With the advent of digital satellite television, the demand for a greater channel choice is increasing as people want alternative programming to that offered by Sky. Here, we take a look at the option of adding extra satellites to a DTH system without the expense of installing motorised equipment.

With the launch of new satellites by Astra and Eutelsat expected over the next few years, the use of triple feed systems to pick up transmissions from 28.5º east to 13º will become more common place.

As we all know, a dish is capable of picking up signals from many different satellites. By positioning three LNBs on an 80cm dish and using an extra LNB bracket, a DTH system can be easily adapted to receive transmissions from three satellite, as long as the satellites are each 6º apart (see fig 1).

The reflected signals will be weaker than the primary feed, but will still maintain significant signal strength for reliable pictures as long as they are being transmitted from a high power satellite, such as Hotbird at 13ºeast, onto an appropriately sized dish.

In order to control LNB’s, a DiSEqC switch is required along with a compatible receiver with DiSEqC software version 1.0, such as the Humax Fox Receiver.

Once the triple feed system is installed along with a DiSEqC switch, switching between the satellites will be automatic so your customer will not need to enter the installation menus again.

A digital receiver with a wide symbol rate that it range should be used in the installation, so that it can handle MCPC (Multiple Channel per Carrier) and SCPC (Single Channel per Carrier).

Astra 1 at 19.2 º east, Astra 2 at 28.2º east and Hotbird at 13 º east are the most popular satellites which transmit a variety of free-to-air television and radio channels covering the majority of European languages as well as a selection of channels from around the world.

To maximise the system’s potential, digital receivers with a common interface should ideally be used so that customers have the option of watching free-to-air channels or subscribing to encrypted services.

Encrypted services can be received via the use of CAMS (Conditional Access Modules) and suitable cards with the digital receiver (see below).

The reception of Sky digital can also be included in a triple feed system, but only if a Sky digibox is installed and provided with its own feed from the Astra satellite at 28.2ºeast (see fig 2).