RF Shorts for Nov. 21, 2012

Viasat-1 and Exede Win Popular Science Award

Viasat announced last week ViaSat-1 and Exede Service Win 2012 Popular Science Best of What's New Award.

“This is a great honor that adds to the very positive feedback we’re seeing in the marketplace for the new brand of high-speed satellite services that ViaSat-1 is enabling,” said Mark Dankberg, chairman and CEO of ViaSat. “The conceptualizing, design, building, and launch of the system took an extraordinary effort by so many of our people and this award is a great testimony to what they accomplished.”

ViaSat's announcement explained that, “ViaSat-1, the highest capacity satellite in the world, is part of a system that is transforming the economics and quality of service that satellite broadband can provide. The technology is elevating satellite into a much more competitive position in the broadband service marketplace with approximately 40 percent of new Exede Internet subscribers switching from slower DSL and wireless services. Exede Internet is four times faster than average DSL speed according to an FCC Broadband study, and eight times faster than traditional satellite Internet service. ViaSat-1 is now hosting service for nearly 150,000 Exede Internet households after its first six months in operation.”

Playing With Antennas

I managed to find Kenneth Wyatt's Playing with antennas - part 2 on the Test and Measurement World web site. Wyatt explains how to build “a simple DIY EMC measurement antenna that is adjustable from about 85 to 200 MHz (depending on the telescoping antennas used), and is small enough to throw into your EMC troubleshooting kit. It also includes a 1:1 balun and additional ferrite choke to suppress common-mode currents from flowing on the outside of the coax shield.”

In Playing with antennas - part 1, which you will want to consult after building your DIY EMC measurement antenna, Wyatt explains how to characterize an antenna using a 20 dB coupler and a spectrum analyzer with a tracking generator. That one brought back memories, as almost 20 years ago, in the April 1993 issue of TV Technology I wrote about using a sideband adapter and mixer as a sweep generator to sweep tube cavities and antennas. Note that the link is to an FTP site, since in 1993 the World Wide Web wasn't widely used and I was making my articles available via FTP on the Internet before getting the transmitter.com domain and setting up a Website. One of these days when I get some time I'll move those articles to a Website.

Comments and RF related news items are welcome. Email me at dlung@transmitter.com.

Doug Lung is one of America's foremost authorities on broadcast RF technology. He has been with NBC since 1985 and is currently vice president of broadcast technology for NBC/Telemundo stations.