Lectrosonics UCR300 User Manual

UCR300

DIVERSITY UHF RECEIVER

OPERATING INSTRUCTIONS

and trouble-shooting guide

LECTROSONICS, INC.

www.lectrosonics.com

0885

Table of Contents

GENERAL TECHNICAL DESCRIPTION ........................................ 3

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

GENERAL TECHNICAL DESCRIPTION ........................................ 5

FRONT PANEL CONTROLS AND FUNCTIONS ........................... 6

REAR PANEL CONTROLS AND FUNCTIONS ............................. 7

ANTENNA USE AND PLACEMENT .............................................. 8

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

UCR300 REPLACEMENT PARTS and ACCESSORIES............... 9

FREQUENCY BLOCKS AND RANGES ...................................... 10

TROUBLESHOOTING ................................................................... 11

SPECIFICATIONS AND FEATURES ............................................ 12

SERVICE AND REPAIR .................................................. Back cover

WARRANTY .................................................................... Back cover

2

UHF Wireless Diversity Receiver

T

GENERAL TECHNICAL DESCRIPTION

The UCR300 is a portable, high performance, dual-conversion,
frequency synthesized, UHF receiver. The RF performance is
extremely stable over a very wide temperature range, making
the UCR300 perfectly suited to the rough environmental condi­tions found in the field. The proprietary audio processing
includes a dual-band compandor 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 a ten LED bar graph meter.

DIVERSITY RECEPTION

The antenna phase switching diversity technique was chosen in
order to keep the receiver compact enough for camera mounted
or shoulder bag applications. This diversity reception tech­nique effectively minimizes dropouts in short range situations
where multi-path reflections can cause serious problems. The
optimum diversity reception is realized with the diversity an­tenna placed away from the receiver, however, dropouts are
significantly reduced with two antennas mounted directly on
the receiver.

RF SECTION

The problem posed to the design staff was to retain the RF
reliability of the Lectrosonics’ fixed frequency designs but add
the 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 very 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 sys-

tem 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 6 transmission line resonators with
variable capacitance applied to each resonator by the hexadeci­mal switches.

This sophistication produced a front end that was as selective as
fixed frequency designs. The next step to improve the front end
was to use good old fashioned “brute force.”

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.

ANTENNA

SWITCHING

RF MODULE

FILTER

SWITCHES

FREQ

uP

AMP

FILTER

uP

SYNTHESIZER

RF LEVEL

HI-LEVEL

DIODE MIXER

455KHZ

BP

FILTER

2ND MIXER

&

IF AMP

XTAL

CONTROLLED

2ND

OSCILLATOR

LEDs

COUNTING

DETECTOR

50KHz

LP FILTER

23 KHZ

LP

FILTER

VARIABLE

CUT-OFF

LP FILTER

SAW

FILTER

70 MHz
IF AMP

AMP

FILTER

VCO

FILTER

uP

2

E PROM

1ST

LOCAL

OSCILLATOR

Rio Rancho, NM – USA

BLOCK DIAGRAM

2:1

EXPANDER

TREBLE

2:1

EXPANDER

BASS

AUDIO

AMP

PILOT
TONE
MUTE

uP

HEADPHONE

OUT

OUTPUT

LEVEL

ADJUST

XLR
OU

TO DATA
DISPLAY

3

UCR300

GENERAL TECHNICAL DESCRIPTION

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 (50 mW). The mixer in the UCR300 produces output at
only the sum and difference signals, with minimal spurious
signals. This mixer offers a very high overload threshold and a
high degree of isolation between ports. 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 or a higher level than our
fixed frequency designs. The mixer is followed by high current,
low noise amplifiers and SAW filters to preserve the superior RF
performance.

SURFACE ACOUSTICWAVE FILTER

The UCR300 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 skirts, 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 filtering 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 quartz, they
are very temperature stable. Conventional LC filters at these
frequencies don’t begin to perform as well and in addition would
drift unacceptably in the elevated temperatures of an equipment
rack. After following the rule in a rigorous way, and due to the
sharp filtering 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 (±50 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 UCR300 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, particularly 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 UCR300 design presents an elegantly simple, yet highly
effective solution to this age old problem. The UCR300 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.

TRI MODE DYNAMIC FILTER

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 particular filter. We have satisfied ourselves
through elaborate tests that this filter is totally transparent.

PILOT TONE MUTE (SQUELCH)

The 300 system utilizes a separate ultrasonic tone modulation of
the basic carrier to operate the receiver squelch. In the transmitter,
a 32kHz tone is injected into the audio signal path 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
received, the receiver will remain open during all signal condi­tions.

4

GENERAL TECHNICAL DESCRIPTION

The mute circuit drives a relay which physically disconnects
the output amplifier from the output. This provides complete
muting of the audio and the noise. The pilot tone function may
be bypassed with the Pilot Tone Disable switch (located on the
front panel.) When the pilot tone has been disabled with this
switch, the Pilot LED will glow red and the MOD function of
the LED bargraph meter on the front panel is disabled. The
Pilot LED on the front panel will glow green when the pilot
tone has enabled the receiver audio output.

OUTPUT LEVEL ADJUST AND RANGE SWITCH

The front panel Output control will adjust the audio output
within the range set by the Lo/Mid/Hi range switch (located on
the back panel.) In the Lo position the adjustment range is from
–50dBu to –20dBu, the Mid position (center) allows an adjust­ment from –30dBu to 0dBu, and the Hi position sets the audio
output to a fixed +8dBu with no front panel control.

POWER SUPPLY

The UCR300 may be operated from an external 10 to 16.5 VDC
source. The power supply has a built in Poly-Fuse to protect the
unit. This fuse resets by simply disconnecting the power supply
for about 15 seconds.

UHF Wireless Diversity Receiver

Rio Rancho, NM – USA

5

FRONT PANEL CONTROLS AND FUNCTIONS

POWER LED

When lit, this LED indicates that power is applied to the UCR300
and adequate voltage is present to operate the unit.

PILOT LED

The audio output muting (squelch) function of the UCR300 is
controlled by a 32kHz tone modulation of the RF carrier. The
audio output is muted until this tone is present. This green LED
will remain on as long as the receiver audio is enabled by the pilot
tone.

TRANSMITTER MOD LEVEL METER

When the meter function switch is in the Mod position, 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. Audio signal peaks easily exceed the response
time of VU meters, however, the LED strip is fast enough to track
even brief transients.

RF LEVEL INDICATORS

With the meter function switch in the RF position, the LED strip
indicates the level of the incoming RF signals. The LED strips 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 LED strip is especially useful in
“troubleshooting” difficult antenna installations.

POWER SWITCH (and PILOT DISABLE)

This slide switch, and its corrosponding LED indicator, switches
the receiver from Off to On with Pilot enabled or ON with Pilot
disabled. The pilot LED will glow green when pilot tone is
present, With the switch in the “ON (Pilot Off)” position, the

LED will glow red. At turn on and off there is a delay 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.

PILOT TONE DISABLE

The Power switch on the front panel is the Pilot Tone Disable.
This is a three position switch. The position toward the right (as
seen looking straight at the front panel) is the normal operating
position and allows the pilot tone to enable or disable the receiver
audio output. The other position, toward the left, will disable the
pilot tone action and will cause the receiver audio output to always
be enabled, even in the absence of a transmitter signal. This
position is only used for troubleshooting and should never be set
during actual use. When the pilot tone is disabled with this
switch, the Mod meter on the front panel is also disabled.

AUDIO OUTPUT LEVEL CONTROL

The front panel Audio Output Level control will adjust the
audio output within the range set by the Lo/Mid/Hi range
switch (located on the rear panel.) In the Low position the
adjustment range is from –50dBu to –20dBu, the Mid position
(center) allows an adjustment from –30dBu to 0dBu, and the Hi
position sets the audio output to a fixed +8dBu with no front
panel control.

ANTENNA CONNECTORS

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

ANTENNA PHASE LEDs

These two LEDs labeled “0” and “180” show the phase differ­ence of the signals being received at the two antennas.

POWER

MAIN DIVERSITY

ON

MOD

RF

1uV

(PILOT OFF)

-42

-36 -30
10uV

OFF

AUDIO OUT

ON

-12 -18 -24

100uV

PILOT

-6

0dB

1mV

0 180

6

UHF Wireless Diversity Receiver

0

1

2

3
4
5

6

7

8

9

A

B

C

D

E

F

0

1

2

3
4
5

6

7

8

9

A

B

C

D

E

F

REAR PANEL CONTROLS AND FUNCTIONS

DC IN JACK

The UCR300 can be powered from external 10 to 16.5 Volts DC
applied directly to this jack, or conventional 220 VAC sources
via the supplied CH20 adapter. The UCR300 is protected from
reverse polarity conditions which prevents damage if a positive
ground power source is applied. The center pin of this jack is
POSITIVE. This power connector is threaded to allow the plug
to be locked in preventing accidental pull-out.

AUDIO OUTPUT XLR JACK

This jack is a standard 3 pin XLR connector. For balanced
applications, Audio High is on pin 2, audio Low is on pin 3, and
audio Common is pin 1. For unbalanced use, the signal is
developed between pin 2 (Audio High) and pin 1 (Audio Com­mon or Ground.) It’s not necessary or desirable to ground pin 3.
(The output is balanced and center tapped.)

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. The level at
this jack is independantly adjustable with the associated knob.

RANGE SWITCH

The audio output range switch is located on the rear panel and
is the switch nearest the front panel. This switch controls the
range of adjustment of the front panel Audio Output control. In
the Low position the adjustment range is from –50dBu to
–20dBu, the High position allows an adjustment from –30dBu
to 0dBu, and the Fixed position sets the audio output to a fixed
+8dBu with no front panel control.

MONITOR

AUDIO OUT

LO MID HI

1 2

3

COARSE

LECTROSONICS

FINE

Rio Rancho, NM – USA

CH20

12VDC

7

ANTENNA USE AND PLACEMENT

There are two antenna assemblies included 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 UCR300 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 UCR300 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.

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.

TRANSMITTER

REFLECTIVE SURFACE

INDIRECT SIGNAL

DIRECT SIGNAL

DIRECT SIGNAL

RECEIVER

INDIRECT SIGNAL

PHASE
CANCELLATION

MULTI-PATH DROPOUT

8

UHF Wireless Diversity Receiver

INSTALLATION AND OPERATING INSTRUCTIONS

1. Connect the power cord.

2. Attach the antennas.

3. Connect the audio cable to the audio output XLR.

4. Set the front panel Audio Output Level control to minimum and set the Power switch to ON (right position.) Check to see that

the front panel Power LED lights up.

5. Adjust the transmitter gain. THIS IS PERHAPS THE MOST IMPORTANT STEP IN THE SET UP PROCEDURE. See your

transmitter manual (Operating Instructions section) for details on how to adjust the transmitter gain. In general, adjust the transmitter
gain so that the voice peaks will cause the 0dB LED on the front of the receiver to light on the loudest peak audio levels. This will
result in the best possible signal to noise ratio for the system without causing overload distortion.

6. Adjust the Audio Output control according to the type of input on your equipment. The Range switch sets the adjustment range of the

front panel Audio Output control and has three positions.

Low: The adjustment range is from –50dBu to –20dBu.

Mid: Allows an adjustment from –30dBu to 0dBu

High: Sets the audio output to a fixed +8dBu with no front panel control.

The input levels of different cameras, VCRs, and PA equipment vary, which may require that you set the Audio Output control
to 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. The UCR300 audio output is designed to drive any audio input device from microphone level to +8dBm line
level.

Note:

When using the +8 dBu HI position of the output range switch, do not ground pin 2 or pin 3 of the XLR output! The output impedance
is only 50 Ohms (unbalanced) when in the HI position and this is not enough to isolate the audio amplifier from a short to ground.
Distortion will result.

MONITOR

AUDIO

AMP

MUTE

RELAY

OUTPUT LEVEL ADJUST

AND RANGE SWITCH

511

50

511

50

LO

511

MID

HI

1k

LO

511

MID

HI

LEVEL

MONITOR

AMP

OUT

XLR

OUT

2 (Hi)

1 (Common or Ground)

3 (Lo)

UCR300 Simplified Audio Output Circuit

UCR300 REPLACEMENT PARTS and ACCESSORIES

Part No. Description

UHF Rubber Duck Antenna, straight connector

32251 Velcro mounting strips
35753 Zippered, padded vinyl system pouch
PS200 Power supply cable locking plug on one end and a

Hirose plug on the other for hookup to a camera.

21586 Power supply cable with locking plug on one end and pigtail leads on the other

Rio Rancho, NM – USA

9

FREQUENCY BLOCKS AND RANGES

The table below lists the factory designated frequency ranges
available for the UCR300 receiver. For convenience, the table
includes information about the UM300B belt-pack transmitter
antennas as well.

Each UCR300 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 UCR300 UHF Receiver antennas (model A8U) are color
coded to indicate the frequency block that they operate within.

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"

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 A8U 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.

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”

Whip Length

A8U Receiver Antenna

10

Whip Length

A6U Transmitter Antenna

TROUBLESHOOTING

UHF Wireless Diversity Receiver

POWER SUPPLY AND FUSE

LEDs not lit or dimly lit

• External power supply disconnected or inadequate.

• Main power supply fuse tripped. Turn the receiver off,

remove the cause of the overload and turn the receiver
back on.

• Wrong polarity power source. The external DC in
requires POSITIVE to be on the center pin.

PILOT TONE SQUELCH

The PILOT indicator lamp on the front panel glows green to
indicate that the audio has been turned on at the transmitter, and
that the audio output on the receiver is enabled. When the lamp is
on, the audio is enabled. When the lamp is off, the audio is muted.

PILOT lamp on, but no sound

• Audio output cable bad or disconnected.

• Audio Output level set too low.

PILOT lamp does not come on 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 3 to 5 seconds for the lamp to come
on.

Normal audio on output but the Mod meter on the front
panel is not working.

• The Power switch may be in the “ON (Pilot Disable)”
position. This front panel switch should be in the right­most position.

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 UCR300
rear panel and see if the noise lowers correspondingly. If
the noise remains, the problem is not in the receiver.

• Receiver output is too low for the input of the device it
is feeding. Try increasing the output level of the UCR300
and lowering the input gain on the device the UCR300 is
feeding.

Distortion

• Transmitter input gain too high. Check and/or re-adjust
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 UCR300 front panel.

• Audio output level too high for the device the UCR300
is feeding. Lower the output level of the UCR300.

ANTENNAS AND RF SIGNAL STRENGTH

RF Level is weak.

• Antenna is disconnected or there is a bad connection

• Antenna may need to be moved or re-oriented

• Improper length of antenna, or wrong antenna. UHF

whip antennas are generally about 3 to 5 inches long.
UHF helical antennas may be shorter, but are often less
efficient.

Rio Rancho, NM – USA

11

SPECIFICATIONS AND FEATURES

2

0

Operating Frequencies:

Frequency Adjustment Range:

Receiver Type:

Frequency Stability:

Front end selectivity:

Sensitivity

20 dB Sinad:
60 dB Quieting:

Squelch quieting:

AM rejection:

Modulation acceptance:

Image and spurious rejection:

Third order intercept:

Diversity method:

FM Detector:

Antenna inputs:

Audio outputs

Rear Panel XLR:

Monitor:

Front Panel Controls and Indicators:

Rear Panel Controls and features:

Power Options:

Weight:

Dimensions:

537.600 to 862.000 MHz

25.5 MHz max

Dual conversion, superheterodyne, 71MHz and 455kHz

±0.002 %

>22 dB at ±4 MHz

0.8 uV (-109 dBm), A weighted (-107 dBm @ 768.0 MHz and above)

1.0 uV (-107 dBm), A weighted (-105 dBm @ 768.0 MHz and above)

Greater than 125 dB

Greater than 60 dB, 2 uV to 1 Volt (Undetectable after processing)

>90 kHz

>100 dB

+12 dBm

Phased antenna diversity

Digital Pulse Counting Detector operating at 455kHz

Dual BNC female; 50 Ohm impedance

Nominal 600 Ohm balanced, three level ranges:
LO - Variable -50 dBm to -20 dBu
MID - Variable -30 dBm to 0 dBu
HI - +8 dBu line level.

0.5VRMS, 50 Ohm load

Main and Diversity antenna BNC connectors; Power on/pilot disable/off switch and LED; Dual
function pilot tone LED; Dual function 10 segment display for RF signal level and transmitter audio
level display; Two LEDs (0 / 180) to indicate the antenna phase.

XLR audio output jack; Monitor output jack and level control; Frequency selection switches;
External DC input; Audio level range select switch.

Minimum 10 Volts to maximum 16.5 Volts DC, 3.1W ,260 mA at 12VDC

12 ozs

3.2" wide x 1.22" high x 5.1" deep

Specifications subject to change without notice.

Typical System Frequency Response

+6

+3

0dB

-3

-6

-9

-12

30 100 1kHz 10k 20k

Adjustable LF Roll-off

12

.0%

1.0%

.5%

0%

Typical System THD + Noise

30 100 1kHz 10k 20k

UHF Wireless Diversity Receiver

This product meets the CE Compliance Standards - ETS 300 445; January

1996. A copy of the Declaration of Conformity may be requested from your
dealer or by contacting the factory directly:

Lectrosonics, Inc.
Marketing Department
581 Laser Rd. NE, Rio Rancho, NM 87124 USA
tel: [phone] fax: [phone] e-mail: [e-mail]

Rio Rancho, NM – USA

13

LIMITED ONE YEAR WARRANTY

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

This warranty applies only to items returned to Lectrosonics, Inc. or an authorized
dealer, shipping costs prepaid, within one year from the date of purchase.

This Limited Warranty is governed by the laws of the State of New Mexico. It states the
entire liablility of Lectrosonics Inc. and the entire remedy of the purchaser for any
breach of warranty as outlined above. NEITHER LECTROSONICS, INC. NOR
ANYONE INVOLVED IN THE PRODUCTION OR DELIVERY OF THE EQUIPMENT
SHALL BE LIABLE FOR ANY INDIRECT, SPECIAL, PUNITIVE, CONSEQUENTIAL,
OR INCIDENTAL DAMAGES ARISING OUT OF THE USE OR INABILITY TO USE
THIS EQUIPMENT EVEN IF LECTROSONICS, INC. HAS BEEN ADVISED OF THE
POSSIBILITY OF SUCH DAMAGES. IN NO EVENT SHALL THE LIABILITY OF
LECTROSONICS, INC. EXCEED THE PURCHASE PRICE OF ANY DEFECTIVE
EQUIPMENT.

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

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 TROUBLESHOOTING 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 drift with age or vibration and never require readjustment. There are no adjustments inside that will make a
malfunctioning unit start working.

LECTROSONICS, INC.

581 LASER ROAD
RIO RANCHO, NM 87124 USA

July 3, 2001