18/07/2022
ZHC HAS DEVELOPED THE COMPACT STRUCTURE OF 1KW DIGITAL TV TRANSMITTER.
Model: ZHC518D-1000W/C3
High reliability, smaller size, smaller weight, easy to transport and cost effective.
Features:
● Adopt the built-in brand-new FPGA+DDS technology structure digital TV
excitation board, which has superior performance, high reliability and good
consistency. It fully supports all working modes covered by various standards of
digital TV, supports single/multi-frequency network mode and supports
multi-carrier and single-carrier at the same time.
● Support linear nonlinear self-adaptive correction pre-distortion function,
advanced self-adaptive algorithm, call corresponding correction curve according to
communication interface command, specially optimized for multi-integrated
high-efficiency power amplifier, the correction effect is excellent.
●The optional digital TV excitation board supports built-in GPS module, 2-way IP
input, supports full-duplex, simultaneous bi-directional transmission of a single
network port, supports automatic switching of four-way input signals, mutual
backup, and supports effective simultaneous access to all input streams The ability
to detect the code rate. When the effective bit rate of the main channel is lower than
the threshold, it will automatically switch to the next channel with an effective bit
rate higher than the threshold for broadcasting, and an alarm will be issued. The
switching time is less than 1 second; If the effective bit rate of the channel does not
reach the threshold value, keep the original main channel broadcast without
switching, and issue an alarm; when the bit rate of a channel is lower than the
threshold value (can be set), an alarm message is issued; no stream input , the RF
power output of the excitation board is normal.
●Support transmitter output signal monitoring, the RF index MER monitoring
accuracy output by the transmitter is not less than 40db, the shoulder monitoring
accuracy is not less than 50db, and the error is not more than 2db.
●Adopting the modular design concept, it is convenient for long-term maintenance
and upgrading, and improves reliability
●Perfect protection measures to reduce equipment damage. With no code flow,
excessive standing wave ratio, over power, over voltage, over current, over
temperature protection functions and lightning protection measures at the whole
machine and component level.
●With MLC and ALC control functions, power control adopts closed-loop automatic
gain control to ensure stable output power without drift. The switch machine has no
impact pulse and power output ramp-up function, which better protects the
transmitter.
●The power amplifier unit consists of a 1000W power amplifier that can work
independently, installed in a 4U high 19-inch standard chassis, and is composed of
eight identical 180W multi-integrated power amplifier modules for low-loss and
high-isolation in-phase synthesis with a maximum output of 1200W power. Large
redundancy and high reliability.
●The power amplifier module uses the latest high-gain anti-high standing wave
ratio LDMOS tube, the single-tube multi-combination efficiency is up to 50%, and
the output matching adopts the micro-band impedance transformation technology,
which is simple, efficient, and consistent, and is convenient for maintenance and
replacement.
●The power amplifier radiator adopts the patented thermal simulation design tooth
shape, which has small wind resistance and large heat dissipation area. With the
large-area copper substrate of the power amplifier module, the heat conduction
efficiency is high, reducing the temperature of the die and greatly improving the
reliability of the long-term operation of the power amplifier tube.
●The whole machine is equipped with RS232/RS485, IP and other communication
interfaces, supports Web network management, and has intelligent network
management and monitoring. The working parameters of the whole machine are
detected in real time. The perfect computer control software has self-diagnosis
function and various monitoring and alarm functions. Various technical parameters
can be read and set through the liquid crystal display on the front panel.
● Adopt 96% high-efficiency modular hot-swap switching power supply, with
over-voltage, over-current, under-voltage, over-temperature, short circuit,
lightning protection and other protection measures, wide range of AC input voltage,
strong ability to adapt to external power changes.
●Using six imported high-quality, long-life, high-volume axial flow fans, with large
air volume redundancy, compact transmitter structure and beautiful appearance,
ensuring the normal operation of the whole machine.
Technical Specifications：
The technical specifications meets the requirements of GB/T 28435-2012
Technical Requirements and Measurement Methods for Terrestrial Digital
TV Broadcasting Transmitters, SJ/T 11574-2016 General Specifications
for Digital TV Terrestrial Broadcasting Transmitters and GY/T 229.4-2008
Terrestrial Digital TV Technical Requirements and Measurement Methods
for Broadcasting Transmitters.
1. Working frequency band: 470~700MHz (frequency can be set arbitrarily)
2. Output power: 1000W (maximum 1200W)
3. Machine efficiency: ≥35% (1200W≥40%)
4. Output impedance: 50Ω
5. Allowable reflection loss of working load: ≥20dB
6. Useless emission: Inside the adjacent channel ≤-50dB
Outside the adjacent channel ≤-60dB
7. In-band unevenness:
