instruction manual
MRK950 s.n.: FW rel.: Options:
MRK950 dual true diversity receiver
Pag. 2
high performances microphone system
Brief description
Table of contents
The MRK950 is a high performance microphone system suitable for broadcast and high professional
application. Thanks to its exceptional selectivity and
intermodulation immunity, MRK950 is able to operate even in the presence of very high DVTB-T transmitter’s signals.
The extreme bandwidth agility of 370 MHz allows you to always find & work on the best frequencies available. MRK 950 is designed to be:
Brief description�������������������������������������� 3
••“easy & quick to use” thanks to automatic setup
functions (i.e. frequencies, squelch), remote configuration utilities (USB/Ethernet), a display with
intuitive context menu navigation.
••“extremely flexible”, with an incredible frequency agility of 330 MHz; more than one rack can be
connected together thru a simple USB cable to act
a multi-channel receiver. Moreover the DSP board
allows the units to work with several digital audio outputs (i.e. AES/EBU, Ethersound, …), with
multi-companding compatibilities and other digital
••“best in class performances”, thanks to the latest Wisycom technology the unit has extreme RF
sensitivity and immunity and superb audio quality.
••“a durable & upgradable investment”, thanks
to the very robust design (aluminum housing) and
the possibility of upgrade/enhance units performances with simple slot in card (pc-like thru the
DEXB expansion bus)
Moreover MRK 950 system is already set up for the
exclusive PTT function (remote command), developed and patented by Wisycom and now appreciated
in the broadcast world:
Simply pushing this button (PTT), the presenter causes the remote switching of the
receiver’s output-line, from the “main line” to
the additional “intercom line”, in order to be
able to talk “off-air” directly with the technical
team. Then all PTT’s MICs can be connected
in pre-fading allowing a clever intercom
Safety instruction ����������������������������������������������� 4
Main features ����������������������������������������������������� 5
Technical description������������������������������ 5
User guide���������������������������������������������������� 7
Front panel functions������������������������������������������� 7
SCAN & SQUELCH & INFRARED��������������������������� 7
RECEIVER 1 and RECEIVER 2 ����������������������������� 7
MONITOR��������������������������������������������������������� 7
POWER & BOOSTER ����������������������������������������� 7
LCD display: Main view ������������������������������������� 8
Menu tree����������������������������������������������������������� 8
Display view:
buttons logical & schematic diagram������������������� 8
Radio menu ������������������������������������������������������� 8
Chan-Group ����������������������������������������������������� 9
Gr. name ��������������������������������������������������������� 9
Squelch ����������������������������������������������������������� 9
Walk test ��������������������������������������������������������� 9
OPTIONS:�������������������������������������������������������� 10
Name������������������������������������������������������������� 10
LCD contr. & LCD light������������������������������������� 10
Info��������������������������������������������������������������� 10
Restore preset������������������������������������������������� 10
Audio menu ��������������������������������������������������� 10
Tone sq.��������������������������������������������������������� 10
Out level ������������������������������������������������������� 11
Cal. tone ������������������������������������������������������� 11
Sync ��������������������������������������������������������������� 11
SQ (squelch autoset)����������������������������������������� 11
SCAN��������������������������������������������������������������� 12
OPERATING INFORMATIONS������������������������������� 13
RF Level led bars��������������������������������������������� 13
Modulation led bar������������������������������������������� 13
Battery indication ������������������������������������������� 13
Rear panel ����������������������������������������������������� 14
RECEIVER CONNECTION ����������������������������������� 15
Antenna Connection����������������������������������������� 15
Analog audio connection����������������������������������� 15
Digital audio AES/EBU������������������������������������� 15
Digital audio Ethersound©�����������������������������������
Link Ethernet 10/100 Mbit/s���������������������������������
USB connection���������������������������������������������������
NETWORK CONNECTION ���������������������������������������
Digital audio Ethersound©����������������������������16
Link Ethernet 10/100 Mbit/s����������������������������� 16
USB connection����������������������������������������������� 16
NETWORK CONNECTION ����������������������������������� 16
Technical specification��������������������������������������� 17
Options specifications:������������������������������������� 18
Pag. 3
MRK950 dual true diversity receiver
Safety instruction
••Read this safety instruction and the manual first.
••Follow all instructions and information.
••Do not loose this manual.
••Do not use this apparatus under the rain or near
the water.
••ATTENTION: supply the apparatus with a correct
mains voltage and with the ground connection.
Check the power cord integrity.
••The power cord must be protected from damage.
••Do not install the apparatus near heaters or in hot
environments, do not use outside the operating
temperature range.
••Mount the apparatus as indicated in the instruction, do not block side grids for air ventilation.
••If the external air filter is mounted, clean it regularly.
••WARNING: do not open the apparatus, RISK OF
••Do not open the apparatus, only qualified service
technician are enabled to operate on it. The apparatus needs servicing when is not properly working
or is damaged by liquids, moisture or other objects
are fallen in the apparatus.
••Use only accessories or replacement parts authorized or specified from the manufacturer.
••Do not supply more than 7 apparatus MRK950
from the mains output, see power requirements
for other apparatus.
••Clean the apparatus only with dry cloths, do not
use liquids.
••The ON/OFF is a double pole circuit breaker, but to
ensure the complete disconnection of the apparatus, disconnect the power cord.
••Report the serial number and the purchasing date
in front of the manual, it is needed to have proper
replacement parts or accessories from the manufacturer.
••When replacement parts are needed, use only
replacement parts authorized from the manufacturer. Substitution with not authorized parts could
result in electric shock, hazards or fire.
Pag. 4
Keep attention on all the labels with warnings
or hazards on the apparatus.
••WARNING: The apparatus is intended for professional use; anyway the manufacturer alerts
the user that the headphone output power of the
apparatus could exceed the level of 85 dB(A) of
sound pressure level and this could be dangerous
for the hearings. Do not use the headphone with
high power level or for long time. Reduce the power or suspend the hearing in the case of any kind
of hearing problem.
high performances microphone system
Main features
MRK 950 is a modular wireless-microphone receiver
System in a 19” 1 unit module, stackable, with dual
true diversity receivers:
••Extreme RF (radiofrequency) performances and
••Tuning windows up to 370 MHz with tunables filters
(2 ch’s independent):
MRK 950-L: 470/670 MHz (TV ch 21/45)
MRK 950-M: 470/678 MHz (TV ch 21/46)
MRK 950-I: 590/830 MHz (TV ch 36/65)
MRK 950-H: 630/870 MHz (TV ch 41/70)
MRK 950-X: 470/800 MHz (TV ch 21/62)
with internal active splitter
MRK 950-w: 470/840 MHz (TV ch 21/67)
with internal active splitter
••Wisycom digital expansion bus (DEXB) for future
upgrade/enhancement thru simple slot-in card
(pc-like). DEXB can host DSP (40bit dsp processing) upgrade cards providing:
••digital output (i.e. AES3, Ethersound)
••multi-companding compatibility
••future digital functionality enhancements.
••Balanced electronic AF output (low impedance
transformer-coupled optional)
••2 USB’s connectors for configuration/monitor and
cascade rack connections
••Automatic scan for best channels, squelch and
other automatic setup
••Infrared interface (i.e. for system setup, microphone programming)
••Automatic transmitter re-programming (thru infrared, sync function)
••Software to monitor/setup units and with spectrum field analysis
••Ethernet 10/100 base Tx network interface for
Technical description
The MRK950 is a professional dual diversity receiver
for wireless microphones reception especially designed for broadcast production, live stages, theatres and top professional applications.
It’s winning performances are:
High immunity on strong rf environment
Huge switching bandwidth
High audio performances and flexibility
with analog or digital processors
High reliability and durability
One of the milestones in the design of the MRK950 is
high reliability: most of the circuitry of the receiver
is independent one from each other.
On next page a schematic with an overview of main
receiver functions.
Starting from the antenna inputs, each antenna
could be powered from a single power regulator
monitored from the microcontroller.
For each antenna the RF signal is splitted in the receiver 1 and in the receiver 2 (antenna A and antenna B) with a wide band splitter. In this way any
one receiver could be tuned in any frequency of the
switching range (typ. 240/330 MHz).
Receiver 1 and 2 are diversity receivers: each one is
made of two receivers tuned on the same frequency,
hereafter called section A and section B. The receiver 1 section A and the receiver 2 section A are
connected to the antenna A, the receiver 1 section
B and the receiver 2 section B are connected at the
antenna B.
Each receiver has its own demodulated signal and
its own RSSI signal (Receiver Signal Strenght Indication); a microcontroller select or combine signals
from section A & B to have the best audio.
The demodulated signal is then splitted on two parts,
one part flows to the analog processor and the other
part flows to the digital audio processor (optional).
••Digital audio interfaces:
••Ethersound® interface
••AES/EBU digital interface (with word-clock in/out)
••Push to Talk (PTT) function with audio exit and GPI
signals (patented)
••Very low impedance transformer outputs
Pag. 5
MRK950 dual true diversity receiver
Receiver - 2- A
Receiver - 2- B
Front panel
Digital output
Antenna inputs
Receiver - 1- B
Line unbal.
Receiver supervisor
and user interface
word clock
Line unbal.
Receiver - 1- A
MRK950: main block diagram
Analog processor: the signal is filtered by a high
pass filter (30Hz) and then splitted in two different
circuits, the audio processor and the data signalling
subcarrier detection and demodulation. The audio
processor has these sections: the de-emphasis (50
microseconds), the low pass filter (20KHz), the excludible ENR expander. The audio signal is now ready
for the audio output drivers.
keep audio delay as short as possible. The DSP unit
also filters and demodulates the data carrier and
communicates all the parameters and informations
to the supervisor microcontroller. The audio output
goes to the digital outputs board options (AES/EBU
or Ethersound) or is converted in the analog domain
with a high quality 24 bits 96KHz D/A converter and
an anti-aliasing filter.
Data signalling detection and demodulation:
the data subcarrier is filtered with a four sections
band pass filter with a bandwidth of about 50Hz, followed by an ultra narrow band crystal filter (3Hz).
Each filter has its own data demodulator, one for
medium speed data detection at the output of the
first filter and one at low speed data detection at the
output of the second filter. All the two demodulators
are connected to the supervisor microcontroller for
the data battery detection and signalling.
Audio output drivers: the audio signal, selected
between the analog processor output and the digital audio board codec output (depending on setup
defined into the active noise reduction system),
is splitted in three parallel ways, LINE, COM and
The HEADPHONE MONITOR amplifier is controlled by
the buttons on the front panel and by the volume
knob. The monitor output depends on the squelch
and on the tone squelch only in the TSQ ON selection. In TSQ OFF and in TSQ ADV the monitor output
is muted only by the squelch control.
The two ways, LINE and COM, are identical and the
audio quality is exactly the same. Each audio driver
has a VCA for the soft switching of the audio signal
and the muting functions, controlled by the supervisor microcontroller. After the VCA, an electronically
balanced amplifier drives the output signal, directly
or thru a very low impedance screened audio transformer (optional). The audio output without transformer could withstand up to +52 Vdc of phantom
supply with no damage and up to 100V with transformer.
Digital audio processor: the demodulated signal
is filtered by an anti aliasing low pass filter and then
converted in the digital domain with a 96KHz 24bit
audio A/D converter. The digital signal processor
(DSP), capable or 40 bits floating point operation,
replicates all the analog functions with very high accuracy, ultra low distortion and without typical analog problems like components tolerances or long
term drifts or temperature drifts etc. The high speed
audio algorithms implemented in assembler into the
MRK950 maintains the audio delay at about 700 microseconds, making it ideally for live events and to
Pag. 6
high performances microphone system
User guide
Front panel functions
MRK950 allows an easy and quick configuration using buttons, push knobs and displays.
The front panel is functionally divided in the following section:
A Scan & Squelch: automatic scan and squelch
Infrared: remote controlling and MIC setup
through infrared interface.
Receiver 1: “receiver 1” configuration and
monitor of radio/audio levels.
Receiver 2: “receiver 2” configuration and
monitor of radio/audio levels.
Monitor: monitoring audio with on headphone
jack (6.3mm - ¼”).
Power & Booster: powering ON or OFF the receiver and the antenna boosters
The function SCAN initiates an automatic procedure
for the choice of the less noisy channel in
the selected group of channels; the scan
function measures the floor noise of all the
channels of the selected group and show
the result in the display. This is a quick way
to find the best channels to use in the selected group. When pushed the scan button, it is needed to setup or confirm the
group of channels for the scan.
SQUELCH initiates the automatic procedure to setup
the level of the squelch. This is an automatic way to
quick setup the squelch for the current frequency.
The transmitter must be off, then push SQ button to
let the system find the optimal value. You can later
accept, modify or discharge this setup.
IR interface window: for communications between
the MRK950 and a transmitter. You have to put the
IR interface of the transmitter, with the IR interface
active, in front of this window. This is needed for
example in the SYNC function.
Area A: 3 LED bars:
• two bars for the RF levels in microVolt (diversity
A & B antenna level),
• FM modulation of the received channel (modulation in % referred to the nominal deviation).
Area B: LCD display.
64 x 160 blue back-lighted display).
Area C: 3 push buttons (membrane).
The function of each button (upper, middle and
lower) will be readable from the context menu
on the display.
Area D: Push rotary knob.
Rotate and push to select.
Monitor 1 and 2:it activates
monitor audio on jack output
(6.3mm - ¼”) for receiver 1 and
2, respectively (a green LED is
lighted when audio is enable).
Audio level can be adjusted
with the rotary knob. The red
led (CLIP) indicates a clipping
in the audio monitor output.
BOOSTER:it activates antenna powering (boosters)
with 12VDC (200mA max) and the
green LED is lighted. Blinking LED indicates a faulty condition, in this case
power down the device and check for
short circuits or overloads in the RF
cables or boosters.
POWER: ON/OFF square powering button turns on/off the receiver.
When in OFF position both phases are disconnected
from power.
Pag. 7
MRK950 dual true diversity receiver
LCD display: Main view
All the basic information on the receiver status are
Display view:
buttons logical & schematic diagram
readable in the main view of the LCD display.
The main view has the following info:
1 receiver name,
2 current tuning frequency
3 current channel number
Press the knob
4 current group number and group name
5 TV channel used for the current frequency
6 Tone Squelch current setup
7 LOCAL or REMOTE receiver management, via
USB or Ethernet connection
8 Squelch level (microVolt)
9 NET connection to a host PC (USB or Ethernet)
Radio menu
The first item on the menu tree is “RADIO”. Pressing
the upper button (RADIO), you go at the RF functions menu of the receiver, as shown below:
10 Analog audio output level at nominal FM devia-
11 status of the output lines (audio line, audio com,
gpi) and detection of the digital data carrier (i.e.
transmitter battery data carrier or tone squelch),
12 transmitter battery charge status.
Thru the main menu on the LCD display and the LED
bars for the RF level and modulation the user has
the complete monitoring in real time of the wireless
channel in use.
Gr. name
Walk test
Menu tree
To access the configuration menu of the receiver
is necessary to press the rotary knob (at the right
of the display). This allows you to access the main
Pressing firt the rotary know shows a hidden window
(area 11 the image of the main view) with three
main headings: “RADIO”, “AUDIO”, “SYNC“.
To activate one of the items in the menu, press the
corresponding button to the right of the display (see
picture hereafter).
Pag. 8
LCD contr.
LCD light
high performances microphone system
Gr. name
The CHANNEL-GROUP item enables the user to
edit channel, channel group and frequency of the
selected itemsl. Change, rotating the knob, the
channel or the group of channels and confirm or exit
with the buttons. To edit the frequency of selected
channel, press the middle button and change it with
the knob. Press the knob to move between MHz and
KHz. Confirm or exit with the buttons.
The second item on the radio menu is GROUP NAME;
with this function is possible to assign or change a
name to a group of channel. This short name (8 character) is displayed at the right of the group number
in the main display view. First chose the the group
and then press the knob. You will be able to edit any
character of the group name rotating the knob. Push
the knob to edit the next character. Confirm or exit
with the buttons.
As shown in the above picture, the display area has
3 rows with:
1] Channel number (0 to 60) and
Channel frequency (in 25kHz step)
2] Group number (1 to 40) and group name (8 char.)
3] Group description (30 char.)
The MRK950 has 40 groups of 60 channels each.
Normally this is too much for wireless microphones
Connecting with computer with WISYCOM MANAGER software, it is possible to hide single channels
or even complete groups of channels: once hidden
those items are not shown anymore on the channels
or groups selection. To show channels or groups hidden use again the WISYCOM MANAGER software.
Using this software it is also possible to lock channels or groups. When a channel is locked, it is not
possible to change the frequency from the front
panel of the receiver. Locking a group means that all
channels are locked. When a channel or a group are
locked, at the left of the group name in the ChanGroup menu will appear a lock icon as shown in the
picture below. When the lock picture is shown, the
central button is not displayed, thus changing frequency is not possible.
The SQUELCH function allows to assign a value at
the squelch of the receiver. Rotating the knob it is
possible to change current squelch level from OFF (it
means no audio squelch) to 1mV. Pressing the knob
you could setup the desired level and also configure you measurement unit between microVolts and
dBµV. At the end confirm or exit with the buttons.
There is also an automatic procedure to set up the
squelch level, it will be discussed later in this document at the Autoset SQUELCH item.
Walk test
The WALK TEST function records the RF level of
the two antenna inputs, separately, for a total time
of 90 seconds. Using the first button, it is possible
to choose what to plot: the rf level of the antenna
A or B, the Max value between antenna A and B
or both antenna levels separately. Press START and
walk on your area with a wirelss MIC (transmitting
at the current frequency) while receiver records all
received RF levels. At the end of the sweep time it
is possible to have a look on the graph and check
if there are some “hole of RF signals” and evaluate
your wireless coverage.
Finally push the 3rd button (EXIT) to leave this
fucntion. As “rule of the thumb”, the signal coverage
of the stage could be considered good if, in all the
stage, the signal “MAX AB” is never lower than
10µV or 20dBµV. The plot in the picture, shows a
very low coverage with some areas not covered by
the two receiving antennas. In this case probably
the position of the antennas must be changed and/
or the gain of the boosters adjusted.
Pag. 9
MRK950 dual true diversity receiver
Note: receiver names, frequencies, groups or
channels information are NOT changed.
Audio menu
The options NAME allow you to change the name of
the receiver. This is the name displayed in the top of
the display in the main view and is the name sent
to the transmitter with the sync function (for transmitters with this advanced capability). Use the knob
to change the name and the buttons to save or exit
from the function.
The second item on the menu tree is “AUDIO”.
Pressing AUDIO (middle button), you enter the AUDIO functions menu, as shown here below:
Noise red.
Tone sq.
Out level
LCD contr. & LCD light
With these two functions it is possible to change the
contrast or the backlight intensity of the LCD display.
Use the knob to change and the buttons to save or
exit from the function.
the INFO function shows many important features
or information of your MRK950 receiver:
»» Range of frequency
»» Internal temperature
»» Serial number
»» Internal errors counter (could be read and reset from the Wisycom Manager software)
»» Bootloader firmware version
»» Application firmware version
»» DSP firmware version
Note: the complete software and hardware
status is displayed switching ON the receiver
with a knob pressed. Press this knob a second time to exit this function.
Restore preset
The RESTORE PRESET resets the following setups
to factory defaults: tone squelch (OFF), noise reduction system (ENR), audio output level (12dBu), cal
tone (OFF), audio matrix, booster supply (OFF) and
headphone selection (OFF).
Pag. 10
Cal. tone
Noise red.
The NOISE REDUCTION SYSTEM is used to select your current noise reduction system in the audio
path. If the DSP board is not installed it is possible
to change only between ENR (the n. r. system of
the Wisycom wireless microphones) and “NONE”.
The NONE position excludes the audio expander and
the receiver works as a normal FM receiver with 50
microseconds of de-emphasys and 20KHz of audio
bandwidth. If the DSP board is installed then it is possible to choose different types of audio processors.
Use the buttons to save or exit from this function.
Depending on selected NOISE REDUCTION SYSTEM,
tone squelch function and transmitter battery status
could be enabled or disabled (since not all the wireless microphones have this enhanced functionality).
Tone sq.
The TONE SQUELCH function is an advanced function (whose behaviour depends on selected noise
reduction system). This chapter explains TONE
SQUELCH operations when associated to a Wisycom
wireless microphone with the ENR as active noise
reduction system. Other types of wireless microphones could have different behaviour or could not
work properly. Here-after the complete tone squelch
function, whenever the receiver does not have all
the options installed, some functions will be hidden. The tone squelch selection could be OFF, ON
or ADV (advanced). Tone squelch OFF enables the
audio output on LINE and COM (if present) connec-
high performances microphone system
tors always, it could be muted only by the squelch
on RF signal (the RF squelch has always priority).
Tone squelch ON enables the audio output on LINE
and COM (if present) only if the transmitter sends
the correct identification tone signal (tone squelch).
The ADV function (with or without PTT options), on
microphone transmitters, gives more possibilities of
audio routing and GPI signalling. In the picture below is displayed the matrix menu. To have access to
this menu is needed to set the tone squelch function
in ADV and then press the upper button “CONFIG”:
Before starting the tone it is possible to select with
the knob the outputs for the tone (only LINE, only
COM or LINE and COM together). With the buttons
it is possible to start, stop and exit from the tone
generation. The calibration tone is generated by an
analog source when the noise reduction system selected is analog. The calibration tone is a very low
distorsion digital generated when the noise reduction system selected is digital (from DSP board).
The output not selected for the tone generation will
be muted.
When the tone is active at least in one output, the
led bar of the deviation indicates the 100%, just to
remember that the tone has the same level of the
nominal deviation in a transmitter.
With the knob and the buttons, it is possible to
choose, for any one of the three TSQ modes, the
status of the audio outputs LINE and COM and in the
TSQ ADV mode it is possible to choose the status
of outputs LINE, COM and GPI, when the transmitter PTT button is released or pushed. The dot in the
circle on the left of the display shows the actual setting for the tone squelch function.
Note: the tone squelch could not substitute
the squelch on the RF signal level. For the
best performance of the receiver it is better to use the SQUELCH & TONE SQUELCH
Out level
The OUT LEVEL function allows the adjustment of
the audio level on the LINE and COM balanced outputs. The nominal level, used also in the technical
specifications of the receiver, is 12dBu at nominal
modulation and could reach 18dBu to 20dBu in clipping. This level could be too high for some audio
mixing units, so with the out level function it is possible to reduce the nominal level from 12dBu to 6dBu
or 0dBu. This setting is unique for LINE and COM and
for all the two receivers.
The SYNC function, selected from the main menu
with the lower button, is useful to tune a transmitter on the same frequency of the receiver via the IR
interface. Before starting the sync function tune the
receiver on desired channel, manually or using the
SCAN utility. After this, enable the IR interface on
the transmitter. Now press the knob and the lower
button to start the SYNC function. Keep the IR window of the transmitter in front of the IR window of
the receiver and, as soon as the connection is done,
the receiver will send to the transmitter all the information needed. If the operation is not possible,
(i.e. the frequency range of the transmitter is not
compatible with the frequency of the receiver), the
display will show an error message. If the transmitter has the function “NAME” enabled, when the sync
function is completed it will show the same name of
the syncronized receiver.
SQ (squelch autoset)
The SQUELCH AUTOSET function helps the user to
set the squelch level of the receiver at a good level
for the selected channel. After pressing the SQ autoset button, the two receivers ask to switch off the
transmitter and then, after the user confirmation (on
one receiver or all the two receivers at the same
time), it starts to measure the noise in the selected
Note: the audio output level could be further
reduced by 30dB with a switch below the XLR
output connector, in the rear panel.
Cal. tone
The CALIBRATION TONE function generates an
1KHz sine audio tone at the audio outputs at the
nominal level on the selected receiver.
A few time later, after some calculation, the receiver
Pag. 11
MRK950 dual true diversity receiver
proposes the new squelch level. The user could then
accept, refuse or modify it by means of the buttons
and of the knob.
Note: during the Autoset SQUELCH function
it is not possible to change the unit of the
squelch voltage.
The SCAN function is very useful to discover the best
channels to use (the channels with lower RF noise)
in the selected group. After pressing the SCAN button, both receivers are ready to start with the SCAN
function. It is possible to select the receiver 1 or the
receiver 2 or both (i.e. simultaneously scan on different groups).
With the first menu on the display it is possible
to choose the group of channels for the scan and,
pressing the knob, is possible to define a reference
line drawing in the final scan result graphic, just for
user reference. Pressing the knob the focus change
between REF LINE and GROUP.
Pressing the START button, an alert window remind
the user to switch off all the transmitters before
starting the SCAN, press START again and the SCAN
function will start. At the end of the analisys, on the
display it is possible to see the graph of the RF levels
measured in each channel and, rotating the knob, it
is possible to move the marker on the bottom of the
graph just to see the channel number and the RF
level measured for that channel.
Pressing the knob it is possible to have a graph in
rank order instead of channels order, so, it is very
simple in rank order to find the less noisy channels
because they are in the left part of the graph.
The marker is always active rotating the knob.
Pressing the knob the graph changes between rank
order to channel order again.
For terminating the SCAN function, press the lower
button on the right of the display.
In the above picture a typical graph of the scan function (only the graph area of the display). This graph,
ordered by channel numbers, shows the RF levels in
dBµV for each channel in the selected group (i.e. Ch:
00). Rotating the knob the small arrow cursor moves
from a channel to the next one; on the right of the
graph it is possible to see the rank of the channel
selected by the cursor, its number, its frequency
and the RF level. Pressing the knob the order of the
graph became the rank, not the channel number. In
this way it is more simple to choose channels with
lower RF noise, they are in the left part of the graph.
See at the picture below:
In this graph the channels are ordered by rank. Turning the knob it is possible to change the channel and
reading its number, frequency and level of RF noise.
The horizontal dashed line is the squelch level set
before starting the scan.
Connecting an headphone at the monitor output, is
possible to ear the signal in the channel selected by
the knob. If the RF signal is below the squelch level,
the upper button near the display disable/enable the
squelch so the audio output is enabled also for weak
RF signal.
The SELECT button is the exit from the SCAN function tuning the receiver on the selected channel, the
EXIT button exits from the SCAN function leaving
the receiver channel unchanged.
Pag. 12
high performances microphone system
RF Level led bars
Two RF level led bars for each receiver indicate measured RF level at the antenna input of the receiver
in the selected channel. For a typical diversity reception it is a good starting point to consider that
the two signals should have the same average level
over time, but this could be different while moving
the transmitter on the stage. The important issue is
that moving the transmitter on the stage, the diversity has to work switching from one receiver to the
other receiver as indicated by the two blue leds on
the top of the bars. When the RF levels of the two
inputs have similar level, the diversity control enable
the two receiver at the same time, further increasing
the S/N ratio at the audio output.
Battery indication
On the main display of each receiver is always well
visible the battery status of the transmitter (area 12
of the main view). The resolution of the indication
depends on the transmitter. Wisycom transmitters
send 8 levels of battery charge status, other competitors 6 or 4 or 3 level (full, half, empty).
When the transmitter is a Wisycom, the display of
the batteries indicate the correct icon and the percentage of the charge but, when the charge reach
the 25% the battery area on the display became
flashing, when the charge reach the 12,5%, the
illumination of the display is flashing to give an
high visibility alarm to the user.
Modulation led bar
The third led bar of each receiver indicates current
channel modulation as percentage of nominal deviation (not the audio output level). The difference
between modulation and audio level is because normally there is a preemphasis on audio transmission
and some manufacturer uses different compression values and different audio frequency equalization. Therefore to have the maximun efficiency of
the radio channel it is important to use the highest
modulation bandwidth possible, in respect to the dynamic range of the audio signal and the manufacturer specifications. If the receiver MRK950 has the
DSP board option, the scale of the modulation will
be changed according to the nominal modulation of
the type of microphone and manufacturer selected
in the NOISE REDUCTION SYSTEM. The modulation
led bar is blank when the squelch and/or the tone
squelch opens the audio output circuit (or if there
is no modulation on the transmitter, of course). Adjust the gain of the audio chain in the transmitter to
have in the maximum modulation peaks the 100%
of modulation bandwidth, leaving the next 6dB of
modulation margin before clipping (red PEAK led) for
extra sound pressure margin. If the audio level is
not exactly known, be conservative and adjust the
microphone gain in a lower position to avoid clippings during the working session.
Pag. 13
MRK950 dual true diversity receiver
Rear panel
INPUT 90-264V~ 47-63Hz
100 Base T
75 Ω
200mA MAX
OUTPUT 90-264V~
200mA MAX
1 Mains output. Do not connect more than 8
16 Unbalanced LINE audio output of receiver 1,
2 Mains socket input.
17 Switches for shorting the pin 1 of the XLR con-
3 Mains fuse (2A-T).
4 Ethernet connector RJ45 for LAN connection of
the receiver. The leds on the connectore indicate the status of the connection (Link and Activity). (Optional)
5 AES/EBU XLR 3 pin output connector, digital
audio output transformer isolated, balanced.
This is part of the AES/EBU optional board, toghether with 6, 7 and 22. Here it is possible to
install different option like Ethersound© I/O.
6 Word clock input for external syncronization of
digital audio output.
7 75 ohms termination switch for word clock input.
8 Antenna B input, BNC connector, DC output for
booster power supply.
9 XLR 3 pin male connector, COM audio output of
the receiver 2, balanced. (Optional)
10 XLR 3 pin male connector, LINE audio output of
the receiver 2, balanced.
11 GPI output of the receiver 2, 1/4” (6,3mm) stereo jack socket. (Optional)
1/4” (6,3mm) stereo jack socket.
nectors of receiver 1 to the receiver ground or
18 Switches for attenuating the audio output level on the XLR connectors. The attenuation is
19 Unbalanced LINE audio output of receiver 2,
1/4” (6,3mm) stereo jack socket.
20 Switches for shorting the pin 1 of the XLR con-
nectors of receiver 2 to the receiver ground or
21 Switches for attenuating the audio output level on the XLR connectors. The attenuation is
22 Word clock output, for daisy chain connection.
BNC connector. (Optional)
23 LINK connection, for cascade connection of re-
ceivers, for remote control functionality. USB-A
24 USB-B connector for PC connection if this
MRK950 is a subnet controller. If this MRK950
is part of a subnet, this connector must be connected to the LINK connector of the previous
25 Product identification label.
12 XLR 3 pin male connector, COM audio output of
the receiver 1, balanced. (Optional)
13 XLR 3 pin male connector, LINE audio output of
the receiver 1, balanced.
14 GPI output of the receiver 1, 1/4” (6,3mm) stereo jack socket. (Optional)
15 Antenna A input, BNC connector, DC output for
booster power supply.
Pag. 14
Note: shaded area represents the room for
digital audio outputs of the receiver. The picture shows the AES-EBU option installed.
MRK950EX has also “RF out” BNC’s for the
antenna splitting.
high performances microphone system
Antenna Connection
The MRK950 has two antenna inputs, necessary for
a true diversity reception system. Each input signal is splitted for the two diversity receivers on the
MRK950. The picture on the bottom of the page
shows the typical connection of four MRK950 receivers. Each antenna input could deliver a booster
supply of 200mA at 12Vdc; this is enough to supply an active antenna like the Wisycom LBNA and
a booster like the Wisycom BAA, needed only when
the antenna cable has a very high attenuation. For
connecting more receivers on same antennas, use
active wideband antenna splitters like the Wisycom
SPL214AW for four MRK950 (8 wireless microphone
channels) or the SPL218AW for eight MRK950 (16
wireless microphone channels). More channels are
possible combining more splitters. In this case the
active antennas and the boosters will be powered
by the splitters. Using the MRK950EX version it is
also possibible to use the integrated active splitter to
connect several MRK950EX in cascade configuration.
Analog audio connection
The MRK950, in the full optional audio output configuration, has three audio outputs for each receiver,
two balanced with XLR connector and one unbalanced with a 1/4” (6.3 mm) stereo jack connector.
The unbalanced audio output has the same audio
signal of the LINE output. The balanced audio out-
puts could be electronically balanced or transformer
isolated with very low impedance when the TRAFO
option is installed.
Below the XLR connectors there are two switches:
The left one (LINE/MIC) inserts a fixed resistive attenuator of 30dB on the audio output; the audio levels on the XLR connector, according to the setting of
the “Out level” and to the setting of the switch below the XLR connectors, at nominal modulation, are:
Att. 0dB
Out lev 12dBu
Out lev 6 dBu
Out lev 0 dBu
12 dBu
-18 dBu
6 dBu
-24 dBu
0 dBu
-30 dBu
The switch on the right (LIFT/) cuts the connection
beetween the pin one of the XLR connector and the
ground of the MRK950 to avoid ground loops.
Digital audio AES/EBU
With the AES/EBU option installed the MRK950 has
an digital audio output channel according to the
AES3 and AES/EBU standards for professional 24 bit
digital audio.
The left channel of the AES3 stream is the audio of
the receiver 1 and the right channel is the audio of
the receiver 2. When no word clock is connected,
the sampling rate of the digital audio output is fixed
at 48KHz, internally crystal generated; with the external word clock the sampling rate could be from
32KHz to 108KHz. The word clock input could be left
at high impedance or loaded to 75 ohms. The word
clock output could be connected to the next MRK950
or could be left open.
Analogue Audio XLR
Link USB
Link Ethernet 10/100 Base-TX
Digital Audio Ethersound
Digital Audio AES/EBU
Pag. 15
MRK950 dual true diversity receiver
Digital audio Ethersound©
The Ethersound option on the MRK950 adds the capability of a connection beetween the MRK950 and
an Ethersound audio distribution system. This option
adds two RJ45 connectors for the ethernet cables,
one is the input and the other is the output of the
Ethersound interface.
configuration and scene backup.
Link Ethernet 10/100 Mbit/s
The Ethernet interface is used to connect an MRK950
to an host PC for remote monitoring. The “WISYCOM MANAGER” is the PC software for the complete
remote monitoring and managing several MRK950
also connected thru an USB cascade.
WISYCOM MANAGER is able to find a configure network parameter of a MRK950 in ethernet connection
without knowing its IP address (this is done thru a
broadcast discovery). Near the ethernet connector there are two led lamps, one for the connection
check and one for the data monitoring.
A receiver connected to a PC could be an subnet
controller for other receivers if the other receivers
are connected in a chain with USB cables as shown
on the picture in the previous page.
USB connection
The MRK950 comes with an USB 1.1 interface that
has has priority over ethernet connection. Near the
USB connector there is another connector named
LINK. This connector could be connected to the USB
port of the next MRK950 with an USB-A to USB-B
cable to build a chain of receivers. The maximum
number of receivers in a chain is four. The receiver
with the USB connector free is the subnet controller
receiver (the one in the upper position on the picture). It must be connected to a PC by means of the
USB port or by means of an ethernet connection.
Once connected, start the WISYCOM MANAGER software to manage the array of receivers (more details
on software manual).
Wisycom Manager software allows to monitor and
configure remotely
complex systems base on
MRK950s connected in USB chain or thru ethernet
4 racks USB CASCADE(8 receiver):
the first is the subnet controller that control up to
other 3 receiver. This entity is seen as single 8 receiver and using the ethernet port of the subnet controller can also be remoted in a computer network.
This way the system has also the information on every single MRK950s location allowing very effective
Pag. 16
Note: it is not possible to connect more than
4 receivers MRK950 in a subnet USB
Several USB cascade can be connected using the
ethernet connection on each MRK950 acting as cascade controller.
Hereafter an example of a 12 rack configuration,
there is no limits to the complexity manageable on
Wisycom Manager software.
Note: If using MRK950EX with antenna
cascade (using its integrated splitter), the
MRK950EX acting as “subnet controller”
must be also the receiver connected with
antennas and boosters. This is to be able
to manage and monitor voltage and current
on antenna boosters.
high performances microphone system
MRK 950
Modular Wireless-Microphone Receiver System
Technical specification
••Two indipendent receivers tunable in all the specified frequency range
••Frequency range:
»» MRK 950-EX: 470/800 MHz (TV ch 21/62)
with internal active splitter
••Memorized channels: up to 2400 divided in 40 groups with
60 channels each
••Frequencies: microprocessor controlled PLL frequency synthesizer circuit, with 25 KHz minimum step (others on request)
••Frequency error: < ± 2.5 ppm, within the rated temperature
••Modulation: FM (50µs de-emphasis), other de-emphasis can
be pre-set on request and can be recalled from the menu.
••Noise Reduction system : compander circuit, can be pre-set
(or switched off) to the following modes:
»» ENR (Wisycom Extended-NR) as default
USTOM (to be compatible with other brands transC
••AF line output level: +12 dBu (3.1 Vrms) @ nominal deviation (could be individually attenuated by 30dB by means of a
switch on the back panel under the XLR connectors)
••AF line output peak level: +20 dBu (7.75Vrms)
••AF line output connector: XLR, pin 1 could be grounded or
floating by means of a switch on the back panel under the
XLR connectors. Could withstand up to +52 Vdc of phantom
••AF output impedance: <= 200 ohms
••Nominal deviation: ±40 KHz @ 1 KHz, ±65 KHz peak with
ENR noise red. system, up to ± 110 KHz without noise reduction system
••AF bandwidth: 40 Hz ÷ 20 KHz
••“A” / “B” antenna inputs: with BNC type female connectors.
••Distortion: < 0.3 % (0.1 % typ.) @ peak deviation, ENR
noise reduction system enabled
••“A” / “B” antenna input booster supply: 12Vdc 200mA max.
»» RF input impedance: 50 ohm (SWR < 1:2)
••Sensitivity [with ENR]:
0.9 µV ( -1 dBµV), for SND/N = 52 dBA, in the
whole switching-range [Rms value A weighted]
10 µV (+20 dBµV), for SND/N = 115dB, in the
whole switching-range [Rms value A weighted]
••Amplitude response: < 0.2 dB (for RF input signal: +4 dBµV
÷ +120 dBµV)
••Co-channel rejection:
»» > -3.5 dB @ 2 µVRF
> -1.5 dB @ 100 µV RF
••Frequency response: < ±0.5 dB (±0.2 dB typ.) in the 50 Hz
÷ 19 KHz range
••SND/N ratio [1] > 110 dB (115 dB typ.) [2]
••Monitor output: 1/4” (6.3 mm) stereo jack connector
••Monitor output level: max 6 Vrms / 150 ohm
••Monitor out impedance: 50 ohm
••Diversity technique: true-diversity (Twin receiver circuits)
••Bar-graph meters:
»» RF field strengths (both “A” and “B” inputs) »»
AF deviation (5% ÷ 150%), with peak-hold mode
••Displays: nr. 2, one each receiver, 64 x 160 pixel LCD dot
Matrix (blue backlighted)
••Adjacent chan. selectivity: > 90dB @ ±300 KHz
••Calibrating AF tone: 1 KHz, +12 dBu (other on request)
••Spurious rec. rejection: > 90 dB
••Powering: 90 ÷ 264 Vac, external 2A T fuse
»» input frequency: 47 ÷ 440 Hz
••IF image rejection: > 110 dB
••IIP3 (Input 3° order Intercept Point):
> 20 dBm
••Spurious emissions: < 1pW (typ. = 0.1 pW)
••Signal strength squelch: menu adjustable threshold from
-6dBµV (0.5µV) to 60dBµV (1000 µV) plus OFF position and
“adaptive type” working: the receiver adapts itself automatically to different conditions of both medium strength and
speed variation of the received signal
»» rated input current 1.5A
inrush current (132/264 VAC) 24/48A (cold start)
Internal security fuse: T2.2AL, 250V not replaceable
Unfused output mains connection, 5A max
••Temperature range: -10 ÷ + 55 °C
••Dimensions: 19”/1U, depth 370mm
••Tone-squelch: it works by decoding the special key, sub-carrier (digitally modulated) present on the carrier of the actual Wisycom transmitters. The tone squelch function can be
inhibited for compatibility with other types of transmitters
Pag. 17
MRK950 dual true diversity receiver
Options specifications:
••Low impedance transformer on audio lines:
Analog audio outputs are galvanically isolated by
means of a high quality low impedance shielded
utput level: 12dBu nom., 18dBu at max FM
output impedance: < 30Ω (e.g. could drive at
least 300m of high quality twisted pair audio
cable without degradation in frequency response)
••COM audio output: same specifications as LINE
audio output
Obblighi di informazione agli utilizzatori
Modello di informazioni agli utenti dei prodotti di tipo
ai sensi dell’art. 13 del Decreto Legislativo 25 luglio
2005, n. 151 “Attuazione delle Direttive 2002/95/CE,
2002/96/CE e 2003/108/CE, relative alla riduzione
dell’uso di sostanze pericolose nelle apparecchiature
elettriche ed elettroniche, nonché allo smaltimento
dei rifiuti”
••GPI output: normally open opto-relay isolated
AC/DC 56Vpk max - 100mAmax.
10 ohm max on resistance.
1/4” (6.3 mm) stereo jack connector (2 pins
for relay contact + receiver ground)
••Ethernet board: ethernet 10/100 base T interface, RJ45 connector with integrated link and activity leds for quick check of the connection. Could
be used with static IP address or in DHCP mode.
••DSP audio board, 40bits floating point DSP processor for high dynamic range low noise multicompander audio processing and digital data detection. A/D and D/A conversions at 96KHz 24 bits.
Ultra low delay processing: tipical audio processing
delay < 700 µsec.
••AES/EBU (AES3) board, externally sincronizable
alanced transformer isolated output
24 bit professional audio stream
word clock input from 32KHz to 108KHz, BNC
word clock input impedance: 75Ω or high Z
externally switchable
word clock output on BNC connector for cascading more units
needs DSP audio board installed
Il simbolo del cassonetto barrato riportato
sull’apparecchiatura o sulla sua confezione indica
che il prodotto alla fine della propria vita utile deve
essere raccolto separatamente dagli altri rifiuti.
La raccolta differenziata della presente apparecchiatura giunta a fine vita e’ organizzata e gestita dal
produttore. L’utente che vorrà disfarsi della presente
apparecchiatura dovrà quindi contattare il produttore e seguire il sistema che questo ha adottato per
consentire la raccolta separata dell’apparecchiatura
giunta a fine vita.
L’adeguata raccolta differenziata per l’avvio successivo dell’apparecchiatura dismessa al riciclaggio,
al trattamento e allo smaltimento ambientalmente
compatibile contribuisce ad evitare possibili effetti
negativi sull’ambiente e sulla salute e favorisce il reimpiego e/o riciclo dei materiali di cui è composta
Lo smaltimento abusivo del prodotto da parte del
detentore comporta l’applicazione delle sanzioni amministrative previste dalla normativa vigente.
Iscrizione al Registro A.E.E. n. IT09100000006319
••Ethersound® interface enable the connection
of the MRK950EX on a Ethersound® network for
multichannel digital audio distribution on a single
cat.5 Ethernet compatible cable.
Needs DSP audio board installed.
Two RJ45 connectors for input and output
data lines
The MRK 950 Receiver System complies with
ETSI ETS 300 422.
Pag. 18
Subject to Change without notice
high performances microphone system
Pag. 19
Printed in Italy - MRK950 r1.0.5ex - 27 July, 2010 1:31 PM
WISYCOM srl reserves the right to make changes at any time and without prior notice
Via Spin, 156 • I-36060 Romano d’Ezzelino • Italy
Tel. +39-0424-382605 • Fax +39-0424-382733 • e-mail:sales @
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