‰  NOW 20 WPM  ‰  TEXT IS FROM SEPTEMBER 2013 QST  PAGE 49‰

RUNNING IN CASE YOU ARE UNFAMILIAR WITH SOFTWARE DEFINED RECEPTION AS
IMPLEMENTED BY FIFI, THIS IS A GOOD TIME TO PAUSE FOR A BRIEF EXPLANATION.
THE SIGNALS ARRIVING AT FIFIS ANTENNA PORT ARE AMPLIFIED BEFORE BEING
FILTERED BY THE PRESELECTOR.  THEY ARE THEN MIXED WITH THE OUTPUT OF A
LOCAL OSCILLATOR WITH THE RESULT BEING TWO BASE BAND AUDIO SIGNALS THAT
COMPRISE THE SO CALLED IN PHASE I AND QUADRATURE Q CHANNELS.  THESE TWO
SIGNALS CONTAIN ALL THE INFORMATION YOUR SOFTWARE NEEDS TO WORK ITS
DEMODULATION MAGIC.  THE NEXT STEP IS TO SEND THE I/Q DATA TO YOUR
COMPUTER.  FIFI GIVES YOU TWO WAYS TO DO THIS.  YOU CAN TRANSFER THE
BASEBAND AUDIO FROM FIFIS 1/8 INCH STEREO OUTPUT JACK TO AN EXTERNAL SOUND
DEVICE SUCH AS THE ONE IN YOUR COMPUTER FOR FINAL CONVERSION AND
‰  END OF 20 WPM TEXT  ‰  QST DE W1AW  ƒ