Category Archives: Ham Radio

Jack finds that chokes have a huge impact on switching power supply noise

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These “Wall Wart” type adapters can create a lot of RFI

Many thanks to SWLing Post contributor, Jack Dully, who writes:

I was putting some things in my radio junk parts box and came across some chokes. So I tried a test with my Tecsun PL-880 on battery and the Tecsun supplied switching AC adapter, with and without chokes on the adapter.

WOW!

I tuned to a vacant station on battery power with headphones on. Then on AC power, the hash and static were incredible. Putting one large choke on the adapter power cord, wrapped about four times and it decreased considerably. So I attached a second choke and once again the static & hash decreased even more, almost to the point of sounding like I was running just on battery power.

Those chokes really do work well.

Thank you for sharing this, Jack. I almost never operate my portables while connected to a power supply, so I often forget about the importance of using a choke with inexpensive, lightweight radio power supplies. Thing is, so many things in our houses and shacks are powered by these QRM generators. In the shack, I’ve added chokes I’ve picked up at hamfests to a number of various power supplies. It does certainly help decrease the noise level. I’ve even used them on power cords for other appliances in the house that tend to spew RFI.

If you ever find a deal on chokes at a hamfest or electronics store, grab some. They can be an affordable solution for those noisy power supplies we still rely on.

Thank you for the reminder and  tip, Jack!

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Radio Waves: Friedrichshafen Cancelled, Coast Guard Seeks Rare Diode, Kindred Spirits in DXing, and DRM Pitch for India’s FM Band

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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 Dennis Dura, Ron Chester, and Mangosman for the following tips:

Ham Radio Verbindung 2021 kommt nicht zustande/Ham Radio convention 2021 has been cancelled (Messe Friedrichshafen)

[Note that the following is a Google translation of the original piece in German]

Ham Radio cannot take place this year either – other trade fair events remain on course

Due to the current corona developments, Messe Friedrichshafen cannot hold the international amateur radio exhibition Ham Radio in the planned period from June 25 to 27, 2021. Instead, the industry meeting will take place from June 24 to 26, 2022.

“The decision was not an easy one for us, but a trade fair like Ham Radio lives from its high level of internationality. Due to the current uncertainties in the travel sector, implementation is currently not feasible, ”explains Klaus Wellmann, Managing Director of Messe Friedrichshafen. All other trade fair events in the second quarter of 2021 and beyond should take place as planned at the present time. “A large percentage of our customers from these industries are still on board at the 2021 events. Together we hope that the immunization of society continues to gain momentum and that we can carry out the events with appropriate protection and hygiene concepts. “

Further information at: www.messe-friedrichshafen.de and http://www.hamradio-friedrichshafen.de/.

Rare Diode Threatens Coast Guard’s Arctic Ambitions (Hackaday)

The United States Coast Guard heavy icebreaker Polar Star is literally a one-of-a-kind ship. After its sister Polar Sea was deactivated in 2010 it became the most powerful icebreaker in the fleet, and one of only two US icebreakers capable of operating in the treacherous polar regions. The vessel is critical to protecting America’s scientific and economic interests in the Arctic, but according to a recent article in Business Insider, the ship’s age and scarcity of spare parts is making an already difficult mission even harder.

In the article, Captain William Woityra specifically mentions that the ship’s diesel-electric propulsion system is running on borrowed time as the diodes used in its AC/DC rectifier are no longer manufactured. With none remaining in the Coast Guard’s inventory, the crew has had to turn to eBay to source as many spares as possible. But once their hoard runs out, Captain Woityra fears his ship will be dead in the water[…]

A toast to the fools standing high on broadcasting’s hill (Doc Searls Weblog)

In Winter, the cap of dark on half the Earth is cocked to the north. So, as the planet spins, places farther north get more night in the winter. In McGrath, Alaska, at close to sixty-three degrees north, most of the day is dark. This would be discouraging to most people, but to Paul B. Walker it’s a blessing. Because Paul is a DXer.

In the radio world, DX stands for for distance, and DXing is listening to distant radio stations. Thanks to that darkness, Paul listens to AM stations of all sizes, from Turkey to Tennessee, Thailand to Norway. And last night, New Zealand. Specifically, NewsTalk ZB‘s main AM signal at 1035 on the AM (what used to be the) dial. According to distancecalculator.net, the signal traveled 11886.34 km, or 7385.83 miles, across the face of the earth. In fact it flew much farther, since the signal needed to bounce up and down off the E layer of the ionosphere and the surface of the ocean multiple times between Wellington and McGrath. While that distance is no big deal on shortwave (which bounces off a higher layer) and no deal at all on the Internet (where we are all zero distance apart), for a DXer that’s like hauling in a fish the size of a boat.

In this sense alone, Paul and I are kindred souls. As a boy and a young man, I was a devout DXer too. I logged thousands of AM and FM stations, from my homes in New Jersey and North Carolina. (Here is a collection of QSL cards I got from stations to which I reported reception, in 1963, when I was a sophomore in high school.) More importantly, learning about all these distant stations sparked my interest in geography, electronics, geology, weather, astronomy, history and other adjacent fields. By the time I was a teen, I could draw all the states of the country, freehand, and name their capitals too. And that was on top of knowing on sight the likely purpose of every broadcast tower and antenna I saw.[…]

DRM Makes Its Pitch for India’s FM Band (Radio World)

In India, where regulators have been working toward recommending a standard to digitize the FM band, Digital Radio Mondiale is presenting its case.

DRM has been conducting trials and demos since late February, when a digital radio transmission with three audio services and Journaline text information went live in Delhi alongside existing analog FM transmissions.

It said it is also showing the possibility of extending a shared transmitter infrastructure by broadcasting up to six individual DRM signals or blocks, carrying up to 18 audio services plus 6 multimedia services, being broadcast from one FM transmitter and antenna. It said the number of individual DRM signals is only limited by the bandwidth of the transmitter. Each signal can have its own power level, and gaps in the spectrum are possible, as are individual SFN networks per DRM signal.

“The transmission is part of an extensive trial and demonstration of DRM conducted by Prasar Bharati and its radio arm, All India Radio (AIR), with the help of the DRM Consortium and its local and international members,” DRM stated in a press release. “The test was officially launched on Feb. 24 and 25 at the headquarters of All India Radio in New Delhi.”

The test was requested by regulator TRAI and the Ministry of Information & Broadcasting.

DRM officials said a presentation to AIR’s committee showed DRM in the FM band on various car radios including line-fit, aftermarket, standalone receivers, mobile phones and tablets. A head unit from Mobis, upgraded for FM via firmware, was installed in a Hyundai Verna. DRM said, “The reception was found to be excellent for over 15 km radius with just 100 W of DRM power in digital,” including 5.1 surround sound test broadcasts on DRM.[…]

You might also check out the article HD Radio and Digital FM in India at Radio World.

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Social DXing: Looking back at one very radio-active year

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One year ago, I posted an article about making the most of social distancing as the world started locking down due to the rapid spread of Covid-19. Here in March 2021, the news is looking much better: vaccines are being distributed at a record pace across the globe and number of cases and deaths are mostly on the decline.

Looking back

As I look back at the Social DX Bucket List I made last year, I’m happy to see that I actually accomplished about 64% of the goals I listed. I knew some of those goals would take well over a year to achieve (the QRP EME one especially).

In particular, I’m chuffed that I braved up and started doing Parks On the Air (POTA) and Summits On The Air (SOTA) activations in CW (Morse Code). That was a huge step for me and I’ll freely admit: I was nervous about it. But in July 2020, I managed to do my first CW activation and since then it has become my choice mode of operating in the field. CW is such a simple mode and so efficient–plus it gives me a sense of connection with the roots of radio communications.

I also accomplished a few things I never set out to do:

Not a typical radio year for me

In a “normal” year, I do way more SWLing than I do ham radio activity.

Last year, I started doing caregiving for my parents in my hometown–I’m typically there 2-3 days a week. While I’ve done shortwave listening and even a little MW DXing in my hometown, I typically don’t have a lot of time, especially in the evening hours. I just want to hit the sack early. QRM is also debilitating there and while I’d like to install a permanent Loop On Ground antenna to mitigate the noise (you heard that right, Andrea!) I’m not entirely sure I’d even have the dedicated listening time to justify it. When I’m there, I like to spend quality time with my folks.

In general, I’ve had much less free time. Indeed, if you’ve written to me via email, you’ll know this based on how long it’s taken me to reply. It can take several weeks especially if the reply requires a detailed response (which many do).

En route to, and on the way back from my hometown, I’ve found that doing park and summit activations has been very rewarding. Last year, I believe I completed a total of 82 park activations.

POTA has given me an excuse to explore public lands I’ve never visited before. Plus, I love nothing more than taking radios to the field–both receivers and transceivers.

Hamming and SWLing

At the end of the day, I’m an SWL and a ham radio operator. I find the two activities complimentary.

Side note: As I mentioned in my Winter SWL Fest presentation this year, it saddens me when I receive angry emails from readers after I post items that are ham radio related. We’ve upwards of 7,000-10,000 daily readers on the SWLing Post and the number of complaints are a teeny, tiny fraction of our readership. I only receive messages like this about once a month and they typically say something akin to “I don’t like the ham radio stuff, so if you don’t stop posting it, I’m leaving!” (FYI: That’s a real quote taken from the last one I received in January). I can only assume that at some point in the past, a ham radio operator has been a jerk to this and other radio enthusiasts. It’s a shame, too. I hate seeing the negative impact of one loud troll compared with the encouragement and support of much better people. All of my ham radio friends are not only supportive of SWLing, but almost all got their start in radio via the shortwaves. I’m certainly a case in point.

I love all things radio and I believe the SWLing Post is a reflection of that. If it offends you, then it might make sense to surf somewhere else.

Now where was I? Oh yeah…

POTA and SOTA outings have helped to satisfy some of my travel cravings as well. I miss going to radio conventions, hamfests, and especially traveling internationally with my family. We are a family who love national parks, forests, and other wildlife areas. Having an excuse to explore public lands we haven’t visited before has been amazing fun.

After POTA activations, I’ll often do a little SWLing since I already have an external antenna up and it’s typically connected to a good general coverage transceiver in a spot with zero RFI or QRM. I’ve especially enjoyed my DXing sessions with the superb Icom IC-705.

Listening habits

One indicator that I did less radio listening last year was the low number of recordings I made. I checked my audio folder recently and saw that I only made a couple dozen recordings–most were staple broadcasters, not rare or special DX.

At the end of the day, I realize that when I do SWLing sessions I like to have dedicated time–at least an hour or two–with headphones on, losing myself on the radio dial.  I simply haven’t had many opportunities this past year to make that a reality.

That’s okay, though. The great thing about the shortwaves is that they’re always there, patiently waiting for us to dive back in!

Looking forward

I’m really not sure what’s in store for me this year, but I know it’ll involve a lot of radio time and that pleases me to no end. I’ve made a few fun goals, but my hope is that, by the end of the year, I may even be able to do some proper travel–maybe even take a flight!

I do know this: I have an even more profound appreciation for my radio enthusiasm as I realize it’s the perfect space to travel and explore the world no matter how “locked down” things are. Based on feedback from readers and contributors to this site, I know I’m not the only one who feels this way.

How about you?

Did your radio activity change or pivot this past year? Did you have more or less time to hit the airwaves? Please comment!

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1940: When Sears Roebuck sold a wide array of radio gear

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Many thanks to SWLing Post contributor, Charlie (W4MEC), who shares a PDF of the 1940 Sears Roebuck Co. catalog section featuring a wide array of radio gear and test equipment.

This file is hosted on the Pro Audio Design forum and can be downloaded as a PDF (15.8 MB) by clicking here.

It’s a real nostalgia trip reading through the fine Hallicrafters, Hammarlund and National HRO descriptions. Thanks so much for sharing this, Charlie!

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Radio Waves: WLW at 100, WWVB Upgrades, Ofcom Radio Amateur Data, and Unlocking the Airwaves

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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 Mike Terry, Dave Zantow, and John Figliozzi  for the following tips:

WLW-AM Begins 100th Year On Air (WVXU)

It wasn’t Cincinnati’s first radio station, but WLW-AM is still the biggest.

Cincinnati industrialist Powel Crosley, Jr. began broadcasting WLW-AM over a 20-watt station from his College Hill home on March 2, 1922 – which means that the station is entering its 100th year today.

WLW-AM wasn’t Cincinnati’s first commercial radio station, but it is the oldest surviving station from the 1920s. WMH was operated by the Precision Instrument Co. from Dec. 30, 1921, to January 1923.  WMH was sold to Crosley and merged into WLW, says Randy Michaels, the former WLW-AM programmer and Jacor/Clear Channel executive who is the best radio historian I know.

In 1934, WLW-AM became “the Nation’s station” when President Franklin D. Roosevelt flipped a switch in the White House to activate the station’s unprecedented 500,000-watt experimental transmitter under its Tylersville Road tower. WLW-AM broadcast at “super power” around the clock for five years, through 1939, and continued the mega-wattage output midnight-2 a.m. until 1943. For years WLW-AM has boasted that the 50,000-watt signal reaches 38 states. (I’ve heard the station in New Jersey, Maryland, North Carolina, Florida, Georgia, Illinois and Missouri.)

For 99 years, WLW-AM has broadcast some of the most popular personalities in town: Jim Scott, Gary Burbank, Bob Trumpy, Marty Brennaman and Joe Nuxhall, Cris Collinsworth, Jim LaBarbara, Bill Cunningham, Mike McConnell and Dale Sommers. Before them came Ruth Lyons, Bob Braun, Doris Day, Rosemary Clooney, newsman Peter Grant, sportscaster Red Barber and comedian Red Skelton.

Although WLW-AM likes to promote itself as “news radio,” it’s perhaps best known for carrying Reds and most Bengals games, plus University of Cincinnati football and basketball and Xavier basketball.[…]

WWVB broadcast system upgrades may include temporary outages (WWV)

The WWVB broadcast system is being upgraded with new equipment to improve the reliability of the signal. In order to install this equipment, beginning on March 9, 2021 the WWVB signal may be operated on a single antenna at approximately 30 kW radiated power for periods up to several days in duration, and may have occasional outages. Periods of reduced power operation lasting longer than 30 minutes will be logged on the WWVB Antenna Configuration and Power web page, and any outage longer than five minutes’ duration will be recorded on the WWVB Outage web page. Upgrades are expected to be complete by March 31, 2021.

Ofcom released age of radio amateurs data (Southgate ARC)

Following a Freedom of Information request about the age of radio amateurs Ofcom said they do not hold Date-of-Birth information for many radio amateurs but released what information they do have

Ofcom say “We do not hold a full breakdown of the age of issued amateur radio licensees as date of birth is not a mandatory field for licence applications.”

In September 2000 the then communications regulator (RA) abolished the ban on people under 14-years-old holding a Full amateur licence, since that time a person’s date of birth has served little regulatory purpose.

The data Ofcom released showed they only had Date-of-Birth information for:
7,312 out of 28,845 Foundation licences
4,104 out of 12,127 Intermediate licences
44,944 out of 54,072 Full licences

As of March 1, 2021 there was a total of 95,044 valid UK amateur radio licences.

Download the FoI reply and the available age data at
https://ofcom.org.uk/__data/assets/pdf_file/0022/214915/age-of-amateur-radio-licensees.pdf

You can submit a Freedom of Information request to Ofcom online at
https://www.whatdotheyknow.com/new/ofcom

Unlocking the Airwaves (UMD)

Unlocking the Airwaves: Revitalizing an Early Public and Educational Radio Collection is a comprehensive online collection of early educational public radio content from the National Association of Educational Broadcasters (NAEB). The forerunner of CPB and its arms, NPR and PBS, the NAEB developed and distributed educational radio programs and accompanying print materials to schools and communities across the United States. What’s more, the NAEB lobbied extensively to unlock the airwaves—to access precious frequency space—in order to bring the voices of poet Robert Frost, architect Frank Lloyd Wright, anthropologist Margaret Mead, and conservationist “Ranger Mac,” among many other individuals, into American homes and classrooms.

The NAEB’s history is the dramatic story of idealists who believed in the utopian possibilities of technology for education and social uplift and who faced considerable challenges in pursuit of those goals, including economic depression, world war, and the scarcity of the electromagnetic spectrum. It’s a story that has much to tell us about 20th century American culture, as well as the 21st century’s environment of online educational technology and podcasting that we live in today.

Despite its historic importance and contemporary relevance, most of the NAEB members’ programs were never heard again after their initial brief moments on the air. The archives for the radio programs and their related paper documentation have been split for over 25 years between two institutions: the University of Maryland and the Wisconsin Historical Society. Unlocking the Airwaves reunites the split collections, finally realizing the potential of the collections of the NAEB for exploration and and the broader public.

Click here to explore Unlocking the Airwaves.

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Radio Waves: Digital Audio via Vintage Radio, “10-Minute-ish” Transmitter, Why No Channel 37, and Inventor of the Audio Cassette Dies at Age 94

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Image by Jon Tyson

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, Valdo Karamitrov, Ronald Kenyon, and the Southgate ARC for the following tips:

‘I play digital music through my 1949 radio’ (BBC News)

When we think of technology our imagination usually takes us to images of the future. But for some, technology links us to the past – whether for nostalgia or for personal reasons

Following our recent feature on vintage technology, we asked you to share some of your collections with us – and people from around the world responded..

Rob Seaward, North Yorkshire, UK: 1949 Murphy A146 radio

I have a collection of older technology which I have collected throughout my life – including old cameras, calculators, hi-fis and radios. I had been interested in music from an early age, but it was really when my father purchased a Bang and Olufsen music centre that my interest in not only music, but style and function really took off.

To me, a lower middle-class grammar school kid living in Bradford, I suddenly had access to a world of real style and glamour.

My favourite piece must be the Murphy A146 console radio designed by Gordon Russell in 1949.

Its nickname is the “Batwing” because of the shape of the back panel. The sound is rich, slightly warm and typical of valve equipment. In its day, the radio cost the equivalent of an average monthly wage, it was built to last and the original valves are still working today.

However, as it pre-dates FM it is a little limited. I’ve had it restored and as part of the process we had a Bluetooth adapter installed which means I can now play my favourite digital music through this wonder from the 1940s – which really amazes people.[…]

Getting on the Air With a 10-minute-ish Ham Transmitter (Hackaday)

Artificially constrained designs can be among the most challenging projects to build, and the most interesting to consider. The amateur radio world is no stranger to this, with homebrew radio designs that set some sort of line in the sand. Such designs usually end up being delightfully minimalist and deeply instructive of first principles, which is one reason we like them so much.

For a perfect example of this design philosophy, take a look at [VK3YE]’s twist on the classic “10-Minute Transmitter”. (Video, embedded below.)

The design dates back to at least the 1980s, when [G4RAW] laid down the challenge to whip up a working transmitter from junk bin parts and make a contact within 15 minutes — ten for the build and five for working the bands. [VK3YE] used the “oner” — one-transistor — design for his 10-minute transmitter, but invested some additional time into adding a low-pass filter to keep his signal clean, and a power amplifier to boost the output a bit.[…]

Why Channel 37 Doesn’t Exist (And What It Has to Do With Aliens) (Vice)

Since the advent of analog TVs, channel 37 has always been static. Here’s why.

A version of this post originally appeared on Tedium, a twice-weekly newsletter that hunts for the end of the long tail.

I’m endlessly fascinated by stories of the quirks that were built into the TV system where the well-laid plans of the system simply fell apart because it was asked to do too many things.

Nearly five years ago, I wrote about one of them, the tale of how radio broadcasters were able to shoehorn an additional FM station into the radio because of the proximity of TV’s channel 6 to the rest of the radio feed.

So when I was informed that there was another oddity kinda like this involving the TV lineups, I decided I had to take a dive in.

It’s a tale that centers around channel 37, which was a giant block of static in most parts of the world during the 20th century.

The reason for that was simple: it couldn’t fend off its scientific competition.

1952

The year that the U.S. Federal Communications Commission opened up the television system to use UHF, or ultra high frequency signals. The practical effect of this addition of bandwidth was that the total number of potential TV stations increased dramatically, from 108 to 2,051, overnight. The first UHF applications were granted on July 11, 1952, according to The History of UHF Television, a site dedicated to the higher-frequency television offerings.

The radio telescope that became a headache for the television industry

Within a 600-mile radius of the city of Danville, Illinois, population 31,246, are numerous major cities—among them Chicago, Detroit, Milwaukee, Atlanta, Minneapolis, Pittsburgh, St. Louis, Toronto, and Washington, DC.

Nearly the entire length of the Mississippi River fits into that radius. If Danville was located just a little farther to the east, the radius would also include Philadelphia and New York City. For all intents and purposes, a 600-mile radius from Eastern Illinois covers basically the entire East Coast except the state of Florida and the Northeast.[…]

Dutch inventor of the audio cassette tape dies aged 94 (Southgate ARC)

Lou Ottens, inventor of the cassette tape and a CD pioneer died aged 94 at his home in Duizel in Brabant on Saturday, Dutch media report.

Ottens, who studied to be an engineer, started working for Philips in 1952. Eight years later he became head of the firm’s recently introduced product development department. Within a year he and his team had developed the first portable tape recorder of which over a million were sold. Two years later he revolutionised the old reel-to-reel tape system by inventing the cassette tape.

‘I got annoyed with the clunky, user-unfriendly reel to reel system, it’s that simple’, Ottens said later. The new carrier had to be small enough to fit into his jacket pocket, Ottens decided, and he had a wooden model made to determine the ideal size. In 1963 the first plastic encased cassette tape was presented at an electronics fair carrying the slogan ‘smaller than a pack of cigarettes!’ The tapes were quickly copied by the Japanese but in different formats!

Ottens managed to make a deal with Sony to use the mechanism patented by Philips to introduce a standard cassette which was then rolled out globally. Over 100 billion were sold worldwide. Ottens went on to develop the CD, which again became a Sony-Philips standard and which sold over 200 billion.

In 1986 Ottens retired but he was often asked if he was proud of his inventions, which allowed millions to have access to music. ‘I have no ‘pride dial’’ Ottens said in an interview, stressing that both inventions were team efforts. His biggest regret was that that Sony, not Philips, invented what he considered to be the ideal application for the cassette tape, the Walkman. ‘That still hurts,’ he said. Dubious about the recent revival of the cassette tape Ottens said ‘nothing could beat the sound of a CD.’

Read more at DutchNews.nl
https://www.dutchnews.nl/news/2021/03/dutch-inventor-of-the-audio-cassette-tape-dies-aged-94/?

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