Why the attenuation link between the LNB and the QO-100 receiver?
It is a habit in amateur radio practice, that we are trying to make a profit, not attenuated. Preamplifiers and amplifiers are perhaps in every receiver. So why the attenuator? The following video vividly illustrates the importance of the attenuation element between the LNB receiver for the satellite QO-100.
But something similar applies to any receiver when we put a preamplifier in front of it. If the profit of this degree is too high, an undesirable result occurs. Lay TV sets often suffer from this – a strong TV signal is picked up by an antenna behind which is a preamplifier with a gain 20 – 40 dB. The TV does not process such a signal properly. In many cases, a TV preamplifier is not required (the signal level is sufficient). This mistake is often made by radio amateurs, who “they help” neighbors to address the issue of TV reception. However, the result can also be a very resilient TV chain and susceptibility to TVI.
So how does the receiver behave with and without the attenuator? Explain the video:
