OMB EM 100 DIG User manual

TECHNICAL MANUAL
v1.2 November 2005
SISTEMAS ELECTRONICOS S.A.
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FM MB BA AN ND DI II I
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EM M1 10 00 0D DI IG G
OMB EUROPE:
Factory: Camino de los Albares,14 -Tlf. 976.50.35.80, Fax: [phone] – 50410 CUARTE DE HUERVA (Zaragoza) ESPAÑA
Sales Dpt.: Avda. San Antonio,41– Tlf. 976.50.46.96, Fax: [phone] – 50410 CUARTE DE HUERVA (Zaragoza) ESPAÑA
E-mail: [email protected]
Web: www.omb.es
OMB USA:
3100 NW 72nd. Avenue Unit 112 – MIAMI, Florida 33122 – Ph.: 305 477-0973, 305 477-0974, Fax: [phone]
E-mail: [email protected]
Web: www.omb.com

LIMITED WARRANTY
About Installation_____________________________________________________________
1. - Mains Voltage must be kept between ±10% about its nominal value, unless otherwise
specified. If were variations exceeding this tolerance, it will be indispensable to install a voltage
stabilizer system within station. If transient overvoltages, due to electric motors, or other devices
of this sort connected to the distribution line, were present, or if the distribution line is exposed
to atmospheric electrical discharges, it must be indispensable the installation of isolation
transformers and gaseous dischargers before connecting any equipment within station.
2. - All equipments must be connected to station ground system in order to avoid damage
both to equipments and maintenance personnel too. It is necessary to connect a differential
automatic switch (lifesaver) at station.
3. - Some equipments does not include interlock protection for open doors, covers or
connectors. In that case, these equipments must be kept in key –locked places, with access
only to conveniently qualified personnel that is previously noticed about not to open doors,
covers or connectors without disconnecting station mains switch before performing this job.
4. - Transmitter equipments NEVER will be operated with output powers over its nominal values,
or with signals or input informations others than those specified in its individual characteristics.
5. - Ambient temperature inside equipments' room, will accomplish technical specifications of
equipments installed at station lodge. In absence of such specifications, maximum allowable
temperatures will be from -5 to + 45ºC for Television equipments, and from 0 to + 40ºC for
Sound Broadcast equipments.
6. - In case of operation at abnormally high or extremely high temperatures (over 30 to 40 º
C), it is obligatory to install a forced cooling system that will keep temperature below its upper
limit. In case of operation at abnormally or extremely low temperatures, it will be obligatory to
install a thermostatic controlled heating system for equipment's room.
7. - Both equipment's surroundings and room must be free of dust and dirt. Ambient relative
humidity will be kept below equipment's extreme specifications. In case of absence of this
specification, allowable maximum will be 90 % of relative humidity, non-condensing. Average
relative humidity will be kept under 70%, non-condensing.
8. - Every transmission equipment that can radiate some quantity of RF power, must be
connected to a load or antenna system, suited to its individual specifications , before being
energized.
9. - Maximum allowable VSWR in antenna systems both for Television or FM Radio Broadcast
operation of a given transmitter, will be 1.25:1, unless otherwise specified.
10.- For those transmitter equipments having power valve amplifiers, and that doesn't has an
automatic shutoff cycle, and must be manually turned off, as a first step high voltage, or
anode voltage, will be disconnected, keeping forced cooling system working during at least 5
minutes after high voltage disconnection, and only after this time, cooling system & filament
voltage can be shutted off. O.M.B. Sistemas Electrónicos, S.A., is not responsible of damages
to those power valves caused by sudden AC mains failures at station where our equipments
are installed.
11.- Periodically, monthly as a maximum, technical personnel must visit station in order to
perform a general equipment maintenance, unless otherwise specified. This maintenance will
include output power check, VSWR of antenna systems, forced cooling or heating systems

checks, both for equipments and station itself, including air filters cleaning, measuring of
transmission frequency with eventual correction if necessary, and will perform a general check
of fundamental parameters of equipments. In the event of any important change in some
operation parameter, that will require replacement or readjustment of any unit, Customer
MUST CONTACT FIRST WITH O.M.B. SISTEMAS ELECTRONICOS, S.A. BEFORE ANY ATTEMPT TO
READJUST OR REPLACE ANY COMPONENT OR UNIT INSIDE EQUIPMENTS, IN ORDER TO KEEP
VALID THIS WARRANTY.
12.- For equipments who are located in fixed racks or cabinets, those equipments must be
effectively connected, according to International Installations Standards, to station ground
system, whose total impedance measured to ground can't be higher than 5 ohms.
Equipments must be connected to ground system so that they can be kept out of main
discharge path between tower and ground.
About Transportation___________________________________________________________
1. - O.M.B. Sistemas Electrónicos, S.A. is not responsible of damages and/or detriments derived
from mishandling, steal, robbery, theft or vandalism during the act of transportation of
equipments to final or intermediate destination.
About Storage________________________________________________________________
1. - O.M.B. Sistemas Electrónicos, S.A. is not responsible of damages and/or detriments derived
from unappropiate storage of equipments, within inadequate warehouses or outdoors, once
equipments are delivered to transportist agency.
About Projects________________________________________________________________
1.- O.M.B. Sistemas Electronicos, S.A. is not responsible of inadequate use of equipments
made or registered by our Company, accomplishing propagation projects that are not
performed by our Specialists.
About Systems________________________________________________________________
1.- O.M.B. Sistemas Electrónicos, S.A. is not responsible for performance of those equipments
or systems that are not made, certified or registered by our Company.
About Operation______________________________________________________________
1.- O.M.B. Sistemas Electrónicos, S.A. is not responsible of damages and/or detriments derived
from inadequate or negligent operation of equipments made, certified or registered by our
Company, once those equipments are operated by personnel hired and/or employed by
Customer.
General______________________________________________________________________
This Warranty covers and protects, during a period of 18 months after start of operations, all
equipments made , certified or registered by O.M.B. Sistemas Electrónicos, S.A., including its
components and units, against failures in workmanship that may occur during operation of
those equipments, with the exception of power valves or semiconductor devices that are
covered by its particular Factory's Guarantee. In this case, O.M.B. Sistemas Electrónicos, S.A.
only can act as intermediary for negotiation with such Factory, about accomplishment of
individual Guarantees.

For Validity of this Warranty, it is indispensable that all Paragraphs be respected by the
Customer. Otherwise, this Warranty will be automatically voided. This Warranty is self-activated
with the reception by OMB Sistemas Electrónicos, S.A. of the "Guarantee Activation Manual"
returned to OMB by Customer. If such Document is not received, this Warranty will be
voided.
All repairings or adjustments covered by this Warranty are free of workmanship & materials
costs and expenses, but postage and transportation expenses of equipments and O.M.B.
technical personnel & specialists, if required, will be carried out by the Customer.
O.M.B. Sistemas Electrónicos, S.A.

FM Transmitter
Sistemas Electrónicos S.A EM 100 DIG
Technical Manual - v1.2 - November 2005 1
LIST OF CONTENTS
SECTION 0. GENERAL RECOMMENDATIONS 2
Gives information on safety procedures and good practices to use the equipment.
SECTION 1. GENERAL DESCRIPTION 6
Introduction to the manual, technical specifications and description of the equipment’s features.
SECTION 2. INSTALLATION, OPERATION AND MAINTENANCE 13
Basic instructions for a correct installation, maintenance and equipment’s operation.
SECTION 3. TECHNICAL INFORMATION 32
Technical information about the modules including schematics and layouts.

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Sistemas Electrónicos S.A EM 100 DIG
Technical Manual - v1.2 - November 2005 3
GENERAL SAFETY RECOMMENDATIONS
When connecting the equipment to the Mains power, please follow these important
recommendations:
This product is intended to operate from a power source that will not apply more than 10% of
the voltage specified on the rear panel between the supply conductors or between either supply
conductor and ground. A protective-ground connection by means of the grounding conductor
in the power cord is essential for a safe operation.
This equipment is also grounded through the grounding conductor of the power cord. To avoid
electrical shock, plug the power cord into a properly wired socket before connecting to the
product input or output terminals.
Upon loss of the protective-ground connection, all accessible conductive parts (including parts
that may appear to be insulated) can render an electric shock. Equipment must be connected
to station's ground system before any attempt to connect it to Mains electrical supply.
To avoid fire hazard, use only fuses of the type, voltage rating, and current rating specified in
this manual. For fuse replacement, always refer to User’s Manual.
To avoid explosion, do not operate this equipment in an explosive atmosphere.
To avoid personal injury, do not remove the product covers or panels. Do not operate the
product without the covers and panels properly installed.
GOOD PRACTICES
During the maintenance of the equipment covered in this Manual, please keep in mind the
following standard good practices:
When connecting any instrument (wattmeter, spectrum analyzer, etc.) to a high frequency output,
use the appropriate attenuator or dummy load to protect the final amplifiers and the instrument
input.
When inserting or removing printed circuit boards (PCBs), cable connectors, or fuses, always turn off
power from the affected part of the equipment. After power is removed, allow sufficient time for the
capacitors to bleed down before reinserting PCBs. Always use discharge stick when available.
When troubleshooting, remember that FETs and other metal-oxide-semiconductor (MOS) devices
may appear defective because of leakage between traces or component leads on the printed
circuit board. Clean the printed circuit board and recheck the MOS device before assuming it is
defective.
When replacing MOS devices, follow standard practices to avoid damage caused by static
charges and soldering.
When removing components from PCBs (particularly ICs), use care to avoid damaging PCB traces.

FM Transmitter
Sistemas Electrónicos S.A EM 100 DIG
Technical Manual - v1.2 - November 2005 4
FIRST AID IN CASE OF ELECTRICAL SHOCK
If someone seems unable to free himself while receiving an electric shock, turn power off before
rendering aid. A muscular spasm or unconsciousness can make a victim unable to free himself from
the electrical power.
If power cannot be turned off immediately, very carefully loop a length of dry non-conducting
material (such as a rope, insulating material, or clothing) around the victim and pull him free of the
power. Carefully avoid touching him or his clothing until free of power.
EMERGENCY RESUSCITATION TECHNIQUE
Step 1
Check the victim for unresponsiveness. If there is no response, immediately call
for medical assistance, and then return to the person.
Step 2
Position the person flat on their back. Kneel by their side and place one hand
on the forehead and the other under the chin. Tilt the head back and lift the
chin until teeth almost touch. Look and listen for breathing.
Step 3
If not breathing normally, pinch the nose and cover the mouth with yours. Give
two full breaths. The person's chest will rise if you are giving enough air.
DO NOT TOUCH VICTIM OR HIS CLOTHING
BEFORE POWER IS DISCONNECTED OR YOU
CAN ALSO BECOME A SHOCK VICTIM

FM Transmitter
Sistemas Electrónicos S.A EM 100 DIG
Technical Manual - v1.2 - November 2005 5
Step 4
Put the fingertips of your hand on the Adam's apple, slide them into the groove
next to the windpipe. Feel for a pulse. If you can not feel a pulse or are unsure,
move on to the next step.
Step 5
Position your hands in the center of the chest between the nipples. Place one
hand on top of the other.
Step 6
Push down firmly two inches. Push on chest 15 times.
CONTINUE WITH 2 BREATHS AND 15 PUMPS UNTIL HELP ARRIVES.
TREATMENT FOR BURNS
Continue treating victim for electrical shock.
Check for points of entry and exit of current.
Cover burned surface with a clean dressing.
Remove all clothing from the injured area, but cut around any clothing that adheres to the skin
and leave it in place. Keep the patient covered, except the injured part, since there is a tendency to
chill.
Splint all fractures. (Violent muscle contractions caused by the electricity may result in fractures.)
Never allow burned surfaces to be in contact with each other, such as: areas between the fingers
or toes, the ears and the side of the head, the undersurface of the arm and the chest wall, the folds
of the groin, and similar places.
Transport the victim as soon as possible to a medical facility.

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CONTENTS :
1.1 Introduction . . . . . . . . . . . . . . . . . 7
1.2 General description . . . . . . . . . . . . 7
1.3 Description of panels . . . . . . . . . . . . 9
1.4 Technical specifications . . . . . . . . . . 12

FM Transmitter
Sistemas Electrónicos S.A EM 100 DIG
Technical Manual - v1.2 - November 2005 7
1.1 Introduction.
The OMB EM-100 DIG series transmitters are the result of experience adquired by OMB during years of
producing FM broadcast equipment, transmitters, STL and stereo encoders. These transmitters were
specifically designed to comply with the latest international standards and the requirements of
advanced broadcasters, meeting tighter specifications than usually required,at an affordable cost.
Great care went into producing a HI-FI-quality modulated signal, with low residual noise and
distortion.The RF signal is also free from spurious and harmonic components to a higher degree than
required by CCIR, European, USA and most other national standards.To obtain this outstanding
performance, OMB strongly recommend to rely on qualified personnel to install and verify the
equipment which makes up the radio station, i.e.the transmitter, the possible STL and power amplifier,
the corresponding antennas,cables and connectors.This will assure to achieve the best performance
and stability in time. To this aim, OMB especially recommend that their equipment should not be
tampered with by unskilled personnel and its after-sale service is available to customers for any
technical problem. Before proceeding to installation, please carefully read at least the general
installation part of this manual, to gain confidence with the equipment.
The EM-100 DIG transmitters are very stable and changes to the internal pre-setting other than
frequency and few other options are not usually required but, if they are, once again they must be
done by skilled personnel, fitted with proper instrumentation and service documentation. Improperly
tampering with the settings may harm the apparatus or jeopardize the guaranteed performance.
THIS EQUIPMENT COMPLIES WITH ALL RELEVANT EMI /EMC AND SAFETY REQUIREMENTS, ETSI EN300384,
ETS300447 AND EN60215 STANDARDS.
NO INTERNAL ADJUSTMENT OR PRESETTING IS REQUIRED DURING NORMAL OPERATION.EQUIPMENT SHALL
BE PROPERLY GROUNDED AND BE OPERATED WITH ALL THE COVERS CLOSED TO PREVENT ELECTRICAL
HAZARDS AND COMPLY WITH EMC STANDARDS.
A good installation,made by skilled and trained personnel will avoid many future troubles during
station's exploitation process. All the operations described in the Certification of Limited Warranty must
be accomplished to have the right of make any claim concerning this Warranty,having free
equipment service by OMB's technical personnel during this first exploitaition phase of Equipment.
1.2 General description.
The EM-100 DIG is a 100W rated, direct-synthesis, FM-modulated transmitter. Being digitally
controlled, it is extensively put on the air on field by front panel or remotely in additional aspects:
frequency, power, channel sensitivity, preemphasis, functioning mode (mono, stereo, external mpx),
clock and date and many other parameters without adjusting or substituting any part. A powerful
3-level password management permits a very high degree of security and privacy as may be
required in different situations. Equipment requires little o no maintenance and its simple modular
layout facilitates stage testing and servicing.

FM Transmitter
Sistemas Electrónicos S.A EM 100 DIG
Technical Manual - v1.2 - November 2005 8
Figure 1-1: EM-100 DIG DIGITALLY-CONTROLLED F.M. TRANSMITTER.
As imposed by various national standards, these transmitters incorporate sophisticated low-pass
audio filters on mono and stereo channels,and a sharp acting modulation limiter, which is usually set
at a peak deviation slightly higher than 75kHz. Its intervention may nevertheless be avoided,if
required,pre-setting its threshold at a deviation higher than 150kHz. Output frequency is phase-locked
to a temperature-compensated crystal oscillator,which ensures superior precision and stability. A
very low noise,low distortion VCO produces a harmonic-free,spurious-free signal. A lock control circuit
inhibits the presence of power on the output until the apparatus is on the right frequency,when
turning on.
To reach a further lowering of noise threshold, the low-frequency inputs are fitted with balanced input
circuitry.The input level is precisely adjustable over a broad range,by means of a 0.5dB stepwise
variable attenuators.The transmitter has an auxiliary input,specifically designed for RDS and SCA
encoders. A modulation sample output permits to control other transmitters or STL's with the same
internally processed high-quality mpx signal.
The alphanumeric display permits easy and accurate metering,adjustment and continuous
monitoring of modulation levels,power,operation and internal parameters.All these information may
be externally available on the same RS-232 I/O bus that may be used to remotely control the
transmitter.
Above Figure 1-1 shows us the external view of Transmitter's cabinet,whose control panel has been
simplified to a maximum, being Microcontroller in charge of practically to select and make all
tests and adjustments of all parameters that are relevant to the normal Equipment's performance.
Due to this fact, Front Panel has only a few control elements, since with only the four push buttons
pertaining to Microcontroller (like those used to control movement of cursor in a Computer) and two
keys, these virtually controlling all processes & parameters having place within Equipment.
Microcontroller uses a Liquid-Crystal dot matrix as Alphanumeric Display unit in order to watch
parameter's values, as it's asked for it, as can be seen in the corresponding Chapter in this Manual.
In addition to the serial I/O port, some signals (RF power, ON THE AIR status, Disable line) are available
on a parallel I/O remote socket for easy interfacing with others analog controllers or supervisory
systems. A top-quality stereo encoder may be factory installed as option and even retrofitted in the
field in a second time, requiring minimum technical skill. The powerful internal software and
monitoring functions recognizes its presence and enables its functions.
The RF power amplifier employs a broadband design and has a lot of of reserve: the output power is
feedback-controlled for increased stability still higher than nominal level. High reflected power is
limited to prevent output stage degradation;direct power is accordingly continuously reduced so as
not to exceed the reflected power safety level. A sturdy telecom-grade high efficiency switch-mode
power supply allows operation in a very wide and noisy mains environment.

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Sistemas Electrónicos S.A EM 100 DIG
Technical Manual - v1.2 - November 2005 9
1.3 Description of panels.
The EM-100 DIG Front Panel is very clean and easy to control. The wide alphanumeric display and
the control keyboard allows a simple self-explanatory menu-driven navigation through the various
options. A great care was taken in the design of the software to allow natural feeling with the controls
to allow operation and programming in every respect of the Equipment without needing to
extensively read this manual. The password management hides some functions and prevents
tampering with the most critical options and data to unauthorized people.
Figure 1-2 shows the simple Equipment's Front Panel, indicating all supervision & control elements:
Figure 1- 2: Transmitter Front Panel.
These supervision &control elements are numbered in Figure 1-2 as follows:
1- STANDBY condition indicator LED.
2- Twin-row Alphanumeric dot-matrix LCD display, working directly with Microcontroller unit.
3- Programming & parameter selection keyboard:
White keyboard to scroll and navigate through the different menus and options.
OK key (blue). Enter key to confirm some order or command.
CANCEL key (orange). Escape key to cancel menu or command.
4- ON/STBY switch. This ON/STANDBY key do not power off equipment, which is still locked on
frequency and ready to transmit as soon the key is pushed or a remote command is sent.
5- ALARM LEDs PANEL:
Alarm red LED lights on in event of any equipment's alarm condition.
VSWR red LED lights on showing that RF output circuit is overloaded by a severe high VSWR
condition.
Limiter red LED lights on showing too high audio signal level at equipment's input,and
subsequent operation of baseband peak clipper.
6- DISPLAY CONTRAST potentiometer, to adjust LCD screen backlighting to a comfortable contrast
level in order to get easy readings.

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Sistemas Electrónicos S.A EM 100 DIG
Technical Manual - v1.2 - November 2005 10
7- OPERATION LEDs PANEL:
Remote amber LED shows remote-controlled operation is being carried on.
Lock green LED shows when Channel Oscillator's PLL is properly locked,some tenths of
second after equipment is turned on.
On the air green LED works together with STANDBY (2) yellow LED. It lights on when equipment
is in normal operating condition, whereas STANDBY (2) LED is turned off, and vice versa.
All transmitter inputs and outputs are allocated on the rear panel.They are:
The audio channels input sockets on balanced female XLR - type connectors ( Left & Right).
The wide-band externally processed / stereo composite signal input on a grounded
unbalanced BNC female connector.
The low - frequency limited (20kHz ~100kHz) auxiliary channel input on a grounded,
unbalanced BNC female connector.
The LF MONITOR output for monitoring, RDS external synchronization or re-broadcasting purpose,
BNC-type female connector.
The inverted wired RS-232, DB9 female remote serial control port.
The parallel REMOTE control port, DB9 male type.
The RF antenna output, N-type, female connector.
The RF sample output for frequency measuring or RF signal monitoring, BNC female type
connector (-50 dBc level).
Figure 1-3 below shows Equipment's Rear Panel indicating all connectors and elements.

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Sistemas Electrónicos S.A EM 100 DIG
Technical Manual - v1.2 - November 2005 11
Figure 1- 3: EM-100 DIG Back panel.
1- Mains IEC ON/OFF switch,mains voltage selector,socket & fuses block (depending on Power
Supply used).
Please note that, in case of using Power Transformers' Supplies having taps, the transmitter is normally
factory pre-set for 220-240VAC nominal Mains voltage as a security factor.
2- Main Power Supply's hot air exhaust from internal cooling blower (depending on Power Supply
used).
3- RF Power Module's hot air exhaust from cooling fan.
4-Output RF connector. Type "N" female.
5- Remote operation DB-9 male connector, whose connections are the following:
6- RS-232 serial interface connector. This RS-232 port manages only Tx,Rx and Return data
signals, with no handshake.Being the two former wired signals inverted to the port,it needs a simple
straight wired serial cable with appropriate connectors: usually a female DB-9 or DB-25 to the
PC port and a male DB-9 connector at the transmitter end. Appropriate OMB software is required
for communication.
WARNING:Do not connect the serial cable with neither transmitter nor PC turned on.
7- RF sample output for frequency measuring or RF signal monitoring, BNC female type
connector ( -50dBc).
8- Right & left channels audio input XLR balanced female connector.For using internal stereo
coder. (See equipment's rear panel for pin connections).
9- MPX input connector.Type BNC female.For use in pre-coded stereo multiplex signal input. Flat
response from 10Hz to 100KHz to feed stereo multiplex signal. Hi - Z unbalanced input (10K:).
10 - AUX connector. Unbalanced Hi-Z BNC female connector,to feed a RDS or SCA coder output
signal.
11 - LF MONITOR output connector. Baseband modulation output for monitoring, re-broadcasting or
RDS external synchronization. BNC female type, unbalanced Hi-Z (10K:).

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Sistemas Electrónicos S.A EM 100 DIG
Technical Manual - v1.2 - November 2005 12
1.4 Technical specifications.
SIGNAL TO NOISE RATIO Monaural
>78dB. typical 86dB from 30 to 20,000Hz.
Stereophonic
>72dB. typical 77dB from 30 to 20,000Hz.
CCIR WEIGHTED S/N Monaural
>75dB. typical 81dB
Stereophonic
>68dB. typical 77dB
HARMONIC DISTORTION1For ± 75KHz dev:
<0.05%. typical 0.02%
For ±150KHz dev:
<0.2%. typical 0.05%
STEREO CROSSTALK w/External Encoder: <-50dB
w/Internal Encoder.From 100 to 5000Hz: <-60dB
w/Internal Encoder.From 30 to 15000Hz: <-50dB
PROGRAM AUDIO CHANNEL FREQUENCY RESPONSE
FROM 30 TO 15000 HZ
± 0.1dB
ATTENUATION AT AUDIO FILTER REJECTION BAND (F
=19KHZ)
>50dB
DEVIATION LIMITER THRESHOLD Adjust.between 0 and +7dBm
STEREO MULTIPLEX INPUT FREQUENCY RESPONSE.
FROM 10HZ TO 100KHZ
±0.1dB
AUXILIARY INPUT FREQUENCY RESPONSE .
FROM 10 TO 100KHZ
±0.2dB
MAINS SUPPLY REQUIREMENTS 115 /230VAC ± 15%.50/60Hz
POWER CONSUMPTION AT 250 WATTS RF OUTPUT LEVEL 250VA / 200W
OPERATING TEMPERATURES RANGE 0 ~+35ºC recomm.
-10 ~ +45º C max.
MOUNTING DIMENSIONS (W/O HANDLES) Width:19" height: 5 1/8".Standard 19" Rack.
DIMENSIONS 483 mm width x 125 mm height x 334 mm depth.
MODULATION Frequency, ± 75KHz. peak dev.
MODULATION CLASS F3E, F8E.
OSCILLATOR'S SYNTHESIS STEPS 10 /100KHz
FREQUENCY ERROR <±200Hz
FREQUENCY DRIFT <250Hz over temperature <100Hz/year.
RF OUTPUT POWER adjustable between 2 and 100Wrms. nominal.
MAXIMUM ALLOWABLE REFLECTED RF POWER 10W
RF HARMONIC PRODUCTS < -70dBc
RF SPURIOUS PRODUCTS <-80dBc. typical -95 dBc.
RF OUTPUT IMPEDANCE 50:unbalanced.N Female connector.
AUDIO /MULTIPLEX INPUT LEVEL Adjustable between -3.5 and +12.5dBm for ±75KHz
peak dev.
AUDIO /MULTIPLEX INPUT IMPEDANCE Select. 10K:/600:,bal./unbal.
COMMON MODE INPUT REJECTION FROM 20 TO
15000HZ
>50 dB.typical >60dB
AUDIO INPUT CONNECTORS XLR Female balanced
SCA/RDS CHANNEL INPUT LEVEL ±7.5KHz dev. Adjust. between -12.5 and +3.5dBm
±2.0KHz dev. adjustable between -24 and -8dBm
SCA/RDS CHANNEL INPUT IMPEDANCE 10 K:unbal.BNC Female conn.
MODULATION OUTPUT LEVEL 0 to +10dBm at ±75KHz peak dev.
PRE-EMPHASIS TIME CONSTANT Variable 0 /50 /75µsec.± 2%.
1: Limiter set to 150KHz deviation threshold.

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Sistemas Electrónicos S.A EM 100 DIG
Technical Manual - v1.2 - November 2005 13
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CONTENTS :
2.1 Introduction. . . . . . . . . . . . . . . . . . . 14
2.2 System connection . . . . . . . . . . . . . . . 14
2.3 Audio Base band connections and presets. . . 15
2.4 Operation. . . . . . . . . . . . . . . . . . . . 19
2.5 Commands and programming. . . . . . . . . 21
2.6 Service and maintenance. . . . . . . . . . . . 31

FM Transmitter
Sistemas Electrónicos S.A EM 100 DIG
Technical Manual - v1.2 - November 2005 14
2.1 Introduction.
Before proceeding further, make sure that mains voltage corresponds to the factory-set value (usually
220/240VAC). In case it differs, change to the proper value. Install the transmitter in a dry, ventilated
and possibly dust-free environment, so that it will operate in the +10 ~+35°C temperature range.
Connect the Transmitter to the load and audio source using suitable cables and connectors, which
should be periodically inspected.
The EM-100 DIG has many features of a hi-fi Transmitter and should be installed and audio-wired with
the same care, avoiding earth loops as much as possible. When these conditions are met,the
transmitter performs superbly.
This Transmitter is adequately shielded and can be installed close to the program Studios without fear
that it will affect the audio equipment.This arrangement has the advantage that the audio
level,deviation and power parameters can be continually monitored. EM-100 DIG can also be
installed away from the studio and connected with several meters of LF coaxial cables with no
adverse effect on modulation quality. A remote installation usually requires a STL (Studio to
Transmitter Link).
As the final modulation performance is dependent on the whole system arrangement, carefully
consider the whole system planning.
2.2 System connection.
1 - Connect the N-type output connector, marked “RF OUT ” to the antenna or RF Power Amplifier with
low-loss 50:coaxial cable, tested to 500W of peak-power rating in the frequency range used.
Andrew LDF4 or 1/2" Cellflex line can be used in some short hops.
2 - Connect the audio inputs as required for operation and detailed in the following chapters for
various situations. If needed, connect the serial and / or parallel remote control I/O ports as
required, or jump this step to a subse-quent moment.
3 - Switch-off the mains rear switch and connect the transmitter to mains and ground system.
4 - Before turning on Transmitter in the system, pre-set if possible frequency and power separately on
a dummy load, to avoid system problems at the first turn-on of the equipment. If this cannot be
done, check that the transmitter's maximum output power (100W)) does not harm any external
supplementary amplifier stage (if any).
5 - Turn-on the rear panel mains switch, then push-on the front panel on/stand-by switch to operate
the transmitter and check that:
-All LEDs and the display briefly lights on and off for the initial check.
-The yellow <STAND-BY> LED turns off.
-The green “<LOCK> LED must light up after a very short time,when frequency is locked at PLL.
Once locked, the RF power will rapidly increase to the pre-set level in a mild increasing mode. Once
preset power is reached, the <ON THE AIR> LED will light completely, if the power is set >5W (at least
5.1W). Till that moment it will turn off and on, signalling the RF power is present but not correct.
Equipment is now functioning in the pre-set mode, delivers power and can be accessed to be
programmed or simply to monitor its functions with the front panel display.

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Sistemas Electrónicos S.A EM 100 DIG
Technical Manual - v1.2 - November 2005 15
The first request it will do will be entering the password for the required level of
authorization/security.The equipment is factory pre-set with the first 2 passwords levels disabled: this
will allow to set most of the operating parameters, including power, frequency, input levels, clock
and date. Some more critical parameters it will require the upper 3rd level: be sure to know it if you
need this access.
EM-100 DIG WILL ALWAYS TURN-ON IN THE SAME STATE AS IT WAS IN THE LAST TIME IT WAS TURNED OFF
FROM MAINS,I.E.POWER,FREQUENCY AND EVEN ON OR STAND-BY CONDITION. AS SOON YOU TURN
ON THE REAR PANEL MAINS SWITCH BE PROMPT TO THAT, EVEN WHEN JUST FACTORY DELIVERED.
6 - The first task to manage when turning on the equipment as factory delivered is to set-up the
passwords. At least the 3rd (the highest) level must be immediately changed: because, if any
unauthorized people change it or you lose it, there is no way to change it for security reasons and the
equipment may become unmanageable.
Gaining again access to the equipment will require factory reprogramming or changing of the
internal Microcontroller unit.
For this reason be sure to write down and keep it immediately in a secure place:there is no way to
read it after you have programmed down and confirmed.
For practically any parameters that may require some setting in the field, the 2nd level password is
enough and may be used for any standard service requirement . The main purpose of the
existence of the 3rd level is a security assurance for the user if he loses control on the lower password
levels.
7 - If not already done,adjust frequency and RF power as required and check reflected power on the
transmitter's display.
To this aim search for RF power menu and read the corresponding value of direct and reflected
output power.
For proper operation, the reflected power reading should typically be less than 10% of the direct
power value, (<10W max). Any higher reading may indicate that the antenna is not properly
connected or the following amplifier input needs to be tuned.
8 - Check and/or set clock and data and all transmission parameters as required, i.e.channel
sensitivity and deviation, mono/stereo, preemphasis etc. Refer to the appropriate section of the
Manual.
2.3 Audio Base band connections and presets.
2.3.1 Baseband Connection & Wiring and Impedance
Selection.
EM-100 DIG supports balanced or unbalanced signals with selectable input impedance.
The audio inputs are basically balanced and have selectable 600/10k:resistive impedance, factory
pre-set at 10k:.They can be connected to the balanced output of a professional mixer console or to
the unbalanced one of a cheaper unit without appreciable degradation.
Audio mono or stereo channels inputs are XLR female connectors.They should be connected to the
output of the mixer console, or of any audio processor that drives it, by a balanced coaxial cable

FM Transmitter
Sistemas Electrónicos S.A EM 100 DIG
Technical Manual - v1.2 - November 2005 16
connected to pin 3 (+) and pin 2 (-). The cable shield, connected to the ground of the driving
equipment,has to be connected to pin 1.
In case of unbalanced drive, input pin 2 shall be short-circuited with ground and shield on pin 1,
while the signal shall be available on pin 3. Higher impedance selection, in this case, will be 5k:
instead of 10k:.
With balanced driving signals,the connecting cables to the audio source may be well more than
100-m long.
MPX or an externally processed signal, usually an unbalanced signal, can be fed to the female BNC
connector, marked <MPX>, which is internally parallel-wired with the <RIGHT> channel
connector:for this reason it is not possible to connect signals to these two connectors at the same
time. Higher impedance position is 5k:in this case too.
Connect this input with a 50-:(RG58) cable for a short distance; if the distance exceeds several tens
of meters, use 75-:(RG59) or 92-:(RG62) coaxial cables.
The auxiliary-channel connector is also of the grounded BNC female type. Use 50:(RG58)or 75:
(RG59) cables to connect to the driver. The same applies to the monitor "MODULATION" output, if
needed.
2.3.2 Pre-emphasis setting.
Non-precoded low frequency mono and stereo channel signals have to be adequately pre-
emphasized. Standard preemphasis time constant is 50 and 75 µs, the former being usually factory
pre-set for Europe countries.
Check whether this is correct for your country (it is usually correct for any European country and part
of the Pacific areas). It is not correct for USA and Center & South America standards,which require 75
µs.
If above correction is needed,simply set it on the <MODE> frame of the transmitter menu, which
also includes mono/stereo operation and frequency. See appropriate section further on in this
Manual.
2.3.3 Audio Baseband Input Level Range, Setting and
Requirements.
In the following paragraph we will refer to 0dBm as the audio signal which produce 1mW on 600:,
i.e. a 775mVrms / 2200mVpp sinusoidal. Irrespective of the impedance, we will continue to assume 0
dBm as an audio signal whose peak is + (or -) 1100mV.
In the same way, when talking of the modulation, we will assume as 0dB the signal which produces
100% maximum allowed modulation, i.e . 75kHz deviation.
There is no absolute worldwide standard regarding audio peak level as modulation signal for a
transmitter, nor for the mean deviation. Many Broadcasters use 0 or +6dBm as LF peak level for
100%modulation, USA often uses +4 or +10dBm.
Many European countries specify +6dBm for 40kHz deviation (which is assumed to be a "mean"
modulation). This allows for 5.5dB headroom to max. 75kHz deviation, i.e.+11.5dBm for
100%modulation.