500W VHF LPT [1+0] TV Transmitter

Model No.: TW/VHF/500W/01

Unattended low power TV Transmission system is found effective to serve isolated and difficult areas of the country.

The System consist of Power Amplifier, Exciter, SMPS, Switch Unit, Band pass Filter, O/P Port and redundancy at Exciter can be offered optional.

Features Transmitter

Twin-12U–500(1+0) is fully solid-state design configuration to the up-to-date technology in the field of broadcasting Equipments.
The equipment is rugged in construction and easier to install at site because of single frame construction of cabinet.
Majority of circuits are designed in the form of Printed Circuit Boards and combined into functional plug-in Modules. Thus maintenance and service is easily carried out.
The transmitter adopts latest state-of-art approach of using intermediate frequency for modulating both vision and sound. This makes the equipment less complex, economical with high flexibility.
More sophisticated mixer technology used for video modulation for better video S/N.
The modulated signal output is partially protected for the group delay (which will be introduced by receiver) by positioning Front Panel Switch “RCVR PRE CORR IN” position at video processor.
Advanced designed for Vestigial Side Band (VSB) filter using Surface Acoustic Wave (SAW) designed technique is employed where minimum group delay correction is required. Also the SAW filter has steeper skirt attenuation outside the channel pass band for improved VSB response.
TV Exciter makes use of Synthesized Local Oscillator having 10 KHz step size with better FM noise where by LO frequency can be varied just by setting PCB mounted switches.
Power Amplifier has been designed to give stable power output for VHF band for continuous operation and modular so as to use part of the unit at lower power in emergency condition.
Power Amplifier having separate palletized amplifier blocks for ease maintenance.
Power Amplifier is having class-A driver for better linearity and class-AB final Power Amplifier for better efficiency with inbuilt solid-state protective circuits.
Band Pass Filter has been used to obtain clean spectrum and eliminates out of band spurious/inter-modulation products.
Class-AB Power Amplifier and Switch Mode Power Supply make the transmitter highly efficient hence more economical by cutting down the recurring expenditure in electricity bills drastically (Overall 28 % efficiency).
n Twin-12V-500(1+0) VHF 500W TV Tx provisions are kept for expansions up to 1 KW by adding additional one power Amplifier, divider and 1 KW combiner.
Remote Control System:
Works in conjunction with S/C-Band TVRO on INSAT Network.
Automatic Switching ON/OFF with the presence and absence of Video Sync in the received S-Band Satellite signal.
Transmitter ‘ON/OFF’ facility.
Redundant operation in Exciter level.
Manual/Auto mode selection of the transmitter.
Switch over from main to standby based on "ON Line testing of health of transmission".
Facility of DG ‘ON/OFF’, Air Conditioners ‘ON/OFF’, Smoke, Room Temperature Sensing etc.
Control and monitoring facility from remote place through dial-up modem.
RS232 Communication for Local PC for monitoring of different parameters of the transmitter.
Ease of operation, maintenance and installation.
Frequency range - Any one channel in Band III /Iv in a frequency range of 174 to 230 Mhz