Raymond A. MackRaymond A. Mack, W5IFS, received his Electrical Engineering degree, with emphasis on biomedical engineering, from Purdue University in 1975. His career in medical devices covered clinical chemistry analyzers, heart pacemakers, electro-surgery, and inant warming therapy. From 1999 he worked in digital television for eight years and is now working in the oil and gas industry at National Oilwell Varco. Ray has worked for QEX magazine for 12 years as a technical proofreader, editor, writes a column on software defined radio, and has authored Switching Power Supplies Demystified. Ray's interests include alternative energy using switching power design, microwave system design, software defined radio, and DSP. Read More Read Less