Tag Archives: NASA

Eclipse Radio: Several NASA-Funded Science Projects

Many thanks to SWLing Post contributor, David Iurescia, who shares the following article via NASA:


The Aug. 21, 2017, total solar eclipse douses Umatilla National Forest in shadow, darkening the sky and rimming the horizon with a 360 degree sunset. Credit: NASA/Mara Johnson-Groh

NASA-Funded Science Projects Tuning In to ‘Eclipse Radio’ (NASA)

On April 8, 2024, a total solar eclipse will cross parts of the United States. For millions of people along the path of totality, where the Moon will completely cover the Sun, it may feel like an eerie daytime darkness has descended as temperatures drop and wind patterns change. But these changes are mild compared to what happens some 100 to 400 miles above our heads in an electrically conductive layer of our atmosphere known as the ionosphere, where the “false night” of an eclipse is amplified a hundredfold. Three NASA-funded experiments will investigate the eclipse’s effects on the ionosphere through the power of radio, a technology well suited to studying this enigmatic layer of our atmosphere.

Whether you’ve heard of the ionosphere or not, you’ve likely taken advantage of its existence. This electric blanket of particles is critical for long-distance AM and shortwave radio. Radio operators aim their transmitters into the sky, “bouncing” signals off this layer and around the curvature of Earth to extend their broadcast by hundreds or even thousands of miles.

The ionosphere is sustained by our Sun. The Sun’s rays separate negatively charged electrons from atoms, creating the positively charged ions that the ionosphere is named for. When night falls, over 60 miles of the ionosphere disappears as ions and electrons recombine into neutral atoms. Come dawn, the electrons are freed again and the ionosphere swells in the Sun’s illumination – a daily cycle of “breathing” in and out at a global scale.

A total solar eclipse is a scientific goldmine – a rare chance to observe a natural experiment in action. On April 8 the three NASA-funded projects listed below are among those “tuning in” to the changes wrought by a blotted-out Sun.

SuperDARN

The Super Dual Auroral Radar Network, or SuperDARN, is a collection of radars located at sites around the world. They bounce radio waves off of the ionosphere and analyze the returning signal. Their data reveals changes in the ionosphere’s density, temperature, and location (i.e. movement).

The 2024 eclipse will pass over three U.S.-based SuperDARN radars. A team of scientists led by Bharat Kunduri, a professor at the Virginia Polytechnic Institute and State University, have been busy preparing for it.

“The changes in solar radiation that occur during a total solar eclipse can result in a ’thinning’ of the ionosphere,” Kunduri said. “During the eclipse, SuperDARN will operate in special modes designed to monitor the changes in the ionosphere at finer spatiotemporal scales.”

Kunduri’s team will compare SuperDARN’s measurements to predictions from computer models to answer questions about how the ionosphere responds to a solar eclipse.

HamSCI

While some experiments rely on massive radio telescopes, others depend more on people power. The Ham Radio Science Citizen Investigation, or HamSCI, is a NASA citizen science project that involves amateur or “ham” radio operators. On April 8, ham radio operators across the country will attempt to send and receive signals to one another before, during, and after the eclipse. Led by Nathaniel Frissell, a professor of Physics and Engineering at the University of Scranton in Pennsylvania, HamSCI participants will share their radio data to catalog how the sudden loss of sunlight during totality affects their radio signals.

This experiment follows similar efforts completed during the 2017 total solar eclipse and the 2023 annular eclipse.

“During the 2017 eclipse, we found that the ionosphere behaved very similar to nighttime,” Frissell said. Radio signals traveled farther, and frequencies that typically work best at night became usable. Frissell hopes to continue the comparison between eclipses and the day/night cycle, assessing how widespread the changes in the ionosphere are and comparing the results to computer models.

RadioJOVE

Some radio signals don’t bounce off of the ionosphere – instead, they pass right through it. Our Sun is constantly roiling with magnetic eruptions, some of which create radio bursts. These long-wavelength bursts of energy can be detected by radio receivers on Earth. But first they must pass through the ionosphere, whose ever-changing characteristics affect whether and how these signals make it to the receiver.

The RadioJOVE project is a team of citizen scientists dedicated to documenting radio signals from space, especially Jupiter. During the total solar eclipse, RadioJOVE participants will focus on the Sun. Using radio antenna kits they set up themselves, they’ll record solar radio bursts before, during, and after the eclipse.

During the 2017 eclipse, some participants recorded a reduced intensity of solar radio bursts. But more observations are needed to draw firm conclusions. “With better training and more observers, we’ll get better coverage to further study radio propagation through the ionosphere,” said Chuck Higgins, a professor at Middle Tennessee State University and founding member of RadioJOVE. “We hope to continue longer-term observations, through the Heliophysics Big Year and beyond.”

Find out more about the April 8, 2024, solar eclipse on NASA’s eclipse page.

By Miles Hatfield
NASA’s Goddard Space Flight Center, Greenbelt, Md.

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Radio Waves: The DLARC, NASA Citizen Science, PopShopRadio DRM to Europe, Hackers Disrupt Russian Radio, and Afghan Radio Closures

Radio Waves:  Stories Making Waves in the World of Radio

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 Trevor Robbins and Dennis Dura for the following tips:


Digital Library Of Amateur Radio And Communications Is A Treasure Trove (Hackaday)

Having a big bookshelf of ham radio books and magazines used to be a point of bragging right for hams. These days, you are more likely to just browse the internet for information. But you can still have, virtually, that big shelf of old ham books, thanks to the DLARC — the digital library of Amateur Radio and Communications.

A grant from a private foundation has enable the Internet Archive to scan and index a trove of ham radio publications, including the old Callbooks, 73 Magazine, several ham radio group’s newsletters from around the globe, Radio Craft, and manuals from Icom, Kenwood, Yaesu, and others.

There are some old QST magazines and the index to newer ones. You can find catalogs and military documents. We miss a lot of these old magazines and newsletters. For example, RCA’s “Ham Tips” is something you won’t find anything like anymore. Most of the material is in English, but there are some other languages represented. For example, the Dutch version of Popular Electronics is available. There’s also material in Afrikaans, Japanese, German, and Spanish. [Continue reading at Hackaday…]

Ham Radio Operators, We Need Your Help During Solar Eclipses! (NASA)

Ham Radio operators, we’re calling you! Members of the Ham Radio Science Citizen Investigation (HamSCI) will be making radio contacts during the 2023 and 2024 North American eclipses, probing the Earth’s ionosphere. It will be a fun, friendly event with a competitive element—and you’re invited to participate.

Both amateur and professional broadcasters have been sending and receiving radio signals around the Earth for over a century. Such communication is possible due to interactions between our Sun and the ionosphere, the ionized region of the Earth’s atmosphere located roughly 80 to 1000 km overhead. The upcoming eclipses (October 14, 2023, and April 8, 2024) provide unique opportunities to study these interactions. As you and other HamSCI members transmit, receive, and record signals across the radio spectrum during the eclipse, you will create valuable data to test computer models of the ionosphere.

For more information, go to https://hamsci.org/festivals-eclipse-ionospheric-science

DRM to Europe (DRM Consortium Newsletter)

The Canadian pop music station PopShopRadio in British Columbia has just announced that they will use the DRM standard to broadcast their best pop music towards Europe on the 5th March 2023 at 2000-2100 CET (GMT+1) on 5875 kHz (85kW) from Wooferton in the UK.

This radio station is specialised in transmissions of well-known pop music from the 60s and 70s or even before that. They are collecting the best tunes from various countries and offer them to the world using shortwave. This time round they wish to also use the DRM standard in SW to be able to reach distant parts of the globe in much better sound quality.

For more details please click here and here.

Hackers Disrupt Russian Radio (Radio World)

Air raid sirens broadcast in a dozen cities

Radio stations in several Russian cities were disrupted on Feb. 22 by the sound of air raid sirens and a warning of imminent missile strikes.

The broadcasts were reportedly heard in Belgorod, Chelyabinsk, Kazan, Magnitogorsk, Nizhny Novgorod, Novouralsk, Pyatigorsk, Stary Oskol, Syktyvkar, Tyumen, Ufa, and Voronezh, among other cities. Recordings of the broadcast were shared on the social media network Telegram and reported on by Meduza.

Meduza, an independent news agency now based in Latvia, was forced to move its operations out of Russia during the media crackdown that followed Russia’s February 2022 invasion of Ukraine. [Continue reading at Radio World…]

Radio Closures Hit Afghanistan Hard (Radio World)

Only 223 stations remain on air 18 months after Taliban regained control of the country

In the 18 months since the Taliban retook full control of Afghanistan, 177 radio stations have gone off the air in the country, displacing about 1,900 journalists and other employees.

In a statement released on World Radio Day 2023, the Afghan Independent Journalists Association noted that during the Islamic Republic period from 2004–2021, there were as many as 401 radio stations operating in Afghanistan. As the Taliban Insurgency increased its control of the country, about 56 stations went off the air before the Taliban took control and reinstated the Islamic Emirate of Afghanistan in August 2021.

Since then, around 120 stations have ceased broadcasting due to economic pressures. The AIJA stated that only 223 stations currently operate in the country.

With these stations going dark, more than 1,900 journalists and media workers are now unemployed in the country, include 1,075 women. [Continue reading at Radio World…]


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Today: HAARP to bounce signal off asteroid; SWLs/Hams asked to listen and record results

Many thanks to a number of SWLing Post readers who share the following announcement–also previously noted by Robert–from the University of Alaska Fairbanks (followed by an announcement from the ARRL):

HAARP to bounce signal off asteroid in NASA experiment (UAF News)

An experiment to bounce a radio signal off an asteroid on Dec. 27 will serve as a test for probing a larger asteroid that in 2029 will pass closer to Earth than the many geostationary satellites that orbit our planet.

The High-frequency Active Auroral Research Program research site in Gakona will transmit radio signals to asteroid 2010 XC15, which could be about 500 feet across. The University of New Mexico Long Wavelength Array near Socorro, New Mexico, and the Owens Valley Radio Observatory Long Wavelength Array near Bishop, California, will receive the signal.

This will be the first use of HAARP to probe an asteroid.

“What’s new and what we are trying to do is probe asteroid interiors with long wavelength radars and radio telescopes from the ground,” said Mark Haynes, lead investigator on the project and a radar systems engineer at NASA’s Jet Propulsion Laboratory in Southern California. “Longer wavelengths can penetrate the interior of an object much better than the radio wavelengths used for communication.”

Knowing more about an asteroid’s interior, especially of an asteroid large enough to cause major damage on Earth, is important for determining how to defend against it.

“If you know the distribution of mass, you can make an impactor more effective, because you’ll know where to hit the asteroid a little better,” Haynes said.

Many programs exist to quickly detect asteroids, determine their orbit and shape and image their surface, either with optical telescopes or the planetary radar of the Deep Space Network, NASA’s network of large and highly sensitive radio antennas in California, Spain and Australia.

Those radar-imaging programs use signals of short wavelengths, which bounce off the surface and provide high-quality external images but don’t penetrate an object.

HAARP will transmit a continually chirping signal to asteroid 2010 XC15 at slightly above and below 9.6 megahertz (9.6 million times per second). The chirp will repeat at two-second intervals. Distance will be a challenge, Haynes said, because the asteroid will be twice as far from Earth as the moon is. [Continue reading…]

The ARRL provides the following specific information about how SWLs and Hams can participate:

Amateur Radio Operators Invited to participate in Asteroid Bounce Experiment (ARRL News)

The High-frequency Active Auroral Research Program (HAARP) will be conducting a research campaign/experiment on December 27, 2022, with transmissions between 1100 – 2300 UTC (0200 – 1400 AKST).

[…]Actual transmit times are highly variable based on real-time ionospheric conditions and all information is subject to change. Currently, the Asteroid Bounce (2010 XC15) experiment will take place Dec. 27, 2022, from 1100 UTC to 2300 UTC; 9.6 MHz, LFM (linear FM), 0.5 Hz WRF (waveform repetition frequency), 30 kHz bandwidth. Reports recording echo are encouraged; demodulated recordings in .wav or .mp3 are recommended.

For real-time ionospheric conditions in Gakona, please consult ionograms from the HAARP Diagnostic Suite at https://haarp.gi.alaska.edu/diagnostic-suite.

Amateur radio and radio astronomy enthusiasts are invited to listen to the transmissions/echoes and submit reception reports to the HAARP facility at [email protected] and request a QSL card by mailing a report to:

HAARP
P.O. Box 271
Gakona AK 99586
USA

Click here to read this announcement on the ARRL News website.

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Radio Waves: Cellular Scale Antennas, Space Comms, New Proposed Ham License in Australia, and Mid Century Television

Apollo 11 (Photo: NASA)

Radio Waves:  Stories Making Waves in the World of Radio

Welcome to the SWLing Post’s Radio Waves, a collection of links to interesting stories making waves in the world of radio. Enjoy!


New miniature antenna can operate wirelessly inside of a living cell (Tech Explorist)

An intracellular antenna that’s compatible with 3D biological systems and can operate wirelessly inside a living cell.

A new study could allow scientists to create cyborgs at a cellular scale, thanks to MIT Media Lab for designing a miniature antenna that can operate wirelessly inside a living cell. This could have applications in medical diagnostics, treatment, and other scientific processes because of the antenna’s potential for real-time monitoring and directing cellular activity.

Scientists named this technology Cell Rover. It represents the first demonstration of an antenna that can operate inside a cell and is compatible with 3D biological systems.

Deblina Sarkar, assistant professor and AT&T Career Development Chair at the MIT Media Lab and head of the Nano-Cybernetic Biotrek Lab, said, “Typical bioelectronic interfaces are millimeters or even centimeters in size and are not only highly invasive but also fail to provide the resolution needed to interact with single cells wirelessly — especially considering that changes to even one cell can affect a whole organism.”

The size of the newly developed antenna is much smaller than a cell. The antenna represented less than .05 percent of the cell volume in research with oocyte cells. It converts electromagnetic waves into acoustic waves, whose wavelengths are five orders of magnitude smaller, representing the velocity of sound divided by the wave frequency — than those of the electromagnetic waves. [Continue reading…]

Space Audity (20,000 Hertz Podcast)

This episode was written and produced by Jack Higgins.

We’ve all heard the iconic recordings from the Apollo missions. But how exactly does NASA manage to run live audio between Earth and the moon? And how might we chat with astronauts on Mars and beyond? Featuring Astronaut Peggy Whitson, NASA Audio Engineer Alexandria Perryman, and Astrophysicist Paul Sutter.

Click here to listen on the 20,000 Hertz webite.

Australia: Proposed new ham radio licence (Southgate ARC)

Australia’s communications regulator ACMA has asked radio amateurs to comment on their proposed amateur class licence and considerations for higher power 1 kW operation

The ACMA say:

Following the extensive 2021 public consultation and associated response to submissions, we have released a consultation paper on the proposed amateur class licence and supporting operational arrangements, along with considerations for higher power operation. This is the next step in our review of regulatory arrangements for the operation of non-assigned amateur stations.

The draft class licence for amateur radio has been amended to incorporate changes suggested by representative bodies, amateur radio clubs and individual amateurs during the 2021 consultation.

The consultation paper, proposed class licence and details about how to make a submission are available on the ACMA website
https://www.acma.gov.au/consultations/2022-09/proposed-amateur-class-licensing-arrangements-and-higher-power-operation-consultation-312022

Submissions close COB, Tuesday 29 November 2022.

Questions about the consultation
If you have an important question about this consultation, please send it directly to [email protected]. Please note, we may use the Amateur radio update e-bulletin to answer frequently asked questions.

Subscribe to the ACMA Amateur Radio newsletter at
https://www.acma.gov.au/subscribe-our-newsletters

Mid Century Television – live, local and unpredictable late 1950s television (Southgate ARC)

In the late 1950s television networks ruled the airwaves from 7 to 11 PM, but outside of that timeslot television was live, local and unpredictable.

Jim Hanlon, W8KGI,  worked as a summer relief engineer at Cincinnati’s WCPO-TV from 1956 to 1958. At that time WCPO-TV did not have any video recording technology, so all local TV was live TV and provided a refreshing dose of live programming, equipment failures and production creativity that been lost in today’s pasteurized, homogenized TV ecosystem.

Join Jim as he recalls what it like producing live TV programming in the early days of television broadcasting.

Click here to view on YouTube.

Help keep communications history alive by becoming a member of the Antique Wireless Association at: https://www.antiquewireless.org/homepage/


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Quindar Tones: From the SWLing Post Archives

I’ve been listening to Apollo 11 in real-time, as mentioned in a previous post. Today, I’ve been listening to NASA communications as the Eagle landed on the moon (53 years ago). 

Of course, any of those Apollo era comms include loads of Quindar Tones, so this reminded me of the following post from the SWLing Post Archives. I thought I might resurrect it for those who might not have caught it when first published. Enjoy:


Quindar Tones: Those iconic NASA PTT confirmation beeps

Apollo 11 (Photo: NASA)

Yesterday, my family watched the successful launch of the NASA Demo-2 SpaceX Dragon via YouTube.

As astronauts Robert Behnken and Douglas Hurley communicated with Mission Control, we heard PTT confirmation beeps after each transmission.

Those beeps, of course, reminded me of past NASA missions and those iconic confirmation tones we heard in audio from the Mercury, Gemini, and Apollo days all the way into Space Shuttle missions.

Quindar Tones

Source: honeysucklecreek.net

Last year, after spending a couple of days at the US Space and Rocket Center (and attending the Huntsville Hamfest), I heard numerous NASA audio clips and that lead me down the path of researching those PTT confirmation tones.

Turns out, they’re called “Quindar Tones.”

I couldn’t find any information about Quindar Tones at the US Space and Rocket Center–although, admittedly, the place is massive and I could have easily overlooked it–so I did a little research when I returned home.

I found this archived post on the NASA’s Apollo Lunar Surface Journal wesbite:

Re: Apollo beeps

Journal Contributor Mark Burckhard writes:

“I’ve always wondered what purpose the ‘beeps’ served that one heard intermittently during the voice communications with the Command and Lunar Modules during the Apollo missions, as well as other space missions.”

Journal Contributor Mike Dinn provides an MP3 clip ( 123k ) from a network audio check that includes numerous Quindar Tones.

Journal Contributor Markus Mehring replies:

“‘Other space missions’ is quite an accurate observation, since the ‘beeps’, in fact, are still in use today on Shuttle flights, at least on the UHF frequencies.”

“These beeps are called ‘Quindar-Tones’. Their purpose is to trigger the ground station transmitters when there is an outgoing transmission from Earth. The CapCom in the Mission Control Center, who is taking care of communications with the crew, uses his communication gear in a PTT mode exclusively. ‘PTT’ is short for Push-To-Talk, which means that the CapCom presses a button every time and as long as he wants to talk. (The crews back during Apollo – and also today – usually communicate via PTT as well, but they also have the so-called ‘VOX mode’ at their disposal, in which their microphones are voice-triggered by a certain adjustable threshold volume levels. VOX is used when they don’t necessarily have their hands free.)

When the CapCom presses his PTT button to start a transmission, an intro tone (2.525KHz sine wave with a length of 250ms) is generated and triggers the ground station transmitters to send. And when he is finished talking and releases the button again, a slightly lower outro tone (2.475KHz, sine, 250ms) is generated to trigger the ground station transmitters to turn off. So in short, these are remote control trigger tones.

CU! Markus”

I then discovered this article via the Internet Archive Wayback Machine, which gave more detail about the Quindar Tones’ name and some of the idiosyncrasies of the system:

The story behind the “Beep”

Steve Schindler, an engineer with voice systems engineering at NASA’s Kennedy Space Center, offers the following history of [Quindar Tones] origins.

“Quindar tones, named after the manufacturer of the tone generation and detection equipment, are actually used to turn on and off, or “key,” the remote transmitters at the various tracking stations (Merritt Island Launch Area–now Kennedy Space Center, Bermuda, Australia, etc.) that were used to communicate with the Mercury through Apollo spacecraft and, in some cases, are still used with the Space Shuttle.”

[…]”Although it usually worked well, there were a couple of peculiarities with this system. If the transmitter was keyed and the telephone line connection broken, the transmitter would never get the tone to turn off. To prevent this there was a “transmitter on” light at each remote site that would come on when the transmitter was keyed. Someone was supposed to monitor the circuit and if the audio dropped, but the “transmitter on” light was still on, they would have to manually unkey the transmitter. Also, just before communications was handed over to a new tracking station, the key-unkey tone pair was sent 10 times to ensure that everything was functioning correctly. This was done before the audio was patched to the tracking station’s line so it wasn’t heard in the control room or on NASA Select audio.

The Quindar system was actually built from a piece of equipment that was used to put multiple teletype circuits on a single phone line by means of frequency domain multiplexing. Because replacement parts are no longer available, an “out-of-band signaling” system was installed in 1998 for the transmitters located in the U.S. This system uses a continuous tone that is below the normal audio frequency range. When the tone is present, the transmitters are keyed. When the tone is not present, the transmitters are unkeyed. It worked fine, but the Astronaut Office complained about the lack of tones which everyone had become accustomed to as an alert that a transmission was about to start. So, the Quindar tone generator, which was still installed in case it was necessary to key the transmitters at an overseas site, was re-enabled.

Even though you won’t hear the same Quindar tones in present-day space missions, you can listen until your heart is content at the website Apollo In Real Time.

The Internet Archive also has a massive collection of Apollo audio free to stream and download.

Quindar Music

If you’re fascinated with the NASA audio soundscape in general, you might check out the electronic music duo Quindar featuring longtime Wilco member Mikael Jorgensen, and art historian-curator James Merle Thomas.

Quindar: Mikael Jorgensen & James Merle Thomas. Photo by Chad Ress, Spacesuits by Cassandra C. Jones

Science Friday featured an extended interview with the group in 2017. If you love electronic music–especially if you’re a fan of Wilco, it’s well worth a listen:

Check out their latest video, Choco Hilton:

Speaking of Mikael Jorgensen and Wilco, I should note here that their album yankee hotel foxtrot has a deep shortwave motif.

Anyone else fascinated with Quindar Tones and NASA audio? Feel free to comment and share any other resources or projects you’ve found.


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Radio Waves: DRM Demo in Australia, Decoding the JWST, the ARDC, and EV Makers Dropping AM Radio

Radio Waves:  Stories Making Waves in the World of Radio

Welcome to the SWLing Post’s Radio Waves, a collection of links to interesting stories making waves in the world of radio. Enjoy!


Australia Demonstrates DRM on AM, FM (Radio World)

Since September 2020, ABC Radio has been quietly trialing DRM technology in Victoria

The public-service Australian Broadcasting Corp. and its transmission contractor BAI Communications Transmission Network hosted a public demonstration of Digital Radio Mondiale broadcasts on June 29, 2022. ABC highlighted the use of DRM on both AM and FM in Wagaratta, Victoria.

According to the DRM Consortium, the demonstration was the culmination of almost two years of COVID-impacted work to assess the performance of DRM services in Australia’s VHF and medium-wave bands.

Previously, the Australian Amateur Radio Experimenters Group reported that AREG member Steve Adler (VK5SFA) had been monitoring “a very un-publicized Digital Radio Mondiale (DRM) trial” on 747 kHz from Wangaratta in August 2021.

The Australian Communications and Media Authority provided ABC with a license variation to conduct the DRM 30 trials from September 1, 2020, to August 31, 2022.

At the public demonstration, senior representatives from the public, commercial and community radio sectors, along with regulators and other interested parties, were able to hear and see the capabilities of DRM broadcasting on AM from Dockers Plains and on FM from Mount Baranduda. They were also able to review the transmission equipment at Wagaratta.[Continue reading…]

Also check out the DRM Consortium’s article on this same topic.

Decoding James Webb Space Telescope (Daniel Estévez)

The James Webb Space Telescope probably needs no introduction, since it is perhaps the most important and well-known mission of the last years. It was launched on Christmas day from Kourou, French Guiana, into a direct transfer orbit to the Sun-Earth L2 Lagrange point. JWST uses S-band at 2270.5 MHz to transmit telemetry. The science data will be transmitted in K-band at 25.9 GHz, with a rate of up to 28 Mbps.

After launch, the first groundstation to pick the S-band signal from JWST was the 10 m antenna from the Italian Space Agency in Malindi, Kenya. This groundstation commanded the telemetry rate to increase from 1 kbps to 4 kbps. After this, the spacecraft’s footprint continued moving to the east, and it was tracked for a few hours by the DSN in Canberra. One of the things that Canberra did was to increase the telemetry rate to 40 kbps, which apparently is the maximum to be used in the mission.

As JWST moved away from Earth, its footprint started moving west. After Canberra, the spacecraft was tracked by Madrid. Edgar Kaiser DF2MZ, Iban Cardona EB3FRN and other amateur observers in Europe received the S-band telemetry signal. When Iban started receiving the signal, it was again using 4 kbps, but some time after, Madrid switched it to 40 kbps.

At 00:50 UTC on December 26, the spacecraft made its first correction burn, which lasted an impressive 65 minutes. Edgar caught this manoeuvre in the Doppler track.

Later on, between 7:30 and 11:30 UTC, I have been receiving the signal with one of the 6.1 metre dishes at Allen Telescope Array. The telemetry rate was 40 kbps and the spacecraft was presumably in lock with Goldstone, though it didn’t appear in DSN now. I will publish the recording in Zenodo as usual, but since the files are rather large I will probably reduce the sample rate, so publishing the files will take some time.

In the rest of this post I give a description of the telemetry of JWST and do a first look at the telemetry data. [Continue reading…]

Helping Secure Amateur Radio’s Digital Future (Hackaday)

The average person’s perception of a ham radio operator, assuming they even know what that means, is more than likely some graybeard huddled over the knobs of a war-surplus transmitter in the wee small hours of the morning. It’s a mental image that, admittedly, isn’t entirely off the mark in some cases. But it’s also a gross over-simplification, and a generalization that isn’t doing the hobby any favors when it comes to bringing in new blood.

In reality, a modern ham’s toolkit includes a wide array of technologies that are about as far away from your grandfather’s kit-built rig as could be — and there’s exciting new protocols and tools on the horizon. To ensure a bright future for amateur radio, these technologies need to be nurtured the word needs to be spread about what they can do. Along the way, we’ll also need to push back against stereotypes that can hinder younger operators from signing on.

On the forefront of these efforts is Amateur Radio Digital Communications (ARDC), a private foundation dedicated to supporting amateur radio and digital communication by providing grants to scholarships, educational programs, and promising open source technical projects. For this week’s Hack Chat, ARDC Executive Director Rosy Schechter (KJ7RYV) and Staff Lead John Hays (K7VE) dropped by to talk about the future of radio and digital communications. [Continue reading…]

Interference causes EV makers to drop AM radio (Radio World via the Southgate ARC)

Radio World reports the Electromagnetic Interference generated by Electric Vehicles is causing some EV automakers to drop AM (medium wave) radio

The article says:

Some EV automakers are dropping AM altogether due to audio quality concerns, but that’s just one piece of the puzzle as radio continues to fight for space on the dash.

“As carmakers increase electric vehicle offerings throughout their lineups, the availability of AM radio to consumers is declining,” said Pooja Nair, communications systems engineer with Xperi Corp., in a Radio World guest commentary. “This is because the effects of electromagnetic interference are more pronounced in EVs than in vehicles with internal-combustion engines.”

In other words, electromagnetic frequencies generated by EV motors occupy the same wavelength as AM radio signals. The competing signals clash, effectively cancelling each other out. As EV motors grow more powerful, AM static tends to increase.

Read the full story at
https://www.radioworld.com/news-and-business/headlines/why-are-some-automakers-ditching-am-radio


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Radio Waves: First Transatlantic Signal 120 Years Today, 100 Years of German Radio, NASA Laser Communications, and Ham Transmitter on the Moon

Marconi watching associates raising the kite (a “Levitor” by B.F.S. Baden-Powell[47]) used to lift the antenna at St. John’s, Newfoundland, December 1901 (via Wikipedia)

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 Trevor R, Andrea Bornino, Wilbur Forcier, and the Southgate ARC for the following tips:


First radio transmission sent across the Atlantic Ocean (History.com)

Italian physicist and radio pioneer Guglielmo Marconi succeeds in sending the first radio transmission across the Atlantic Ocean, disproving detractors who told him that the curvature of the earth would limit transmission to 200 miles or less. The message–simply the Morse-code signal for the letter “s”–traveled more than 2,000 miles from Poldhu in Cornwall, England, to Newfoundland, Canada.

Born in Bologna, Italy, in 1874 to an Italian father and an Irish mother, Marconi studied physics and became interested in the transmission of radio waves after learning of the experiments of the German physicist Heinrich Hertz. He began his own experiments in Bologna beginning in 1894 and soon succeeded in sending a radio signal over a distance of 1.5 miles. Receiving little encouragement for his experiments in Italy, he went to England in 1896. He formed a wireless telegraph company and soon was sending transmissions from distances farther than 10 miles. In 1899, he succeeded in sending a transmission across the English Channel. That year, he also equipped two U.S. ships to report to New York newspapers on the progress of the America’s Cup yacht race. That successful endeavor aroused widespread interest in Marconi and his wireless company. Continue reading

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