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(Source: arstechnica via Scott Schad)

A new antenna using single atoms could usher in the age of atomic radio

The team tested their device by recording themselves singing “Mary Had a Little Lamb”

JENNIFER OUELLETTE

In the 1950s, atomic clocks revolutionized precision time-keeping. Now we may be on the verge of so-called “atomic radio,” thanks to the development of a new type of antenna capable of receiving signals across a much wider range of frequencies (more than four octaves) that is highly resistant to electromagnetic interference.

An antenna is typically a collection of metal rods that pick up passing radio waves and convert their energy into an electrical current, which is then amplified. One might argue that the good old-fashioned radio antenna has served us well since the dawn of the 20th century, so why do we need anything to replace it?

According to David Anderson of Rydberg Technologies, those antennae are wavelength-dependent, so their size depends on whatever wavelength of signal they are trying to measure (they need to be about half the size of whatever wavelength they are designed to receive). That means you need antennae of several different sizes to measure different radio frequencies.

Anderson is a co-author of a new paper posted to the arXiv describing a novel alternative to conventional antennae, based on vapor cells filled with a gas of so-called “Rydberg atoms.” That just means the atoms are in an especially excited state, well above their ground (lowest-energy) state. This makes them especially sensitive to passing electric fields, like the alternating fields of radio waves. All you need is a means of detecting those interactions to turn them into quantum sensors.[…]

Read the full article at arstechnica.

Click here to download the research paper: An atomic receiver for AM and FM radio communication (PDF).

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IEEE Spectrum: “Long-Running U.S. Federal Radio Stations, Beloved by Hams, in Danger of Shutdown”

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A WWV Time Code Generator

(Source: IEEE Spectrum Magazine)

Several public radio stations that have broadcast the time of day continuously for nearly 100 years are on the chopping block

By Julianne Pepitone

Starting in May 1920, the U.S. federal WWV radio stations have broadcast the official time without fail. For ham radio fans, hearing the friendly “National Institute of Standards and Technology Time!” announcement is a comforting old refrain. For others, it’s a service they’ve never heard of—yet in the background, it’s what keeps the clocks and appliances in their daily lives automatically ticking along on time.

But after 98 years, this constant companion could soon go off the air. The proposed 2019 U.S. presidential budget calls for a 34 percent cut in NIST funding; in response, the Institute compiled a budget-use plan that would eliminate the WWV stations.

At first blush it might sound like the natural end to a quaint public service from a bygone era. Do we really need radio-broadcast time signals in an era of Internet-connected devices and GPS?

Many would argue: Yes, we really do. More than 50 million devices in the United States—including wall clocks, wristwatches, and industrial appliances—keep time through the signal from NIST’s WWVB station, operating from a site near Fort Collins, Colo., where it reads the time directly from an atomic clock. These radio-equipped clocks are permanently tuned to WWVB’s low-frequency 60 kHz signal.

“WWVB is the pacemaker for the world around us, even if we don’t realize it,” says Thomas Witherspoon, editor of shortwave radio news site The SWLing Post. “It’s why factory workers and schools don’t need to drag out the stepladder every time we switch between Daylight and Standard Time. Without WWVB, these devices won’t magically update themselves.”[…]

Click here to read the full article including comments from WWVB’s Station Manager.

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Arcing can produce nasty broadband radio interference

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On this trip to Québec, indoor listening has been more productive than listening from our balcony.

I mentioned in a previous post that, this year, QRM levels here at the condo in Québec are higher on our balcony than they are inside the building.

I think I found the source.

A couple weeks ago, on my morning walk, I passed underneath some high voltage power lines about 1 km from the condo. I noticed the sound of arcing coming from a pole nearby. No doubt, something metal–a staple, a cable, a pin, etc.–is the culprit.

I pulled out my smart phone and made this short video. If you turn up the volume, you might hear the noise especially at the end of the clip.:

I took a portable radio back to the site later and heard the same broadband noise I heard from the condo.

Although we only rent this condo a couple months a year, I’ll try to report the noise to the Hydro Québec. I know that our utility company in the States must follow up with requests like this and do their best to eliminate unintentional sources of RFI. These issues can also be an indication of something in the system failing, so power companies can actually be quite grateful for the feedback.

If you have persistent broadband noise at home, check out some of the trouble shooting tutorials at K3RFI’s website for a little guidance.

Despite all of this noise, I’m pleased I can still receive a few of my favorite shortwave stations. And, of course, escape to the KiwiSDR network and hit the field from time to time!

No worries, though, I’ll be back at my home station soon and can once again enjoy a relatively RFI-free radio space!

Post readers: Have you ever been plagued with power line noise? What did you do about it? Any tips? Please comment!

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