‰ NOW 7 1/2 WPM ‰ TEXT IS FROM JANUARY 2016 QST PAGE 54 ‰ WITH THE LO OUTPUT AND PRODUCES A SIGNAL AT THE IF INTERMEDIATE FREQUENCY, WHICH IS THEN FILTERED AND AMPLIFIED. A PRODUCT DETECTOR COMBINES THE IF OUTPUT SIGNAL WITH THE BFO BEAT FREQUENCY OSCILLATOR SIGNAL TO PRODUCE THE AUDIO SIGNALS CALLED BEAT NOTES OR HETERODYNES. IN AN SDR SOFTWARE DEFINED ‰ END OF 7 1/2 WPM TEXT ‰ QST DE W1AW ƒ