1. Press the [NOTCH] button to activate the Notch filter. The DSP graphic display will illuminate and the current "null" position of the NOTCH filter will appear in the NOTCH indicator on the display. The [NOTCH] knob functions aa the Notch adjustment knob.     2. Rotate the [NOTCH] knob to adjust the "null" position of the Notch filter. ADVICE: The frequency display will show the Notch frequency for 3 seconds whenever the [NOTCH] knob is turned.     3. To cancel the [NOTCH] filter, press the [NOTCH] button momentarily. The graphic disappears from the NOTCH indicator on the display, confirming that the NOTCH filter is no longer in operation. ADVICE: Alternate presses of the [NOTCH] button, will switch the NOTCH filter between on and off. ADVICE: The bandwidth of the NOTCH filter (either narrow or wide) may be adjusted using Menu item "111 IF NOTCH WIDTH". The Factory default setting is "WIDE".

The performance of the IF NOTCH filter is is illustrated in Figure "A", where the effect of rotation of the [NOTCH] knob is depicted. In Figure "B" you can see the notching effect of the IF NOTCH filter as you rotate the [NOTCH] knob to eliminate the interfering hetrodyne. End of "IF Notch Filter Operation (SSB/CW/RTTY/DATA AM Modes) "