Lectrosonics HMa User manual

HMa
Wideband Plug-On Transmitter
With Digital Hybrid Wireless®Technology
INSTRUCTION MANUAL
Rio Rancho, NM, USA
www.lectrosonics.com
Fill in for your records:
Serial Number:
Purchase Date:
Digital Hybrid Wireless®
US Patent 7,225,135

HMa
LECTROSONICS, INC.
2

Wideband Digital Hybrid®Plug-On Transmitter
Rio Rancho, NM 3
Thank you for selecting a Lectrosonics HMa plug-On
transmitter. The unique design provides several distinct
features for professional applications:
• Outstanding RF operating range
• Superb audio quality
• Corrosion-resistant housing
• Programmable compatibility modes for use with a
wide variety of different receivers
The Digital Hybrid Wireless®design (US Patent
7,225,135) combines 24-bit digital audio with analog
FM resulting in a system that has the same operating
range as analog systems, the same spectral efficiency
as analog systems, the same long battery life as analog
systems, plus the excellent audio fidelity typical of pure
digital systems.
The transmitter uses a standard 3-pin XLR input jack for
use with any microphone with a a mating XLR connec-
tor. An LCD, membrane switches and multi-color LEDs
on the control panel make input gain adjustments and
frequency and compatibility mode selection quick and
accurate, without having to view the receiver. The hous-
ing is machined from a solid aluminum block to provide
a lightweight and rugged package. A special non-corro-
sive finish resists salt water exposure and perspiration
in extreme environments.
The DSP-based design works with all Digital Hybrid
receivers, and is backward compatible for use with
Lectrosonics 200 and 100 Series and IFB receivers and
some other brands of analog wireless receivers. Com-
panion receivers are covered in separate manuals.
Table of Contents
General Technical Description ...............................................4
Wideband Design...................................................................4
Digital Hybrid Wireless®Technology ......................................4
No Pre-Emphasis/De-Emphasis ............................................4
Low Frequency Roll-Off .........................................................4
Input Limiter ...........................................................................5
Signal Encoding and Pilot Tone .............................................5
Microprocessor and DSP.......................................................5
Compatibility Modes...............................................................5
Control Panel .........................................................................5
Battery Options and Operating Time .....................................5
Frequency Blocks and Bands ................................................5
Controls and Functions ..........................................................6
LCD Screen ...........................................................................6
Power LED .............................................................................6
Audio Input Jack.....................................................................6
Battery Compartment.............................................................6
Modulation LEDs....................................................................6
Audio Button ..........................................................................6
Up/Down Arrows and Panel Lockout......................................6
Antenna..................................................................................6
Battery Installation ..................................................................7
Attaching/Removing a Microphone .......................................7
Operating Instructions............................................................8
Power Up and Boot Sequence...............................................8
Power Down...........................................................................8
Automatic Power Restore.......................................................8
Standby Mode........................................................................8
Compatibility Mode Screen....................................................8
Selecting the Audio Polarity ...................................................8
LCD Backlight Settings ..........................................................9
Selecting Step Size mode......................................................9
Setting Transmitter Operating Frequency...............................9
Lock/Unlock Screen ...............................................................9
Audio Screen .......................................................................10
Adjusting the Input Gain.......................................................10
Adjusting the Low Frequency Roll-off ..................................10
Selecting the Phantom Power Supply..................................10
About the Phantom Power Supply .......................................11
Special Purpose Barrel Adapters.........................................12
MCA-M30.............................................................................12
Accessories ...........................................................................13
Troubleshooting.....................................................................14
Specifications and Features.................................................16
Service and Repair ................................................................17
Returning Units for Repair ...................................................17
Consumer Alert for US Users - FCC Order DA 10-92
Most users do not need a license to operate this wireless microphone system. Nevertheless, operating this microphone system
without a license is subject to certain restrictions: the system may not cause harmful interference; it must operate at a low power
level (not in excess of 50 milliwatts); and it has no protection from interference received from any other device. Purchasers should
also be aware that the FCC is currently evaluating use of wireless microphone systems, and these rules are subject to change. For
more information, call the FCC at 1-888- CALL-FCC (TTY: 1-888-TELL-FCC) or visit the FCC’s wireless microphone website at
www.fcc.gov/cgb/wirelessmicrophones. To operate wireless microphone systems at power greater than 50mW, you must qualify as
a Part 74 user and be licensed. If you qualify and wish to apply for a license go to: http://www.fcc.gov/Forms/Form601/601.html

HMa
LECTROSONICS, INC.
4
Wideband Design
The HMa transmitter uses ±75 kHz wide deviation for
an excellent signal to noise ratio and wide dynamic
range. The DSP controlled input limiter features a wide
range dual envelope design which cleanly limits input
signal peaks over 30 dB above full modulation. Switch-
ing power supplies to provide constant voltages to the
transmitter circuits from the beginning (3 Volts) to the
end (1.7 Volts) of battery life, and an ultra low noise
input amplifier for quiet operation.
Digital Hybrid Wireless®Technology
All wireless links suffer from channel noise to some de-
gree, and all wireless microphone systems seek to mini-
mize the impact of that noise on the desired signal. Con-
ventional 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.
Lectrosonics Digital Hybrid Wireless®systems over-
come 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 informa-
tion via an analog FM wireless link. This proprietary
algorithm is not a digital implementation of an analog
compandor but a technique that can be accomplished
only in the digital domain, even though the inputs and
outputs are analog.
Channel noise still impacts received signal quality and
will eventually overwhelm a receiver. Digital Hybrid
Wireless®simply encodes the signal to use a noisy
General Technical Description
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.
Because it uses an analog FM link, Digital Hybrid
Wireless®enjoys all the benefits of conventional FM
wireless systems, such as excellent range, efficient
use of RF spectrum, and resistance to interference.
However, unlike conventional FM systems, it does
away with the analog compandor and its artifacts.
No Pre-Emphasis/De-Emphasis
The Digital Hybrid Wireless®design results in a signal-to-
noise ratio high enough to preclude the need for con-
ventional pre-emphasis (HF boost) in the transmitter and
de-emphasis (HF roll-off) in the receiver. This eliminates
the potential for extreme distortion on signals with
abundant high-frequency information.
Low Frequency Roll-Off
The low frequency roll-off can be set for a 3 dB down
point at 35, 50 or 70 Hz to control subsonic and very
low frequency audio content in the audio. The actual
roll-off frequency will vary slightly depending upon the
low frequency response of the microphone.
Excessive low frequency content can drive the trans-
mitter into limiting, or in the case of high level sound
systems, can even cause damage to loudspeaker
systems. The roll-off is normally adjusted by ear while
listening as the system is operating.
Bias Voltage
42V,15V, 5V
+4V
Input
Amp
Shunt
Limiter
AUDIO
FREQ
UP
DWN
Reference
Crystal
Reference
Crystal
3 V
Battery
Hi.Lo
Pass
Filter
Digital
PotAudio
Level
Phantom
Power
Audio A-D
Converter
11001001
D-A
Converter
11001001
Control Panel
Microprocessor
Voltage
Controlled
Oscillator
Final
Amplifier
Filter
Amp
Encoded Audio
and Pilot Tone
Bicolor
Modulation
LEDs
Switching
Power
Supply
Digital Signal Processor
Phase Locked Loop
LCD
1.2V
4V
-3.3V
+3.3V

Wideband Digital Hybrid®Plug-On Transmitter
Rio Rancho, NM 5
Input Limiter
A DSP-controlled analog audio limiter is employed
before the analog-to-digital (A-D) 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 distor-
tion. It can be thought of as two limiters in series, a
fast attack and release limiter followed by a slow attack
and release limiter. The limiter recovers quickly from
brief transients, with no audible side effects, and also
recovers slowly from sustained high levels, to keep
audio distortion low and while preserving short term
dynamics.
Signal Encoding and Pilot Tone
In addition to controlling the limiter, the DSP also
encodes the digitized audio from the A-D converter
and adds an ultrasonic pilot tone to control the re-
ceiver’s squelch. A pilot tone squelch system provides
a reliable method of keeping a receiver output muted
(squelched) even in the presence of significant inter-
ference. When the system is operating in the hybrid
mode, a different pilot tone frequency is generated for
each carrier frequency to prevent inadvertent squelch
problems and simplify multi-channel coordination.
Microprocessor and DSP
A microprocessor monitors user command inputs from
the control panel buttons and numerous other internal
signals. It works intimately with the DSP to ensure the
audio is encoded according to the selected Compatibil-
ity Mode and that the correct pilot tone is added to the
encoded signal.
Compatibility Modes
The transmitter was designed to operate with Lectro-
sonics Digital Hybrid Wirteless® receivers and will yield
the best performance when doing so. However, due to
the flexibility of digital signal processing, the transmit-
ters can also operate in various compatibility modes
for use with Lectrosonics 100 and 200 Series and IFB
receivers. It will also work with certain non-Lectroson-
ics receivers. Contact your sales representative or the
factory for a complete list of compatible non-Lectroson-
ics receivers.
Control Panel
The control panel includes four membrane switches and
an LCD screen to adjust the operational settings. Multi-
color LEDs are used to indicate audio signal levels for
accurate gain adjustment and for battery status.
Battery Options and Operating Time
Switching power supplies convert battery voltages to
operate various circuit stages with maximum efficiency.
Frequency Blocks and Bands
Lectrosonics established a “block” numbering system
years ago to organize the range of frequencies avail-
able from the low 500 MHz band to the upper 700
MHz band. Each block includes 256 frequencies in 100
kHz increments. The block number is part of a simple
formula to derive the frequency. The block number is
multiplied by 25.6 to produce the lowest frequency in
the block. For example, block 27 x 25.6 = 691.200.
The HMa transmitter features a wideband tuning range
that covers three blocks. This tuning range is referred
to as a BAND rather than a block.
Band Tuning Range (MHz)
A1 170.100 - 534.575
B1 537.600 - 614.375
C1 614.400 - 691.175

HMa
LECTROSONICS, INC.
6
Controls and Functions
LCD Screen
The LCD is a numeric-type Liquid Crystal Display with
several screens that allow settings to be made with the
AUDIO, FREQ, UP and DOWN buttons to configure
the transmitter. The transmitter can be turned on in a
Standby mode to make adjustments without the risk of
interfering with other wireless systems nearby. Coun-
ters are presented on the LCD enabling this function.
Power LED
The PWR LED glows green when the batteries are
good. The color changes to red when there is about 20
minutes of life left. When the LED begins to blink red,
there are only a few minutes of life.
A weak battery will sometimes cause the PWR LED to
glow green immediately after being put into the unit,
but will soon discharge to the point where the LED will
go red or shut off completely.
Audio Input Jack
The XLR input jack on the transmitter accommodates
most hand-held microphones. Phantom power can
be set at various levels for use with a wide variety of
electret microphones.
Battery Compartment
The battery compartment door is made of machined
aluminum and is hinged to the housing to prevent it
being damaged or lost.
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 indi-
cate modulation levels. Full modulation (0 dB) occurs
when the -20 LED first turns 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
Audio Button
The AUDIO button is used to display the audio level
setting, low frequency roll-off and phantom power
mode. Repeatedly pressing the button will cycle
through the available settings, allowing the UP and
DOWN arrow buttons to adjust the values.
Freq Button
The FREQ Button displays the selected operating fre-
quency and also toggles the LCD between displaying
the actual operating frequency in MHz and a two-digit
hexadecimal number. Frequencies can be selected in
either 100kHz or 25kHz steps. The appearance of the
hexadecimal number is different in the 100kHz step
size mode than in the 25kHz step size mode.
NOTE: The FREQ and AUDIO buttons are used
together to enter the standby mode and to turn the
power on or off.
Up/Down Arrows and Panel Lockout
The Up and Down arrow buttons are used to select the
operating frequency, adjust the audio level, or set the
Compatibility Mode.
Pressing both arrows simultaneously enters the lock
countdown. Holding the two buttons in until the count-
down is completed locks the control panel buttons so
they can only be used to display current settings. “Loc”
is displayed to indicate the controls are locked when a
button is pressed while the panel is locked.
Once locked, the buttons are unlocked by removing
the battery.
Antenna
An antenna is formed between the housing and the at-
tached microphone, operating much like a dipole type.
At UHF frequencies the length of the housing is similar
to 1/4 wavelength of the operating frequency, so the
antenna is surprisingly efficient, which helps extend
the operating range and suppress noise and interfer-
ence.
Battery
Compartment
XLR Input Jack
AUDIO Button
LCD
Input
Coupler
FREQ Button
Modulation
LEDs
PWR LED
UP Arrow
DOWN Arrow

Wideband Digital Hybrid®Plug-On Transmitter
Rio Rancho, NM 7
Battery Installation
The transmitter is powered by two AA batteries.
Note: Standard zinc-carbon batteries marked
“heavy-duty” or “long-lasting” are not adequate.
Batteries operate in series, with a connecting plate
built into the battery door
To install new batteries:
1. Slide open the Battery Cover and remove any old
batteries.
2. Insert the new batteries into the housing. One bat-
tery goes in positive (+) end first, the other negative
(-) end first. Look into the battery compartment to
determine which end goes in which side. The side
with the plastic ring is the side which accepts the
positive end of the battery.
positive (+)
terminal
negative (–)
terminal
Note: It is possible to install the batteries backward
and close the battery door, but the batteries will
not make contact and the unit will not work.
3. Slide the Battery Cover until it snaps securely shut.
Attaching/Removing a
Microphone
The spring loaded coupler under the XLR jack main-
tains a secure fit to the microphone jack with continu-
ous pressure applied by an internal spring.
To attach the microphone, simply align the XLR pins
and press the microphone onto the transmitter until
the coupler retracts and latches. A click sound will be
heard as the connector latches.
To remove the microphone, hold the transmitter body
in one hand with the microphone pointing upward. Use
your other hand to rotate the coupler until the latch
releases and the coupler rises slightly.
TO AT TA CH
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!
NOTE: Do not hold or apply any pressure to the
microphone body while trying to remove it, as
this may prevent the latch from releasing.

HMa
LECTROSONICS, INC.
8
Operating Instructions
AUDIO
Button FREQ
Button
Modulation
LEDs
PWR LED
UP Arrow
DOWN Arrow
Power Up and Boot Sequence
1) Ensure that good batteries are installed in the unit.
2) Simultaneously press and hold the AUDIO and
FREQ buttons. Continue holding the buttons until
On and the characters 1, 2, 3 have appeared. The
boot sequence will then initiate.
Initial Power On
Timer Screen
As the unit turns on, the
Modulation LEDs and PWR
LED all glow red, then green,
and then they revert to normal
operation.
The LCD displays a bootup sequence which con-
sists of five screens:
Category: Example
Company Name: Lectro
Frequency Band (XX) and
Firmware Version (rX.XX):
A1 r1.00
Compatibility Mode: CP 400
RF Power Output: 100
Operating Frequency 482.875
Power Down
Simultaneously press and hold the AUDIO and
FREQ buttons. Continue holding the buttons until
OFF and the countdown characters 3, 2, 1 have ap-
peared. The unit will then power down.
Initial Power Off
Timer Screen
If the AUDIO and FREQ
buttons are released before
the LCD goes blank at the end
of the countdown, the unit will
not turn off. Instead, it will stay
on and the LCD will return to the previous screen.
NOTE: If batteries are removed or reach the end
of life while the unit is turned on, the unit will turn
back on with a brief, simultaneous press of the
AUDIO and FREQ buttons. The counting sequence
will not be displayed in this instance.
Automatic Power Restore
The firmware will remember the power on/off state
and the settings when batteries reach their end of life
or are removed. When fresh batteries are installed,
the unit will reboot and return to the previous set-
tings without the need to press any buttons. This only
works when the unit is fully on and transmitting. It
does not work in the Standby Mode.
Standby Mode
Standby Screen
Standby Mode allows you to
verify or change the trans-
mitter’s operating frequency
or audio input level without
transmitting a signal. Quickly press and release both
the AUDIO and FREQ buttons simultaneously to enter
and exit this mode. The characters rF OFF will appear
on the LCD while the unit is in the standby mode.
Up Button Menu
Hold the UP button while powering up the unit.
Then press the AUDIO button repeatedly to scroll
through the following settings. Use the UP and DOWN
arrow to select the available options under each set-
ting.
Compatibility Mode Screen (Up Button Menu)
CP (Compatibility Mode);
press the UP and DOWN
arrows to select one of the
following:
Note: RF transmission is prevented while
selecting Compatibility Modes. Also, the HM
exits this screen to the Standby Mode.
• 400 - For Digital Hybrid Wireless®receivers.
• 200 - For Lectrosonics 200 Series receivers.
• 100 - For Lectrosonics 100 Series receivers.
• 3 - (Mode 3) For non-Lectrosonics analog receiv-
ers. Contact the the factory for details.
• IFB - For Lectrosonics IFB receivers.
• 6 - (Mode 6) For non-Lectrosonics analog receiv-
ers. Contact the factory for details.
• 7 - (Mode 7) For non-Lectrosonics analog receiv-
ers. Contact the factory for details.
While in the compatibility mode screen, pressing
either the AUDIO or FREQ button exits to standby
mode. To power off from the compatibility mode
screen, press and hold AUDIO and FREQ together.
RF Power Output (Up Button Menu)
Pr (RF Power output) may be selected as either 100
or 50.

Wideband Digital Hybrid®Plug-On Transmitter
Rio Rancho, NM 9
Selecting the Audio Polarity (Up Button Menu)
The character Pdenotes
“positive” polarity and
the character ndenotes
“negative” polarity.
NOTE: The audio polarity can
also be reversed at the output of
most Lectrosonics receivers.
Selecting Step Size mode (Up Button Menu)
The frequency increments can be set at either 25 kHz
or 100 kHz. Hold the UP arrow in while powering up the
unit to enter the setup screen. Press the AUDIO button
repeatedly to step through the setup items to reach the
Step Size Mode screen. Use the UP or DOWN arrow
button to select the desired setting.
DOWN Button Menu
Hold the DOWN button while powering up the unit.
Then press the AUDIO button repeatedly to scroll
through the following settings. Use the UP and DOWN
arrow to select the available options under each setting.
Power Back On (DOWN Button Menu)
PBAC (Power back on after power loss) allows the unit
to either (1) turn back on after power loss or (0) remain
off.
LCD Backlight Setting (Down Button Menu)
The LCD backlight can be set to turn off after either 5
minutes or 30 seconds or stay on continuously. Hold
the UP arrow in while powering up the unit to enter
the setup screen. Press the AUDIO button repeatedly
to step through the setup items to reach the backlight
settings screen. Use the UP or DOWN arrow button to
select the desired setting.
Audio Screen Menu
The Audio Screen is used to
adjust input gain and low
frequency roll-off, and to turn
phantom power on and off.
Repeatedly pressing the
AUDIO button selects the
setting. Press and hold the
AUDIO button and use the
UP and DOWN arrows to
adjust the value.
Adjusting the Input Gain (Audio Screen Menu)
The control panel Modulation LEDs indicate the
modulation level and limiter activity. This gain adjust-
ment matches the transmitter gain with the micro-
phone’s output level, the user’s voice level and the
position of the microphone. Once set, the transmitter’s
audio level setting should not be used to control the
volume of your sound system or recorder levels. The
audio input level can be set with the unit in Standby
Mode or while powered up in normal operation.
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
Note: Voice levels vary significantly between
different people. 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.
1) With the HMa powered off, insert the microphone
plug into the XLR Input Jack, aligning the pins
and ensuring that the connector locks.
2) Place the transmitter in the Standby Mode, or if
the unit is to be powered up and adjusted, mute
the main sound system prior to powering up the
transmitter.
3) Position the microphone in the location where it
will be used in actual operation.
4) Observe the audio level LEDs while speaking or
singing into the microphone at the same voice
level that will be used during use. While holding
the AUDIO button, press the UP or DOWN arrows
until the both the -20 and -10 LEDs glow green,
with the -20 LED flickering red on louder peaks.
This will optimize the signal to noise ratio of the
system with full modulation and adequate head-
room to prevent overload and audible compres-
sion of signal peaks.
Note: Setting the audio level too high reduces
the dynamic range of the audio signal. Setting
the audio level too low may cause hiss and
noise in the audio.
Continued on pg 10

HMa
LECTROSONICS, INC.
10
5) If the unit was set up in Standby Mode, it will be
necessary to turn the transmitter off, then power it
up again in normal operation so the RF output will
be on. Then the other components in the sound or
recording system can be adjusted.
Adjusting the Low Frequency Roll-off (Audio Screen
Menu)
Repeatedly press the AUDIO button until the LF roll-
off adjustment screen appears. Then press and hold
the AUDIO button while selecting the desired roll-off
frequency with the UP and DOWN arrows.
The roll-off frequency can be set to 35, 50 or 70 Hz.
Selecting the Phantom Power Supply (Audio Screen
Menu)
The transmitter input jack can provide phantom power
for the attached microphone if needed, with voltages
at 5, 15 or 48. Phantom power will consume a slight
amount of battery power, so it can also be turned off.
With the transmitter powered on and in the normal or
standby mode, press and hold the audio button and ob-
serve the LCD. Release the button and press and hold
it again. Repeat this process until the display indicates
the PH.
Once you get to the PH setting, keep the AUDIO button
pressed, then use the UP and DOWN arrow keys to
cycle through the available settings (off, 5, 15, 48 volts)
until the desired setting is displayed.
When you release the AUDIO button, the setting will be
stored to the value you selected.
About the Phantom Power Supply
Three phantom voltages are selectable from the control
panel. The voltages are:
• 5 Volts for lavaliere microphones,
• 15 Volts for some professional mics requiring high
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.
• 48 Volts for microphones that do in fact require a
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
voltage necessary for the microphone. Many stage
microphones 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 microphone for the input device, or are
using a microphone that does not require phantom
power, turn the phantom power off.
Phantom 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 maxi-
mum current from the power supply. The HM is fully
protected against such shorts but the batteries will be
drained at twice the normal rate.
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 mi-
crophone as the DIN standard arrangement due to a
dynamic biasing scheme that does not have as much
voltage drop as the DIN standard. The 48 Volt DIN
standard arrangement protects against shorts and
high fault current with high resistance in the power
supply feeds to pins 2 and 3. This provides protection
if the supply current is accidentally shorted to ground
and also keeps the microphone from being attenu-
ated by the power supply.
The HMa improves on those functions and is able to
use less power from the battery by using constant
current sources and current limiters. With this dynam-
ic arrangement the HMa 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.
Setting Transmitter Operating Frequency
1) If the LCD is displaying something other than the
Frequency Screen, press the FREQ button on the
Control Panel to enter this screen.
Note: The default display is in MHz. Pressing
the FREQ button again displays the operating
frequency as a two-digit hexadecimal number
that corresponds to legacy Lectrosonics
products that used two 16-position switches to
set the frequency.
2) While holding the FREQ button, use the UP or
DOWN arrow buttons to move the operating fre-
quency up or down.
Note: The operating frequency displayed on
the LCD wraps as it reaches the upper or lower
end of its range. Thus, if you intend to move
the operating frequency from the lower end of
the range to the upper end, it may be faster
to do this by using the DOWN arrow until the
frequency wraps to the upper end.

Wideband Digital Hybrid®Plug-On Transmitter
Rio Rancho, NM 11
Set Up in 100kHz Mode
Frequency displayed as
two-digit hexadecimal
number
Frequency displayed
in MHz
The operating frequency can
be displayed either in MHz or
as a two-digit hexadecimal
number. The example of the
two-digit display shown here
indicates CH (channel) and 2C
as the frequency.
The frequency can be set with
the unit in standby mode or
when powered up for normal
operation.
Set Up in 25kHz Mode
The hexadecimal display in the 25 kHz mode will ap-
pear with a decimal suffix to indicate the 25 kHz steps.
644.400 MHz
644.425 MHz
644.450 MHz
644.475 MHz
Lock/Unlock Screen
Simultaneously pressing and holding both the UP and
DOWN arrow buttons during normal operation starts the
Lock timer. The timer starts at three and counts down to
zero. When the timer reaches zero, the keypad controls
are locked.
The LCD will display the locked condition as long as the
arrow buttons are held, then revert back to the previous
screen when either button is released.
With the controls locked, the AUDIO and FREQ buttons
can still be used to display current settings. Any attempt
to change a setting by pressing either the UP or DOWN
arrow button will result in an on-screen Loc reminder
that the controls are locked. Remove the batteries to
unlock the control panel.
Important: Once the transmitter is locked,
it cannot be unlocked or powered off using
the buttons.The only way to unlock a locked
transmitter is to remove the batteries.

HMa
LECTROSONICS, INC.
12
Special Purpose Barrel Adapters
P/N 21750
Polarity Reversing
Barrel Adapter
Mic adapter for Earthworks M30 microphone with HM,
HMa and UH400a/TM transmitters.
This polarity reversing adapter may be needed to
correct for asymmetrical current draw in some P48
powered condenser microphones, including older
Neumann 100 Series, Rode NTG3 and others. If your
microphone does not power on correctly when used
with these transmitters, insert the adapter between the
transmitter and microphone.
MCA-M30
This adapter may be needed if you are experiencing
noise or distortion with measurement microphones,
particularly the Earthworks M30. The adapter has
common mode checks for suppressing RF noise. If
your microphone signal exhibits the problems listed
above when connected to a UH400, HM or HMa trans-
mitter, insert the adapter between the microphone and
the transmitter.
Insert the adapter between the transmitter and micro-
phone to alleviate the problems listed above.
Barrel Adapter
Earthworks M30

Wideband Digital Hybrid®Plug-On Transmitter
Rio Rancho, NM 13
MCA-TPOWER
This cable adapter is to be used with the UH200D,
UH400, HM and HMa plug-on transmitters with
T-powered microphones. It will protect a T-power
mic against the 48V phantom power setting in the
transmitter while allowing normal operation. The
transmitter should be set to the 15V position for best
operation and minimum battery drain.
Accessories
PHTRAN3
Replacement leather pouch with clear plastic screen
cover, rotating belt clip and snap closure. Included with
transmitter at purchase.
MC5AX
Optional adapter for connecting a lavaliere microphone
to the HMa or HM transmitters. TA5M to XLR3-M
connectors. Passes transmitter phantom power to
bias the electret lavaliere microphone. Includes zener
protection to limit bias voltage to protect the microphone
if transmitter phantom power is set too high.

HMa
LECTROSONICS, INC.
14
Before going through the following chart, be sure that you have good batteries in the transmitter. It is important that
you follow these steps in the sequence listed.
SYMPTOM POSSIBLE CAUSE
TRANSMITTER PWR LED OFF 1) Batteries are inserted backwards or dead.
2) Transmitter not powered up. (See Operating Instructions,
Power UP and Boot Sequence.)
AUDIO LEVEL LEDs NOT LIGHTING 1) Gain control set to minimum.
2) Batteries are inserted backwards or dead. Check PWR LED.
3) Mic capsule is damaged or malfunctioning.
4) Mic connector is damaged or mis-wired.
RECEIVER RF INDICATOR OFF 1) Transmitter not turned on, or is in Standby Mode.
2) Transmitter batteries are dead.
3) Receiver antenna missing or improperly positioned.
4) Transmitter and receiver not on same frequency.
Check switches/display on transmitter and receiver.
5) Transmitter and receiver not on same frequency band.
6) Operating range is too great.
NO SOUND (OR LOW SOUND LEVEL), RECEIVER INDICATES PROPER AUDIO MODULATION
1) Receiver output level set too low.
2) Receiver output disconnected, or cable defective or mis-wired.
3) Sound system or recorder input is turned down.
DISTORTED SOUND 1) Transmitter gain (audio level) is far too high. Check audio level
LEDs and receiver audio levels during use.
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. (Use the receiver’s Tone
function to check level.)
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
operating frequency on receiver and transmitter match.
5) Receiver/Transmitter Compatibility Mode mismatched.
EXCESSIVE FEEDBACK 1) Transmitter gain (audio level) too high. Check gain adjustment
and/or reduce receiver output level.
2) Talent standing too close to speaker system.
3) Mic is too far from user’s mouth.
Troubleshooting

Wideband Digital Hybrid®Plug-On Transmitter
Rio Rancho, NM 15
SYMPTOM POSSIBLE CAUSE
HISS AND NOISE -- AUDIBLE DROPOUTS 1) Transmitter gain (audio level) far too low.
2) Receiver antenna missing or obstructed.
3) Operating range too great.
4) Signal interference. Turn off transmitter. If receiver’s signal
strength indicator does not drop to nearly zero, this indicates an
interfering signal may be the problem.
Use a clear operating frequency.
“Loc” APPEARS IN DISPLAY WHEN ANY BUTTON IS PRESSED
1) Control Panel is locked. (See Operating Instructions, Locking
and Unlocking the Control Panel.)
“Hold” APPEARS IN DISPLAY WHEN ARROW BUTTONS ARE PRESSED
Reminder that it is necessary to hold down the AUDIO or FREQ
button to make adjustments to the audio gain or frequency settings.
“PLL” APPEARS IN DISPLAY Indication that the PLL is not locked. This is a serious condition
that requires factory repair. It may be possible to operate on
another frequency far removed from the one that was selected
when the unlocked condition was indicated.

HMa
LECTROSONICS, INC.
16
Low frequency roll-off: Selectable; -3dB at 35, 50 or 70 Hz.
Audio Frequency Response: 35 Hz to 20 kHz, +/-1 dB (The low
frequency roll-off is adjustable)
Signal to Noise Ratio (dB):
(overall system, 400 Series mode)
SmartNR No Limiting w/Limiting
OFF 103.5 108.0
NORMAL 107.0 111.5
FULL 108.5 113.0
The dual envelope “soft”
limiter provides exceptionally
good handling of transients
using variable attack and release
time constants. The limiter reduces 30
dB of dynamic range into 4.5 dB, which
reduces the measured figure for SNR
without limiting by 4.5 dB.
Total Harmonic Distortion: 0.2% typical (400 Series mode)
Audio Input Jack: 3-pin Female XLR
Phantom Power: • 5V @ 18 mA max.
• 15V @ 15 mA max.
• 48 V @ 4 mA max.
• OFF
Antenna: Housing and attached microphone form
the antenna
Batteries:* Two 1.5 Volt AA alkaline
Battery Life:* • AA alkaline; No Phantom: 5h 0m
• AA alkaline; 48V Phantom: 3h 30m
* Duracell Quantum alkaline
Weight: 6.7 oz (190 grams) without batteries
Overall Dimensions: 4.25x1.62x1.38 inches
Emission Designator: 180KF3E
Specifications subject to change without notice.
Operating frequencies: (Frequency usage varies by country)
Band A1: 470.100 - 537.575
Band B1: 537.600 - 614.375
Band C1: 614.400 - 691.175
Channel Step Size:
Normal Tuning mode: 100 kHz
Fine Tuning mode: 25 kHz
Frequency selection: Control panel mounted membrane
switches
RF Power output: 100 mW (nominal)
Compatibility Modes (6) Digital Hybrid Wireless™ (400 Series),
200 Series, 100 Series, analog modes
3, 6, 7 and IFB mode
Pilot tone: 25 to 32 kHz; 5 kHz deviation
` (in Digital Hybrid Mode)
Frequency stability: ± 0.002%
Deviation: ± 75 kHz max. (in 400 Series Mode)
Spurious radiation: 60 dB below carrier
Equivalent input noise: –125 dBV, A-weighted
Input level:
If set for dynamic mic: 0.5 mV to 50 mV before limiting.
Greater than 1 V with limiting.
If set for electret lavaliere mic: 1.7 uA to 170 uA before limiting.
Greater than 5000 uA (5 mA) with
limiting.
Line level input: 17 mV to 1.7 V before limiting.
Greater than 50 V with limiting.
Input impedance: 300 Ohms
Input limiter: Soft limiter, 30 dB range
Gain control range: 55 dB
Modulation indicators: Dual bicolor LEDs indicate modulation
of –20, -10, 0, +10 dB referenced to full
modulation.
Controls: Control panel with LCD and four
membrane switches.
Specifications and Features

Wideband Digital Hybrid®Plug-On Transmitter
Rio Rancho, NM 17
FCC Notice:
For body worn operation, this transmitter model has been tested and meets the
FCC RF exposure guidelines when used with the Lectrosonics accessories sup-
plied or designated for this product. Use of other accessories may not ensure
compliance with FCC RF exposure guidelines. Contact Lectrosonics if you have
any questions or need more information about RF exposure using this product.
FCC Compliance:
This device complies with FCC radiation exposure limits as set forth for an un-
controlled 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.
Industry Canada Compliance:
This device operates on a no-protection no-interference basis. Should the user
seek to obtain protection from other radio services operating in the same TV
bands, a radio license is required. Please consult Industry Canada’s document
CPC-2-1-28, Optional Licensing for Low-Power Radio Apparatus in the TV Bands,
for details.
This device complies with Industry Canada license-exempt RSS standard(s). Op-
eration is subject to the following two conditions:
1. This device may not cause harmful interference;
2. This device must accept any interference received, including interference that
may cause undesired operation of the device.
Cet appareil est conforme à Industrie Canada une licence standard RSS exonérés
(s). Son fonctionnement est soumis aux deux conditions suivantes:
1. Cet appareil ne doit pas provoquer d’interférences
2. Cet appareil doit accepter toute interférence reçue, y compris les interférences
pouvant provoquer un fonctionnement indésirable de l’appareil

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. [phone]
PO Box 15900 581 Laser Rd. [phone] Toll-free
Rio Rancho, NM 87174 Rio Rancho, NM 87124 [phone] Fax
USA USA
Web: E-mail:
www.lectrosonics.com [email protected]
Lectrosonics Canada:
Mailing Address: Telephone: E-mail:
720 Spadina Avenue, [phone] Sales: [email protected]
Suite 600 [phone] Toll-free Service: [email protected]
Toronto, Ontario M5S 2T9 (877-7LECTRO)
[phone] Fax

26 January 2016
581 Laser Road NE • Rio Rancho, NM 87124 USA • www.lectrosonics.com
[phone] • fax [phone] • [phone] US and Canada • [email protected]
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.