Doug Lung /
RF Shorts for Dec. 13, 2012
A review of RF-related news during the past week.
John Silva Dies— Invented TV News Chopper
John Silva, former chief engineer for KTLA in Los Angeles, died on Nov. 27 at the age of 92 in Camarillo, Calif. Silva's career is outlined a blog posting John Silva: He Invented the TV News Chopper by Patrick Kiger.
Kiger writes, “Silva, the chief engineer for KTLA Channel 5 in Los Angeles, was a visionary who helped create the modern age of on-location TV news gathering in the early 1950s by designing camera trucks that could roll to the scene of breaking news and broadcast from that spot. But according to a 2009 article in Smithsonian Air & Space magazine, the highly competitive former U.S. Navy radar officer was driving down the congested Hollywood Freeway one morning when he thought of an even better way to rise above the competition. What if he could transmit live pictures from the air? 'The logical next step had to be a helicopter,' he recalled.”
Kiger's posting describes the challenges associated with putting vacuum tube-era equipment in a small Bell 47G2 helicopter. There are links to KTLA's Sam Rubin's on-air tribute to Silva and a segment of an interview Silva did for the Archive of American Television in 2002.
Using a Raspberry Pi as an FM transmitter
The Raspberry Pi is a low-cost credit card-sized Linux based computer that has seen a wide range of applications. I was surprised, however, to see this Hackaday posting on Turning the Raspberry Pi Into an FM Transmitter. It’s very simple, but I wonder if it complies with FCC Part 15 rules.
Microwave Links Beat Fiber in Fast Finances
Microwave beats fiber when speed is important. Joab Jackson with IDG News Service writes Microwave vies with fiber for fast finance transport: High-frequency traders are turning to legacy microwave technologies for faster communications. In the article, Stéphane Ty, co-founder of Quincy Data, explains, “If you want to transport a little bit of data very fast, physics tells you that you have to go through air. Fiber is just not a good idea. It will slow you down.”
John Schneider has a more detailed discussion on the role of microwave links in the financial industry in his June 2012 IEEE Spectrum article The Microsecond Market: Sophisticated technology now drives global financial trading to extremes of time and space.
Now that Part 101 licensees can use TV BAS bands at 7 and 13 GHz, it’s important that broadcasters make sure their licenses are correct and that precise receive sites are specified. Licenses that don't specify a receive site, or operations that don't match the authorization will not be protected.
I've heard reports of some of these financial trading networks using C-band frequencies in the Chicago area, so it may be a good idea to make sure C-band receive sites are registered. This should also help when the FCC rolls its 3.5-3.7 GHz Citizens Broadband Service.
Home Wi-Fi Coverage Map
Nothing scientific here--just a map of your Wi-Fi router coverage that you may find amusing!