer. The captured values are
combined to create the eight, 16-bit segments of the 128­bit encryption key.

With the exception of Security Level 3, any number of
transmitters can be connected during a single setup
procedure to share a common encryption key. Regardless
of which Security Level is selected, only one receiver can
share the key with the transmitter(s). This prevents the
use of a second receiver to eavesdrop on the transmitted
signal.

The 700 System offers three levels of security, trading off
ease of use for immunity to attack.

Level 1

Security Level 1 offers the most intuitive operation. Once
the key has been set, the equipment may be operated
exactly the same as a traditional analog system. The
transmitter and receiver may be powered on in any
sequence, and the transmitter may move in and out of
range without consequence (except normal squelching).
Security in this mode is excellent, but the scrambling
sequence repeats approximately every 20,000 bits,
theoretically exposing the user to differential attacks. Due
to its ease of use and quite effective security, Level 1 is the
default security level.

Level 2

Security Level 2 offers much greater encryption strength,
at the cost of slightly less intuitive operation. In Level 2,
the scrambling sequence never repeats (i.e. the PRNG is
free-running), so the receiver must be on and ready to
receive when the transmitter is first switched on. Some
signal loss is tolerated but if the transmitter should wander
out of range for more than ten seconds, it will be neces­sary to switch it off and on again to restart the sequence,
resynchronizing with the receiver. Security in this mode is
a great deal stronger than Level 1, since the scrambling
sequence never repeats. Only if the sequence is deliber­ately reused (i.e. by cycling transmitter power after
prolonged signal loss, or by reusing the same key session
after session) is a differential attack possible even in
theory.

Level 3

Security Level 3 offers the strongest encryption of all,
again at the cost of some convenience. Level 3 is much
like Level 2, except that the equipment itself enforces a
policy that

ever be used more than once

of cryptography: key reuse leads to vulnerability. Thus,
Level 3 security is about as close to the holy grail of the
one-time pad as any wireless vendor is likely to offer at a
reasonable price. Operation is a little different in Level 3:

1. The transmitter will not send any audio until a new key

2. Only one transmitter may receive each key.

3. If the transmitter is out of range of the receiver for more

All three levels offer strong encryption, so each user may
make a policy decision based on an assessment of risk.
Those requiring ease of use may relax, knowing that
eavesdropping is extremely difficult even in Level 1. Many
users may find Level 2 to be just as convenient, allowing
them to use greater encryption strength. Those users
willing to follow stricter security procedures can use Level
3, the strongest encryption available today from a wireless
microphone.

no portion of any scrambling sequence shall

. This is a fundamental tenet

is transferred from the receiver.

than ten seconds, it will be necessary to generate a
new key in order to continue using the system.

RANDOM

BUTTON

PRESSES

Rio Rancho, NM 9

ENTROPY

HARVESTER

AUDIO
INPUT

ENCRYPTION KEY CREATION PROCESSOR FROM RECEIVER

128-BIT KEY

(SEED)

24-BIT

A/D CONVERTER

PRNG

BIT STREAM

(SCRAMBLING SEQUENCE)

BIT STREAM

HIGH ENTROPY

(DIGITAL COMPRESSION)

ENCODER

BIT STREAM

ENCRYPTER

MODULATOR

DIGITAL TRANSMITTER HARDWARE

ANTENNA

OUTPUT SECTION

UDR700 / UM700 / UT700

LECTROSONICS, INC. 10

UDR700 Controls and Functions

UDR700 Front Panel

Information and Status Display SELECT Up/Down Buttons POWER On/Off Switch

RF Level Indicator

Antenna Phase Combining Indicator

Encrypted Digital Wireless System

MENU Button

Transmitter Audio Level ROTA-VERSITY Switch Audio Monitor Level Control

RF Level Indicator

A 10-segment LED strip indicates the level of the
incoming RF signal. The strip is calibrated to provide
accurate indications from 1 uV to 1 mV. The LEDs are
highly visible from a distance.

Note: A digital wireless receiver behaves differently
than an analog receiver during weak RF signal
conditions. The audio signal to noise ratio of an
analog receiver will gradually deteriorate as the RF
signal level drops, and the receiver will continue to
produce audio (accompanied by some noise) even
at very low RF levels. The signal to noise ratio of a
digital receiver remains largely unchanged as the
RF signal level drops, until suddenly, over a range
of just a few dB, the signal abruptly degrades and
then is muted altogether.

The RF Level Indicator can accurately display signals
as low as 1 uV to permit checking for interfering signals
just below the squelch threshold of the receiver. With
the transmitter turned off, the LEDs will indicate the
presence of interference.

Transmitter Audio Level

The 10-segment Transmitter Audio Level indicator strip
displays the modulation (audio level) of the incoming
signal. The strip is calibrated in 6 dB steps over an
expanded scale (54 dB) providing an extremely accu­rate visual “picture” of the signal dynamics.

Information and Status Display

A 16-segment Information and Status Display provides
information about the security level, selected frequency,
or tuning group, transmitter Frequency Select Switch
setting, TV channel, transmitter battery level and
system locked/unlocked status.

Audio Monitor Jack SECURITY Jack

Select Up/Down Buttons

The SELECT Up/Down buttons are used to select
various options within each display selection and for
setting the operating frequency of the receiver.

Rota-Versity™ Switch

The Rota-Versity™ switch is a three-position switch
used to either enable diversity operation, or to tempo­rarily disable diversity operation (by selecting antenna A
or antenna B) for diagnostic purposes.

Antenna Phase Combining Indicator

Indicates the phase relationship between antenna A
and right for antenna B. Also provides a visual warning
if the Rota-Versity switch is not in the normal (centered)
position, or if one of the antennas is malfunctioning.

Power Switch

The Power switch applies AC or External DC power to
the unit. This switch, in conjunction with the MENU
button, can also be used to lock, or unlock the front
panel buttons (see Disabling Front Panel Buttons), and
in conjunction with the SELECT Down button, can used
to set the Security Level. (See Installation and Operat­ing Instructions, Setting the Security Level.)

Security Jack

The Security Jack is a 3.5 mm mono connector used to
set the security level of the associated transmitter(s).
(See Installation and Operation Instructions, Setting the
Security Level.)

Audio Monitor Level

The Audio Monitor Level controls the amplitude of the
audio output from the Audio Monitor Jack.

Menu Button

The MENU button steps the Information and Status
Display through six different displays used for setup and
operation. (See Information and Status Display Menus
and Functions and Installation and Operating Instructions.)

Rio Rancho, NM 11

Audio Monitor Jack

The 1/4-inch, stereo, Audio Monitor Jack will drive a
wide variety of different types of headphones and can
also be used as a second high quality audio output to
drive recorders or other external audio devices.