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Message: <blockquote data-quote="workshoppete" data-source="post: 25209" data-attributes="member: 176420">A point to note is that it is correct that the BBC channels are broadcast in the KU Low band.However because the universal LNB is switched between 10.6GHZ for high band and 9.75GHZ for low band, it means that the IF range is also switched to a different set of frequencies. In effect what happens is that the low band frequencies are relayed from the LNB at a HIGHER range of frequencies than that of the high band.The significance is apparrant when there is a long cable run from the dish to the satellite receiver,the higher block of frequencies (and therefore the LOW band) are attenuated more than the lower block.This impacts on the BBC channels as they are broadcast in the Low band and as a consequence are typically received at the satellite tuner at a much lower power level than the High band channels. Clearly the amount of attenuation along the cable between LNB to satellite tuner is dependant on the local oscillator setting of the LNB, (and of the quality and length of the cable) the higher the setting the less the attennuation.Note :- The IF frequency is determined by the frequency of the incoming signal to the LNB minus the local oscillator frequency. ie  12.00GHz incoming would be mixed with a 10.7 GHZ local oscillator to produce an IF frequency of 1.3GHZ (1300MHZ). Note that typically the changeover point for the band is 11.7GHZ- ie  anything under 11.7GHZ is switched to low band Anything above 11.7GHZ is switched to high bandAn interesting point to observe is when measuring the power levels with a spectrum analyser. It is possible to measure the signal power levels of the lower band with both 22khz band switching applied and not applied The two measurements give 2 entirely different readings but both are absolutely correct!  I guess you could improve your chances of picking up low band signals by purchasing a FTA receiver that you can alter the L.O frequency on . By raising the frequency of the low band oscillator slightly you will lower the IF frequency and therefore increase the signal level received by the satellite tuner.(however some of the channels would fall outside of the band because of this)</blockquote>

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