‰  NOW 30 WPM  ‰  TEXT IS FROM SEPTEMBER 2015 QST  PAGE 53‰

WAS MINIMAL.  FOR STRONG INTERFERING SIGNALS, YOU CAN TURN OFF YOUR
RECEIVERS AGC AND CONTROL THE LEVEL WITH YOUR RF GAIN CONTROL.  I ALSO
EXPERIMENTED WITH THE MFJ 752D LOW PASS AND HIGH PASS FILTER MODES AS THESE
HELP REDUCE HIGH OR LOW FREQUENCY NOISE.  AS THE ARRL LAB DATA SHOWS, THE
FREQUENCY RESPONSE SHIFTS WHEN THE SELECTIVITY CONTROL IS ADJUSTED IN BOTH
THE LOW PASS AND HIGH PASS MODES.  HOWEVER, AS PART OF THE TUNING PROCESS
BOTH THE SELECTIVITY AND FREQUENCY KNOBS ARE NORMALLY TUNED FOR BEST
SOUNDING AUDIO.  IN MY OPINION, CAREFUL USE OF THE PEAK FUNCTION WAS EASIER
AND PROVIDED MORE EFFECTIVE BANDWIDTH LIMITING AND FILTERING.  WHILE THE
PEAK MODE PROVIDES THE NECESSARY SELECTIVITY FOR MOST USES, THE NOTCH MODE
CAN HELP WHEN OPERATING WITH A CLOSE IN INTERFERING CW SIGNAL.  AGAIN, A
STRONG INTERFERING SIGNAL CAN CAPTURE OR PUMP YOUR RECEIVERS AGC UNLESS THE
INTERFERING SIGNAL IS AT LEAST 6 DB BELOW THE DESIRED SIGNAL.  TABLE 4
INDICATES THAT THE ARRL LAB ACHIEVED 41 DB OF NOTCH PERFORMANCE FOR A
SIGNAL JUST 200 HZ AWAY FROM THE DESIRED SIGNAL.  HOWEVER, I FOUND THAT
ACHIEVING THIS LEVEL OF NOTCH REDUCTION REQUIRED CRITICAL TUNING OF THE
‰  END OF 30 WPM TEXT  ‰  QST DE W1AW  ƒ