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


Do you enjoy the SWLing Post?

Please consider supporting us via Patreon or our Coffee Fund!

Your support makes articles like this one possible. Thank you!

Spread the radio love

April’s collection of Japanese language WebSDR recordings for December 2020

Many thanks to SWLing Post contributor, April TimeLady, who shares her latest collection of Japanese language WebSDR recordings–this time, for December 2020. April notes:

Please find in this email a link to another batch of SDR recordings I have uploaded on archive.org that I made over the course of December.

I concentrated mostly on mediumwave stations to get Christmas music, and I also have New Year’s recordings in it too. I also have shortwave recordings too, but not as much as I have in the past few months.

Feel free to listen to her recordings via the clickable playlist below, or on her Archive.org page.

Thank you, April for once again uploading and sharing your recordings!

Click here for a link to this and all of April’s archived recordings.

Spread the radio love

New SDRplay-related software installer scripts

SDRplay RSPdx SDR

Many thanks to Jon Hudson with SDRPlay who notes:

Want to add SDR software to an existing Raspberry Pi setup? Check out our new SDRplay-related software installer scripts: Add SDRplay-related software to your existing Raspberry Pi SD card – SDRplay

Click here to view at SDRplay.

Spread the radio love

Dan’s thoughts on a Panasonic RF-9000 up for auction

Many thanks to SWLing Post contributor, Dan Robinson, who writes:

Appearing on the Japanese Buyee website is this RF-9000, which was the “King of Radios” of the heavy multiband “portable” era.

In recent years, RF-9000s in excellent to LNIB condition have sold for $10,000 or more.

A tour d’force of technology in its day, the 9000 featured room-filling main speakers and PLL technology that was advanced for its time.

The shortwave receiver section of the 9000 was plagued by PLL artifacts which prevented the radio from achieving what it could have had this problem not been solved in advance by Panasonic engineers.

A LNIB RF-9000 that I purchased for near $5,000 sold to a Hong Kong collector for $10,000 a few years ago. While I do miss its amazing FM quality and looks, the receiver ultimately lagged behind others, such as the SONY CRF-330K and 320 in performance.

The asking price for this 9000, which appears to have cosmetic issues, is in my view high.

Click here to view the RF-9000 auction.

Thank you for your insights, Dan!

Spread the radio love

FTIOM & UBMP, January 10-16


From the Isle of Music, January 10-16:
This week, we present a Cuban dance party.
The broadcasts take place:
1. For Eastern Europe but audible well beyond the target area in most of the Eastern Hemisphere (including parts of East Asia and Oceania) with 100Kw, Sunday 1500-1600 UTC on SpaceLine, 9400 KHz, from Sofia, Bulgaria (1800-1900 MSK)
2. For the Americas and parts of Europe, Tuesday 0100-0200 on WBCQ, 7490 kHz from Monticello, ME, USA (Monday 8-9PM EST in the US).
3 & 4. For Europe and sometimes beyond, Tuesday 1900-2000 UTC and Saturday 1300-1400 UTC on Channel 292, 6070 kHz from Rohrbach, Germany.
Our Facebook page is https://www.facebook.com/fromtheisleofmusic/
Our V-Kontakte page is https://vk.com/fromtheisleofmusic
Our Patreon page is https://www.patreon.com/tilford

Uncle Bill’s Melting Pot, January 10-16:
In episode 199, we enjoy traditional and modern music from the Central African Republic and the Western Sahara.
The transmissions take place:
1.Sunday 2300-0000 (6:00PM -7:00PM EST) on WBCQ The Planet 7490 kHz from the US to the Americas and parts of Europe
2. Tuesday 2000-2100 UTC on Channel 292, 6070 kHz from Rohrbach, Germany for Europe.
3. Saturday 0800-0900 UTC on Channel 292, 9670 kHz from Rohrbach, Germany for Europe with a directional booster aimed eastward.
Our Facebook page is https://www.facebook.com/UncleBillsMeltingPot/
Our V-Kontakte page is https://vk.com/fromtheisleofmusic
Our Patreon page is https://www.patreon.com/tilford

Spread the radio love

Any off-air recordings of “The Famous Computer Cafe”–?

Many thanks to SWLing Post contributor, Devin, who writes:

I am a game historian conducting research on early computer games. There is one radio program of particular historical significance called The Famous Computer Cafe that interviewed all the early movers and shakers of early computing, including Philip Estridge, Bill Gates, Bill Atkinson, Gene Rodenberry, and Stewart Brand. The show ran from 1983-1986 primarily in the Los Angeles area, but was distributed nationally over NPR starting in 1985. Only one recording is known to exist, along with a few transcripts, as the original tapes were lost years ago.

Here are more details on the show:

“There were several versions of the show, which aired on several radio stations, primarily in California. A live, daily half-hour version allowed phone calls from listeners. Taped versions (running a half-hour and up to two hours) also aired daily. The show started in 1983 on two stations in the Los Angeles area: KFOX 93.5 FM and KIEV 870 AM. In 1985 it began airing in the California Bay Area: on KXLR 1260 AM in San Francisco and KCSM 91.1 FM in San Matro, and KSDO 1130 AM in San Diego. [Note: KIEV ran 3:30-4pm M-F and KFOX 7:30am-8:00am and 6:00pm-6:30pm. I do not have information on the times for the 1 hour show.]

Also in 1985 a nationally syndicated, half-hour non-commercial version of The Famous Computer Cafe was available via satellite to National Public Radio stations around the United States, though it’s not clear today which stations ran it.”

https://ataripodcast.libsyn.com/antic-interview-402-the-famous-computer-cafe

I was hoping the Spectrum Archive might have some recordings within some of your files, particularly from the LA area. What additional information would I need to provide you in order to better locate some recordings?

Thank you for your help,

Devin

Thank you for your inquiry, Devin. I’m a huge fan of early personal computing and game broadcasts, but never heard the The Famous Computer Cafe. Unfortunately–as I mentioned via email–the Spectrum Archive nor the Shortwave Radio Audio Archive have any recordings of the program.

I’m willing to bet an SWLing Post reader may be familiar with the show, however.

Post Readers: If you have any information that could help Devin, please comment on this post. It would be brilliant if someone actually made an off-air recording of the show back int he day.

Spread the radio love