Lectrosonics UH400E WIRELESS MICROPHONE TRANSMITTER User Manual USERS MANUAL
Lectrosonics Inc WIRELESS MICROPHONE TRANSMITTER USERS MANUAL
USERS MANUAL
UH400A
UH400TM
Frequency Agile Plug-On UHF Transmitter
Featuring Digital Hybrid Wireless™ Technology
U.S. Patent 7,225,135
INSTRUCTION MANUAL
Rio Rancho, NM, USA
www.lectrosonics.com
Fill in for your records:
Serial Number:
Purchase Date:
UH400A/UH400TM
LECTROSONICS, INC.
2
This plug-on transmitter is an advanced design that
has evolved since the first models appeared in the late
1980’s serving ENG applications at television stations
across the USA. In the mid-1990’s, the first UHF ver-
sions became available and the use of plug-on transmit-
ters in motion picture production increased significantly.
The current UH400A model has evolved to include
every improvement and feature developed since the first
model was introduced.
The UH400A is a rugged, machined aluminum pack-
age with selectable phantom power for use with a wide
variety of microphones. LEDs located on the top panel
make quick and accurate level settings without having
to view the receiver. The battery compartment accepts
any 9 volt alkaline, LiPolymer or lithium battery and
makes a positive connection via self-adjusting contacts.
The UH400TM is a specialized version of the UH400A
that is an integral part of a highly accurate wireless test
and measurement system.
Only the UH400A and UH400TM transmitters are cov-
ered in this manual. Companion receivers are covered
in separate manuals. The UH400A and UH400TM will
operate with any 100 Series, 200 Series, 400 Series,
IFB Lectrosonics receiver in the same frequency group,
or selected analog receivers from other manufacturers
operating in the same frequency range. (Contact fac-
tory for details.)
Frequency Agile Plug-On UHF Transmitter
Rio Rancho, NM 3
Table of Contents
General Technical Description ..............................................................................................................................................................4
Introduction ...........................................................................................................................................................................................4
Digital Hybrid Technology .....................................................................................................................................................................4
Input Limiter ..........................................................................................................................................................................................5
No Pre-Emphasis/De-Emphasis ...........................................................................................................................................................5
Pilot Tone Squelch ................................................................................................................................................................................5
Long Battery Life ...................................................................................................................................................................................5
Frequency Agility...................................................................................................................................................................................5
Controls and Functions .........................................................................................................................................................................6
Power Switch ........................................................................................................................................................................................6
Power ON/OFF LED .............................................................................................................................................................................6
Phantom Power Voltage Select Switch .................................................................................................................................................6
Frequency Select Switches ...................................................................................................................................................................7
Input Jack ..............................................................................................................................................................................................7
Modulation LEDs ...................................................................................................................................................................................7
Input Signal Level ..................................................................................................................................................................................7
Input Gain Adjustment ..........................................................................................................................................................................7
Compatibility Mode Indicators ...............................................................................................................................................................8
Block Numbers and Freqeuncy Ranges ...............................................................................................................................................9
Operating Instructions .........................................................................................................................................................................10
Attaching the Microphone ...................................................................................................................................................................10
Selecting the Compatibility Mode ........................................................................................................................................................10
Adjusting the Transmitter Frequency ...................................................................................................................................................11
Battery Replacement ..........................................................................................................................................................................11
Using the Polarity- Reversing Barrel Adapter ....................................................................................................................................12
Accessories ..........................................................................................................................................................................................12
Troubleshooting ....................................................................................................................................................................................13
Specifications and Features ................................................................................................................................................................14
Service and Repair ...............................................................................................................................................................................15
Returning Units for Repair ..................................................................................................................................................................15
UH400A/UH400TM
LECTROSONICS, INC.
4
General Technical Description
Introduction
Digital Hybrid Wireless™ is a wideband design with
±75 kHz deviation produding an excellent audio signal
to noise ratio and wide dynamic range. The switching
power supplies provide constant voltages to the trans-
mitter circuits from the beginning (9.3 Volts) to the end
(5.5 Volts) of battery life. The input amplifier uses an
ultra low noise op amp for quiet operation. It is gain con-
trolled with a wide range dual envelope input compres-
sor 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 signal to noise ratio, 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 combina-
tion of power, bandwidth and resistance to interference.
The Lectrosonics Digital Hybrid Wireless™ 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 implementa-
tion 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.
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, yield-
ing audio performance that rivals that of wholly digital
systems, without the power and bandwidth problems
inherent in digital transmission. 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 frequency response
and distortion characteristics than that required by con-
ventional 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 con-
ventional FM systems, the Digital Hybrid has done away
with the analog compandor and its artifacts.
UH400A Block Diagram
Frequency Agile Plug-On UHF Transmitter
Rio Rancho, NM 5
Input Limiter
The Digital Hybrid Wireless™ transmitters employ a
digitally-controlled analog audio limiter just before the
analog-to-digital converter. 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 dy-
namic 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. A highly trained ear would hear only
the compression of the peaks in the audio signal, which
is desirable with most recorders and many sound rein-
forcement systems.
No Pre-Emphasis/De-Emphasis
The signal to noise ratio of the Digital Hybrid Wireless™
system is high enough to preclude the need for conven-
tional 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 pro-
vides 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 Digi-
tal Hybrid system.
Pilot Tone Squelch
The Digital Hybrid Wireless™ system uses one of 256
different ultrasonic tones between 25 and 32 kHz, that
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 basic 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.
Wide-Band Deviation
A ±75 kHz deviation improves the capture ratio, signal
to noise ratio and AM rejection of a wireless system
dramatically, compared to the more commonly used ±
15 kHz deviation.
Long Battery Life
Switching power supplies throughout the design allow
over 4.5 hours of operation using a single 9 Volt alka-
line battery. 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 rotary switches, located on the side panel of the
unit, provide 256 frequencies in 100 kHz steps over a
25.5 MHz range. This alleviates carrier interference
problems in mobile or traveling applications.
UH400A/UH400TM
LECTROSONICS, INC.
6
This transmitter may be used with a wide variety of mi-
crophones. The 3-pin XLR connector allows the trans-
mitter to be used with any dynamic microphone, as well
as many two wire positive bias lavaliere systems (such
as those supplied by Lectrosonics).
Power Switch
The three position switch turns the unit on or off, and
selects either phantom power, or no phantom power.
Regardless of which position the switch is set, the pilot
tone muting system effectively prevents “thumps” or
transients from occurring during power up or power
down.
The PHTM (center) position of the power switch turns
on the phantom power value selected by the Phantom
Power Voltage Select switch, while the NO PHTM (fully
on) position disables phantom power.
Note: In order to avoid damage to some
microphones, be careful to use the center (PHTM)
position only when necessary and keep the
Phantom Power Voltage Select switch in the 5
V position. (See Phantom Power Voltage Select
switch.)
Power ON/OFF LED
This LED glows green when the battery is good. When
the lamp glows red, there will be about 20 minutes of
battery life left with an alkaline battery. The lamp will
blink red when there are only a few minutes of life re-
maining.
Note: A NiMH battery will give little or no warning
when it is depleted. If you wish to use NiMH
batteries in this unit, we recommend installing a
fully charged batteries, noting the length of time
that the batteries will run the unit and in the future
use somewhat less than that time to determine
when the battery needs to be replaced.
A weak battery will sometimes light the POWER LED to
the “good” green indication immediately after being put
in the unit, but will soon discharge to the point where the
LED will go red or shut down (just like a flashlight with
“dead” batteries). If the Power LED fails to light when
power is applied, replace the battery.
Phantom Power Voltage Select Switch
Note: The UH400TM can be used with the
Earthworks M30 Test Microphone if pins 2 and 3
are reversed. A barrel adapter is provided for this
purpose.
This switch selects from three phantom voltages when
the PWR switch is in the mid position. The voltages are:
• 5Voltsforlavalieremicrophones,
• 15Voltsforsomeprofessionalmicsrequiringhigh
current and for many common stage mics that will
operate over a wide phantom Voltage range of 12 to
48 Volts. With the proper adapter, this position can
also be used with T power microphones. See our
web site for details on finding or making the proper
adapter.
• 48Voltsformicrophonesthatdoinfactrequirea
supply greater than 18 Volts. (See below for a dis-
cussion of why 42 and not a “true” 48 Volts.)
For longest battery life use the minimum phantom volt-
age necessary for the microphone. Many stage micro-
phones regulate the 48 Volts down to 10 Volts internally
anyway, so you might as well use the 15 Volt setting and
save some battery power. If you are not using a micro-
phone for the input device, or are using a microphone
that does not require phantom power, set the Power
Switch to the NO PHTM position (No Phantom Power).
This is the fully up position of the Power Switch. Phan-
tom power should only be used with a fully floating,
balanced device such as most microphones with a 3-pin
XLR connector. If you use the phantom power with an
unbalanced device or if pins 2 or 3 are DC connected
to ground, then you will draw maximum current from the
power supply. The UH400A is fully protected against
such shorts but the 9 Volt battery will be drained at
twice its normal rate.
Controls and Functions
1.6MHz 100kHz
012
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4
5
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A
B
C
D
EF012
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A
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EF
1.6MHz 100kHz
PHTM
NO PHTM
PWR OFF
LEVEL 15V
48 V
5V
POWER
SWITCH
PHANTOM POWER
VOLTAGE SELECT
POWER
ON/OFF
LED
INPUT
JACK
MIC LEVEL
Top View Control Panel
MODULATION LEDS
-10
-20
INPUT
JACK
Side View
FREQUENCY SWITCHES
(BEHIND DOOR)
FREQUENCY
Frequency Agile Plug-On UHF Transmitter
Rio Rancho, NM 7
The transmitter can supply 4 mA at 42 Volts, 8 mA at 15
Volts, and 8 mA at 5 Volts. The 42 Volts setting actually
supplies the same voltage to a 48 Volt microphone as
the DIN standard arrangement due to a dynamic bias-
ing scheme that does not have as much voltage drop
as the DIN standard. The 48 Volt DIN standard arrange-
ment protects against shorts and high fault current with
high resistance in the power supply feeds to pins 2 and
3. This protects the supply if the supply current is ac-
cidentally shorted to ground and also keeps the micro-
phone from being attenuated by the power supply. The
UH400A improves on those functions and is able to use
less power from the battery by using constant current
sources and current limiters. With this dynamic arrange-
ment the UH400A can also supply more than twice the
current of competing 48 Volt plug on units and provide
four times the current for some very high end 15 Volt
microphones.
The 5 Volt setting is provided for lavaliere microphones
made by us and others. Do not power lavalieres from
the 15 or 48 Volt setting as the microphone will most
likely be destroyed. Lectrosonics makes an adapter,
MCA5X, that will adapt our standard TA5F 5 pin mi-
crophones to the UH400A. This adapter also provides
protection against excessive phantom voltage. If volt-
ages higher than 5 Volts are applied to the adapter, a
Zener diode will shunt excess voltage to ground. The
microphone won’t work until the voltage is correctly
reduced to 5 Volts. If you have an older lavaliere mic
that was wired directly to an XLR for use with the earlier
UH200’s, we strongly recommend building our protec-
tion circuit into the XLR to prevent accidental destruc-
tion of the lavaliere.
Frequency Select Switches
Two 16 position rotary switches adjust the operating
frequency and are also used for setting Compatibility
Modes.
The 1.6 MHz is a coarse adjustment and the 100 kHz is
the fine adjustment. Each transmitter is factory aligned
at the center of its operating range. The default position
of the frequency select switches is in the center of the
transmitter’s range.
Input Jack
Standard 3-pin Switchcraft XLR type with locking collar.
Pin 2 is signal, pin 3 is a floating signal ground, and pin
1 is case ground (see schematic below).
Modulation LEDs
The Modulation LEDs
indicate the proper setting
of the MIC LEVEL control.
There are two bicolor modu-
lation LEDs that can light
either red or green depend-
ing on the amount of gain
applied. The transmitter
should be set so that both
LEDs glow green, with the
-20 LED occasionally blink-
ing red.
Signal Level -20 LED -10 LED
Less than -20 dB Off Off
-20 dB to -10 dB Green Off
-10 dB to +0 dB Green Green
+0 dB to +10 dB Red Green
Greater than +10 dB Red Red
Input Signal Level
LEDs on the panel next to
the input coupler display the
modulation level for proper
input gain adjustment.
Input Gain Adjustment
The rotary control on the
recessed panel adjusts the
gain over a 43 dB range to
set the proper modulation.
Left Switch
1.6 MHz
Right Switch
100 kHz
1
2
3
+5V / +18V / +48V
4.7uf
1uh
1uh
1uh
To Mic
Preamp
1000
I
100 pf
511
1000
-10 dB LEVEL
-20 dB LEVEL
PHTM
NO PHTM
PWR OFF
LEVEL 15V
48 V
5V
INPUT GAIN ADJUSTMENT
UH400A/UH400TM
LECTROSONICS, INC.
8
Compatibility Mode Indicators
At power up, all three LEDS will blink together red, then
green, followed by the -20 and -10 dB LEVEL LEDs
blinking together to indicate the operating mode.
The –20 and –10 LEDs will blink:
• Oncefor100Seriesmode
• Twicefor200Seriesmode
• Threetimesformode3
(Contact Factory for Details)
• Fourtimesfor400Seriesmode
(Native Hybrid mode)
• FivetimesforIFBSeriesmode
• Sixtimesformode6
(Contact Factory for Details)
-10 dB LEVEL
-20 dB LEVEL
Frequency Agile Plug-On UHF Transmitter
Rio Rancho, NM 9
The transmitter will tune to any of 256 different frequen-
cies within a factory assigned block.
Two 16- position switches adjust the operating
frequency in 100 kHz steps yielding the 256 in a
block (16 x 16 = 256).
To determine a frequency from a block number:
25.6 × Block Number = Lowest freq. (MHz) in the block
Example: 25.6 x 24 = 614.400
To determine a block number from a frequency:
Freq. (MHz) divided by 25.6 = Block number
(first two digits are the block number)
Example: 685.500 divided by 25.6 = 26.77734375
The first two digits left of the decimal are the block num-
ber. In this case, 685.500 MHz falls within block 26.
It is handy to remember these formulas, in case you do
not have a copy of the table.
Block Numbers and Freqeuncy Ranges
Block Numbers and Frequency Ranges (MHz):
Block 470 470.100 - 495.600
Block 19 486.400 - 511.900
Block 20 512.000 - 537.500
Block 21 537.600 - 563.100
Block 22 563.200 - 588.700
Block 23 (lower) 588.8 00- 607.900
Block 23 (upper) 614.100 - 614.300
Block 24 614.400 - 639.900
Block 25 640.000 - 665.500
Block 26 665.600 - 691.100
Block 27 691.200 - 716.700
Block 28 716.800 - 742.300
Block 29 742.400 - 767.900
Part of block 23 (TV channel 37) is not available since it
covers a 608 to 614 MHz band that is allocated for radio
astronomy.
012
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EF
UH400A/UH400TM
LECTROSONICS, INC.
10
Operating Instructions
Attaching the Microphone
1. Set the correct phantom power voltage for the mic.
If the mic does not require phantom voltage, set the
Phantom Voltage Select switch to 5 VDC to reduce
the possibility of damage to the mic when the trans-
mitter is powered up.
2. Insert the UH400A into the XLR connector on the
bottom of the selected microphone. Listen for the
“click” that indicates the transmitter assembly has
locked on to the microphone. Gently pull on the mic
to ensure proper locking has occurred.
3. Set the LEVEL control to minimum (fully counter-
clockwise).
4. Turn on the transmitter by setting the Power Switch
to PHTM if the mic requires phantom power, or
to NO PHTM if the mic does not require phantom
power. (Refer to the specifications for the mic you
are using to determine if phantom power is re-
quired.)
5. Position the mic as it will be used and speak into it
at the same voice level that will actually be used
during the program or production.
5. Start with the Input Gain Control control at maxi-
mum counterclockwise, then observe the Modula-
tion LEDs next to the input coupler as you turn the
gain control up. Turn the gain up until the -20 LED
glows red and the -10 dB glows green with occa-
sional red flicker. This indicates full modulation.
The Input Gain Control on the transmitter should
not be used to control the volume of your sound
system or recording level. The control is used only
to achieve optimal modulation with the voice level
and mic position.
If the audio level is too high — both red LEDs will
glow solid red. This condition may reduce the
dynamic range of the audio signal with compression
being audible in severe cases.
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.
6. Once the gain has been adjusted, leave the gain
control where it is and adjust the receiver output
level to match the recorder or sound system.
Different voices will usually require different settings of
the gain control, so check this adjustment as each new
person uses the system. If several different people will
be using the transmitter and there is not time to make
the adjustment for each individual, It is generally best to
adjust it for the loudest voice.
Selecting the Compatibility Mode
This unit is capable of working with Lectrosonics 400
series digital hybrid receivers, 200 Series, 100 Series
and IFB analog receivers. It is also capable of working
with analog wireless receivers from other manufacturers
(contact the factory for details). Select the compatibility
mode for the matching receiver.
Note: The UH400A is supplied from the factory in
the Digital Hybrid (400 series mode).
1. If the Power LED lights up when the Power Switch
is set to PHTM or NO PHTM, the battery is good
and correctly installed.
2. Turn off the transmitter.
3. With a small screwdriver (included with your unit),
set the frequency change switches to CC. (for
Change, Change). To gain access to these switch-
es, slide the access door open with a fingernail.
TO AT TACH
TO REMOVE
Hold the
transmitter
case with the
microphone
pointed
upward.
Rotate the
collar in the
direction
shown.
Pull on mic to ensure it is locked.
Press firmly, listen for click.
Depress collar fully.
Click!
PHTM
NO PHTM
PWR OFF
LEVEL 15V
48 V
5V
INPUT
GAIN CONTROL
PHANTOM
VOLTAGE
SELECTOR
POWER SWITCH
Frequency Agile Plug-On UHF Transmitter
Rio Rancho, NM 11
4. Set the Power Switch to NO PHTM briefly – just a
couple of seconds for the front panel LED’s to light
up, then turn the unit off.
5. Change the Frequency Select switches to one of the
following settings:
MODE SWITCH SETTINGS
100 Series 1,1
200 Series 2,2
Mode 3* 3,3
400 Series (Digital Hybrid) 4,4
IFB Mode 5,5
Mode 6* 6,6
*Contact factory for details.
6. Turn the transmitter on, four about 1 sec. then back
off.
7. Change the switches to 0,0.
8. Turn the transmitter on and verify the new compatibility
mode. The front panel -20 and -10 LEDs will blink:
•Oncefor100Seriesmode
•Twotimesfor200Seriesmode
•Threetimesformode3(contactfactory)
• Four times for 400 Series mode
• Five times for IFB mode
•Sixtimesformode6(contactfactory)
The Compatibility Mode will remain as set until changed
with the above procedure.
Adjusting the Transmitter Frequency
The receiver is normally used to find and verify a
clear frequency for operation. Some receiver models
have built-in scanning capability to quickly find a clear
frequency. In other cases you may need to use pre-
coordinated frequencies from the Lectrosonics tables
or someone else. Set the left and right switches on the
transmitter to match the receiver. The alpha-numeric
settings are displayed as a pair, ie. A-6, 8-5, 4-B, etc.,
with the left character for the left hand switch and the
right character for the right hand switch.
Battery Replacement
The transmitter is powered by a standard 9 volt battery.
Alkaline, Li Polymer rechargeable and lithium types can
be used. Standard zinc-carbon batteries marked “heavy
duty” or “long-lasting” are not adequate. They will
provide only about five minutes of operation. Similarly,
ni-cad rechargeable batteries only give one hour of
operation, and will also run down quite abruptly. Alka-
line batteries provide about 4.5 hours of operation while
lithium batteries will run the unit for about 12 hours.
To open the battery compartment, press upward on the
cover door in the direction of the arrow as shown in the
drawing. Only slight, sliding pressure is needed to open
and close the battery door.
Swing the door open and take note of the location of
the positive (+) and negative (-) terminals. Insert the
new battery correctly and close the cover by reversing
the opening procedure. Note that the battery door will
NOT close if the battery is inserted incorrectly, since the
terminals will hit a protective polarity barrier. Don’t force
the battery door closed. If it is difficult to close, the bat-
tery is in backwards.
The battery life will be affected by the amount of phan-
tom power supplied to any microphones that require
it. A high drain 48 volt microphone can shorten battery
life by 40% or more. A light drain 18 volt microphone
will make little or no difference in battery life. The only
way to be sure is to test the transmitter and microphone
combination with a brand new battery.
CAUTION: Lithium batteries will expand and
swell if allowed to go into a deep discharge.
Be sure to remove them as soon as the battery
is depleted. Stuck lithium batteries can be
avoided by removing the label wrapping
around the battery before use. This will allow
the battery to swell but will still leave enough
room in the compartment for the battery to be
removed normally.
Left Switch
1.6 MHz
Right Switch
100 kHz
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EF012
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Battery Compartment Action
UH400A/UH400TM
LECTROSONICS, INC.
12
Part #21750
Accessories
PHTRAN2
MC5AX
PHTRAN2
Cordura Pouch with belt clip and velcro flap.
(Included with TX)
MC5AX (optional)
TA5 to XLR adapter for connecting a lavaliere
microphone to the UH400.
Using the Polarity-
Reversing Barrel Adapter
The UH400TM transmitter comes with a polar-
ity-reversing XLR barrel adapter for use with
Earthworks M30 measurement micro-
phones. Simply connect the adapter
between the transmitter and
microphone.
Earthworks M30
Barrel Adapter
UH400TM
Frequency Agile Plug-On UHF Transmitter
Rio Rancho, NM 13
Troubleshooting
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
Transmitter Battery LED Off 1. Battery is inserted backwards.
2. Battery is dead.
No Transmitter Modulation LEDs 1. Gain control turned all the way down.
2. Battery is in backwards. Check power LED.
3. Mic capsule is damaged or malfunctioning.
4. Mic cable damaged or mis-wired.
5. Phantom power not enabled for mic that requires it.
Receiver RF Lamp Off 1. Transmitter not turned on.
2. Transmitter battery is dead.
3. Receiver antenna missing or improperly positioned.
4. Transmitter and receiver not on same frequency.
Check switches/display on transmitter and receiver.
5. Operating range is too great.
No Sound (or Low Sound Level), Receiver Mod Level LEDs Are On
1. Receiver output level set too low.
2. Receiver output is disconnected; cable is defective or mis-wired.
3. Sound system input is turned down.
No Sound (or Low Sound Level), Receiver Mod Level LEDs Are Off
1. Transmitter gain (audio level) set too low.
2. Faulty microphone
3. Phantom power not enabled for mic that requires it.
4. Not enough current to power microphone. (Earthworks M30 is
only known microphone we’ve found to exhibit this issue.)
Distorted Sound 1. Transmitter gain (audio level) is far too high. Check mod level
lamps on transmitter and receiver as it is being used. (Refer to
the Operating Instructions section for details on gain adjustment)
2. Receiver output may be mismatched with the sound system or
recorder input. Adjust output level on receiver to the correct level
for the recorder, mixer or sound system.
3. Excessive wind noise or breath “pops.” Reposition microphone
and/or use a larger windscreen.
4. Transmitter is not set to same frequency as receiver. Check that
frequency select switches on receiver and transmitter match.
Hiss and Noise - Audible Dropouts 1. Transmitter gain (audio level) far too low.
2. Receiver antenna missing or obstructed.
3. Operating range too great.
Excessive Feedback 1. Transmitter gain (audio level) too high causing the limiter to
reduce the dynamic range which in turn causes feedback.
Check gain adjustment and/or reduce receiver output level.
(Refer to the Operating Instructions section for details on gain
adjustment)
2. Transmitter too close to speaker system.
3. Mic is too far from user’s mouth.
UH400A/UH400TM
LECTROSONICS, INC.
14
Operating frequencies: 470.100 to 607.900 MHz; 614.100 to 767.900 MHz
Frequency selection: 256 frequencies in 100 kHz steps
RF Power output: 100 mW
Pilot tone: 25 to 32 kHz; 5 kHz deviation (in 400 Series (hybrid) mode)
Frequency stability: ± 0.002%
Deviation: ± 75 kHz max. (in 400 Series mode)
Spurious radiation: 60 dB below carrier
Equivalent input noise: –118 dBV, A-weighted
Input level: Nominal 2 mV to 300 mV, before limiting; Greater than 1.0 V maximum, with limiting.
Input impedance: 1 k Ohm
Phantom power: Selectable; 5, 15, 48 VD (see details in Controls and Functions section)
Input limiter: Soft limiter, >30 dB range
Gain control range: 43 dB; semi-log rotary control
Modulation indicators: Dual bi-color LEDs indicate modulation of –20, -10, 0 and +10 dB referenced to full modulation.
Low frequency roll-off: –12 dB/octave; 70 Hz (35 Hz for UH400TM)
Controls: Control panel knob adjusts audio gain.
Rotary switches on bottom panel adjust transmitter frequency.
Audio Frequency Response: 90 Hz to 20 kHz, +/-1 dB (40 Hz to 20 kHz, +/- 1 db for UH400TM)
Note: The audio is deliberately rolled off at 70Hz using a 12 dB/octave filter on the UH400A. This filter cannot be disabled.
Signal to Noise Ratio (dB):
Note: The dual envelope “soft” limiter provides
exceptionally good handling of transients using
variable attack and release time constants.
Once activated, the limiter compresses 30+ dB
of transmitter input range into 4.5 dB of receiver
output range, thus reducing the measured figure f
or SNR without limiting by 4.5 dB
Total Harmonic Distortion: 0.2% typical (400 Series mode)
Antenna: Built-in; housing and input coupler form a dipole configuration
Battery Type: 9V Li Polymer rechargeable, Lithium
Battery Life: 4.5 Hours with alkaline or Li Polymer, 12 hrs with lithium
(Battery life will vary with battery brand, phantom power voltage setting and mic current drain.)
Weight: 7.873 oz. 223.2 grams with lithium battery, no mic
Overall Dimensions: 1.5 x 1.5 x 4.2 inches (Not including microphone.)
Emission Designator: 190KF3E
Specifications subject to change without notice.
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 conjunction with any other
antenna or transmitter.
Specifications and Features
SmartNR No Limiting w/Limiting
OFF 103.5 108.5
NORMAL 107.0 111.5
FULL 108.5 113.0
Frequency Agile Plug-On UHF Transmitter
Rio Rancho, NM 15
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 the interconnecting
cables and then go through the Troubleshooting section in this manual.
We strongly recommend that you do not try to repair the equipment yourself and do not have the local repair shop at-
tempt 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’ 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.
Returning Units for Repair
For timely service, please follow the steps below:
A. DO NOT return equipment to the factory for repair without first contacting us by email 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 dam-
age to equipment that you ship. Of course, we insure the equipment when we ship it back to you.
Lectrosonics USA:
Mailing address: Shipping address: Telephone:
Lectrosonics, Inc. Lectrosonics, Inc. (505) 892-4501
PO Box 15900 581 Laser Rd. (800) 821-1121 Toll-free
Rio Rancho, NM 87174 Rio Rancho, NM 87124 (505) 892-6243 Fax
USA USA
Web: E-mail:
www.lectrosonics.com sales@lectrosonics.com
Lectrosonics Canada:
Mailing Address: Telephone: E-mail:
49 Spadina Avenue, (416) 596-2202 Sales: colinb@lectrosonics.com
Suite 303A (877) 753-2876 Toll-free Service: joeb@lectrosonics.com
Toronto, Ontario M5V 2J1 (877-7LECTRO)
(416) 596-6648 Fax
14 April 2008
581 Laser Road NE • Rio Rancho, NM 87124 USA • www.lectrosonics.com
(505) 892-4501 • (800) 821-1121 • fax (505) 892-6243 • sales@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.