‰  NOW 15 WPM  ‰  TEXT IS FROM JANUARY 2016 QST  PAGE 54  ‰

WHAT HAPPENS AS YOU TURN THE VFO KNOB THE FREQUENCY OF THE SIGNALS FROM THE
IF AMPLIFIER CHANGES WHILE THE BFO OUTPUT STAYS FIXED, CREATING AN AUDIO
SIGNAL THAT ALSO CHANGES IN FREQUENCY.  NOTE THAT NOWHERE IN THE
SUPERHETERODYNE RECEIVER IS THERE A SIGNAL GENERATED AT THE SAME FREQUENCY
AS THE RF SIGNAL.  SO WHAT IS THE FREQUENCY SHOWN ON THE RADIO DISPLAY
DIAL?  IT IS THE FREQUENCY AT WHICH ALL OF THE OSCILLATORS AND IF FILTERS
AND MIXERS COMBINE TO PRODUCE AN AUDIBLE OUTPUT SIGNAL FROM THE INCOMING RF
‰  END OF 15 WPM TEXT  ‚