C O N T E N T S All about Antennas: Part 1 ......................................... 12 By Bob Grove W8JHD MT Publisher, Bob Grove W8JHD, focuses on the basics of the antennas that hams and shortwave listeners alike take for granted. In the first part of this series, Bob looks at the essential radio wave, propagation, and antenna patterns. TCAS Technology ......................................................... 15 A low-cost, no-license communications method revisited By Peter Mac Dougall EI/G7VEW In our rush to embrace digital technology some very useful communica- tions concepts get swept aside. Peter urges readers to take another look at a standby technology that never goes out of style. Amateur Radio Weather Watchers ............................. 16 A National Public Service By Gregory Smith WB2PPQ April weather is unpredictable with many parts of the U.S. still not out of threat of snow while others are dodging severe thun- derstorms. Greg writes about the National Weather Service’s SKY- WARN program and tells where to tune when the weather gets rough. First Person Radio ...................................................... 19 Crystal Set Leads to Lifelong Hobby and Career By Maury Midlo What started with a crystal set for a boy, ended up as a lifelong hobby that led Maury to VHF/UHF communications in the service and to a satisfying career at a major AM/FM/TV station. Vol. 29 No. 4 April 2010 001010011001010101010100101 0010110101010101001111010101101101 010100101001010110010010010011001010011001010101010100101 00 11010101010100111101010110110101010100101001010110010010010011 1010011001010101010100101 0010110101010101001111010101101101010 100101001010110010010010011001010011001010101010100101 0010 01010101010011110101011011010101010010100101011001001001001100 10011001010101010100101 001011010101010100111101010110110101010 0101001010110010010010011001010011001010101010100101 001011 0101010100111101010110110101010100101001010110010010010011001 0011001010101010100101 0010110101010101001111010101101101010101 101001010110010010010011001010011001010101010100101 00101101 0101010011110101011011010101010010100101011001001001001100101 11001010101010100101 001011010101010100111101010110110101010100 1001010110010010010011001010011001010101010100101 0010110101 0101001111010101101101010101001010010101100100100100110010100 001010101010100101 00101101010101010011110101011011010101010010 01010110010010010011001010011001010101010100101 001011010101 0100111101010110110101010100101001010110010010010011001010011 1010101010100101 001011010101010100111101010110110101010100101 1010110010010010011001010011001010101010100101 0010110101010 1001111010101101101010101001010010101100100100100110010100110 010101010100101 00101101010101010011110101011011010101010010100 10110010010010011001010011001010101010100101 001011010101010 0111101010110110101010100101001010110010010010011001010011001 0101010100101 0010110101010101001111010101101101010101001010010 110010010010011001010011001010101010100101 00101101010101010 1101010110110101010100101001010110010010010011001010011001010 1010100101 001011010101010100111101010110110101010100101001010 Volume 29, No. 4 April 2010 U.S. $6.95 Can. $6.95 Printed in the United States A Publication of Grove Enterprises Scanning - Shortwave - Ham Radio - Equipment Internet Streaming - Computers - Antique Radio ® In this issue: • Learning Antenna Basics • SKYWARN: A National Public Service • TCAS Technology: Old Tech Can Work! Can DRM Save Shortwave? Logitech Squeezebox Radio ........................................ 67 By Loyd Van Horn W4LVH The latest in Internet radio from Logitech is loaded with features. Loyd says, “If you’ve been holding out and waiting for the perfect WiFi radio to come along, wait no further, this is it!” R E V I E W S Chasing DRM.......8 The Elusive Dream of Digital Audio via Shortwave By Ken Reitz KS4ZR, Ken Barber W2DTC and Dave Schmarder N2DS Long after satellite TV, musical re- cordings, terrestrial TV, satellite radio and even terrestrial radio have carved niches in the digital world, shortwave radio continues to meander at a snail’s pace towards a digital future. And, even though its platform, Digital Radio Mondiale (DRM), was launched before most digital services we take for granted today, shortwave’s digital future remains uncertain. This month MT examines the 12 year wait for shortwave broadcasting to find its digital voice. In this progress report, Ken Reitz KS4ZR looks at where we are on the road to digital shortwave and reviews the first stand-alone, portable DRM shortwave radio. Ken Barber W2DTC finds a way to hear DRM broadcasts without modifying his computer- based shortwave radio. And, Dave Schmarder N2DS shows how to home- brew a tube-fired, DRM converter that works! On Our Cover Continental Electronics’ 418DRM 100 kW transmitter for DRM shortwave broadcasts (Courtesy: Continental Electronics); WiNRADiO tuning page (Courtesy: WiNRADiO); UniWave Di- Wave 100 portable shortwave radio (Courtesy: Universal Electronics)