<P> With lower frequencies, C - band for example, dish designers have a wider choice of materials . The large size of dish required for lower frequencies led to the dishes being constructed from metal mesh on a metal framework . At higher frequencies, mesh type designs are rarer though some designs have used a solid dish with perforations . </P> <P> A common misconception is that the LNBF (low - noise block / feedhorn), the device at the front of the dish, receives the signal directly from the atmosphere . For instance, one BBC News downlink shows a "red signal" being received by the LNBF directly instead of being beamed to the dish, which because of its parabolic shape will collect the signal into a smaller area and deliver it to the LNBF . </P> <P> Modern dishes intended for home television use are generally 43 cm (18 in) to 80 cm (31 in) in diameter, and are fixed in one position, for Ku - band reception from one orbital position . Prior to the existence of direct broadcast satellite services, home users would generally have a motorised C - band dish of up to 3 m in diameter for reception of channels from different satellites . Overly small dishes can still cause problems, however, including rain fade and interference from adjacent satellites . </P> <P> In Europe, the frequencies used by DBS services are 10.7--12.75 GHz on two polarisations H (Horizontal) and V (Vertical). This range is divided into a "low band" with 10.7--11.7 GHz, and a "high band" with 11.7--12.75 GHz . This results in two frequency bands, each with a bandwidth of about 1 GHz, each with two possible polarizations . In the LNB they become down converted to 950--2150 MHz, which is the frequency range allocated for the satellite service on the coaxial cable between LNBF and receiver . Lower frequencies are allocated to cable and terrestrial TV, FM radio, etc . Only one of these frequency bands fits on the coaxial cable, so each of these bands needs a separate cable from the LNBF to a switching matrix or the receiver needs to select one of the 4 possibilities at a time . </P>

Does the size of a satellite dish matter