Tag Archives: Richard Langley

Radio Waves: Solar Radios Help Kenyan Children, Synchronous AM’s History, FM Radio on Jupiter, and New WSJT mode Q65

Radio Waves:  Stories Making Waves in the World of Radio

Because I keep my ear to the waves, as well as receive many tips from others who do the same, I find myself privy to radio-related stories that might interest SWLing Post readers.  To that end: Welcome to the SWLing Post’s Radio Waves, a collection of links to interesting stories making waves in the world of radio. Enjoy!

Many thanks to SWLing Post contributors Tracy Wood, Richard Langley, and the Southgate ARC for the following tips:


With schools shut by pandemic, solar radios keep Kenyan children learning (Thomson Reuters Foundation)

Solar-powered radios have been distributed to the poorest homes that lack electricity access, with lessons broadcast daily during the COVID-19 crisis – and perhaps beyond

TANA RIVER, Kenya, Dec 23 (Thomson Reuters Foundation) – Deep in Tana River County, in southeastern Kenya, a group of pupils formed a circle around their teacher, jotting down notes as they listened to a Swahili diction lesson coming from the solar-powered radio sitting in their teacher’s lap.

The radio the children from Dida Ade primary school gathered around was one of hundreds distributed for free to the most vulnerable households in the semi-arid region east of Kenya’s capital, Nairobi.

The radios allow children without internet access or electricity at home to continue studying while schools are closed to slow the spread of COVID-19, in a project that could also help children stay in education after the pandemic.

Funded by the Zizi Afrique Foundation, a Kenyan non-governmental organisation that produces research to drive education policy, the solar-powered radios also come with bulbs for household lighting and slots for phone-charging.

When schools across Kenya shut in March to slow the spread of COVID-19, Zizi Afrique did a survey in Tana Delta sub-county and found that just over one-fifth of households owned a radio and only 18% had access to electricity.[]

Synchronous AM’s Long and Tortuous History (Radio World)

AM boosters repeatedly have been proven effective, but the FCC consistently has declined to allow their wide use

With AM improvement on the radars of broadcasters and the FCC, there has been renewed talk in recent years about the subject of AM “boosters,” the carrier frequency synchronization of multiple transmitters. The commission opened a comment period on AM boosters in 2017.

It wasn’t the first time the FCC has explored this topic and failed to act on it. In fact, AM boosters have been proposed and tested dozens of times since the early days of radio. But even though the technology has repeatedly been proven effective, the commission consistently has declined to allow the operation of AM boosters on anything more than an experimental basis, for a variety of reasons.

Let’s take a moment to look back at the history of this beleaguered technology.

BOSTON REPEATER
In 1930, crystal control of transmitter frequencies was still an emerging technology, and the allowable frequency tolerance of a broadcast transmitter was +/- 500 Hz. Two stations operating on the same channel, even if widely geographically separated, could generate a heterodyne beat note of up to 1 kHz, a disconcerting annoyance to listeners.

Consequently, only a few stations were allowed to operate nationwide evenings on any one channel at the same time. Further, there were 40 clear-channel stations, each one having exclusive nationwide use of its frequency. As most of these clear-channel stations were network affiliates, many channels were wastefully duplicating the same programs.

In 1929, the respected radio engineer Frederick Terman proposed that, if all stations of the two networks (NBC and CBS) could synchronize their carrier frequencies within +/- 0.1 Hz to eliminate the heterodyne beat notes, they could all coexist on a single channel per network, freeing up dozens of channels for new stations.

Synchronization was first proved successful by the Westinghouse station WBZ in Springfield, Mass. Broadcasting from the roof of the Westinghouse factory, WBZ failed to cover Boston, so WBZA was opened as a Boston repeater. The two stations were synchronized on the same frequency beginning in 1926, using a tuning fork as a frequency reference.[]

FM Radio on Jupiter, Brought to You by Ganymede (EOS)

Another first from NASA’s Juno spacecraft: the detection of radio emissions from the Moon Ganymede, over a range of about 250 kilometers in the polar region of Jupiter.

Louis et al. [2020] present exciting new observations of radio emissions on Jupiter from the NASA Juno spacecraft – the first direct detection of decametric radio emissions originating from its Moon Ganymede. These observations were made as Juno crossed a polar region of the Giant Planet where the magnetic field lines are connected to Ganymede.

The radio emissions were produced by electrons at relativistic energy (a few thousand electron volts) in a region where the electron’s oscillation frequency (“plasma frequency”) is much lower than its gyration frequency (“cyclotron frequency”). Such electrons can amplify radio waves very close to the electron cyclotron frequency very rapidly, via a physical process called electron cyclotron maser instability (CMI). They can as well produce aurora in the far-ultraviolet – which was also observed by the camera on Juno.

Juno was traveling at a speed of approximately 50 kilometers per second, and it spent at least about 5 seconds crossing the source region of the emission, which was therefore at least about 250 kilometers in size.

The observed decametric radiation on Jupiter is clearly the “shorter cousin” (in wavelength) of the auroral kilometric radiation on both Earth and Saturn: the CMI being responsible for their production on the three planets.

Citation: Louis, C. K., Louarn, P., Allegrini, F., Kurth, W. S., & Szalay, J. R. [2020]. Ganymede?induced decametric radio emission: In situ observations and measurements by Juno. Geophysical Research Letters, 47, e2020GL090021. https://doi.org/10.1029/2020GL090021

Andrew Yau, Editor, Geophysical Research Letters[]

New WSJT mode Q65 (Southgate ARC)

WSJT-X 2.4.0 will introduce Q65, a digital protocol designed for minimal two-way QSOs over especially difficult propagation paths

On paths with Doppler spread more than a few Hz, the weak-signal performance of Q65 is the best among all WSJT-X modes.  Q65 is particularly effective for tropospheric scatter, ionospheric scatter, and EME on VHF and higher bands, as well as other types of fast-fading signals.

Q65 uses 65-tone frequency-shift keying and builds on the demonstrated weak-signal strengths of QRA64, a mode introduced to WSJT-X in 2016.  Q65 differs from QRA64 in the following important ways:
•A new low-rate Q-ary Repeat Accumulate code for forward error correction
•User messages and sequencing identical to those in FT4, FT8, FST4, and MSK144
•A unique tone for time and frequency synchronization.  As with JT65, this “sync tone” is readilyvisible on the waterfall spectral display.  Unlike JT65, synchronization and decoding are effective even when meteor pings or other short signal enhancements are present.
•Optional submodes with T/R sequence lengths 15, 30, 60, 120, and 300 s.
•A new, highly reliable list-decoding technique for messages that contain previously copied message fragments.

Read the new Q65 Quick Start Guide at
https://physics.princeton.edu/pulsar/k1jt/Q65_Quick_Start.pdf


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The new Raspberry Pi 400 All-In-One Keyboard PC Released

On Monday, I received the announcement about the new Raspberry Pi 400 via the Pi Hut.

The Pi 400 is essentially a Raspberry Pi 4 built into a keyboard. Wonderful concept that very much takes me back to my first personal computer.

Of course, in the spirit of all things Raspberry, the complete kit price is pretty reasonable at about $100 US. Here are details via Pi Hut:

The Pi400 has all of the great features of a Raspberry Pi 4 wrapped in a convenient and compact keyboard – it’s the ultimate coding machine!

The keyboard is available as a kit with everything you need in one box (minus a monitor), or on its own.

The Pi400 doesn’t compromise on performance either – in fact, the CPU is clocked to a whopping 1.8GHz which is made possible thanks to the large metal heatsink inside the keyboard.

CPU aside, the Pi400 boasts the same great specs and connectivity as a Raspberry Pi 4 – 4GB RAM, dual-band wireless networking, Gigabit Ethernet, dual-display output and 4K video playback.

USB, power, video, Ethernet and SD ports are located at the rear of the keyboard, including the familiar 40-pin GPIO connector.

The Raspberry Pi 400 is also available in a number of different regional variants (some international variants coming soon!).

Many thanks to SWLing Post contributor, Richard Langley, who shares the following Pi 400 review from Tom’s Hardware:

The Raspberry Pi Model B has seen the same board layout since the Raspberry Pi B+ arrived in 2014. Sure the Raspberry Pi 4 swapped the Ethernet and USB ports around, but the same basic design has persisted. So when we received a parcel from Raspberry Pi Trading and opened the box to find a keyboard, we were somewhat puzzled as to the contents. Inside this compact and well designed keyboard is a Raspberry Pi 400, a variant of the Raspberry Pi 4 4GB designed specifically for this purpose.

Retailing as a single unit for $70 or as a complete $100 kit with mouse, power supply, cables, micro SD card and a copy of the Raspberry Pi Beginner’s Guide, the Raspberry Pi 400 could be the ideal way to introduce the Raspberry Pi to your home.

[…]Despite the change in form factor, this is still a Raspberry Pi 4 4GB and, as such, it behaves in exactly the same manner, with one exception. The Raspberry Pi 400 lacks the CSI and DSI connectors, used for the Camera and Official Touchscreen. Without these connectors there is no way to use those devices. This loss of the touchscreen connector is not such a big deal, but the camera connector is.

The range of Raspberry Pi cameras are cheap and effective add-ons (see our list of best Raspberry Pi accessories) that provide a fun stream of projects. If you want to create camera projects, then the Raspberry Pi 400 is not for you.[…]

Click here to read the full review.

I normally scoop up new Raspberry Pi products as soon as they’re released, but I’m flush with RPi’s at the moment! I do believe, however, I’ll eventually replace out my daughters’ Pi 4s with these all-in-ones.

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Radio Algérie Internationale now broadcasting one hour via Issoudun transmitter

Many thanks to SWLing Post contributor, Richard Langley, who writes:

Just a quick note to let you know that Radio Algérie Internationale is now broadcasting for an hour on SW using an Issoudun transmitter. The multilingual (French, Arabic, English, and Spanish) broadcast is at 18:00 UTC, presumed daily, is on 13820 kHz. I heard it very well yesterday using the U.Twente SDR receiver but it might also be heard well in eastern North America.

Richard did include a small disclaimer that Issoudun seems to be using their faulty transmitter with a “squeaky” sound in the background. I’m sure many of you are familiar with this–fortunately, it’s not too distracting.

Thank you for the tip, Richard!

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Reminder: Help record the 2020 BBC Antarctic Midwinter Broadcast today (June 21)

Halley VI Research Station on the Brunt Ice Shelf in Antarctica (Source: British Antarctic Survey Team)

Every year, the BBC broadcasts a special program to the scientists and support staff in the British Antarctic Survey Team. The BBC plays music requests and sends special messages to the small team of 40+ located at various Antarctic research stations. Each year, the thirty minute show is guaranteed to be quirky, nostalgic, and certainly a DX-worthy catch!

After successful listener events from years past, I’m once again calling on all SWLing Post readers and shortwave radio listeners to make a short recording (say, 30-60 seconds) of the BBC Antarctic Midwinter Broadcast today and share it here at the Post.

Important: Time and frequencies

There has been some confusion about the broadcast time.

Trusted DXers have reported the time as 21:30 UTC–this is the time when the broadcast has taken place in years past, no doubt coinciding with events at the BAS bases in Antarctica.

The BBC website has reported the broadcast time as 21:30 BST which would equate to 20:30 UTC.

I will listen at both times, but perhaps this is when the BBC are to broadcast the stream online? Likely a mistake on their part.

Many thanks to SWLing Post contributor, Richard Langley, who confirms the three frequencies the BBC plan to use this year:

  • 5790 kHz from Woofferton UK
  • 7360 kHz from Woofferton UK
  • 9580 kHz from Ascension Island

Recording the Midwinter Broadcast has become an SWLing Post community tradition! Read our previous post for more details. We will also publish a reminder on June 21, prior to the broadcast.

I’m especially fond of this broadcast as it always falls on my birthday and–this year–Father’s day as well!

If you would like to participate in our BBC Antarctic Midwinter Broadcast recording event, please read our original post which includes all relevant details.

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2020 BBC Midwinter Broadcast to Antarctica: Time and Frequencies

The BBC Antarctica winter solstice broadcast will take place on June 21, 2020 at 2130-2200 UTC.

Many thanks to SWLing Post contributor, Richard Langley, who confirms the three frequencies the BBC plan to use this year:

  • 5790 kHz from Woofferton UK
  • 7360 kHz from Woofferton UK
  • 9580 kHz from Ascension Island

Recording the Midwinter Broadcast has become an SWLing Post community tradition! Read our previous post for more details. We will also publish a reminder on June 21, prior to the broadcast.

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Radio Waves: Libre Space Foundation Reviews SDRs, ARRL VEC Statement, Pandemic Pastime, and Former CEO of RadioShack Now C-19 ER doctor

Radio Waves:  Stories Making Waves in the World of Radio

Because I keep my ear to the waves, as well as receive many tips from others who do the same, I find myself privy to radio-related stories that might interest SWLing Post readers.  To that end: Welcome to the SWLing Post’s Radio Waves, a collection of links to interesting stories making waves in the world of radio. Enjoy!

Many thanks to SWLing Post contributors Ron, Paul, Marco Zennaro, and Richard Langley for the following tips:


The Libre Space Foundation reviews software defined radios (Hackaday)

If you want to go to the next level with software defined radio (SDR), there are a lot of choices. The RTL-SDR dongles are fine, but if you get serious you’ll probably want something else. How do you choose? Well, your friends at the European Space Agency Libre Space Foundation have published a paper comparing many common options. True, they are mostly looking at how the receivers work with CubeSats, but it is still a good comparison.

The devices they examine are:

  • RTS-SDR v3
  • Airspy Mini
  • SDRPlay RSPduo
  • LimeSDR Mini
  • BladeRF 2.0 Micro
  • Ettus USRP B210
  • Pluto SDR

They looked at several bands of interest, but not the HF bands — not surprising considering that some of the devices can’t even operate on HF. They did examine VHF, UHF, L band, S band, and C band performance. Some of the SDRs have transmit capabilities, and for those devices, they tested the transmit function as well as receive.

The review isn’t just subjective. They calculate noise figures and dynamic range, along with other technical parameters. They also include GNURadio flowgraphs for their test setups, which would be a great place to start if you wanted to do these kinds of measurements yourself.[]

ARRL VEC Issues Statement on Video-Supervised Online Exam Sessions (ARRL News)

Very few ARRL Volunteer Examiner teams have successfully conducted in-person exam sessions (following social distancing guidelines) and video-supervised exam sessions using fillable PDF exams and documents. So far, we have found that both types of sessions take volunteer teams two to three times longer to conduct and accommodate fewer candidates than sessions conducted prior to the COVID-19 pandemic. So far, the video sessions have included only one examinee per session.

We ask the community to be patient with our volunteer teams as they navigate uncharted territory. Please remember with the introduction of significant new processes such as these, that there should be proof of concept, establishment of protocols and procedures, and beta testing before expanding to a larger audience. Video-supervised exam sessions require a different skillset than in-person exam administration. Not all teams will be equipped to deliver video exams right away.

The ARRL Volunteer Examiner Coordinator (VEC) has been investigating options for an online examination system.

Fillable PDFs are cumbersome within a video-supervised exam session process. We recognize that online testing would represent a large-scale solution for our thousands of VEs and would make session procedures easier for our teams, but this will not happen overnight.

The ARRL VEC will continue to adapt and respond to the evolving crisis as we search for viable and easy-to-use online examination system solutions and conduct exam sessions in innovative ways.[]

Pandemic Pastime – Shortwave Radio (KFGO)

Ever since I was a little kid, I was fascinated that at night you could listen to radio stations from all over the country. My little Heathkit radio, which I built myself, could pick up stations in Minneapolis, Chicago, St. Louis, Denver, Little Rock, Pittsburgh to name a few. West coast stations were rare because it was tough getting a signal over the Rocky Mountains.

Then there was shortwave radio. A buddy of mine had one and he showed me a list of all the countries he was picking up. England, France, Germany, Latin American countries, numerous stations on the shortwave bands in America. Even Radio Havana coming out of Cuba. Anything from religion to hard edge rock and roll. He also noted he picked up Radio Free Europe and the Voice of America.

Well years later I would stop by my local Radio Shack and decided it was my turn to take up this hobby of monitoring shortwave radio. This particular radio also had a built in cassette player so you could record your found stations as well. It was really interesting to hear the news from other countries and get their take on what was happening in America.

One of the first frequencies I tuned in was WWV a shortwave radio station out of Fort Collins Colorado, that broadcasts the time via the atomic clock. The seconds tick off until the top of the hour when you hear a voice announce the time, followed by a tone that hits the top of the minute exactly on the nose. Great way to set the clock.

Now I know you can probably find all these shortwave stations on the internet, but what fun is that right?

With the covid-19 pandemic, this is a little something different than binge watching television, or building that 10th jigsaw puzzle or cleaning out that closet again and again.

Have a chair on the patio, a glass of your favorite beverage, extend the antenna, and start turning up and down the dial and see what you can find. I had a little notebook that I kept track of my searches. Don’t have it now though…lost it.

I’ll start a new one.

Stay safe everyone![]

Former CEO of RadioShack now an ER doctor (National Post)

‘I am just one of those people who was very fortunate, where things worked out, and where I could do not just do one thing I really enjoyed in life, but two’

Brian Levy loved science as a kid. He had a microscope, read up on stuff in the encyclopedia and messed around with home experiment kits. During his high school years, he took every science credit possible. By his own admission, he was a “geek,” one with an equally strong passion, alongside science, for electronics.

Levy knew how to operate a shortwave radio. Weekend teenage heaven, in his mind, was hanging around the local RadioShack store, a warehouse of gizmos where he scored his first part-time job in 1974, earning US$1.40 an hour at a shop in downtown Atlanta. He was 15, which, alas, was too young to be working for the company, according to the folks at corporate headquarters in Texas, who fired him upon receiving his paperwork.

The dismissal didn’t sit well with Levy.

“I actually called the vice president of human resources in Texas,” he says. The executive was impressed by the moxie of the kid. On the day he turned 16, Levy was hired back.

[…]Levy did not foresee the premature end to his business career. When it came, rather than being crestfallen, he felt liberated, and free to pursue an “itch” that he had always felt the need to scratch. So he applied to medical school at McMaster University in Hamilton, ON. (Levy came to Canada in the first place after relocating RadioShack HQ north of the border as CEO. He is now a dual citizen, although his soft, buttery accent betrays his roots in the American south.)[]


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