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This project converts a monophonic radio speaker/headphone signal into a pseudo-stereo headphone signal. Based on Karl Fischer's (DJ5IL) The Codephaser, this ingenious circuit does a great job of
simulating CW and SSB in stereo. Although the effect is subtle, it helps to improve intelligibility and reduce listening
fatigue, especially during long contests. I call it the Phaser because it will be used mainly for SSB. The unit is housed
in a very small extruded aluminunm enclosure (4.7"x2.13"x0.9") with stereo balance and volume preset by internal trim
pots. Two external pushbuttons control stereo/mono and normal/reverse stereo. All lettering was done on a Dymo LabelWriter
450 Duo with 45021 white on black tape. The 20 second MP3 sound files alternate between 5 seconds of mono and 5 seconds of stereo. Listen with stereo headphones to get the full effect.