Category Archives: Nostalgia

Radio Waves: The Future of On-Air DJs, SDR Comparison, Radios That Never Were, and an Internet Radio Player for Linux

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 Jack Kratoville, Dave Zantow, and Dennis Dura for the following tips:


Live From Everywhere? The American Radio DJ In An On-Demand World (1A)

iHeartMedia owns and operates 858 broadcast radio stations, serving more than 150 markets throughout the U.S. The company reaches over a quarter billion monthly listeners ?in America.

In January, news hit that iHeartMedia was reassessing its ability to adapt to the modern music industry. The company said that it plans to make “significant investments … in technology and artificial intelligence.”

However, its on-air DJs were caught off guard when they found out that the company’s restructuring plan didn’t include them.

Streaming platforms has ushered in the digital age of music where each person make their own playlists. What does that mean for the future of the on-air DJ in the United States?

Click here to listen to the audio.

A comprehensive lab comparison between multiple software defined radios (RTL-SDR.com)

Librespace, who are the people behind the open hardware/source SatNOGS satellite ground station project have recently released a comprehensive paper (pdf) that compares multiple software defined radios available on the market in a realistic laboratory based signal environment. The testing was performed by Alexandru Csete (@csete) who is the programmer behind GQRX and Gpredict and Sheila Christiansen (@astro_sheila) who is a Space Systems Engineer at Alexandru’s company AC Satcom. Their goal was to evaluate multiple SDRs for use in SatNOGS ground stations and other satellite receiving applications.

The SDRs tested include the RTL-SDR Blog V3, Airspy Mini, SDRplay RSPduo, LimeSDR Mini, BladeRF 2.0 Micro, Ettus USRP B210 and the PlutoSDR. In their tests they measure the noise figure, dynamic range, RX/TX spectral purity, TX power output and transmitter modulation error ratio of each SDR in various satellite bands from VHF to C-band.

The paper is an excellent read, however the results are summarized below. In terms of noise figure, the SDRplay RSPduo with it’s built in LNA performed the best, with all other SDRs apart from the LimeSDR being similar. The LimeSDR had the worst noise figure by a large margin.[]

Radios that Never Were (N9EWO)

Dave Zantow (N9EWO) shares a new page on his website devoted to receivers and amateur transceivers that never quite made it to the marketplace. []

Shortwave: A Modern Internet Radio Player for Linux (It’s Floss)

Brief: Shortwave is a modern looking open source Internet Radio player for Linux desktop. We take a quick look at it after its recent stable release.

Shortwave is an interesting open-source radio player that offers a good-looking user interface along with a great experience listening to the Internet stations. It utilizes a community-powered database for the Internet stations it lists.

Shortwave is actually a successor of the popular radio app for Linux, Gradio. Its developer Felix joined GNOME and discontinued Gradio to create Shortwave from scratch in Rust programming language. If you were using Gradio as your preferred Internet radio station player, you can import the library as well.

Recently, Shortwave released its first stable version and seems to push new updates after that as well.[]


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Jon’s Sony CRF-160: Should it stay or should it go?

Many thanks to SWLing Post contributor, Jon Helberg, who writes:

Greetings!

During our COVID-19 shutdown I located my old Sony CRF-160 which has been closet bound for some years now, however it has always worked as new.

[…]Other than the broken toggle switch for the light, all knobs and dials work, are present and accounted for. Upon powering up after many years in storage it lights up just fine and appears to be operational, however once powered up the volume control and every knob I turned brought loads of static to the speakers indicating corrosion of contacts, etc., so I just shut it down without testing any further.

The power cord has become a bit sticky as some plastics and rubber do over time, but of course that easily can be cleaned up. The entire radio case and front cover is intact (nothing broken, warped or bent), with the standard wear marks on the outside but otherwise fine. I do not have the box, manual, or any other accessories. The telescoping antenna looks as if it may have been slightly bent at one time (not kinked), and it extends and retracts just fine.

I have owned this radio since new but raised a family who used it as well (kids broke the light switch), so I do know it worked the last time I used it before storage, but I haven’t used it since other than just turning it on as I have mentioned above.

Photos

I don’t do much with radio any longer other than listening to AM, therefore this radio had no value to me other than sentimental (purchased it after an Army tour with ASA as a radio intercept operator), therefore looking for your thoughts on whether it’s worth getting repaired, or just focus on selling on eBay, or somewhere else?

I would have no idea as to its value, who could repair it, or the cost involved.

Tough decision, Jon, so thanks in advance for allowing me to share your inquiry here with the SWLing Post community.

I’m hoping readers can comment with thoughts on the actual value of the radio, the availability of spare parts (toggle switch), and their thoughts on whether you should keep or sell it.

I’m a nostalgic guy, so my inclination would be to keep it unless you really wanted to liquidate it for funds, or you simply have no attachment to it at all.  As custodians of vintage radios, I also feel we should try to keep them in working order.

In terms of repairs, I know my good friend Vlado (at HamRadio.repair) could re-cap it and make it like new. If you could locate a parts radio or simply a similar toggle switch, Vlado could sort that out too I’m sure.

Post readers: What are your thoughts? Should Jon keep the Sony or sell it? Are parts easy to find. Please comment and include any relevant links!

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Adam’s Andes DXers International certificate

Many thanks to SWLing Post contributor, Adam Smith, who shares the following certificate and writes:

I was going to share a piece of history I just came across going through some of my shortwave radio boxes. Lots of QSLs but this its a membership in ANDES DX Club!

Good times!

Thank you for sharing this bit of shortwave radio nostalgia, Adam! Any others in the SWLing Post community belong to the Andes DXers International? Do you still have your certificate? Please comment!

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CPRM Lisboa: Another mystery signal solved

In response to our latest mystery utility signal challenge, SWLing Post contributor, Dean Bianco replies:

This is the musical marker for CPRM Lisboa, a radiotelephone terminal that provided overseas telephone and telegraph communications in the days prior to satellites.

I remembered the non-broadcast HF frequencies being loaded to bursting with many of these radio services. When not scrambled for privacy, one could hear a telephone call in progress. Instead of a musical IS such as this one, most were loop tape voice ID’s in several languages (almost always including English). So naturally these musical loops made it quite difficult to know what exactly one was hearing, to say the least!

To verify check out the following embedded audio file made by Willi Passmann  (via the excellent UtilityRadio.com website):

Once again, thanks to Dean Bianco for solving yet another mystery! Obviously, Dean is a Black Belt SWL and DXer!

FYI: I’ve received a number of emails from readers who really enjoy these mystery signals. Since we all seem to have more time at home these days, I’ll plan to keep them coming!


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One amazing SWL QSL card from 1995

Many thanks to SWLing Post contributor, Ulis (K3LU), who shares the following note:

I have one of the most detailed SWL QSL cards that was given to me by Fred Laun, K3ZO who is a very well known Contester and DXer. A retired USIA officer, Fred had an amazing career.

Fred runs the ARRL Third Area QSL Bureau and I am one of his sorters. We have long shared many common interests and one day he surprised me with this QSL card (see below). [L]ike you and I, Fred started out SWLing as a kid.

I suspect the SWL who wrote this card is now QRT. But it’s spectacular that he wrote all of this and with a real typewriter:

Click to enlarge

Click to enlarge

Wow, Ulis! What a treasure of a QSL card! Thank you so much for taking the time to share it with us.

I can’t imagine using a typewriter to pack so much information onto a QSL card. I struggled using a typewriter for letter sized pages!

I am curious if anyone knows the SWL who created this card: Mr. Hank Holbrook. If so, please comment!

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Radio Waves: Quantum Sensors, Sinking Mi Amigo, Submarine Radio Network, and Video Games Over The Air

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’sRadio Waves, a collection of links to interesting stories making waves in the world of radio. Enjoy!

Many thanks to SWLing Post contributors Kim Elliott and Dennis Dura for the following tips:


Scientists create quantum sensor that covers entire radio frequency spectrum (Phys.org)

A quantum sensor could give Soldiers a way to detect communication signals over the entire radio frequency spectrum, from 0 to 100 GHz, said researchers from the Army.

Such wide spectral coverage by a single antenna is impossible with a traditional receiver system, and would require multiple systems of individual antennas, amplifiers and other components.

In 2018, Army scientists were the first in the world to create a quantum receiver that uses highly excited, super-sensitive atoms—known as Rydberg atoms—to detect communications signals, said David Meyer, a scientist at the U.S. Army Combat Capabilities Development Command’s Army Research Laboratory. The researchers calculated the receiver’s channel capacity, or rate of data transmission, based on fundamental principles, and then achieved that performance experimentally in their lab—improving on other groups’ results by orders of magnitude, Meyer said.

“These new sensors can be very small and virtually undetectable, giving Soldiers a disruptive advantage,” Meyer said. “Rydberg-atom based sensors have only recently been considered for general electric field sensing applications, including as a communications receiver. While Rydberg atoms are known to be broadly sensitive, a quantitative description of the sensitivity over the entire operational range has never been done.”[]

Forty years ago today Sheerness lifeboat crew rescued Radio Caroline DJs from the sinking Mi Amigo (Kent Online)

It was the original ‘ship that rocked.’ But 40 years ago today (Thursday)the Mi Amigo, home to original pop pirates Radio Caroline, finally disappeared beneath the waves in a violent force 10 storm.

In a daring rescue which lasted 12 hours in appalling weather, the crew of the Sheerness lifeboat saved the lives of everyone onboard – including the ship’s canary.

Leading the operation was colourful RNLI coxswain Charlie Bowry, who was later presented with the Institute’s coveted silver medal.

It was during the day that the radio station’s 60-year-old ship started dragging its anchor and drifted 10 nautical miles onto the Long Sand sandbank off Southend.

As the tide rose, the ship started to float free. But the bottom of the boat began being buffeted on the seabed with such a force the steel plates sprung a leak and water gushed into the engine room.

When the bilge pumps couldn’t cope, the three British DJs and a Dutch engineer called the Coastguard who dispatched Sheerness lifeboat the Helen Turnbull.[]

The Radio Network that Allowed Communication with Submarines (Interesting Engineering)

Communicating with covert fleets during WWII required some special equipment.

What do you do when you need to communicate with a crew of 50 sailors submerged in a submarine in an undisclosed location across the world’s oceans? That was a difficult question to answer for Navy leaders in WWII.

Radio waves don’t easily travel through saltwater, which meant that getting active communication with a submarine crew meant making the submarine surface an antenna. This was the obvious solution, but it made a previously covert submarine now a visible target.

[…]Engineers tasked with finding a more covert solution soon discovered that radio waves with low frequencies, around 10 kHz, could penetrate saltwater to depths up to around 20 meters. They realized that if the transponders on submarines were switched to these frequency ranges, then they communicate with leadership on land.

The problem with this idea was that creating and broadcasting these low-frequency radio waves required massive antennas. Essentially, the lower the frequency of a radio wave, the longer and larger the antenna is required to be.[]

You Could Download Video Games From the Radio in the 1980s (Interesting Engineering)

Certain radio programs broadcast the raw data to video games for viewers to download.

[…]In 1977, the world’s first microprocessor-driven PCs were released. These were the Apple II, the Commodore PET, and the TRS-80. All these machines had one thing in common – they used audio cassettes for storage.

Hard drives at the time were still quite expensive, and everyone at the time had access to cheap audio cassettes. Early computer designers actually flaunted cassette storage as it aided in the early adoption of personal computers. As PCs became more common, so to did the emergence of their use as video game machines.

As the 1980s rolled around, engineers at the Nederlandse Omroep Stichting, NOS, a Dutch broadcasting organization, realized something incredible. Since computer programs and video games were stored on audio cassettes, it meant that their data could be transmitted with ease over the radio. They started taking programs and video games and setting up broadcasts where people could “download” games onto their own personal computers.

The audio that was transmitted would’ve sounded reminiscent of a dial-up modem booting up.

[…]NOS started a radio program specifically for transmitting gaming data called “Hobbyscoop,” and it became incredibly popular. The company even created a standard cassette format called BASICODE to ensure computer compatibility.

Eventually, transmitting games through computers became so popular that radio shows popped up all around the world. A Yugoslovik station called “Ventilator 202” broadcasted 150 programs between 1983 and 1986. As the practice evolved, it became less of a novelty and rather a practical way for people to share calculation programs, educational tools, encyclopedias, and even flight simulators.[]


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Smithsonian Open Access: Take a deep radio nostalgia dive!

“Radio owned by Herman and Minnie Roundtree” (Source: Smithsonian Open Access)

Many thanks to SWLing Post contributor, Balázs Kovács, who shares the following announcement:

[Check out the] Smithsonian Open Access, where you can download, share, and reuse millions of the Smithsonian’s images—right now, without asking. With new platforms and tools, you have easier access to nearly 3 million 2D and 3D digital items from our collections—with many more to come. This includes images and data from across the Smithsonian’s 19 museums, nine research centers, libraries, archives, and the National Zoo.

As Balázs points out, there are hundreds of radio photos in the archive.

What a treasure trove! Since many of us are sheltering at home, it’s the perfect time to take a deep dive into the SOA archive!  Thank you for sharing!

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