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RF Shorts for Dec. 15, 2014

The Radio Hat

Today people want to walk around and display their latest smartphone or Apple iFashion. In 1949, if you were interested in the latest wearable technology you might have sought out the “Man-from-Mars Radio Hat.” Amanda Uren has a great description of the radio hat along with many photos from the period in the article 1949 – Sporting the Radio Hat. It costs $7.95 and came with two vacuum tubes (valves), a tuning knob positioned in-between them, and a loop antenna. The battery was carried in the user's pocket.

Uren writes, “Although the Radio Hat was well received at the outset, the reception did not last, and advertisements ceased to run in the 1950s. Its failure was primarily due to technical limitations. It had only two valves, while household radios featured five or six, and thus, performed better. A superior FM radio format was becoming available in the U.S. from the late 1930s, but the Radio Hat could only receive AM frequencies. The loop antenna was directional and signal could be lost as the user turned his or her head. The Radio Hat had an advertised range of 20 miles; sometimes when tuning, it picked up stations further away, but these would be received as an annoying squeal, as the hat did not have the necessary circuitry.”

Does anyone have a schematic of the radio hat? I'd be interested in the circuitry. The “squeal” leads me to suspect it had a regenerative detector, although I would expect that would make it too difficult to adjust for the average radio hat wearer.

Why Google and Facebook Need Balloons, Drones and Rockets

Mike Elgan answers the question Why Google and Facebook need balloons, drones and rockets in an article on His answer is that Google and Facebook are launching these schemes “to bring to the majority of people what we in the privileged minority enjoy every day -- the ability to get online.”

People who live in the right countries can already get free data connectivity, to the associated websites, using Facebook Zero, Wikipedia Zero and Google Free Zone. These subsidized plans only work for people who live in areas where mobile connectivity exists. Elgan explains, “Here's the problem: Wireless Internet access is not possible without a cell tower. A tower requires a cable-based connection and electrical power. If a company wants to put up a cell tower, it first needs to buy, or otherwise secure, rights to the land it wants to build on. Because of those obstacles, billions of people have no chance of living within range of a cell tower in the foreseeable future. But Google and Facebook think they can make a difference by providing Internet connectivity via other means.”

He goes on to describe Google's Project Loon and its purchase of Titan Aerospace, a start up that makes solar-powered drones. Facebook's efforts, including Mark Zuckerberg's organization, whose stated goal is to connect everyone in the world to the Internet, are also outlined.

Regarding these schemes, which may seem outlandish, Elgan says, “Cynics can scoff and say that these ideas are impractical and self-serving. But I think that not only are they some of the most interesting and worthy projects currently being attempted, but also that they represent sensible thinking about connecting people at the lowest possible cost. And low cost is the most important aspect of these programs. Unless they're doable and sustainable, it's never going to happen. Connecting the two-thirds majority who are without any Internet access is a worthy goal. Who else besides Google and Facebook is going to do it?”

While reading Mike Elgan's article, I couldn't help but draw comparisons to what these Internet giants are aiming for and what broadcasting offers today – free, unencumbered access to news, information and, of course, paid advertisements. I can't help think that these Internet companies are also looking for a way to gain what broadcasters have today – direct access to viewers, even those without cable or phone!