Transmitters TT-U/L Series Liquid-cooled transmitters
Frequency range 470MHz to 860MHz
- Advanced LDMOS technology power amplifiers
- Pre correction
- High redundancy
- Touch Screen Control Logic
- Highly compact for minimum space requirements
- Cost effective installation
- All stand-by concepts possible
- (single transmitter, active or passive
output stage stand-by, exciter stand-by).
- Web and SMS Remote Control
ITEL’s TT/TV Transmitters series is a new generation of air cooled
UHF analogue and digital TV transmitters (DVB-T/H - ATSC Ready) consisting
of the following components:
> Single Driver (Dual on request)
> Power RF Amplifiers included power supply
> Microprocessor transmitter control
> Band Pass Filter
The UHF transmitters are available for analogue TV powers from 100W to
10kW and for
DVB-T powers from 30W to 3kW rms.
As an available option, all transmitters can be equipped with a second
Driver and the associated automatic switchover unit .
Loss of input video signal.
Overloads and short-circuits.
Inefficiency of the cooling system.
Absence of mains AC (phase control).
Automatic reduction of the RF output
power in real time in case of excessive VSWR.
RF amplifier overdrive.
Serial interface IEC 864-2
Stereo (IRT – NICAM – BTSC).
Dual Mains AC input line.
Interactive control with data storage (Data can be elaborated by PC).
Thanks to the advanced LDMOS technology, the power amplifiers yields high
linearity, excellent efficiency and compact design. The two power supplies
are integrated into the amplifier module, which is an enclosed unit.
The amplifier is equipped of one cooling system composed by two fans that
are able to dissipate the heat and to maintain constant the temperatures
of the junction of the transistors around the 95°C to an environment
temperature of 25°C.
Very compact size: simplifies transportation and installation.
Modular design: increases reliability and simplifies maintenance operation.
Low operating cost. RF output obtained from the amplifiers modules in
parallel, each module with its own individual power supply to maximize
High performance linearity corrector.
Very high MTBF.
Full band coverage with broadband amplifiers requiring no adjustments.
Synthesized local oscillator with external reference input for precision
Graphic LCD Panel
Revolutionary new generation driver with graphic LCD panel for full control
Front panel instant frequency programmability, RF power settings, audio
settings, deviation controls, alarms status are only some of the main
functions available in the graphic display.
Touch Screen Control Logic
The control logic allows full remote control capability thanks to the
microprocessor on the front panel control board: power output adjustment,
deviation adjustment, general on/off, alarm reset, forward and reverse
power measure, frequency deviation measure and alarm status are the main
functions of remote control function.
The display touch screen can change the colour depending on the operation
state of the equipment. The colours are:
> Green perfect operation of the equipment
> Red generic alarm
> Orange Stand-by of the equipment
Automatic or Manual (Local or Remote)
Parallel interface according to IEC 864-1.
Serial interface RS232 or 485.
Web server – TC/IP remote control
SMS remote control
TC/IP WEB server (option) and SMS Remote Control
Full monitoring and control of the equipment via Intranet or Internet
and via SMS message. It is possible to have a complete view of the status
of the equipment periodically or on request by a direct connection with
an Internet browser or sending a SMS.
The system automatically contacts via mail (fax) or via SMS the user in
case of alarm and can repeat the call more than one time until its alarm
status is present.
Password protection present to access the system: using this password
it is possible to access all the control functions of the equipment.
Comparison between liquid and air-cooling systems in solid-state
Broadcast Radio and TV Transmitters.
The transistors of the new generation become every day more powerful having
the same dimensions and this forces the designers to adopt cooling systems
The traditional air cooling systems become insufficient with environment
temperatures >30°C and they need to be helped by expensive and
complicated systems of air conditioning.
The most reliable and less expensive solution to this problem is ITEL
Telecommunication and Broadcasting Service new generation of liquid coolers.
The main substantial differences between liquid cooling and air cooling
Longer device life .. With the liquid coolers even with
environment temperatures of 45°C
The temperature of the flange of the devices does not overcome the safety
limit of 55°C,
This increases the device’s life.
Acoustic Noise. This is very low because of the absence
of airflow inside the transmitter cabinet and above all it is possible
to install the liquid/air heat exchange elsewhere; even outside the building
as long as antifreeze is added to the cooling liquid.
The continuous presence 24/24 hours of forced air on the electric
mechanic parts causes salty deposits and corrosions that reduce
the life of the parts.
This corrosion is avoided using the liquid cooling systems.
The liquid of cooling is normal water not treated.
The hydraulic circuit is a closed type with a capacity of about
30 litres (for a 10 kW tv): thanks to this characteristic it does
not need continuous additions of water and it is only necessary
an addition of about 2 litres every 6 months.
With the liquid cooling system, an environmental temperature of up to
45°C is acceptable whereas with the air-cooling system the maximum
environmental temperature would be 30°C. The liquid cooling systems,
in fact, have a higher efficiency in the transfer of heat.
It is not necessary to install any bulky air ducts at the input as well
as at the output of the Amplifier cabinet. The air/liquid heat exchanger
can be easily placed outside the room where the transmitter is installed
and it is connected to the transmitter only with standard flexible
Radiation of heat into the environment.
In the liquid cooling system there is practically no radiation of heat
into the environment, if one takes into consideration the possibility
of installing the heat exchanger in a different place to the transmitter.
Thus the use of costly air conditioning installations is avoided.