1. Press the [CONT/APF] button to activage the Contour filter. The DSP graphic display will illuminate and the currant "null" (or "peak") position of the Contour filter will appear in the CONTOUR indicator on the display.     2. Rotate the [CONT/APF] knob to achieve the most natural-sounding audio reproduction on the incoming signal. ADVICE: The display will show the Contour frequency for 3 seconds whenever the [CONT/APF] knob is turned.     3. To cancel Contour tuning, press the [CONT/APF] button momentarily. ADVICE: Alternate presses of the [CONT/APF] button will switch the Contour filter between on and off. ADVICE: The Contour filter level (either a null or a peak) may be adjusted using Menu item "108 CONTOUR LEVEL". The factory default setting is for a null of -15 (dB). The bandwidth over which the Contour filter effect is applied may be adjusted using Menu item "109 CONTOUR WIDTH". The factory default setting is 10. When the set value is increased, the bandwidth becomes wider.

Refer to Figure "B", this illustrates an "indentation" of the Contour filter in the center of the passband. The Contour filter places a low Q "notch" in the passband, per the settings of Menu items "108 CONTOUR LEVEL" and "109 CONTOUR WIDTH" (referenced above). Counter-clockwise rotation (to the left) of the [CONT/APF] knob causes the notch to move toward a lower frequency within the passband, while clockwise rotation (to the right) casues the notch to move towards a higher frequency within the passband. By removing interferenc or unwanted frequency components of the incoming signal, it is possible to make the desired signal rise out of the background noise/interference, enhancing intelligibilty.

QUICK POINT: By judicious use the Contour filter, the "shoulder" of the passband response may be altered, or components may be removed from within the passband, allowing the desired signal to rice above the background noise and interference in a manner not obtainable with other filtering systems. End of "Contour Control Operation"