This page provides options for new "black spot" digital television repeater sites and also upgrades to digital of existing analog television "black spot" repeater sites.

TERRESTRIAL RECEPTION

Where digital signals can be received off-air, each channel can be translated, amplified and then combined with other channels into the transmit antenna. This arrangement shown on the right is basically the same system that has been used in the past for analog television. However, digital television allows a simpler solution that is much more economical on power consumption and occupied spectrum.

This system shown on the right takes advantage of the fact that up to five standard definition television channels can be broadcast on the one 7MHz wide signal. It provides a massive improvement in energy efficiency and spectrum efficiency. At no time is the picture information converted back to analog, so picture quality is unaffected.

Listed below is equipment required to implement the system shown in Fig 2. This equipment is supplied by Fordray and is suitable for broadcast in Australia. 

COFDM to ASI Demodulator:     DALVI DC6000 DVB-T COFDM Receiver/Decoder.

MULTIPLEXER :                        DALVI DX3003 Data Stream Multiplexer.

COFDM MODULATOR:           DALVI DQ4003 DVB-T COFDM Modulator.

RF POWER AMPLIFIER           One of Fordray's range of UHF Power Amplifiers for Digital Television.

Where there is a need to upgrade an existing analog satellite rebroadcast site to digital, the arrangement on the right (Fig 3) can be used. The MPEG Encoder and  COFDM Modulator are the additional items of equipment required. The RF Power Amplifier would need to be replaced. The satellite receiving equipment need not be changed. The five audio and video signals in this arrangement are encoded into the one 7MHz digital channel.

Listed below is equipment required to implement the system shown in Fig 3. This equipment is supplied by Fordray and is suitable for broadcast in Australia. 

5 INPUT MPEG ENCODER      DALVI  DM2005

COFDM MODULATOR:           DALVI  DQ4003 DVB-T COFDM Modulator.

RF POWER AMPLIFIER           One of Fordray's range of UHF Power Amplifiers for Digital Television.

The system shown on the right (Fig 4) is the preferred system for a new broadcast site. Unlike the system shown in Fig 3, the signal is not decoded to analog and then re-encoded, thus avoiding loss of quality.

Listed below is equipment required to implement the system shown in Fig 4. This equipment is supplied by Fordray and is suitable for broadcast in Australia.

SATELLITE RECEIVER :           DALVI DS1000 Satellite receiver with ASI output.

MULTIPLEXER :                        DALVI DX3003 Data Stream Multiplexer.

COFDM MODULATOR:           DALVI DQ4003 DVB-T COFDM Modulator.

RF POWER AMPLIFIER           One of Fordray's range of UHF Power Amplifiers for Digital Television.