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Syllabus Sections:- Receiver Concepts 3H3 25
Understand that overloading a receiver causes
intermodulation products and that those close to or within
the wanted signal bandwidth limit the ability of the
Receiver to detect weak signal When those signals are close to, or within the bandwidth of the wanted signal, the receiver will find it very hard to detect the wanted weak signal. The ability to detect weak signals is called "Sensitivity". So if you were to build a receiver you would need to consider in your designs the quality of components, to limit the amount of internal noise from those components and use the minimum amount of bandwidth within the receiver which would then minimise external noise picked up by your receiver.. Recall that the dynamic range of a receiver is
the difference between the minimum discernible signal and
the maximum signal without overload. There will be some signals that you receiver will just not be able to hear because they are below the noise floor level of the receiver and those that are so strong that they overload the receiver. This is much like you can hear a conversation from across the room - until someone next to you starts shouting which overloads your ears and cuts out the weaker signal. Recall the dynamic range is expressed in decibels. The
"dynamic range" is expressed in decibels dB. Dynamic range is the difference between the receiver’s sensitivity (from the weakest signal it can detect) and to the point where overloading is about to occur in the receiver. ---------------------------------------------------------------------------------------------------
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