Lectrosonics UT400 User manual

OPERATING INSTRUCTIONS
UT400UT400
UT400UT400
UT400
DIGITAL HYBRID
FREQUENCY AGILE
HAND-HELD TRANSMITTER
LECTROSONICS, INC.
Rio Rancho, NM
www.lectrosonics.com
FEATURING DIGITAL HYBRID WIRELESSTM TECHNOLOGY
(US PATENT PENDING)

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UT400
LECTROSONICS, INC.

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Rio Rancho, NM - USA
Digital Hybrid, Frequency Agile, Hand-held Transmitter
Table of Contents
GENERAL TECHNICAL DESCRIPTION ........................................................................... 4
GENERAL ................................................................................................................... 4
DIGITAL HYBRID TECHNOLOGY .............................................................................. 4
NO PRE-EMPHASIS/DE-EMPHASIS ......................................................................... 5
PILOT TONE SQUELCH ............................................................................................ 5
WIDE-BAND DEVIATION ............................................................................................ 5
INPUT LIMITER ........................................................................................................... 5
LONG BATTERY LIFE ................................................................................................. 5
FREQUENCY AGILITY ............................................................................................... 5
ANTENNA.................................................................................................................... 5
MICROPHONE ELEMENT .......................................................................................... 5
CONTROLS AND FUNCTIONS ......................................................................................... 6
POWER SWITCH – POWER ON/OFF ....................................................................... 6
LED POWERUP SEQUENCE ..................................................................................... 6
LOCKED MODE .......................................................................................................... 6
HIDING THE POWER LED ......................................................................................... 7
FREQUENCY Switches .............................................................................................. 7
AUDIO LEVEL LEDS ................................................................................................... 7
AUDIO LEVEL CONTROL .......................................................................................... 7
VariMicTM CONTROLS ...................................................................................................... 8
BASS / MID / TREBLE (LO / MID / HI) ....................................................................... 8
PREAMP LEVEL CONTROL ...................................................................................... 8
SUBSONIC NOISE FILTER ........................................................................................ 9
BATTERY INSTALLATION .................................................................................................. 9
OPERATING INSTRUCTIONS ......................................................................................... 10
SELECTING COMPATIBILITY MODE ...................................................................... 10
ADJUSTING THE AUDIO GAIN ................................................................................ 10
OPERATING NOTES ........................................................................................................ 11
ADJUSTING THE TRANSMITTER FREQUENCY ........................................................... 11
TROUBLESHOOTING ...................................................................................................... 12
SPECIFICATIONS ............................................................................................................ 13
SERVICE AND REPAIR ................................................................................................... 14
RETURNING UNITS FOR REPAIR .................................................................................. 14
LIMITED ONE YEAR WARRANTY .................................................................... Back Cover
INTRODUCTION
Thank you for selecting the Lectrosonics UT400 hand-held wireless transmitter. The UT400 combines over
80 years of engineering experience with the very latest components in a design that addresses the most
demanding professional applications.
The design of the UT400 was the direct result of numerous conversations with users, staging and touring
companies, and dealers across the US. The specific concerns and needs brought up in these conversa-
tions led directly to the development of the operational features offered on the UT400. Two hundred fifty six
frequencies are user selectable in 100 kHz steps to alleviate interference problems in travelling venues.
The UT400 is an integral microphone/transmitter with an internal antenna. The antenna is a dipole type
using the two printed circuit boards as the elements. The housing is composed of durable PVC, machined
to a natural, comfortable shape. Internal mechanical parts are machined aluminum and brass.
Only the UT400 transmitters are covered in this manual. Companion receivers are covered in separate
manuals. The UT400 will operate with any 100 Series, 200 Series and 400 Series Lectrosonics receiver in
the same frequency group.

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UT400
LECTROSONICS, INC.
Phase Locked Loop
Voltage
Controlled
Oscillator
Freq
Switches
11001001
A-D
Converter
Digital Signal Processor
11001001
D-A
Converter
Shunt
Limiter
Bicolor
Modulation
LEDs
Microprocessor
9V
Battery
Switching
Power
Supply
+3.3v
+1.8v
+9v
-3v
Audio
Encoded
Audio +
Pilot Tone
11.3 MHz
Reference
Bicolor
Power
LED
Audio
Level
Input
Amp
Final
Amplifier
50 Isolator
Preamp
Mic
Element
Preamp
Level
Tone
GENERAL TECHNICAL DESCRIPTION
GENERAL
The 400 system uses 75 kHz wide deviation for an extremely high signal to noise ratio. The switching power supplies
provide constant voltages to the transmitter circuits from the beginning (9.3 V) to the end (5.5 V) of battery life. The
input amplifier uses an ultra low noise op amp for quiet operation. It is gain controlled with a wide range dual envelope
input compressor which cleanly limits input signal peaks over 30 dB above full modulation.
DIGITAL HYBRID TECHNOLOGY
All wireless links suffer from channel noise to some degree and all wireless microphone systems seek to minimize the
impact of that noise on the desired signal. Conventional analog systems use compandors for enhanced dynamic
range, at the cost of subtle artifacts (known as “pumping” and “breathing”). Wholly digital systems defeat the noise by
sending the audio information in digital form, at the cost of some combination of power, bandwidth and resistance to
interference.
The Lectrosonics Digital Hybrid WirelessTM system (hereafter called Digital Hybrid) overcomes channel noise in a
dramatically new way, digitally encoding the audio in the transmitter and decoding it in the receiver, yet still sending
the encoded information via an analog FM wireless link. This proprietary algorithm is not a digital implementation of
an analog compandor but a technique which can be accomplished only in the digital domain, even though the inputs
and outputs are analog signals. (As of this writing, the patent is still pending, so we cannot reveal detailed informa-
tion about the algorithm at this time.)
Channel noise still has an impact on received signal quality and will eventually overwhelm the receiver. The Digital
Hybrid simply encodes the signal to use a noisy channel as efficiently and robustly as possible, yielding audio perfor-
mance that rivals that of wholly digital systems, without the power and bandwidth problems inherent in digital trans-
mission. As always, these advantages come at a cost. The Digital Hybrid system requires fairly intensive digital
processing in both the transmitter and the receiver. These processors cost money, take up space and consume
power. The Digital Hybrid system also requires that the underlying RF link be of excellent quality, with better fre-
quency response and distortion characteristics than that required by conventional systems.
Because it uses an analog FM link, the Digital Hybrid enjoys all the benefits of conventional FM wireless systems,
such as excellent range, efficient use of RF spectrum, and long battery life. However, unlike conventional FM sys-
tems, the Digital Hybrid has done away with the analog compandor and its artifacts.

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Rio Rancho, NM - USA
Digital Hybrid, Frequency Agile, Hand-held Transmitter
NO PRE-EMPHASIS/DE-EMPHASIS
The signal to noise ratio of the 400 system is high enough to preclude the need for conventional pre-emphasis (HF
boost) in the transmitter and de-emphasis (HF roll off) in the receiver. Pre-emphasis and de-emphasis in an FM radio
system usually provides about a 10 dB improvement in the signal to noise ratio of the system, but the high frequency
boost in the transmitter must be removed in a purely complementary manner or else the frequency response of the
original audio signal will be altered. Pre-emphasis can also cause distortion in the receiver. As this signal is passed
through the IF filters in the receiver, distortion can be produced, most noticeably at full modulation. De-emphasis
cannot be applied until the signal is converted into audio, so there is no way around this problem short of eliminating
pre-emphasis altogether. Neither of these problems occur in the 400 system
PILOT TONE SQUELCH
The 400 system uses one of 256 different ultrasonic tones between 25 and 32 kHz to modulate the carrier to operate
the receiver squelch. The pilot tone frequency is chosen according to which of the 256 channels has been selected
by the frequency switch setting. The benefit of the pilot tone squelch system is that the receiver will remain 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. The UT400 extends this concept even further by ensuring that all transmitters in a system have differ-
ent pilot tone frequencies so that even spurious RF from the wrong transmitters can’t open the receiver squelch.
WIDE-BAND DEVIATION
The ±75 kHz deviation improves the capture ratio, signal to noise ratio and AM rejection of a wireless system dramati-
cally, compared to the more commonly used ±15 kHz deviation.
INPUT LIMITER
The 400 series transmitters employ a digitally-controlled analog audio limiter just before the analog-to-digital con-
verter. The limiter has a range of more than 30 dB for excellent overload protection. A dual release envelope makes
the limiter acoustically transparent while maintaining low distortion. It can be thought of as two limiters in series,
connected as a fast attack and release limiter followed by a slow attack and release limiter. The limiter recovers
quickly from brief transients, so that its action is hidden from the listener, but recovers slowly from sustained high
levels, to both keep audio distortion low and preserve short term dynamic changes. Generally speaking, some limiting
is desirable in normal operation to improve the signal to noise ratio of the system. The limiting action is not audible
and does not create distortion.
LONG BATTERY LIFE
Switching power supplies throughout the design allow over 3.5 hours of operation using a single 9 VDC alkaline
battery. (A 9 VDC lithium battery will provide over 6.5 hours of operation.) The battery contacts are spring loaded to
prevent “rattle” as the unit is handled.
FREQUENCY AGILITY
The transmitter section uses a synthesized, frequency selectable main oscillator. The frequency is extremely stable
over a wide temperature range and over time. Two 16-position rotary switches, located under the battery door,
provide 256 frequencies in 100 kHz steps over a 25.5 MHz range. This alleviates carrier interference problems in
mobile or traveling applications.
ANTENNA
The high output antenna uses the lower half of the printed circuit boards as one radiating element, with the upper half
of the PC boards and the mic capsule as the other half of the dipole configuration. This allows the mic to be held in
any position, since the user’s hands have little or no effect on the radiated power.
MICROPHONE ELEMENT
Several optional microphone capsules are available with the UT400, including the Lectrosonics VariMicTM and AKG
C5900 models. The VariMicTM is a high quality electret model with a cardioid pattern. The AKG C5900 electret
provides a hypercardioid pattern popular in live sound venues. Both are mounted in a tuned resonance suspension,
which reduces handling and low frequency noise (rumble or wind), along with the Lectrosonics VariMicTM preamplifier.
The VariMicTM uses an unusual pumped-source FET circuit to increase usable dynamic range to 12 dB and greatly
reduce distortion, just as if the FET were being supplied with 48 Volts. In addition, a unique 16-position attenuation
control at the element itself can adjust the sensitivity in 15 steps (in 1 dB increments) over a 15 dB range. This is in
addition to the normal gain control in the wireless microphone. The result is the widest dynamic range of any con-
denser mic in a wireless microphone.

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UT400
LECTROSONICS, INC.
Power
LED
Power
Switch
CONTROLS AND FUNCTIONS
POWER SWITCH – POWER ON/OFF
A slide switch located on the outside bottom of the unit
turns the unit on and off. The pilot tone muting system
prevents “thumps” or transients from occurring even
when this switch is turned off or on abruptly,
When the unit is powered, the Power LED glows green
to indicate that the is good. The lamp will glow red as
the battery voltage drops and finally flashes when there
is about 30 minutes of operation left with the recom-
mended alkaline battery. A NiMH battery will give little
or no warning when it is depleted. If you wish to use
NiMH batteries in the unit, we recommend trying fully
charged batteries, noting the length of time that the
batteries will power the unit. Then, use slightly less
time to determine when the battery needs to be re-
placed. A weak battery will sometimes indicate good
(green) on the Power LED immediately after being put
in the unit, but will soon discharge to the point where
the LED will go red or shut down. If the lamp fails to
light, the battery should be replaced.
LED POWER-UP SEQUENCE
The UT400 is unique among 400 series transmitters in
that its Audio Level LEDs are located under a cover and often aren’t visible. Because of this, the blinking code indicat-
ing the current operating mode is issued using the Power LED instead of the Audio Level LEDs.
LOCKED MODE
The UT400 can be placed in a locked mode where neither the Power switch nor the Frequency Switches have any
further effect on operation. This protects the unit from accidental power-off or misadjustment after it has been pre-
pared for use.
Power LED
Power On/Off
Frequency
Switches
Audio Level Control
Modulation
Level LEDs
Battery Compartment
Locking ring (Open
Position)
Battery Compartment
Cover
Windscreen

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Rio Rancho, NM - USA
Digital Hybrid, Frequency Agile, Hand-held Transmitter
Audio Level LEDs
-20 -10
Frequency Switches
Coarse Fine
Audio Level
To enter locked mode, toggle the Power switch off and on again rapidly three times. (Each toggle must take no longer
than two seconds and no more than ten seconds may elapse between successive toggles.) During the first two
toggles, the Power LED will behave normally, blinking slowly red while the switch is in the off position to warn that the
power will go off, then returning to normal battery status indication when the switch is on again. After the third toggle,
the Power LED will go out briefly, then blink the code that indicates the current mode, just as it does when the unit is
first powered on. This blinking code serves as a confirmation that the switches are now locked.
Locked mode can be cleared by removing the battery. Note that since removing the battery bypasses the normal
delayed power-off circuit, it may cause noise at the receiver.
HIDING THE POWER LED
This unit has no provision for disabling the LEDs. The Audio Level LEDs are covered during normal use but the Power
LED is exposed. If the light is objectionable, we recommend covering it with a piece of tape.
FREQUENCY SWITCHES
Two rotary switches (located under the battery door) adjust the center frequency of the carrier. The Coarse adjust-
ment adjusts the frequency in 1.6 MHz steps and the fine in 100 kHz steps. Each transmitter is factory aligned at the
center of its operating range for uniform operation across the entire band. The default position of the Frequency
Switches is in the center of the transmitter range.
AUDIO LEVEL LEDS
These LEDs (located under the battery door) indicate the proper modulation level setting of the MIC LEVEL control.
There are two bicolor modulation LEDs that can light either red or green.
“-20dB level” Begins glowing green when transmitter is 20 dB below full modulation and changes
to red as transmitter approaches 0 dB or full modulation.
“-10 dB level” Begins glowing green as transmitter approaches -10 dB below full modulation and
changes to red as the modulation level rises to +10 dB.
AUDIO LEVEL CONTROL
The Audio Level control (located under the battery door) is used to adjust the transmitter’s gain (modulation).

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UT400
LECTROSONICS, INC.
Preamp Level Control
Bass (LO) Mid (MID) Treble (HI)
+10
0
dB
-10 10Hz 100Hz 1KHz 10KHz
+5
-5
UT200 Bass/Midrange/Treble Boost/Cut
VARIMICTM CONTROLS
Caution - Due to the high RF levels surrounding the
transmitter, the sound of the VariMicTM capsule may be
temporarily affected if the metal windscreen is not in place.
Always make the final decision about sound balance and
quality with the windscreen in place.
The VariMicTM head includes adjustments for Bass,
Midrange (Mid) and Treble response. There is also an
attenuation adjustment to provide up to 15 dB of addi-
tional headroom if needed.
BASS / MID / TREBLE (LO / MID / HI)
The bass and treble controls will boost/cut by up to
approximately 8 dB while the Mid control will boost/cut up
to about 6 dB. These controls operate as standard tone
controls. Counterclockwise will reduce the response in
that band and clockwise will provide a true boost. These
controls can be accessed by removing the windscreen.
To remove the windscreen, grasp the body of the trans-
mitter in one hand and the windscreen in the other hand.
Carefully unscrew the windscreen counterclockwise until it
comes off, then carefully slide the windscreen past the mic
element.
Control Settings:
• Set flat, the mic capsule is very wide range and sounds
a lot like a large competitor’s top line condenser mic.
• Bass cut gives a dry but highly intelligible sound. Crisp.
• Bass boost “fattens” the sound but is very listenable.
Does not get midbass boomy.
• Midrange cut sounds very smooth. Almost a “crooner”
quality. A sweet sound.
• Midrange boost is likely to be useful in a system that is
midrange shy.
• Treble cut has a “mellow” sound. The capsule has a
solid high end so a little cut does not ruin the re-
sponse.
• Treble boost might be fine on some sound systems.
The sound doesn’t get harsh (showing that the re-
sponse was smooth) but sibilants are a little too much.
Should be used in moderation.
PREAMP LEVEL CONTROL
The VariMicTM head includes an attenuator to provide an
additional 15 dB of headroom when needed. The attenua-
tor should only be used when the normal Audio Level
control is already turned down as far as it will go and the
signal through the mic is still too high. The attenuator
control is a 16-position switch marked “0” through “F.” “F”
is minimum attenuation. It allows the highest signal level
to pass. “0” is maximum attenuation. It allows the lowest
signal level to pass. For the maximum amount of head-
room, set the switch to “0.”

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Rio Rancho, NM - USA
Digital Hybrid, Frequency Agile, Hand-held Transmitter
20
0dB
-20
-40
-60
10Hz 100Hz 1KHz 10KHz
VariMic Low Frequency Roll-off Filter
-3dB @ 71Hz
-20dB @ 50Hz
P
P
+
–
+
–
Pull Ring
Outward
Rotate Ring
1/8 Turn
Remove
Cover
Insert
Battery
Rotate Ring To
Lock Closed
Replace
Cover
Ring will sit flush in the
closed position.
Depress the plunger with
the corner of the battery
and slide the battery into
the compartment. Note that
the locking ring is in the
closed position for this
procedure.
Alternate Method
STEP 1
STEP 2
STEP 3
STEP 4
STEP 5
STEP 6
Note: The attenuator should not be used as a level
control. The Audio Level control inside the battery
compartment is the main level control. Adjust the
Preamp Level Control only when the Audio Level
control is turned completely down and more
headroom is still needed. Be sure to set the
Preamp Level Control back to its original setting
for normal operation.
SUBSONIC NOISE FILTER
In addition to the tone controls, the UT400
also has a built in subsonic noise (or high
pass) filter. This filter is fixed and cannot be
adjusted or defeated. Low frequency noise is
much more of a problem with wireless micro-
phones than with conventional microphones. With a regular mic, low frequency wind noise, breath thumps or han-
dling rumble can be filtered out at the control board before the noise causes problems with the following electronics or
speaker systems. But with a wireless microphone, the electronics that will be overdriven are right in the wireless
microphone. Filtering at the control board is too late. To solve this problem, the VariMicTM has a subsonic noise filter
that is so sharp that it can remove low frequency noise without affecting any wanted vocals. It consists of a 36 dB per
octave filter circuit to sharply remove low frequency noise below 75 Hz without affecting vocal fundamentals. (The
lowest operatic bass voice fundamental is 82 Hz.)
BATTERY INSTALLATION
The transmitter is powered by a standard alkaline or lithium 9 Volt battery. It is important that you use only
Alkaline or lithium batteries for reliable operation. Alkaline batteries will provide about 3.5 hours of operation
while the lithium batteries will operate the transmitter for about 6.5 hours. The battery status lamp will function
normally only with alkaline or lithium batteries. Standard zinc-carbon batteries marked “heavy duty” or “long-
lasting” are not adequate. They will provide only about 30 minutes of operation. Similarly, nicad rechargeable
batteries only provide about one hour of operation and will run down quite abruptly.
The battery compartment is located in the lower
section of the transmitter, between the two printed
circuit boards. Follow the steps illustrated to the right
to install a fresh battery.
Note the two differently sized holes in the battery
contact pad inside the Battery Compartment. Insert
the battery so that the large hole in the battery
contact pad will line up with the large contact on the
battery. A spring-loaded plunger in the bottom of the
compartment (opposite the contact pad) secures the
battery in place.
The battery status is indicated by an LED on the
bottom panel. The LED glows bright green when a
new battery is installed, dims to red as battery
condition deteriorates, then blinks red as the battery
nears depletion. Battery status is also displayed on
the Information Display on the front panel of the
associated receiver. See the receiver manual for
further details.
Note: It is possible to insert the battery backwards and still
be able to close the battery door. No damage will occur but
the transmitter will not operate in this condition.

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UT400
LECTROSONICS, INC.
SELECTING COMPATIBILITY MODE
This transmitter is capable of working with Lectrosonics 400 series Digital Hybrid WirelessTM, 200 series analog, 100
series analog, and some analog wireless receivers from other manufacturers (contact the factory for details). The
transmitter must be set for compatibility with the matching receiver, which is easily done using the supplied screw-
driver and a battery.
Note: The unit is supplied from the factory as a 400 series transmitter
1) Ensure a good battery is installed.
2) Turn off (power down) the transmitter.
3) With a small screwdriver (included with your unit), set the Frequency Switches to “CC.” (for Change,
Change).
4) Turn on (power up) the unit. Watch for the LED’s to glow and then immediately turn the unit off.
5) Change the switches to one of the following settings:
• For Lectrosonics 100 mode: Set switches to 1,1
• For Lectrosonics 200 mode: Set switches to 2,2
• For Mode 3: Set switches to 3,3* (contact the factory for details)
• For Lectro Digital Hybrid WirelessTM mode: Set switches to 4,4
6) Turn on (power up) the unit. Watch for the LED’s to glow and then immediately turn the unit off.
7) Set both Frequency Switches to “0.”
8) Turn on the unit to finish setting the Compatibility Mode.
The Audio Level LEDS will blink to indicate the Compatibility Mode. Immediately after powering up, all
LEDS will blink together red, then green, followed by the Audio Level LEDs (-20 and -10) blinking a code
to indicate the operating mode.
To identify the operating mode, the –20 and –10 LEDs will blink:
• Once for 100 mode
• Two times for 200 mode
• Three times for other receivers (contact factory for details)
• Four times for Digital Hybrid WirelessTM, or 400 mode
At initial turn on, the transmitter will confirm the current Compatibility Mode according to the above code.
The setting will remain the same until reset with the above procedure.
ADJUSTING THE AUDIO GAIN
1) Install a fresh battery. Leave the battery cover off for further adjustment.
2) On the bottom panel, set the Power switch to ON (up). The Power LED glows green to indicate a good
battery. If the LED glows red or not at all, replace the battery.
3) Hold the microphone in the same position that it will be used in actual operation.
4) While speaking or singing at the same voice level that will actually be used during the program, observe
the Audio Level LEDs. Adjust the Audio Level control until the –20 dB LED glows red and the -10 dB
glows green.
Note: If you find that the Audio Level control is set to minimum and both Audio Level LEDs are
glowing red, then it may be necessary to adjust the Preamp Level Control. This control is located
under the UT400’s windscreen. Unscrew the windscreen and carefully lift it off the top of the unit. See
the VARIMICTM CONTROLS section for these adjustments. If the Preamp Level Control is adjusted,
ensure to repeat the audio gain adjustment procedure beginning at step 3.
5) Once the audio gain has been set, the rest of the audio system can be turned on to make level adjust-
ments in the main audio system.
OPERATING INSTRUCTIONS

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Rio Rancho, NM - USA
Digital Hybrid, Frequency Agile, Hand-held Transmitter
If you are experiencing interference from another signal,
you may want to change the operating frequency of your
transmitter/receiver. Locate a clear channel, then change
the operating frequency of the transmitter to match that
frequency, then set the transmitter to match the receiver.
(Some receiver models will indicate the correct transmitter
switch settings on the receiver control panel.)
On the UT400, the Fine Frequency Select Switch changes
the operating frequency in 100 kHz increments. The
Coarse Frequency Select Switch changes the operating
frequency in 1.6 MHz increments.
OPERATING NOTES
The Audio Level control should not be used to control the volume of the overall sound system or recorder levels.
This gain adjustment is used to match the transmitter gain with the user’s voice level and microphone positioning.
If the audio level is too high — both Audio Level LEDs will glow red. This condition may reduce
the dynamic range of the audio signal.
If the audio level is too low — neither LED will glow, or only the -20 LED will glow green. This
condition may cause hiss and noise in the audio.
Different voices will usually require different settings of the Audio Level control, so check the Audio Level settings as
each new person uses the UT400. If several different people will be using the same UT400 and there is not time to
make the adjustment for each individual, adjust it for the loudest voice.
ADJUSTING THE TRANSMITTER FREQUENCY
012
3
4
5
6
7
8
9
A
B
C
D
EF012
3
4
5
6
7
8
9
A
B
C
D
EF
Frequency Select Switches
Coarse Fine

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UT400
LECTROSONICS, INC.
Before going through the following chart, be sure that you have a good battery in the transmitter. It is important that
you follow these steps in the sequence listed.
SYMPTOM POSSIBLE CAUSE
UT400 POWER LED OFF 1) Battery is inserted backwards.
2) Battery is dead, or too low to be used.
UT400 AUDIO LEVEL LEDs OFF 1) Audio Level Control turned all the way down.
2) Battery is in backwards. Check Power LED.
3) Mic capsule is damaged or malfunctioning. Contact the factory for
repair.
RECEIVER RF LAMP OFF 1) UT400 not turned on.
2) UT400 battery is dead.
3) Receiver antenna missing or improperly positioned.
4) UT400 and receiver not on same frequency. Check labels
on UT400 and receiver and the associated frequency switch
settings.
5) Operating range is too great.
NO SOUND BUT RECEIVER AUDIO
LEVEL METER INDICATES SOUND 1) Receiver audio is muted or set too low.
2) Receiver audio output is disconnected or cable defective or
miswired.
3) Sound system or recorder input is turned down.
DISTORTED SOUND, MOTORBOATING
OR BOTH 1) UT400 Audio Level Control set too high. Speak or sing into the
UT400 and check the UT400 Audio Level LEDs and corresponding
indicators on the receiver.
2) Receiver output level may be too high for the sound system or
recorder input.
3) Excessive wind noise or breath “pops.” Microphone may require
an additional wind screen.
4) UT400 Frequency Switches set incorrectly.
5) RF feedback getting into VariMicTM mic capsule. Ensure that the
windscreen is present and screwed down snugly.
HISS AND NOISE -- AUDIBLE DROPOUTS 1) UT400 Audio Level Control set too low.
2) Receiver antenna missing or obstructed.
3) Operating range too great.
4) UT400 Frequency Switches set incorrectly.
EXCESSIVE FEEDBACK 1) UT400 Audio Level Control set too high. Check level adjustment,
reduce receiver output level, or both.
2) Microphone too close to speaker system.
3) Move microphone closer to the user’s mouth and lower the
sound system volume.
TROUBLESHOOTING

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Rio Rancho, NM - USA
Digital Hybrid, Frequency Agile, Hand-held Transmitter
Operating frequencies: 537.600 to 607.900 MHz
614.100 to 793.500 MHz
Frequency selection: 256 frequencies in 100 kHz steps
RF Power output: 100 mW (nominal)
Pilot tone: 25 to 32 kHz frequency; 5 kHz deviation
Frequency stability: ± 0.002%
Deviation: ± 75 kHz (max)
Spurious radiation: 90 dB below carrier
Equivalent input noise: –120 dBV, A-weighted
Input level: Nominal 2 mV to 300 mV, before limiting.
Greater than 1V maximum, with limiting.
Input compressor: Dual envelope compressor, >30 dB range
Gain control range: 43 dB; semi-log rotary control
Modulation indicators: Dual bicolor LEDs indicate modulation of -20, -10, 0, +10 dB
referenced to full modulation.
Low frequency roll-off: 36 dB/octave; 35 Hz to 70 Hz
Audio frequency response (overall system): 80 Hz to 20 kHz (+/- 1dB)
Controls: 2 position “OFF-ON” slide Power switch for noiseless turn on/off operation.
Audio Level Control in Battery Compartment adjusts audio gain. Two rotary
switches in Battery Compartment adjust transmitter operating frequency.
Battery: Precision compartment auto-adjusts to accept any known alkaline 9 Volt
battery. (We’ve tried 243 different ones!)
Battery Life: 3.5 hours (alkaline); 6.5 hours (lithium)
Weight: 12.4 ozs. with VeriMic capsule and lithium battery
Dimensions: 9” long x 2.05” diameter at largest point with VariMic
TM
capsule
Emission Designator: 180KF3E
Specifications subject to change without notice.
SPECIFICATIONS
The FCC requires that the following statement be included in this manual:
This device complies with FCC radiation exposure limits as set forth for an uncontrolled environment. This
device should be installed and operated so that its antenna(s) are not co-located or operating in conjunc-
tion with any other antenna or transmitter.

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UT400
LECTROSONICS, INC.
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 intercon-
necting 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 connec-
tion, send the unit to the factory for repair and service. Don’t attempt to adjust any controls inside the units, other
than the ones indicated in this manual. 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.
The LECTROSONICS Service Department 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.
SERVICE AND REPAIR
You will save yourself time and trouble if you will follow the steps below:
A. DO NOT return equipment to the factory for repair without first contacting Lectrosonics 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 a.m. to 4 p.m. (U.S. 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 authorization 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 responsible 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
World Wide Web: http://www.lectrosonics.com Email: [e-mail]
RETURNING UNITS FOR REPAIR

581 LASER ROAD
RIO RANCHO, NM 87124 USA
www.lectrosonics.com
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.
LIMITED ONE YEAR WARRANTY
LECTROSONICS, INC. June 3, 2004