Lectrosonics UM400 User manual

UM400UM400
UM400UM400
UM400
FREQUENCY-AGILE UHF
BELT-PACK TRANSMITTER
(Includes IFB Compatibility Mode)
OPERATING INSTRUCTIONS
LECTROSONICS, INC.
Rio Rancho, NM
www.lectrosonics.com

2
UM400
LECTROSONICS®
The UM400 transmitter is FCC type accepted under Part 74: 536-608 MHz and 614-806 MHz

3
Frequency-Agile UHF Belt-Pack Transmitter
Rio Rancho, NM – USA
TABLE OF CONTENTS
GENERAL TECHNICAL DESCRIPTION ........................................................... 4
GENERAL ...................................................................................................... 4
DIGITAL HYBRID TECHNOLOGY ................................................................. 4
NO PRE-EMPHASIS/DE-EMPHASIS ............................................................ 5
PILOT TONE SQUELCH ............................................................................... 5
INPUT LIMITER ............................................................................................. 5
WIDE-BAND DEVIATION............................................................................... 5
LONG BATTERY LIFE ................................................................................... 5
FREQUENCY AGILITY .................................................................................. 5
ANTENNA ...................................................................................................... 5
CONTROLS AND FUNCTIONS ......................................................................... 6
INPUT JACK .................................................................................................. 6
POWER ON/OFF SWITCH ............................................................................ 6
POWER ON LED ........................................................................................... 6
AUDIO LEVEL CONTROL ............................................................................. 6
AUDIO LEVEL................................................................................................ 6
MODULATION LEDS ..................................................................................... 7
ANTENNA ...................................................................................................... 7
FREQUENCY SELECT SWITCHES .............................................................. 7
ADJUSTABLE LOW FREQUENCY ROLL-OFF ............................................. 7
BELT CLIP ..................................................................................................... 7
BATTERY INSTALLATION ................................................................................. 8
OPERATING INSTRUCTIONS ........................................................................... 8
SELECTING THE COMPATIBILITY MODE.................................................... 8
ATTACHING A MICROPHONE AND ADJUSTING GAIN ............................... 9
OPERATING NOTES .......................................................................................... 9
ADJUSTING THE TRANSMITTER FREQUENCY ............................................ 9
MICROPHONE CORD TERMINATION ............................................................ 10
5-PIN INPUT JACK WIRING ............................................................................ 11
RF BYPASSING ........................................................................................... 11
LINE LEVEL SIGNALS ................................................................................ 12
WIRING HOOKUPS FOR DIFFERENT SOURCES.................................... 12
TROUBLESHOOTING ...................................................................................... 13
SPECIFICATIONS AND FEATURES ............................................................... 14
SERVICE AND REPAIR ................................................................................... 15
RETURNING UNITS FOR REPAIR.................................................................. 15
LIMITED ONE YEAR WARRANTY ..................................................Back Cover
Thank you for selecting the Lectrosonics UM400 frequency agile, belt-pack transmitter. The UM400
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 UM400 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
conversations led directly to the development of the operational features offered on the UM400. Two
hundred fifty six frequencies are user selectable in 100kHz steps to alleviate interference problems
in traveling venues, and the low frequency roll-off is user adjustable to adapt to varying acoustic
environments and preferences.
The UM400 is a rugged, machined aluminum package with a removable, spring loaded belt clip. The
input section provides a correct input tap for virtually any microphone or line level audio source. Five
volts of bias voltage is available to power electret mics with either positive or negative bias. Level
indicating LEDs are provided on the control panel to make level settings quick and accurate, without
having to view the receiver. The battery compartment accepts any 9 Volt alkaline battery and makes a
positive connection via self-adjusting contacts. The antenna is a detachable, locking 1/4 wavelength
flexible galvanized steel cable that connects to a 50 Ohm SMA port on the transmitter.
Only the UM400 transmitter is covered in this manual. Companion receivers are covered in separate
manuals. The UM400 will operate with any 400 Series Lectrosonics receiver in the same frequency
group.

4
UM400
LECTROSONICS®
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
Hi/Lo
Pass
Filter
Audio
Encoded
Audio +
Pilot Tone
4MHz
Reference
Bicolor
Power
LED
Mic
Jack
+5V Bias
Supply
Audio
Level
Input
Amp
5
4
3
2
1
Final
Amplifier
50 Isolator
LF
Roll Off
<--See 5-Pin Input Jack Wiring for details.
GENERAL TECHNICAL DESCRIPTION
INTRODUCTION
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 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 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 system 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 information 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
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 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.
UM400 Block Diagram

5
Frequency-Agile UHF Belt-Pack Transmitter
Rio Rancho, NM – USA
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 utilizes 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. The UM400 extends this concept even further by insuring that all transmitters in
a system have different pilot tone frequencies so that even spurious RF from the wrong transmitters can’t open the
receiver squelch.
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.
The audio level LEDs indicate limiter activity. The first red LED indicates that the limiter is active and that the trans-
mitter is fully modulated (audio level is between +0 and +10 dB). The second red LED indicates that the level is 10
dB or more into limiting. Occasional forays into the red are desirable for most applications, since the distortion
introduced by the limiter is so minimal, and full modulation is thus assured. We strongly recommend setting the gain
of the transmitter high enough so that the first red LED occasionally lights.
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 compres-
sion of the peaks in the audio signal, which is desirable with most recorders and many sound reinforcement systems.
WIDE-BAND DEVIATION
± 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.
LONG BATTERY LIFE
Switching power supplies throughout the design allow over five hours of operation using a single 9 VDC alkaline
battery. (A 9 V lithium battery will provide over 10 hours of continuous 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 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.
ANTENNA
The antenna on the UM400 consists of a flexible 1/4 wavelength galvanized steel cable, detachable via an SMA
connector. The impedance of this connector is 50 Ohms.

6
UM400
LECTROSONICS®
INPUT JACK
The input on the UM400 accommodates virtually every lavaliere, hand-held or shotgun microphone available. Differ-
ent line level signals can also be accommodated. (See Line Level Signals and Transmitter 5-Pin Input Jack Wiring.)
POWER ON/OFF SWITCH
Turns the transmitter on and off. Even when the switch is turned off or on abruptly, the pilot tone muting system
prevents “thumps” or transients from occurring.
POWER ON LED
The Power LED glows green when the battery is good and the transmitter is turned on. The LED will glow yellow/
orange as the battery voltage drops and finally glows red when there are about 30 minutes of operation left (when
using the recommended alkaline battery). The LED blinks red when there are only a few minutes of life left.
Note
A NiMH battery will give little or no warning when it is depleted. If you wish to use NiMH batteries in the UM400, we
recommend trying fully charged batteries in the unit, 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 quickly discharge to the point where the LED will go red or shut down (just like a flashlight with “dead”
batteries). If the lamp fails to light, the battery should be replaced.
AUDIO LEVEL CONTROL
The front panel AUDIO LEVEL Control is used to adjust the incoming audio input level for proper modulation.
AUDIO LEVEL
Used to adjust the audio input level for the proper modulation.
Input Jack
Power ON/OFF Switch
AUDIO LEVEL Control
Modulation LEDs
ANTENNA Jack
Power LED
1.6M 100K
Frequency Select Switches
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
Low Frequency Roll Off
Control
CONTROLS AND FUNCTIONS

7
Frequency-Agile UHF Belt-Pack Transmitter
Rio Rancho, NM – USA
Belt Clip
Belt Clip Retaining Screw Location
MODULATION LEDS
The Modulation LEDs provide a visual indication of the input audio signal level from the microphone. These two
bicolor LEDs can glow either red or green to indicate modulation
levels.
The Modulation LEDs are also used to indicate the Compatibility
Mode when the transmitter is initially turned on. The Modulation
LEDs will blink simultaneously:
• Once for 100 Series mode
• Two times for 200 Series mode
• Three times for mode 3
• Four times for Digital Hybrid Wireless™ or 400 Series mode
• Five times for IFB mode*
ANTENNA
The flexible galvanized steel cable antenna supplied with the transmitter is cut to 1/4 wavelength of the center of the
frequency block (the frequency range) of the transmitter. It is removable via an SMA connector. The SMA connector
is a 50 Ohm RF port which can also be connected directly to test equipment. Replacement antennas are available in
pre-cut lengths for specific frequency blocks, or as a kit with instructions to cut the antenna for any frequency block.
FREQUENCY SELECT SWITCHES
Two 16-position rotary switches adjust the center frequency of the carrier. The 1.6M is a coarse adjustment and the
100K is the fine adjustment.
ADJUSTABLE LOW FREQUENCY ROLL-OFF
A 18dB per octave low frequency roll-off is provided in the audio section, with the -3dB point adjustable from 35Hz to
150Hz. The actual roll-off frequency will vary somewhat according to the low frequency response of the mic capsule
being used.
The low frequency roll-off control is used to remove subsonic (or very low frequency) audio, often produced by air
conditioning systems, automobile traffic and other sources from the audio signal. Excessive low frequency content
in the audio input can cause a variety of audio problems including driving the transmitter into limiting. In sound
reinforcement systems, as one instance, excessive low frequency content can cause excessive power amplifier drain
or even damage to loudspeaker systems. By rotating the control clockwise, the hinge point of the roll-off is increased
to reduce the level of low frequencies. In controlled situations, such as a motion picture production set indoors
where environmental noise is minimal, the control can be rotated counter-clockwise to permit low frequency audio to
be captured.
BELT CLIP
The belt clip may be removed for special applications by removing one screw.
WARNING
USE ONLY THE SCREW THAT IS SUPPLIED
The circuitry is tightly packed into this unit. A longer screw will permanently damage the transmitter! Use only
Lectrosonics PN:28528 which is a Phillips head, 4-40 x 3/16", FL100 screw.
Signal Level
Less than -20 dB
-20 dB to -10 dB
-10 dB to +0 dB
+0 dB to +10 dB
Greater than +10 dB
-20 LED -10 LED
Off
Green
Green
Red
Red
Off
Off
Green
Green
Red
*Not available on earlier units.

8
UM400
LECTROSONICS®
Swing the
door open
Press outward on the
battery door in this
direction
OPERATING INSTRUCTIONS
SELECTING THE COMPATIBILITY MODE
All units with serial number 601 and up are capable of working with Lectrosonics 400 Series Digital Hybrid Wire-
less™, 200 Series analog, 100 Sseries analog and some non-Lectrosonics analog wireless receivers (contact the
factory for details). The transmitter must be set to the operating mode of the matching receiver, which is easily done
using only the supplied screwdriver and a battery.
NOTE
The unit is supplied from the factory as a 400 series transmitter.
1) Ensure the battery is good.
2) Turn off the transmitter.
3) With a small screwdriver (one is included with your unit), set the Frequency Select Switches to CC. (for
Change, Change).
4) Power up the unit briefly – just long enough for the LED’s to light up and then turn it off.
5) Change the Frequency Select Switches to one of the following settings:
• To set Lectrosonics 100 Series mode: set switches to 1,1
• To set Lectrosonics 200 Series mode: set switches to 2,2
• To set mode 3: set switches to 3,3 (contact the factory for details)
• To set Lectro 400 Series mode: set switches to 4,4
• To set IFB mode: set switches to 5,5*
6) Turn the unit on, wait a couple of seconds and turn off again.
7) Change the Frequency Select Switches to 0,0.
8) Turn on the transmitter to complete the operation.
The LEDS will blink to indicate the selected compatibility mode. Immediately after power up, all LEDS will
blink together red, then green, followed by the audio level LEDs (-20 and -10) blinking to indicate the
mode.
BATTERY INSTALLATION
The transmitter is powered by a standard alkaline or lithium 9 Volt battery. It is important that you use ONLY an
ALKALINE or LITHIUM battery for longest life. Standard
zinc-carbon batteries marked “heavy-duty” or “long-
lasting” are not adequate. Ni-cad rechargeable batter-
ies will only provide 1.5 hours of operation, or less, and
will run down quite abruptly. Alkaline batteries provide
over 5 hours of operation. Lithium batteries can be used
to provide up to 16 hours. Care should be taken not to
leave a fully discharged lithium battery in the transmitter,
as swelling of the battery can make it difficult to remove
from the compartment. The battery status circuitry is
designed for the voltage drop over the life of alkaline
batteries.
To open the battery compartment, press outward on the
cover door in the direction of the arrow as shown in the
drawing. Only firm, sliding pressure is needed to open
and close the battery door. Swing the door open and
take note of the polarity marked inside showing the
location of the positive (+) and negative (-) terminals.
You can see the large and small contact holes inside the
battery compartment with the door open.
Insert the battery correctly and close the cover by
pressing the door closed and across, reversing the opening procedure illustrated above. If the battery is inserted
incorrectly, the door will not close. Do not force the door closed.
*Not available on earlier units.

9
Frequency-Agile UHF Belt-Pack Transmitter
Rio Rancho, NM – USA
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
1.6M 100K
ADJUSTING THE TRANSMITTER FREQUENCY
If you are experiencing interference from another signal on your fre-
quency, you may want to change the operating frequency of your
system. The left switch changes the operating frequency by
1.6 MHz per step and the right switch changes it 100 kHz per
step. Start by changing the operating frequency in 100 kHz
increments to find a clear channel. If it is not possible to find a
clear channel using the 100 kHz switch, return it to its original
position and change the 1.6 MHz switch by one click then try
the 100 kHz switch again.
To gain access to these switches, slide the access door sideways
with a fingernail.
With the 400 Series receivers, a front panel LCD character display will
indicate the correct transmitter switch settings.
OPERATING NOTES
If the audio level is too high — both LEDs will blink red frequently or glow a steady 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 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, adjust it for the loudest voice.
The –20 and –10 LEDs will blink:
• Once for 100 Series mode
• Two times for 200 Series mode
• Three times for some other receivers
• Four times for 400 Series mode
• Five times for IFB mode*
At powerup the transmitter will confirm the current compatibility mode with the number of blinks listed
here. This setting will remain the same until you reset it with the procedure listed above.
ATTACHING A MICROPHONE AND ADJUSTING GAIN
1) Ensure the battery is in good condition.
2) Insert the microphone plug into the input jack, aligning the pins; be sure that the connector locks.
3) Attach the antenna to the SMA connector on the top of the transmitter.
4) Mute the associated receiver’s audio output.
5) Turn on the transmitter.
6) Position the microphone in the location you will use in actual
operation. While speaking or singing at the same voice level
that will actually be used, observe the Modulation LEDs. Adjust
the AUDIO LEVEL control until the –20 dB LED glows green
with occasional red flickers and -10 dB glows green. This will
set the gain of your transmitter to between +0 dB and +10 dB
modulation. (See chart to right.)
7) Once the gain has been adjusted, the audio system audio can
be turned on to make level adjustments in the main audio
system.
Note
The transmitter Audio Level Control should not be used to control the volume of your sound system or recorder levels. This gain
adjustment matches the transmitter gain with the user’s voice level and microphone positioning.
Signal Level
Less than -20 dB
-20 dB to -10 dB
-10 dB to +0 dB
+0 dB to +10 dB
Greater than +10 dB
-20 LED -10 LED
Off
Green
Green
Red
Red
Off
Off
Green
Green
Red
*Not available on earlier units.

10
UM400
LECTROSONICS®
1
23
4
5
VIEW FROM SOLDER
SIDE OF PINS
0.3"
0.15"
Heatshrink
Tubing
TA5F Connector Assembly
Mic Cord Stripping Instructions
Caution!
Do not allow the shield wire to touch any
metal part of the connector shell.
The shield wire is the antenna on VHF
models and poor operating range will result.
Shield Wire
Crimp
Tabs
Rubber
Insulation
Crimp
Tabs
Rubber
Insulation
This is the correct way. Don't do it this way!
MICROPHONE CORD TERMINATION
Caution
When wiring the connector, do not use the connector body for any electrical connections. A common mistake is to use the
connector body as an audio ground. The connector body is already used as an RF ground on VHF models and no other use
is permitted.
Note
This termination is required on VHF transmitters and will still work fine on UHF transmitters.

11
Frequency-Agile UHF Belt-Pack Transmitter
Rio Rancho, NM – USA
5-PIN INPUT JACK WIRING
The wiring diagrams shown on the next page represent the basic wiring necessary for the most common types of
microphones and other audio inputs. Some microphones may require extra jumpers or a slight variation on the
diagrams shown.
Caution
When wiring the connector, do not use the connector body for any electrical connections.
A common mistake is to use the connector body as an audio ground. The connector body is
already used as an RF ground on VHF models and no other use is permitted.
It’s virtually impossible to keep completely up to date on changes that other manufacturers make to their products. It
is possible that you may encounter a microphone that differs from these instructions. If this occurs please call our
toll-free number listed on page 15 of this instruction manual. Our service department can answer your questions
regarding microphone compatibility.
When used on a wireless transmitter, the microphone element is in the proximity of the RF coming from the transmit-
ter. The nature of electret microphones makes them sensitive to RF, which can cause problems with the microphone/
transmitter compatibility. If the electret microphone is not designed properly for use with wireless transmitters, it may
be necessary to install a chip capacitor in the mic capsule or connector to block the RF from entering the electret
capsule. This modification is shown on the next page.
VHF transmitters use the shield of the microphone cord as the antenna. This transmitter uses a 1/4 wave flexible
wire to radiate the RF signal. There is really not much difference between these two approaches, with respect to the
effect of the RF on the microphone capsule. Even in transmitters that utilize a “dangling wire,” the microphone is still
part of the “ground plane” and is therefore still in the antenna circuit.
PIN 1 Shield (ground) for positive biased electret lavaliere microphones. Bias voltage source for negative biased
electret lavaliere microphones. Shield (ground) for dynamic microphones and line level inputs.
PIN 2 Shield (ground) for negative biased electret lavaliere microphones. Bias voltage source for positive biased
electret lavaliere microphones.
PIN 3 Low impedance microphone level input for dynamic microphones. Also accepts hand-held electret micro-
phones provided the microphone has its own built-in battery.
PIN 4 1K Ohm source load for non-Lectrosonics electret microphones. Use in conjunction with other pins to
provide attenuation of high level input signals.
PIN 5 High impedance, line level input for tape decks, mixer outputs, musical instruments, etc.
RF BYPASSING
Some mics require RF protection to keep the radio signal from affecting the capsule, even though the transmitter
input circuitry is already RF bypassed (see schematic diagram).
If the mic is wired as directed, and you are having difficulty with squealing, high noise, or poor frequency response;
RF is likely to be the cause.
43
2
1
5
LECTROSONICS
FB
40k
4k
5
100
4
3
2
1
+
5V Mic Bias
To Mic Amp
POS BIAS (OR GND)
MIC
SOURCE LOAD
LINE IN
NEG GND (OR BIAS)
+
1k
10uF
330pF
330pF
330pF
330pF
Input Jack Wiring Diagram

12
UM400
LECTROSONICS®
3 WIRE MIC2 WIRE MIC
CAPSULE CAPSULE
SHIELD
AUDIO
SHIELD
AUDIO
BIAS
TA5F
CONNECTOR
TA5F
CONNECTO
R
Preferred locations for bypass capacitors
Alternate locations for bypass capacitors
PIN
5
4
3
2
1
SHIELD
AUDIO
BIAS
3 WIRE ELECTRET MIC
POSITIVE BIAS
1
2
3
45
TA5F
PLUG
1
2
3
4
5
PIN
SHIELD
AUDIO
2 WIRE ELECTRET MIC
POSITIVE BIAS
1
2
3
45
TA5F
PLUG
1
2
3
4
5
PIN
SHIELD
BIAS
AUDIO
3
WIRE ELECTRET MIC
NEGATIVE BIAS
1
2
3
45
TA5F
PLUG
1
2
3
4
5
PIN
SHIELD
AUDIO
2 WIRE ELECTRET MIC
NEGATIVE BIAS
1
2
3
45
TA5F
PLUG
SHIELD
TIP
PIN
5
4
3
2
1
SLEEVE
LINE LEVEL
RCA or 1/4 " PLUG
AUDIO 1
2
3
45
TA5F
PLUG
3
1
2
DYNAMIC
MIC LEVEL
1
2
3
4
5
3
2
1
PIN PIN
SHIELD
Dynamic LO Z mic or electret with
manufacturers power supply.
1
2
3
45
TA5F
PLUG
(See notes on ‘LINE LEVEL SIGNALS” above.)
The best RF protection is accomplished by installing
RF bypass capacitors at the mic capsule. If this is not
possible, or if you are still having problems, capacitors
can be installed on the mic pins inside the TA5F
connector housing.
Install the capacitors as follows: Use 330 pF capaci-
tors. Capacitors are available from Lectrosonics.
Please specify the part number for the desired lead
style.
Leaded capacitors: P/N 15117
Leadless capacitors: P/N SCC330P
All Lectrosonics lavaliere mics are already bypassed
and do not need any additional capacitors installed for proper operation.
Caution
When wiring the connector, do not use the connector body for any electrical connections. A common mistake is to use the
connector body as an audio ground. The connector body is already used as an RF ground on VHF models and no other use s
permitted.
LINE LEVEL SIGNALS
The normal hookup for line level signals is: Signal Hot to pin 5, Signal
Gnd to pin 1, pin 4 jumped to pin 1, and pin 3 jumped to pin 1. This
gives a 40dB attenuator that allows signal levels much higher than 3V
to be applied without limiting.
If more headroom is needed, insert a 100k resistor in series with pin 5.
Put this resistor inside the TA5F connector to minimize noise pickup.
If lower than normal line levels (less than 1V) are expected, use this
hookup: Signal Hot to pin 5, Signal Gnd to pin 1, and pin 4 jumpered
to pin 1. This provides a 20dB attenuator allowing signals as high as
3V to be applied without limiting.
WIRING HOOKUPS FOR DIFFERENT SOURCES
PIN
5
4
3
2
1
SHIELD (GND)
AUDIO
Normal Hookup
1
2
3
45
TA 5 F
PLUG
PIN
5
4
3
2
1
AUDIO
More Headroom
1
2
3
45
TA 5 F
PLUG
PIN
5
4
3
2
1
AUDIO
Lower Line Level
Hookup
1
2
3
45
TA 5 F
PLUG
100k
SHIELD (GND)
SHIELD (GND)

13
Frequency-Agile UHF Belt-Pack Transmitter
Rio Rancho, NM – USA
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.
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.
6) Transmitter antenna not connected
NO SOUND (OR LOW SOUND LEVEL), 1) Receiver output level set too low.
RECEIVER INDICATES PROPER AUDIO 2) Receiver output is disconnected; cable is defective
MODULATION or mis-wired.
3) Sound system or recorder input is turned down.
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 pages 8/9 for details on gain adjustment)
2) Receiver output may be mis-matched 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) Transmitter antenna missing.
4) Operating range too great.
EXCESSIVE FEEDBACK 1) Transmitter gain (audio level) too high. Check gain
adjustment and/or reduce receiver output level.
2) Transmitter too close to speaker system.
3) Mic is too far from user’s mouth.

14
UM400
LECTROSONICS®
SPECIFICATIONS AND FEATURES
Operating frequencies: Block 21: 537.600 - 563.100
Block 22: 563.200 - 588.700
Block 23: 588.800 - 607.900 and 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
Block 30: 768.000 - 793.500 (Export)
Block 31: 793.600 - 805.600 (Export)
Frequency selection: 256 frequencies in 100kHz steps
RF Power output: 100 mW (nominal)
Pilot tone: 25 to 32 kHz frequency; 5kHz 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 impedance: Taps provided for 200, 4k, 40k Ohm
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: –18dB/octave; 35Hz to 150Hz
Audio frequency response (overall system): 32 Hz to 20 kHz (+/- 1dB)
Controls: 2 position “OFF-ON” slide switch for noiseless turn on/turn off operation.
Front panel knob adjusts audio gain. Recessed control on side panel adjusts low
frequency rolloff. Rotary switches on side panel adjust transmitter frequency.
Audio Input Jack: Switchcraft 5 pin locking (TA5F)
Antenna: Detachable, flexible wire supplied. 50 Ohm port allows
connection to test equipment.
Battery: Precision compartment auto-adjusts to accept any known alkaline 9 Volt battery.
(We’ve tried 243 different ones!)
Battery Life: 5 hours (alkaline); 10 hours (lithium)
Weight: 6.3 ozs. including battery
Dimensions: 3.1 x 2.4 x .75 inches
Emission Designator: 180KF3E
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.

15
Frequency-Agile UHF Belt-Pack Transmitter
Rio Rancho, NM – USA
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 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 con-
nection, 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 read-
justment. 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
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 us by letter or by phone. We need to
know the nature of the problem, the model number and the serial number of the equipment. We also need a
phone number where you can be reached 8 am to 4 pm (Mountain Standard Time).
B. After receiving your request, we will issue you a return authorization number (R.A.). This number will help speed
your repair through our receiving and repair departments. The return 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
Web: http://www.lectrosonics.com Email: [e-mail]

LECTROSONICS, INC.
581 LASER ROAD
RIO RANCHO, NM 87124 USA
www.lectrosonics.com
July 14, 2004
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