Lectrosonics UDR200b User Manual

UDR200B

RATIO DIVERSITY UHF RECEIVER

OPERATING INSTRUCTIONS

and trouble-shooting guide

LECTROSONICS, INC.

Rio Rancho, NM

Wireless Diversity Receiver

TABLE OF CONTENTS

GENERAL TECHNICAL DESCRIPTION ............................................................. 4

FRONT PANEL CONTROLS AND FUNCTIONS ................................................. 7

REAR PANEL CONTROLS AND FUNCTIONS ................................................... 8

INSTALLATION AND OPERATING INSTRUCTIONS ......................................... 9

USING THE LED INFORMATION DISPLAY ...................................................... 10

LecNet

FREQUENCY BLOCKS AND RANGES ............................................................ 14

TM

COMPUTER INTERFACE................................................................... 12

ANTENNA USE AND PLACEMENT................................................................... 15

TROUBLESHOOTING ......................................................................................... 16

UDR200B REPLACEMENT PARTS and ACCESSORIES................................ 16

SERVICE AND REPAIR ...................................................................................... 17

RETURNING UNITS FOR REPAIR .................................................................... 17

SPECIFICATIONS AND FEATURES .................................................................. 18

LecNet SOFTWARE PROTOCOL ...................................................................... 19

WARRANTY ........................................................................................... Back c over

Rio Rancho, NM – USA

3

GENERAL TECHNICAL DESCRIPTION

FILTER

AMP

1ST

LOCAL

OSCILLATOR

455KHZ

BP

FILTER

RATIO

COMBINER

&

OPTI-BLEND

455KHZ

BP

FILTER

2:1

EXPANDER

TREBLE

2:1

EXPANDER

BASS

23 KHZ

LP

FILTER

HEADPHONE

OUT

OUTPUT

LEVEL

ADJUST

XLR
OUT

PILOT
TONE
MUTE

FILTER

uP

AMP

FILTER

HI-LEVEL

DIODE MIXER

HI-LEVEL

DIODE MIXER

RF MODULE

2ND MIXER

&

IF AMP

2ND MIXER

&

IF AMP

50KHz

LP FILTER

50KHz

LP FILTER

XTAL

CONTROLLED

2ND

OSCILLATOR

RF LEVEL

LEDs

RF LEVEL

LEDs

SAW

FILTER

SAW

FILTER

70 MHz
IF AMP

70 MHz
IF AMP

COUNTING

DETECTOR

COUNTING
DETECTOR

FILTER

AMP

FILTER

AMP

FILTER

CENTER

FREQUENCY

DETECTOR

CENTER

FREQUENCY

DETECTOR

AUDIO

AMP

uP

UDR200B

BLOCK DIAGRAM

uP

RF
ONLY

TRI-MODE

DYNAMIC

uP

uP

uP

uP uP

VARIABLE

CUT-OFF

LP FILTER

TO DATA
DISPLAY

The UDR200B consists of two high performance, dual-conver­sion receivers operating simultaneously. The audio outputs of
the receivers are blended in a ratio controlled by the compara­tive RF levels in the receivers. The multistage RF front end is
a unique design that is tuned by a microprocessor to the
selected frequency. The RF and audio performance is ex­tremely stable over a very wide temperature range, making the
UDR200B perfectly suited to mounting in studio equipment
racks. The proprietar y audio processing includes a dual-band
compandor and dynamic noise filter for very low distortion and
a superior signal to noise ratio. The squelch system is oper­ated by a separate pilot tone and mutes the audio output
directly at the output connector. The audio output is calibrated
for exact level matching, with wide range, peak responding
LED indicators.

RF SECTION

The problem posed to the design staff was to retain the RF
reliability of the Lectrosonics’ fixed frequency designs but add
the frequency flexibility of a frequency agile design. The uni­versal (and poor) way to build frequency agile systems is to
design a wide open front end that will pass any frequency
within the tuning range of the system. This leads to ver y poor
RF performance with lots of interference, driving the user to
switch frequencies in an attempt to sidestep the interference.
This makes frequency agile receivers a self fulfilling system;
you have to use the frequency agility to get away from the
problems caused by the frequency agile design compromises.

The problem of frequency agility is further compounded when
you realize that frequency changes “on the fly” cannot be
made on any type of wireless system. For example, if there is
suddenly an interference problem with a system in use, on
stage for instance, a frequency change cannot be made
without interrupting the program. Basically, the show must go
on. In multi-channel applications, changing the frequency of
one system will usually produce all kinds of new
intermodulation problems with the other systems operating in
the same location. Frequency agility is not the universal
panacea for interference problems. It is only another tool and

a limited tool at that. The first line of defense must be the
system’s basic immunity to interference. That required a new
look at frequency agile receiver design.

FREQUENCY TRACKING FRONT-END

Our solution to the wide open front end problem was to design
a selective front end that can be tuned to the frequency in use.
Since we wanted this front end to be equivalent to our fixed
frequency front ends, this was a daunting task. Lectrosonics
has always used front ends with more sections and much
more selectivity than any other wireless manufacturer. The
final design consisted of a total of 12 transmission line resona­tors with variable capacitance applied to each resonator by a
microprocessor. This allows each resonator to be individually
tuned by the microprocessor for any user selected frequency
in a 25 MHz band. This sophistication produced a front end
that was as selective as fixed frequency designs, yet could
cover the entire 25 MHz range.

HIGH CURRENT LOW NOISE AMPLIFIERS

The gain stages in the front end use some rather special
transistors in a feedback regulated high current circuit that
combine three parameters that are generally at odds with one
another. These are: low noise, low gain and relatively high
power. It is easy to understand the advantages of low noise
and high power capability but why is low gain desirable? The
answer is that in a receiver, low gain allows the front end to
handle stronger RF signals without output overload, which is
“increased headroom,” so to speak. The result of a design that
takes all three of these parameters into consideration at once,
is a low noise RF amplifier with a sensitivity rating equal or
better than the best conventional design with a hundred times
less susceptibility to intermodulation interference.

Combining the high power gain stages with the tracking front
end produces a receiver that is unusually immune to single
and multiple interfering signals close to the operating fre­quency and in addition strongly rejects signals that are much
farther away.

4

Wireless Diversity Receiver

DOUBLE BALANCED DIODE MIXERS

In all wireless receivers, a mixer is used to convert the carrier
frequency to the IF frequency where most of the filtering and
gain in the receiver takes place. After doing all the right things
in the front end, it would be a shame to waste the performance
with a second rate mixer. In other designs that is exactly what
happens since mediocre mixers cause more intermodulation
problems than mediocre front ends. The only solution was a
high power, double balanced diode mixer driven by a local
oscillator with more output power than most wireless transmit­ters (100 mW). The mixer in the UDR200B produces output at
only the sum and difference signals, with minimal spurious
signals. This mixer offers a very high overload threshold. The
IF output of this mixer is at 71 MHz which is unusually high for
a wireless receiver. This high frequency was chosen to in­crease the image rejection in the front end to as high as our
fixed frequency designs. The mixer is followed by low noise
amplifiers and SAW filters to preserve the superior RF perfor­mance.

SURF ACE ACOUSTIC WAVE FILTER

The UDR200B is unique in that it uses state of the art SAW
filters in each IF section. The SAW filters are the only filter that
can combine sharp skir ts, constant group delay, and wide
bandwidth in one filter. Though expensive, this special type of
filter allows us to follow the basic receiver rule of doing the
primary filter ing as early as possible, at as high a frequency as
possible and before high gain is applied to the signal. Since
these filters are made of quar tz, they are very temperature
stable. Conventional LC filters at these frequencies would drift
unacceptably in the elevated temperatures of an equipment
rack. After following the rule in a r igorous way, and due to the
sharp filter ing action of the SAW filters, the 71MHz signal is
converted to the low frequency of 455 kHz. Lots of gain is
then applied in a conventional IC and the signal is then con­verted to audio. 455 kHz is very unconventional for a second
IF in a wide deviation (±75 kHz) system. We chose to use 455
kHz to obtain an outstanding AM rejection figure over a very
wide range of signal strengths and to produce an excellent
noise improvement at low signal strengths (capture ratio). To
use an IF at 455 kHz requires an unusual circuit to convert the
IF to audio.

DIGITAL PULSE COUNTING DETECTOR

The UDR200B receiver uses an advanced digital pulse detec­tor to demodulate the FM signal, rather than a conventional
quadrature detector. The common problem with quadrature
detectors is thermal drift, par ticular ly those that operate at
higher frequencies like 10.7 MHz. Though the quadrature
detectors may work well at room temperature, if they are not
carefully compensated, they will produce amplitude changes
and audio distortion in the elevated temperatures of an equip­ment rack. Some manufacturers try to get around the problem
by tuning their systems at higher temperatures after they’ve
been on for some time. This just means that for the first hours
in a cool room the receiver is well out of specification or after a
few hours in a hot rack.

The UDR200B design presents an elegantly simple, yet highly
effective solution to this age old problem. The UDR200B

detector basically works like this: A stream of precision pulses
is generated at 455KHz locked to the FM signal coming from
the 455 kHz IF section. The pulse width is constant, but the
timing between pulses varies with the frequency shift of the
FM signal. The integrated voltage of the pulses within any
given time interval varies in direct proportion to the frequency
modulation of the radio signal. Another way of describing it is
that as the FM modulation increases the frequency, the circuit
produces more pulses and as the modulation decreases the
frequency, the circuit produces fewer pulses. More pulses
produces a higher voltage and fewer pulses a lower voltage.
The resultant varying voltage is the audio signal.

This type of detector eliminates the traditional problems with
quadrature detectors and provides very low audio distortion,
high temperature stability and stable audio level. The counting
detector also adds additional AM rejection, in addition to the
limiting in the IF section. The amplitude of the pulses is con­stant, so level differences in the IF signal do not affect the
pulse. The two resulting audio signals from the A and B re­ceiver channels are then combined to achieve the maximum
benefits of diversity reception.

RATIO COMBINING DIVERSITY WITH OPTI­BLEND

Instead of the usual audio switching between the two receiv­ers, we blend the audio outputs of the receivers in a ratio
controlled by the RF level of the received signals in the two
receivers. This totally eliminates any of the switching noise
sometimes heard in other designs and improves the signal to
noise ratio an additional 6 dB under weak signal conditions
and 3 dB in strong signal conditions.

TM

TRI MODE DYNAMIC FILTER

After being combined in the Opti-Blend circuit, the audio signal
is passed through a “dynamic noise reduction circuit”. The
cutoff frequency of this filter is varied automatically by measur­ing the amplitude and frequency of the audio signal and the
quality of the RF signal. The audio bandwidth is held only to
that point necessary to pass the highest frequency audio
signal present at the time. If the RF level is weak, then the
filter becomes more aggressive. This results in a dramatic
reduction of “hiss” at all times. During passages with a high
frequency content, this filter gets completely “out of the way”
and passes the signal with no decrease in high-frequency
response. Keep in mind that if hiss is added to a signal, there
is a psycho acoustic effect that makes the sound seem
brighter. The other side of this is that if hiss is removed from a
signal it will sound duller. Basically the ear’s detection appara­tus is pre-sensitized to high frequency sounds by small
amounts of high frequency hiss. Consider this effect when
making a judgment about the sound quality of various wireless
systems and this par ticular filter. We have satisfied ourselves
through elaborate tests that this filter is totally transparent.
There is one circumstance where a good argument can be
made for bypassing this filter, so a switch is provided to do just
that.

RF ONLY NOISE FILTER

A small switch on the rear of the receiver will allow the noise
filter to be set for RF ONLY. In this mode the filter is held out of

Rio Rancho, NM – USA

5

the audio frequency range unless the RF level drops to very
low levels. At weak RF levels, the filter operates in the TRI
MODE state until the RF level rises back to acceptable levels.
This has the desirable effect of softening dropouts. We recom­mend using the RF ONLY setting when it is desirable to pick up
high frequency background noise, such as for a location shot
for a movie. This might be machinery noise, compressed air,
etc. If the desirable background noise is at a low level, the Tri
Mode Dynamic Filter will identify this as undesirable hiss and
effectively remove it.

2:1 EXPANDER (Dual–Band Compandor)

“Dual-band Companding” is a complimentary system, that is,
whatever is done in the transmitter must be exactly mirrored in
the receiver. The transmitter compresses the audio signal in
two separate audio bands using four separate time constants
to avoid the inevitable trade-offs in attack and decay times that
occur in a single-band compandor. The companion circuit in
the receiver then re-expands this compressed signal restoring
the original dynamic range and frequency characteristics of the
signal.

The mixed audio signal leaves the Opti-Blend circuit and is fed
through a 23 kHz low pass filter where all the high frequency
noise (including the 32 kHz pilot tone) is filtered out. After the
23 kHz low pass filter, the signal is split into two parts via a 1
kHz low pass filter and a 1 kHz high pass filter. The separated
signals are then processed in separate channels of the 2:1
expander. Each channel of the 2:1 expander is optimized for
its respective frequency band. By optimizing the compandors
for high and low frequencies we can handle sounds such as
clicks, sibilants and fast transients produced by plucked or
struck instruments in the high frequency section without com­promising the performance in the main voice range. The two
outputs of the 2:1 expander are then summed in an op-amp
and sent to an audio amplifier as one signal.

PILOT TONE MUTE (SQUELCH)

The 200 system utilizes a separate ultrasonic tone modulation
of the basic carrier to operate the receiver squelch. In the
transmitter, a 32.765 kHz tone is injected into the audio signal
after the microphone preamp, just after the compandor. The
supersonic pilot tone is filtered out of the audio signal immedi­ately after the detector in the receiver so that it does not
influence the compandor or various gain stages.

The basic benefit of the pilot tone squelch system is that the
receiver will remain squelched (muted) until it receives the pilot
tone from the matching transmitter, even if a strong RF signal
is present on the carrier frequency of the system. Once a pilot
tone is detected, the receiver will remain open during all signal
conditions. If the transmitter signal degrades to the point
where hiss and noise may become objectionable, the Opti­Blend circuitry and Tr i Mode Dynamic Filter will work to reduce
or eliminate the unwanted noise. Since the pilot tone keeps
the receiver audio output open, as soon as the transmitter
signal returns to nor mal, the audio signal is instantly available
with no delays. A conventional squelch system, on the other
hand, can briefly interrupt the audio during a near drop-out
condition.

The pilot tone mute circuit drives a relay which physically
disconnects the output amplifier from the output audio trans-

former. The relay then connects the transformer primary to
ground to prevent hum pickup in the transformer due to an
open primar y winding. This provides complete muting of the
audio and the noise. The pilot tone function may be bypassed
with a rear panel push button. Once pushed, the pilot tone
mute is “latched” in a disabled condition until the receiver is
powered off then back on. When the pilot tone is disabled,
there is still a “squelching” function provided by the Opti-Blend
circuitry and Tri Mode Dynamic Filter. These circuits can
provide approximately 50 dB of muting during weak or no
signal conditions when the pilot tone is disabled. If you hear
moderate hiss when the transmitter is off, the pilot tone has
probably been bypassed.

AUDIO OUTPUT

The audio is a fully floating, transformer coupled, balanced
signal. Pin 2 is “high” or in phase with the transmitter input. A
precision attenuator allows you to adjust the output level from
+20 to -35 dBu. The output always runs “wide open” and is
only attenuated by this output level control. Neither the noise
level in the receiver nor headroom is affected. You can, how­ever, over drive or under drive attached audio equipment.

A ground lift switch is available to disconnect pin 1 of the 3 pin
XLR if a hum loop is encountered. Never, never cut off the
ground plug on the AC cable. The ground lift switch will ac­complish the same audio results without the safety hazard.

If a single ended output is necessary, pin 3 (or pin2) must be
tied to ground, preferably at the end of the cable with the single
ended connector. Other Lectrosonics equipment is not trans­former coupled and will work without the pin 3 ground connec­tion. This fully floating output will not.

The headphone output is a high quality signal derived from 4
high current op amps operating in parallel to provide a low
noise, low distortion signal. This output can be used as an
unbalanced output if needed. Unlike the rear panel balanced
output, this output can be overdriven if the headphone volume
control is set too high. As with any headphone output, keep
the sound levels in the headphones at a moderate level. When
the output is not being used, turn it all the way down. Be
careful to not turn up the headphone gain if the receiver is
muted or squelched. As with any output that is m uted, there is
no way of knowing what the level will be when the receiver
audio is opened.

6

Wireless Diversity Receiver

FRONT PANEL CONTROLS AND FUNCTIONS

TRANSMITTER AUDIO LEVEL

The modulation (audio level) of the incoming signal is indicated
by a fast responding LED strip. The strip is calibrated in 6dB
steps over an expanded scale (54dB) which provides an
extremely accurate visual “picture” of the signal dynamics,
even at a distance away from the receiver. The LED str ip is
fast enough to track even brief transients, easily exceeding the
response time of conventional VU meters.

RF LEVEL INDICATORS

Two separate LED strips are provided to indicate the level of
the incoming RF signals. The LED str ips are calibrated to
provide accurate indications from 1uV to 1mV. The LEDs are
highly visible from a distance, making antenna set up more
accurate. The dual LED strips are especially useful in “trouble-
shooting” difficult antenna installations.

OPTI-BLEND LEDs

The UDR200B receiver operates with a method of audio ratio
blending of two audio outputs. RF level in each receiver is
compared and the audio signals from the two receivers are
mixed together in a ratio that favors the quieter receiver. As
this blending action occurs, the brightness of the two OPTI­BLEND LEDs will vary. The br ighter the LED, the more audio
is being mixed in from that receiver.

FULL INFORMATION DISPLAY

The UDR200B receiver includes a 16-segment LED character
strip that provides information about the selected frequency,
group, required transmitter setting, TV channel, assigned user
name, locked/unlocked status and pilot tone status.

PILOT INDICATOR

The audio output muting (squelch) function of the UDR200B is
controlled by a 33kHz tone modulation of the RF carrier. The
audio output is muted until this tone is present. The m uted
condition is indicated by a blinking TX switch setting in the LED
display.

The pilot tone function can be defeated by pressing a switch
on the rear panel. The PILOT indicator, however, operates the
same regardless of whether or not the defeat switch is
pressed. The PILOT indicator strictly indicates the presence of
the pilot tone carrier from the transmitter.

DIVERSITY MODE

This switch is set to the DIVERSITY position for normal opera­tion. For trouble-shooting or when the receiver is used with a
single antenna, the switch can be set to select a single an­tenna only.

MONITOR

This is an audio output to drive a wide variety of different types
of headphones. It is also usable as a second high quality
audio output to drive recorders or external audio devices.

POWER

Pressing the upper half of the rocker switch applies power to
the receiver. At turn on, there are various relays and delays
built into the receiver to allow various stages to stabilize before
the audio output is activated. This will prevent an audio
“thump” when powering up the receiver and/or the transmitter.

The UDR200B has a universal switching power supply which
will operate on AC voltages from 95 to 240Volts, 50 or 60Hz.

10

1uV

5

2 1mV

615.1

10

1uV

LECTROSONICS

5

2 1mV

UDR200B Front Panel

250

100

50

25

RF LEVEL

TX:B3 T

RF LEVEL

25

250

100

50

500

500

A

OPTI

BLEND

3

2

V

OPTI

BLEND

B

FREQ

SELECT

-48

MENU

-36

-42

TX AUDIO LEVEL dB

DIVERSITY

A B

MODE

-30

-18-24

Rio Rancho, NM – USA

-12

-6

MONITOR

LIM0

POWER

7

REAR PANEL CONTROLS AND FUNCTIONS

AUDIO OUTPUT

A calibrated control on the rear panel adjusts the output level
in 5 dB steps, referenced in dBu. This control knob adjusts the
absolute output level at the XLR connector. The AUDIO OUT­PUT level control is located after the output transformer. This
allows the signal to noise ratio to remain constant regardless
of the setting of the control. As the audio level is reduced, the
noise is also reduced maintaining the same ratio.

PHASE REV

This switch reverses the polarity of the audio output signal.
The "0" setting corresponds to a positive signal at the transmit­ter input producing a positive output on pin 2 of the XLR audio
output connector.

AC POWER SUPPLIES

The UDR200B has a universal switching power supply which
will operate on AC voltages from 95 to 240 Volts, 50 or 60 Hz.
There is no external fuse since the power supply is self pro­tected against line transients, short circuits, and over current
conditions.

EXT DC IN

The primary pur pose of this jack is to provide battery backup
in case of a loss of normal AC power. The receiver will accept
power from this jack under two conditions. The first is when­ever the front panel power switch is in the OFF position and
the second is when the front panel power switch is in the ON
position

and the normal AC power fails or is removed. This

jack can also be used to provide normal DC power to the
receiver, if desired, although the power switch OFF position
will not function as expected. When using this jack to provide
normal DC power the receiver will always be ON regardless of
the position of the front panel power switch.

The external DC source can be 12 to 26 VDC. Pin 4 is positive
and pin 1 is ground. This jack will accept a standard 4-pin
female XLR connector. The relays and power supply stage are
fully protected by automatic reset poly fuses. The ground side
of the power supply is protected with a self resetting poly fuse
in case the UDR200B is connected to a positive ground device
through the audio cabling. The poly fuse will trip to protect the
receiver and the offending ground path can then be removed.

LecNet (RS232) JACK

This 3.5mm stereo mini jack provides the serial connection
between the receiver and the computer. A stereo mini to DB9
cable is supplied with the receiver.

ANTENNA JACKS

These are standard 50 Ohm BNC terminals for the RF input to
the receiver.

EXPANSION OUT, EXPANSION IN

These miniature jacks provide the serial por t interface for
multi-channel systems in a “daisy chain” manner. The receiver
that connects to the computer uses the IN jack to receive
signals and information from the OUT jack on the next receiver
in the chain.

See the interconnect diagram on the next page.

PILOT TONE BYPASS

This switch defeats the audio output muting and triggering
action of the pilot tone. When the pilot tone is bypassed, the
Opti-Blend and the Variable Cutoff Low Pass Filter will still
provide a squelching action during weak signal conditions.
These circuits will still provide approximately 50 dB of muting
when the pilot tone is bypassed. When bypassed, a warning
message is displayed on the front panel LED character strip.

NOISE FILTER

A sophisticated dynamic noise reduction filter can be switched
to operate in two different modes. The most effective mode is
the “TRI MODE DYNAMIC”. This mode derives a signal that is
proportional to the high frequency content of the desired audio
signal multiplied by the amplitude of the desired audio signal
and divided by the RF noise level. This derived signal controls
a propor tional low pass noise filter that responds to transient
high frequency signals in less than a millisecond; this speed is
commonly accepted as much faster than the human ear can
resolve. Basically, the filter gets out of the way of high fre­quency audio information so quickly that the ear cannot detect
its operation. In addition this filter reduces high frequency
room noise and also the electronic microphone noise that is
present to some extent in all small electret microphones.

It may sound as if the filter is dulling the sound but this is a
well known psycho acoustic effect of reducing high frequency
noise. The ear is sensitized or fooled by hiss to “hear” more
high frequencies. The second mode, “LOW RF ONLY”, oper­ates the filter only when the RF link between transmitter and
receiver is unusually weak, less than 5uV at the receiver
antennas. This is a relatively rare circumstance and so the
noise filter is effectively out of the circuit except when abso­lutely needed.

90 - 240 VAC

UDR200B Rear Panel

8

EXT DC IN
+12 TO 26V

dBu

-10

-15

5

-0

-20

-25

10

-30

15

20

-35

ANT B

-5

4

1

3

2

M

1

3

2

PHASE

0 180

AUDIO OUTPUT

LIFT

GND

OUT

NOISE FILTER

TRI MODE

DYNAMIC

LecNet

(RS232)

EXPANSION

LOW RF
ONLY

IN

PILOT
TONE

BYPASS

ANT A

Wireless Diversity Receiver

INSTALLATION AND OPERATING INSTRUCTIONS

1) Locate a suitable operating location where the receiver will

not be subjected to extreme temperature variations and
possible bumps and drops. Try to route all wiring so it will
not cross walkways or isles.

2) Connect the power. For AC operation, connect the power
cord to the AC input jack on the rear panel and plug the
other end into a suitable electrical outlet. If 12 to 26V DC
operation
to be fabricated. Use a standard 4-pin female XLR con­nector for the receiver end. Pin 4 is positive and pin 1 is
ground. Make the length of the DC cable long enough to
suit your installation and prepare and connect the source
end of the cable.

3) Attach the antenna cables to the BNC jacks on the rear of
the UDR200B and place the antennas. Best perfor mance
will be obtained if the antennas are placed at least 3 feet
from each other. Try to mount them as high as possible
with a direct line of sight path to the transmitter if possible.

4) Set the Audio Output level control to minimum (CCW) and
connect the Audio Output XLR jack to the mixer input. Pins
2 and 3 of the XLR jack are HI and LO and can be re­versed with the Phase switch, pin 1 is common.

5) Preset the following controls:
MODE (front panel) to DIVERSITY

MONITOR (front panel) to minimum (CCW)
PHASE (rear panel) to 0
AUDIO OUTPUT (rear panel) to -40 (full CCW)

/battery backup is desired, a power cord will need

6) Turn the unit on with the front panel POWER switch and
check to see that the PILOT indicator is blinking indicating
that the pilot tone is not being received (be sure the trans­mitter is turned off.)

7) Set the operating frequency on the transmitter and receiver.
(See “Using the LED Information Display” below.)

8) Turn on the transmitter and adjust the transmitter gain.

This is the most important step

in the setup procedure!

Adjust the transmitter so that voice peaks will light the 0
LED on the receiver front panel Transmitter Audio Level dB
strip. The red "0" or LIMIT LED on the transmitter may
flash occasionally. This is nor mal but it should not happen
continuously. See your transmitter manual (Operating
Instructions section) for specific directions on how to adjust
the gain of your particular transmitter.

9) After adjusting the transmitter gain, set the rear panel
Audio Output level control to the desired level. The -40
setting is approximately equal to 10mV, the 0 position will
give 0.775VRMS, and the +15 setting will allow up to 4.4
VRMS. This setting will depend on the requirements of
your system.

10) Operate the system and readjust the receiver output level
as required for your equipment. The input levels on differ­ent VCR’s and PA equipment vary, which may require that
you set the Audio Output control in an intermediate posi­tion. Try different settings and listen to the results. If the
output of the receiver is too high, you may hear distortion
or a loss of the natural dynamics of the audio signal. If the
output is too low, you may hear steady noise (hiss) along
with the audio.

Note: If two or more UDR200B receivers are used together

and the LecNet computer interface is used, a unique
LecNet address must be entered into each receiver. See
page 10 under

Set LecNet Address

.

Rio Rancho, NM – USA

9

USING THE LED INFORMATION DISPLAY

1uV 2 1mV

668.

1uV 2 1mV

5

RF LEVEL

1 0 8.7 1

0 V

RF LEVEL

25

10

5

100

50

100

50

25

10

500 250

500 250

A

OPTI

BLEND

9

OPTI

BLEND

B

FREQ

SELECT

MENU

-36 -42 -48

-30

TX AUDIO LEVEL dB

DIVERSITY

A B

MODE

-12 -18 -24

-6

MONITOR

LIM 0

POWER

The UDR200B has three power up options and four menu
options which control all aspects of the receiver’s operation.

POWER UP OPTIONS

Toggle Batter y Monitor Display- Holding in the UP button

while powering on the receiver will toggle on and off the LED
display that indicates the transmitter battery voltage. (Note:
the battery status display will not function unless a valid pilot
tone is being received.)

FREQ

SELECT

MENU

Turning off the batter y status display prevents confusion when
the UDR200B receiver is used with 195 Series or early 200
Series transmitters that lack the battery monitor function.
When toggled off, the first LED display to appear (following the
brief status displays) will indicate the receiver frequency and
TV channel.

Set/Reset Hard Lock Mode - Holding down the MENU button
while powering on the receiver will switch the receiver between
the UNLOCKED mode and the HARD LOCKED mode.

POWER

more than one receiver is connected to a PC. The address
setting should be accomplished before star ting the LecNet
Master Pro application. UDR200Bs are shipped from the
factory with a LecNet address of 150. Multiple UDR200Bs in a
system should be assigned unique addresses above 150. You
will see the following displayed on the LED display of the
UDR200B in the address setting mode:

L E C N E T A D D R : 1 5 0

Use the UP and DOWN buttons to set the receiver to an
unused address. Then press the MENU button. This will store
the new address, and put the UDR200B in its normal operating
mode.

MENU OPTIONS

Press the menu button to select the desired menu option.
Each menu option is described below.

Set Receiver Frequency/Display Tx Battery Voltage - When
the receiver is powered up in the “Display Battery Status”
power up mode and the transmitter is turned on, the following
will be shown:

668.100 8.7V 19

FREQ

SELECT

MENU

POWER

In the UNLOCKED mode, all receiver menu options may be
adjusted. In the HARD LOCKED mode, the MENU button may
be used to scroll through the menus, but no adjustments may
be made. If this option is selected, the receiver will display its
current status for about 2 seconds after turn on before revert­ing to the Set Receiver Frequency menu.

Set LecNet Address - Holding down the DOWN button while
powering on the receiver allows the LecNet address of the
receiver to be set.

FREQ

SELECT

MENU

POWER

Setting each UDR200B to a unique address is critical when

10

This display is only shown in the “Display Battery Status”
power up mode. It will not appear when the battery status
display is toggled off.

Set Receiver Frequency/Display TV Channel - This display
will appear first when the battery monitor option is toggled off.
It will also appear when the MENU buttion is pressed if the
battery monitor option is toggled on. This menu allows the
receiver frequency to be set either to the stored frequencies in
the currently active group or to any frequency in the receiver’s
block in 100kHz steps. You will see the following menu option
displayed on the LED display of the UDR200B in the frequency
setting mode:

668.100 TV47 19

The first number shows the current receiver frequency in MHz,
the second shows the UHF TV channel in which the current
frequency falls, and the third shows the transmitter (TX) setting
which matches the current receiver frequency. The TX setting
will flash if no valid Pilot Tone is detected at the current fre-

quency, and will stop flashing when a valid Pilot Tone is de-

SRCH:668.100 20

GROUP1: UNLOCKED

GROUP1: LOCKED

GROUP1: HRD LOCK

tected.
Use the UP and DOWN buttons on the receiver front panel to

select from frequencies stored in the currently active group.
The UP and DOWN buttons will repeat if pushed and held.
The display will blink to indicate that the highest or lowest
frequency in the current group has been reached. To select
frequencies in 100kHz steps, press the MENU button plus the
UP or DOWN buttons. Press the MENU button to move to the
next menu option.

Set Receiver Frequency by Name/Modify Frequency Name

- The second menu option shows the name associated with

each frequency stored in the current active group. This option
allows you to choose receiver frequencies by name from
among those pre-programmed into the current active group.
The name associated with the stored frequency can also be
modified. If the current receiver frequency is one stored in the
current active group, you will see the following menu option
displayed on the LED display of the UDR200B:

LECTRO 1 19

The first group of characters, up to 13, is the name assigned to
the stored frequency. The last two digits are the transmitter
(TX) setting which matches the current receiver frequency. If
the current receiver frequency is not one stored in the current
active group, you will see the following menu option displayed
on the LED display of the UDR200B:

GRP1 SELECT 20

Wireless Diversity Receiver

The display shows the current frequency, and the TX setting
associated with that frequency.

To search only the active group frequencies, press only the UP
or the DOWN buttons as shown below.

FREQ

SELECT

MENU

To search by 100kHz steps, hold the MENU button in while
pressing the UP or DOWN buttons as shown below.

FREQ

SELECT

MENU

As a search progresses, the current search frequency will be
displayed. Press the MENU button to end the search mode
and move back to the last menu option.

Change Active Group/Operational Mode - The last menu
option allows selection of the current active group to be used
with the other three menu options. In addition, the operational
mode may be switched between UNLOCKED and LOCKED.
You will see one of the following displayed on the LED display
of the UDR200B, depending on the current operational mode:

POWER

POWER

This indicates the current frequency is not a stored frequency
in the currently active group, and that no name can be associ­ated with it.

The UP and DOWN FREQ SELECT buttons will select from
stored frequencies in the current group. To modify the name
associated with the stored frequency, press the MENU button
plus the UP or DOWN buttons. The first press of either the UP
or DOWN plus MENU buttons will start the name modification
process. The letter to be changed will begin to flash to signal
the name modification mode. To change this letter, press the
UP or DOWN buttons to cycle through all the allowable charac­ters until the desired character is reached. To leave this letter
unmodified and move to a new letter, press the MENU plus UP
buttons to select the next letter to the right, or the MENU plus
DOWN buttons to select the next letter to the left. If there is no
letter in a selected character position, a flashing underscore
will be displayed as a position indicator. After all desired
modifications have been made, press the MENU button. The
name, as modified, will be shown in the display. Press the
MENU button again to move to the next menu option.

Frequency Search - The third menu option sets the receiver
to search for RF signal energy above a minimum threshold,
which is 2uV at either antenna port. The receiver will search
all frequencies in 100kHz steps, or will search only the stored
frequencies for the current active group. You will see the follow­ing menu option displayed on the LED display of the UDR200B
in the frequency setting mode:

or

or

The group number just to the left of the colon is the current
active group. The current operational status is shown to the
right of the colon. The UP and DOWN buttons may be used to
select from among up to four stored groups (i.e. groups 1, 2, 3,
and 4). Only groups in which frequencies are actually stored
appear as selections when the UP or DOWN buttons are
pushed.

To change the operational mode, use the MENU plus UP or
DOWN buttons. In the UNLOCKED mode, all receiver menu
options may be adjusted. In the LOCKED mode, the MENU
button may be used to scroll through the menus, but no menu
options may be adjusted until the mode is changed back to
UNLOCKED. The system may be changed from UNLOCKED
to LOCKED mode and back in this menu. In the HARD
LOCKED mode, the MENU button may be used to scroll
through the menus, but no adjustments may be made. This
must be done using the Set/Reset Hard Lock Mode power up
option (see Set/Reset Hard Lock Mode section above).

Changes to the contents of stored groups cannot be made
from the receiver front panel. These changes must be made
from an external PC using the LecNet software.

Rio Rancho, NM – USA

11

LecNetTM COMPUTER INTERFACE

Lectrosonics’ LecNet system is a unique implementation of
standard RS-232 serial communications. Since it is compat­ible with RS-232 serial ports found on all PCs, no extra inter­face cards are necessary to add computer control to your
LecNet equipment. The figure below shows a representation
of a LecNet setup. Unlike standard RS-232 equipment, where
one serial por t connects to only one device, as many as 127
LecNet devices may be simultaneously connected to a single
serial por t.

As the figure shows, LecNet devices can always receive

Host TX

Host
RX

Device

RX

Device
TX

Device

RX

Device
TX

Device

RX

Device
TX

information from the host. In this way, each LecNet device
“listens” for its unique network address “broadcast” from the
host PC. When a device “hears” its address, it closes its
Device Tx switch to reply to the host. The Device Tx switch is
held closed until the data exchange with the host is complete.
The device then opens its Device Tx switch. In this way,
device contention is avoided. Each LecNet device must have a
unique address between 128 and 254. Any device address is
reassignable using the LecNet Master Pro application (sup­plied free with every LecNet device).

The LecNet runs at a fixed rate of 9600 bps, which is not user
adjustable. This is fast enough to provide quasi-real time
response to the control panels while insuring reliable commu­nications over reasonable distances (100 feet from host to
LecNet device). The ser ial communications parameters used
are 8 data bits, no parity, 1 stop bit.

LecNet HARDWARE HINTS

Connecting LecNet devices to a host using the LecNet is
straightforward. Using the special LecNet RS-232 cable
(Lectrosonics Part #21529), simply connect Com1, 2, 3 or 4 on
the host to the LecNet 3.5mm input on one of the LecNet
devices. If a custom length cable is necessary, the figure to
the right shows the cable connection schematic. The host-to-

device connection assumes that multiple LecNet devices (if
more than one are used) are interconnected using the 8 pin
expansion cable (Lectrosonics Part #21551).

While Lectrosonics has made every effort to make the serial
communications software as compatible as possible with a
wide range of serial por ts, some serial por ts are not well
behaved. Some problems occur with older serial por ts, be­cause they may not be reliable at 9600 bps or higher. Soft­ware is available (from Norton, for example) which will test
serial por ts and determine the highest reliable data rate.

In addition, Windows video drivers sometimes interfere with
com port operation. For example, the custom video driver
supplied with the Toshiba 1900/1910 series laptop computers
will crash the com port when it is used for LecNet operation.
The fix for this situation is simply to use the generic VGA video
driver (chosen from the Windows Setup application). Watch for
video driver interactions any time a nonstandard video driver is
used.

SERIAL HARDWARE CONNECTIONS

9 OR 25 PIN

3.5MM STEREO PLUG

LecNet Device Transmit

TIP

LecNet Device Receive

RING

GND

SLEEVE

LecNet Port

LecNet Device Transmit

TIP

LecNet Device Receive

RING

GND

SLEEVE

LecNet Port

WIRING DIAGRAM, 9 PIN D-SUB

WIRING DIAGRAM, 25 PIN D-SUB

FEMALE D-SUBMINIATURE

N/C

N/C

1
2
3
4

Host

5

Serial Port
(PC)

6
7
8
9

3
2
7
1

Host

5

Serial Port
(PC)

6
8

20

12

LecNetTM COMPUTER INTERFACE

Wireless Diversity Receiver

MICROPROCESSOR CONTROL

An internal microprocessor controls the frequency
settings and display, and provides a user friendly
interface for setup and operation. 256 frequencies
are available in 100KHz steps. The 25.6 MHz
bandwidth covers more than four UHF television
channels to allow maximum flexibility in frequency
coordination for congested RF environments and
in travelling venues.

THE LecNetTM INTERFACE

All setup functions and almost all operational
functions are available from the UDR200B front
panel without the use of a PC. Via a PC, several
other features are added to simplify setup and
enhance monitoring during operation. LecNet
supplied with the UDR200B.

The first display that appears when the UDR200B software is
loaded is a composite summary of up to 8 receivers, showing
basic RF and audio levels and frequency settings. Each of the
8 display screens includes a button to switch to the complete
control panel for that specific receiver.

TM

software is

For multi-channel systems, each UDR200B

receiver is assigned a unique serial address

from the front panel of the receiver. When

TM

the LecNet

Master Pro software is then

launched, a role call is initially taken to

identify all devices that are connected.

AUTO SEARCH FUNCTION

The UDR200B provides the installer with a convenient method
of conducting a “site survey” when setting up for a new venue
or installation. The Auto Search function scans either the
entire tuning range of the receiver, or a selected frequency
group, and locates RF signals in the vicinity. The results are
graphically displayed in the lower section of the screen. The
screen markers are a peak holding type to record activity over
any chosen time period. The Auto Search procedure is espe­cially valuable in travelling or rental venues that set up and tear
down frequently.

When the “Receiver Setup” button is clicked, a detailed display
appears with a wide variety of information dynamically dis­played. RF and audio levels, Opti-Blend
frequency, pilot tone status, user and group names for each
receiver, and all infor mation provided by the front panel LED
character strip is clearly displayed. Frequencies can be
changed to any frequency within the range of the receiver, or
to only those included in a previously selected, compatible
grouping.

The individual receiver control panel includes three sections to
display current settings, provide a workspace for new fre­quency groups and a spectrum analyzer section for site sur­veys.

TM

panning activity,

Rio Rancho, NM – USA

13

FREQUENCY BLOCKS AND RANGES

The table below lists the factory designated frequency ranges
available for the UDR200B receiver. For convenience, the
table includes information about the UM200B belt-pack trans­mitter antennas as well.

Each UDR200B receiver is built to cover a pre-selected range
of frequencies (a “block”) as shown below. The receiver will
tune to any of 256 different frequencies within this factory
assigned block.

The block number is determined by this formula:

25.6 × Freq. (MHz) = Lowest freq. (MHz) in the block

To determine a block number from a frequency:

Freq. (MHz) divided by 25.6 = Block number

It is handy to remember these formulas, in case you do not
have a copy of the table. For example, suppose you need to
know which block covers 685.500 MHz, without using the
table:

685.500 divided by 25.6 = 26.77734375

The first two digits left of the decimal are the block number. In

this case, 685.500 MHz falls within block 26.
These factory defined "blocks" of frequencies should not be

confused with the user defined "groups" that can be stored in
the receiver memory.

Four user defined groups of frequencies can be stored in the
receiver memory. The groups are numbered 1 through 4 as
depicted on the Receiver Setup Panel (see the section on
COMPUTER INTERFACE). Each frequency in a group can be
individually named for convenience.

The UM200B belt-pack transmitter antennas (model A6U) are
color coded to indicate the frequency block that they operate
within. The length of the antenna varies with the frequency
block. The actual length of the antenna is not as critical as it
might appear in the table below. The usable bandwidth of the
A6U antennas are +/- 50 MHz from the center frequency, so it
is acceptable to use an antenna from an adjacent block above
or below the operating frequency.

The color of the antenna sleeve is in keeping with standard
resistor value color codes for the second digit of the block
number. Block 23 is not used since it covers a 608 to 614 MHz
band that is illegal for use with wireless microphones.

FREQUENCY ANT SLEEVE ANTENNA

BLOCK RANGE COLOR

WHIP LENGTH

21 537.600 - 563.100 Brown 4.74"
22 563.200 - 588.700 Red 4.48"
23 588.800 - 614.300 Orange 4.24”
24 614.400 - 639.900 Yellow 4.01"
25 640.000 - 665.500 Green 3.81"
26 665.600 - 691.100 Blue 3.62"
27 691.200 - 716.700 Violet (Pink) 3.46"
28 716.800 - 742.300 Grey 3.31"
29 742.400 - 767.900 White 3.18"
30 768.000 - 793.500 Orange/Black 3.08"
31 793.600 - 819.100 Orange/Brown 2.99”
32 819.200 - 844.700 Orange/Red 2.92”
33 844.800 - 865.000 Orange/Orange 2.87”

14

INDIRECT SIGNAL

ANT B

PHASE
CANCELLATION

ANTENNA USE AND PLACEMENT

REFLECTIVE SURFACE

DIRECT SIGNAL

TRANSMITTER

DIRECT SIGNAL

INDIRECT SIGNAL

PHASE
CANCELLATION

ANT A

A

500

250 100

50251051uV 2 1mV

OPTI

BLEND

500

250 100

50251051uV 2 1mV

OPTI

BLEND
B

LIM0-6-12-18-24

-30

-36

-42

-48

TX AUDIO LEVEL dB

RF LEVEL

RF LEVEL

LECTROSONICS

FREQ

SELECT

POWER

MONITOR

MODE

A B

DIVERSITY

MENU

615.

1 TX:B3 TV2

3

RECEIVER

MULTI-PATH DROPOUT
AT ANTENNA B

Wireless Diversity Receiver

When using a remote antenna with this receiver, position the
antennas at least three or four feet apart and so that they are
not within 3 or 4 feet of large metal surfaces. If this is not
possible, try to position the antennas so that they are as far
away from the metal surface as is practical. It is also good to
position the receiver so that there is a direct “line of sight”
between the transmitter and the receiver antenna. In situa­tions where the operating range is less than about 100 feet,
the antenna positioning is much less critical. The antennas
can also be configured with one whip mounted directly onto
the rear panel of the UDR200B receiver, and the other one
mounted remotely.

A wireless transmitter sends a radio signal out in all directions.
This signal will often bounce off nearby walls, ceilings, etc. and
a strong reflection can arrive at the receiver antenna along
with the direct signal. If the direct and reflected signals are out
of phase with each other a cancellation may occur. The result
would be a “drop-out.” A drop-out sounds like either audible
noise (hiss), or in severe cases, may result in a complete loss
of the carrier and the sound when the transmitter is positioned
in certain locations in the room. A drop-out normally sounds

like “hiss” or a “swishing” sound. Moving the transmitter even a
few inches will change the sound of the hum or hiss, or elimi­nate it. A drop-out situation may be either better or worse as
the crowd fills and/or leaves the room, or when the transmitter
or receiver is operated in a different location.

The UDR200B receiver offers a sophisticated diversity design
which overcomes drop-out problems in almost any imaginable
situation. In the event, however, that you do encounter a
dropout problem, first try moving the antenna at least 3 or 4
feet from where it was. This may alleviate the drop-out prob­lem on that antenna. If drop-outs are still a problem, try mov­ing the antenna to an entirely different location in the room or
moving the antennas in closer to the transmitter location. By
observing the OPTI-BLEND LEDs on the front panel, you can
determine which antenna is suffering weak signals.

Lectrosonics transmitters radiate power very efficiently, and
the receivers are very sensitive. This reduces drop-outs to an
insignificant level. If, however, you do encounter drop-outs
frequently, call the factory or consult your dealer. There is
probably a simple solution.

Rio Rancho, NM – USA

15

TROUBLESHOOTING

POWER SUPPLY AND FUSE

Display not lit or dimly lit

• AC power cord disconnected.

• External power supply disconnected or inadequate.

• Main power supply defective.

• The External DC power input is protected by an auto-reset

polyfuse. Disconnect power and wait about 10 seconds for
the fuse to reset.

Receiver won’t turn off

• This is normal when the unit is being operated from exter­nal DC power.

PILOT T ONE SQUELCH

The pilot indicator is the transmitter switch settings display.
When solid on, it indicates that the audio has been turned on
at the transmitter, and that the audio output on the receiver is
enabled. (When the indicator is solid on, the audio is on.)
When the indicator is blinking, the audio is muted.

PILOT indicator solid on, but no sound

• Audio output cable bad or disconnected. Tr y monitor ing at
the headphone output on the front panel. The headphone
output signal is taken just ahead of the output transformer.

• AUDIO OUTPUT level set too low.

PILOT indicator blinking, but sound still comes through

• PILOT TONE BYPASS switch may have been pressed.
Turn receiver power off and then back on again to reset the
audio output relays.

PILOT indicator does not stop blinking when transmitter
audio switch is turned on

• It takes several seconds for the relay to actuate the PILOT
lamp. Turn the transmitter power and audio switches on and
wait 2 to 5 seconds for the lamp to come on.

ANTENNAS AND RF SIGNAL STRENGTH

RF LEVEL is weak on one (or both) channels

• Antenna is disconnected or there is a bad connection

• Antenna may need to be moved or reoriented

• Improper length of antenna, or wrong antenna. UHF whip

antennas should be about 3 to 5 inches long.

• Transmitter is 100kHz (one switch position) off from the
receiver frequency.

One OPTI BLEND LED does not come on or is dimly lit

• DIVERSITY switch is set to one or the other channels.
Needs to be in the center position for normal operation.

• Reverse the antennas on the rear panel inputs. If the
opposite OPTI BLEND LED now indicates the same prob­lem, there may be an antenna or cabling problem. Try
repositioning the antenna(s).

AUDIO SIGNAL QUALITY

Poor signal to noise ratio

• Transmitter gain set too low

• Noise may not be in wireless system. Mute the audio

signal at the transmitter and see if noise remains. If the
noise remains, then turn the power off at the transmitter and
see if it remains. If the noise is still present, then the prob­lem is not in the transmitter.

• If noise is still present when the transmitter is turned off,
try lowering the audio output level on the UDR200B rear
panel and see if the noise lowers correspondingly. If the
noise remains, the problem is not in the receiver.

• Receiver output does not match the input of the device it is
feeding. Tr y increasing the output level of the UDR200B
and lowering the input gain on the device the UDR200B is
feeding.

Distor tion

• Transmitter input gain too high. Check and/or readjust
input gain on transmitter according to the LEDs on the
transmitter and then verify the setting with the transmitter
audio level LED strip on the UDR200B front panel.

• Audio output level too high for the device the UDR200B is
feeding.

• Transmitter is 100kHz (one switch position) off from the
receiver frequency.

16

UDR200B REPLACEMENT PARTS and ACCESSORIES

Part No. Description
A500RA Right angle, flexible whip UHF antenna
21499 Replacement AC power cord
RMP200-1 Rack mount kit for single UDR200B receiver
RMP200-2 Rack mount kit for two UDR200B receivers
Optional Remote Antennas
AY3U-550 3-element YAGI, +4.5dBD, 500 to 600 MHz range
AY3U-650 3-element YAGI, +4.5dBD, 600 to 700 MHz range
AGPU UHF ground plane, 470 to 608 MHz range

Wireless Diversity Receiver

SERVICE AND REPAIR

If your system malfunctions, you should attempt to correct or isolate the trouble before con­cluding that the equipment needs repair. Make sure you have followed the setup procedure
and operating instructions. Check out the interconnecting cords and then go through the
TROUBLE SHOOTING section in the manual

We strongly recommend that you do not try to repair the equipment yourself and do not
have the local repair shop attempt anything other than the simplest repair. If the repair is
more complicated than a broken wire or loose connection, send the unit to the factory for
repair and service. Don’t attempt to adjust any controls inside the units. Once set at the
factory, the various controls and trimmers do not dr ift with age or vibration and never require
readjustment. There are no adjustments inside that will make a malfunctioning unit
start working.

LECTROSONICS service depar tment is equipped and staffed to quickly repair your equip­ment. In-warranty repairs are made at no charge in accordance with the terms of the war­ranty. Out of warranty repairs are charged at a modest flat rate plus parts and shipping.
Since it takes almost as much time and effort to determine what is wrong as it does to make
the repair, there is a charge for an exact quotation. We will be happy to quote approximate
charges by phone for out of warranty repairs.

RETURNING UNITS FOR REPAIR

You will save yourself time and trouble if you will follow the steps below:
A. DO NOT retur n equipment to the factor y for repair without first contacting us by letter or by

phone. We need to know the nature of the problem, the model number and the serial
number of the equipment. We also need a phone number where you can be reached 8 am
to 4 pm (Mountain Standard Time).

B. After receiving your request, we will issue you a return authorization number (R.A.). This

number will help speed your repair through our receiving and repair departments. The
return author ization number must be clearly shown on the outside of the shipping con­tainer.

C. Pack the equipment carefully and ship to us, shipping costs prepaid. If necessary, we can

provide you with the proper packing materials. UPS is usually the best way to ship the
units. Heavy units should be “double-boxed” for safe transport.

D. We also strongly recommend that you insure the equipment, since we cannot be respon-

sible for loss of or damage to equipment that you ship. Of course, we insure the equip­ment when we ship it back to you.

Mailing address: Shipping address: Telephones:

Lectrosonics, Inc. Lectrosonics, Inc. Regular : [phone]
PO Box 15900 581 Laser Rd. Toll Free [phone]
Rio Rancho, NM 87174 Rio Rancho, NM 87124 FAX: [phone]
USA USA

W orl d Wide Web: http://www.lectrosonics.com Email: [e-mail]

Rio Rancho, NM – USA

17

SPECIFICATIONS AND FEATURES

0

2

Operating Frequencies:
Frequency Adjustment Range:
Receiver Type:
Frequency Stability:
Front end selectivit y:
Sensitiv i t y

20 dB Sinad:

60 dB Quieting:
Squelch quieting:
AM rejection:
Modulation acceptance:
Image and spurious rejection:
Third order intercept:
Diversity technique:

FM Detector:
Antenna inputs:
Audio outputs

Rear Panel XLR:

Monitor out:

Front Panel Controls and Indicat ors:

Rear Panel Controls and features:

Power Options:

Weight:
Dimensions:

537.600 to 588.700 MHz; 614.400 to 793.500 MHz

25.5 MHz
Dual conversion, superheterodyne, 71MHz and 455kHz
±0.002 %
>22 dB at ±4 MHz

0.707 uV (-110 dBm), A weighted

1.0 uV (-107 dBm), A weighted
Greater than 125 dB
Greater than 60 dB, 2 uV to 1 Volt (Undetectable after processing)
>90 kHz
>100 dB
+12 dBm
Ratio diversity. Dual simultaneous receivers with

dynamic audio combining (Opti-blend).
Digital Pulse Counting Detector operating at 455kHz
Dual BNC female; 50 Ohm impedance

600 Ohm Balanced, transformer isolated, adjustable from -40 dBu
to +20 dBu in 5 dB steps, at 60 kHz deviation

Front panel ¼” Phone jack, adjustable from 0 to 635 mV RMS into
8 Ohms at 60 kHz deviation; 0 to 5.7V RMS into 600 Ohms at
60 kHz deviation.

Power on/off switch and LED; Dual 10 segment RF signal level
display; 10 segment transmit ter audio level display; Multifunction
LED graphic display; Up/Down/Menu buttons; Diversity operation
selector switch; Opti-Blend operation LEDs; Monitor output jack
and level control.

Ant A and Ant B BNC connectors; Pilot tone bypass switch; Audio
phase reversal switch; Noise filter mode switch; XLR audio output
jack and 12-step audio attenuator; Ex ternal DC input; 95 to
240 VAC input jack.

95 to 240 VAC, 50/60 Hz, 10 Watts
12 to 26 VDC, 10W total

3 lbs, 14 ozs

8.2" wide x 1.73" high x 10.6" deep

Typical System Frequency Response

+6

+3

0dB

-3

-6

-9

-12

30 100 1kHz 10k 20k

Adjustable LF Roll-off

.0%

1.0%

.5%

0%

Typical System THD + Noise

30 100 1kHz 10k 20k

Specifications subject to change without notice

18

Wireless Diversity Receiver

LecNet SOFTWARE PROTOCOL

Note: This section is for developement of custom control applications and is not necessary for general operation of the receiver

and the LecNet control software provided by the factory.

The UDR200B uses a modification of the typical one-to-one
connection between two RS-232 compatible devices. The
UDR200B has both an RS-232 transmitter and receiver sec­tion. The tr ansmitter section is "tri-stated", or placed in a high
impedance mode, until the particular device is addressed. To
facilitate the simple parallel connection of multiple devices on a
single RS-232 port, an addressing scheme is employed to
route commands from the host to the proper device. When a
device receives its address from the host computer, it tempo­rarily turns on its RS-232 transmitter long enough to send
whatever data is requested by the host. In this way, multiple
devices may drive a single transmit signal back to the host,
because only the addressed UDR200B will turn on its transmit­ter.

The following code fragment, in BASIC, would be used to get
an "Acknowledge" name string back from an UDR200B:

OPEN "COM1:9600,N,8,1" FOR RANDOM AS #1 LEN = 25

...
...

PRINT #1, CHR$(150)

DataByte% = ASC(INPUT$(1,#1))

PRINT #1, CHR$(1)

Valid address values are 128-254 (80h-FEh). 255 (FFh) is an
invalid address and must not be used. Because the UDR200B
will interpret any single data byte whose value is greater than
127 as an address, single byte data (as opposed to addresses)
sent from the host must be in the range of 0-127. If a data
value needs to be output that exceeds 127, two bytes are
output such that the first byte is the lower 7 bits of the 8 bit
value, and the second byte is 1 if the MSB of the data byte is
1, or 0 if the MSB of the data byte is 0 (see the Two Byte
Format guidelines below).

Every UDR200B command must be preceded by the address
of the device to be controlled. If a device with the requested
address exists on the system, it will respond by sending a "0"
back to the host.

'Open Com1:9600, N, 8, 1.

'Output the device address. Default address of
‘UDR200B is 150.

'Receive "0" byte. The ASC function is used to convert
‘the received string data to numeric data.

'Output the "Acknowledge" command.

DataByte% = ASC(INPUT$(1,#1))

Name$ = INPUT$(DataByte%,#1)

The first PRINT and INPUT$ sequence must precede every
command sent, even if the command is sent to the same
UDR200B as the previous command. Thus, each interchange
with an UDR200B follows this pattern:

1) Host sends device address (1 byte);

2) Host receives byte of “0” from UDR200B as
acknowledgement;

3) Host sends command (1 byte) to UDR200B;

4) Host and UDR200B interact based on par ticular
command sent.

This process must be followed for every command that is sent
to the LecNet device. The implication here is that even if the
host sends several commands to the same device, each
command must be preceded by the LecNet address/acknowl­edge byte exchange.

'Receive the length of the acknowledge string
‘(7 for the UDR200B).

'Receive the name string ("UDR200B")

Rio Rancho, NM – USA

19

LecNet SOFTWARE PROTOCOL

Two Byte Format for Data sent from Host

When the host must send data to a LecNet device whose
value exceeds 127, the data must be broken into two succes­sive bytes. This avoids having other LecNet devices interpret
the host data as an address, since the address space is 128-

254. If the host must send a data value that exceeds 127, two
bytes are output such that the first byte is the lower 7 bits of
the 8 bit value. The second byte is 1 if the original data value
is greater than 127, and 0 otherwise.

UDR200B Serial Commands

The following is a listing of available commands grouped
based on the UDR200B function to which the commands are
related. The word "Host" in the command descr iptions means
the IBM PC, PC compatible, or other control system (like AMX
or Crestron) to which the UDR200B is connected. In any
commands where the host must send data to the UDR200B
whose value can legitimately exceed 127, refer to the Two Byte
Format guidelines above.

General Device Commands

Acknowledge - Causes the UDR200B sends its "name" string

back to the host.

Host sends command - 1
Host receives 7 data bytes: Byte 1 is the number of bytes

in the name string (7 for the UDR200B), followed by the
ASCII characters "UDR200B".

Change Device Address - Changes the UDR200B device
address and stores the new address in EEPROM.

Host sends command - 2
Host sends data byte: new device address, valid range

128 to 254.

Output Firmware Version - Outputs the version number of the
current firmware. For example, Version 1.0 software would be
returned as 10.

Host sends command - 25
Host receives data byte: firmware version.

Set Local/Remote Mode - Allows the Local/Remote status of

the UDR200B to be set. 0 is Local mode, 1 is Remote. The
Local/Remote setting is volatile, and the power-up default is
Local.

Host sends command - 30
Host sends data byte: Status data (0 or 1 as above)

Other Commands

Output Receiver Block Number - Outputs the block number

of the receiver.

Host sends command - 4
Host receives data byte: Block number 19 - 30

Output Current Receiver Frequency - Outputs the current

frequency of the receiver.

Host sends command - 6
Host receives data byte: Current frequency 0 - 255.

(note: the actual frequency may be calculated as:
block number x 25.6 MHz + current frequency
x .1 MHz)

Set Current Receiver Frequency - Allows the current fre­quency for the receiver to be set. Also allows the option of
storing the new frequency in non-volatile memory. If the new
frequency is not stored, the receiver will revert to the last
saved frequency on next power up.

Host sends command - 5
Host sends two data bytes: Bytes 1 and 2: New fre-

quency, 0 - 255 Byte 3: 1 - Store new frequency in non­volatile memory, 0 - no store.

Output Operational Status - Outputs the current opera­tional status of the receiver.

Host sends command - 8
Host receives data byte: Status, 0 - 2. 0 - Hard Locked,

1- Unlocked, 2 - Locked.

Set Operational Status - Allows the current operational status
of the receiver to be set. The new status value is stored in
non-volatile memory.

Host sends command - 7
Host sends data byte: Status, 0 - 2. 0 - Hard Locked, 1 -

Unlocked, 2 - Locked.

Output Current Group Number - Outputs the current group
number of the receiver.

Host sends command - 10
Host receives data byte: Group number, 1 - 4.

Set Current Group Number - Allows the current group num-

ber of the receiver to be set. The new group number is stored
in non-volatile memory.

Host sends command - 9
Host sends data byte: Group number, 1 - 4.

Output Number of Group Entries in a Specified Group -

Outputs the number of name/frequency entries in a specified
group stored in non-volatile memory.

Host sends command - 16
Host sends data byte: Group (1 - 4) for which the number

of entries is desired.
Host receives data byte: Number of entries, 0 - 16. 0
entries means the group is currently unused.

Set Number of Group Entries in a Specified Group - Allows
the number of name/frequency entries to be set. The new
number is stored in non-volatile memory.

Host sends command - 15
Host sends data bytes: Byte 1: Group number, 1 - 4.

Byte 2: Number of entries in the group, 0 - 16.

20

Wireless Diversity Receiver

Output Group Frequency and Name - Outputs specific

name/frequency entries stored in non-volatile memory. Each
of the entries, up to a total of 16 in each group, consists of 14
bytes. The first byte is the frequency, and the next thirteen are
the name associated with that frequency.

Host sends command - 18
Host sends data bytes: Byte 1: Group number to down

load to, 1 - 4. Byte 2: Group entry number, 1 - 16.
Host receives data bytes: Byte 1: Frequency, 0 - 255
Bytes 2 - 14: Name

Set Group Frequency and Name - Allows specific name/
frequency associations to be entered in non-volatile memory.
Each of the entries, up to a total of 16 in each group, consists
of 14 bytes. The first byte is the frequency, and the next thir­teen are the desired name to associate with that frequency.
The name may consist only of capital letters A-Z, numerals 0­9, and spaces. All thirteen name bytes must be sent, and if
the name is less than 13 characters long. simply pad it with
trailing spaces (ASCII 32). Note that it is prohibited to have
two or more names associated with the same frequency in a
group. In other words, all frequency entries in a given group
must be unique in that group. This does not preclude having
the same frequency in another group.

Host sends command - 17
Host sends data bytes:

Byte 1: Group number to download to, 1 - 4.
Byte 2: Group entry number, 1 - 16.
Bytes 3 and 4: Frequency, 0 - 255
Bytes 5 - 17: Name, can only be ASCII characters A-Z,
0-9, and space.
Host receives data byte: 100, to signify that the data has
been stored in non-volatile memory.

Output Audio Modulation - Outputs the current audio modu­lation level. A retur ned value of 120 is equivalent to a 0dB
modulation level (as indicated on the front panel Audio modu­lation meter). Values greater than 170 indicate Limiting.

Host sends command - 27
Host receives data byte: Audio modulation level, 0 - 255.

Output RF Levels - Outputs the current RF level of channels

A and B. Data values range from 0 - 255, where 0 equals 1uV
(-107dBm) and 255 equals 1mV (-47dBm). The RF level in
dBm can be calculated as RF Level in dBm = -107 + Data
value x .235.

Host sends command - 35
Host receives data bytes: Byte 1: RF Level Channel A, 0 -

255. Byte 2: RF Level Channel B, 0 - 255

Output Pilot Tone Status - Outputs the receiver status with
respect to whether a valid pilot tone is detected.

Host sends command - 34
Host receives data byte: Pilot status, 0 - No pilot tone, 1 -

Pilot tone present

Output Battery Status - Outputs the battery status of the
associated transmitter, if the transmitter is on and the receiver
recognizes the transmitter's pilot tone.

Host sends command - 62
Host receives data byte: Battery status, range between 0

and 28. The following list gives the actual battery voltage
associated with each status number.

0 - Greater than 9.2V (or not available because the
transmitter is not on or the pilot tone is not valid)

1 - Greater than 9.2V (or not available because the
transmitter is not on or the pilot tone is not valid)
2 - 9.2V
3 - 9.1V
4 - 9.0V
5 - 8.8V
6 - 8.7V
7 - 8.6V
8 - 8.5V
9 - 8.4V
10 - 8.3V
11 - 8.1V
12 - 8.0V
13 - 7.9V
14 - 7.8V
15 - 7.7V
16 - 7.6V
17 - 7.5V
18 - 7.4V
19 - 7.4V
20 - 7.3V
21 - 7.2V
22 - 7.2V
23 - 7.0V
24 - 6.8V
25 - 6.7V
26 - 6.6V
27 - 6.5V
28 - Less than 6.5V (i.e. Dead)

Rio Rancho, NM – USA

21

LIMITED ONE YEAR WARRANTY

The equipment is warranted for one year from date of purchase against defects in materials
or workmanship provided it was purchased from an authorized dealer. This warranty does
not cover equipment which has been abused or damaged by careless handling or shipping.
This warranty does not apply to used or demonstrator equipment.

Should any defect develop, we will, at our option, repair or replace any defective parts without
charge for either parts or labor. If we cannot correct the defect in your equipment, we will
replace it at no charge with a similar new item. We will pay for the cost of returning your
merchandise to you.

This warranty applies only to items returned to us, shipping costs prepaid, within one year
from the date of purchase.

This warranty gives you specific legal rights. You may have additional legal r ights which vary
from state to state.

LECTROSONICS, INC.

581 LASER ROAD
RIO RANCHO, NM 87124 USA

PH [phone] (toll-free)
PH [phone] (local)
FAX [phone]
E-mail: [e-mail]
Web: www.lectrosonics.com

September 23, 1999