text:  It should be borne in mind that the characteristics of the filter predicted by the image method are only accurate if the section is terminated with its image <unk> . This is usually not true of the sections at either end , which are usually terminated with a fixed resistance . The further the section is from the end of the filter , the more accurate the prediction will become , since the effects of the terminating <unk> are masked by the intervening sections . 
  