Author Archives: Thomas

Radio Waves: Eugène Aisberg, Filter Design, ABC Workers Face Cuts, and Data via Web SDRs

Radio Waves: Stories Making Waves in the World of Broadcasting

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 Paul, Marty, and Michael Bird for the following tips:

Eugène Aisberg, Radio Writer (OneTubeRadio.com)

After a wartime absence, the January 1946 issue of Radio Craft carried an article by writer Eugène Aisberg. While that name might not be familiar to American readers, Aisberg was a prolific author in the early days of radio, and wrote some of the best treatises on radio for the popular audience. He was fluent in French, Esperanto, German, Russian, and English.

Aisberg was born in Odessa, Ukraine, in 1905, and lived most of his life in France. He was the director of the French magazine Toute la Radio and a prolific author of a number of books. His most popular book, which is still in print, is La Radio? Mais c’est très simple (Radio? But It’s So Simple!) The book, currently in its 29th edition, an extremely solid background covering all aspects of electronics, and is written in a popular, easy-to-read style. While the book was ultimately translated into several languages, it was apparently never published in English.[…]

Filter Design Software (Nuts and Volts)

If you’ve ever lived close to an AM broadcast station, you probably experienced the phenomenon known as fundamental overload. It occurs when a receiving device is functioning entirely properly but unable to reject a strong signal. The receiver might be a wireless telephone, a scanner, or even a TV or radio receiver. The AM signal is completely legal but just too strong, disrupting the function of the receiver or overriding the desired programming.

[…]Hams often experience fundamental overload on the 160 meter band (1.8–2.0 MHz) which is adjacent to the AM broadcast (BC) band (550 kHz–1.7 MHz). Antennas for those frequencies pick up a lot of AM band RF, overloading the input circuits and creating distortion or false signals inside the receiver. The usual solution is to install a high-pass broadcast-reject filter at the receiver input, attenuating the unwanted AM signals below 1.6 MHz while passing the desired 160 meter signals with little attenuation.

So far, so good, but a filter that doesn’t attenuate signals very much above 1.8 MHz while attenuating them significantly in the adjacent broadcast band is not a simple thing to design. There are tables and equations, but they are tedious to work with. Practically, you’ll need to build the filter with standard-value components as well, and that will affect filter performance too. Sounds like a job for some filter design software, doesn’t it?

There are several filter design software packages ranging from simple calculators to sophisticated CAD programs. Luckily for hams and other experimenters, there are plenty of free or low-cost programs to try.[…]

ABC workers face anxious wait over job, program cuts (The Age)

David Anderson did not mince words at a Senate Estimates hearing last October. “There will be job losses,” ABC’s managing director warned. “It’s not something I can quantify at this point in time. There’s still more work to be done.”

Towards the end of March, Anderson will reveal a five-year plan for the national broadcaster. To the frustration of staff, it’s unlikely to specify which parts of the organisation will bear the brunt of these cuts or how many workers they might lose.

Several senior sources spoke about the situation at ABC on the condition of anonymity, given sensitive funding negotiations are yet to be finalised.

“All these media reports claiming the redundancy numbers will be finalised in March are just wrong,” says one ABC executive. “What we need is some clarity [about long-term resourcing] from the government.”[…]

Receiving Data With Web Based Shortwave Radios (Nuts and Volts)

Your computer and the Internet give you free access to over 100 web based shortwave receivers that you can use as if they were your own. Unfortunately, employing these radios to decode data transmissions can be very difficult or impossible — unless you know the secret. So, read on and we’ll guide you through the details of how to do it.

Web based shortwave radios are an amazing new implementation of software defined radios (SDR). These SDRs are free to use and widely available on the Internet. Even more remarkable is that they are located in countries all around the world.[…]

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Let’s solve another interval signal mystery!

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Last month, we published a post asking SWLing Readers to help Brian (W9IND) identify an elusive interval signal. Turns out, the interval signal belonged to the Voice Mirror of the PTT Habana, Cuba station.

This month, SWLing Post contributor, David Crawford is asking for help to ID another interval signal which likely belongs to a utility station. David writes:

In follow-up to the La Habana utility mystery, here’s another one from the same era, 14985 kHz or thereabouts. Somewhere along the line I came to the conclusion that it might be El Salvador, but I don’t remember what led to that. The [recording embedded below] isn’t my own recording of it.

The tune is composed of individual DTMF tones, and when I was a bored youth I discovered that it could be played on an AT&T desk touch tone phone by pressing two keys at a time to remove the second tone. This one would repeat for hours at a time, interrupted by manually patched telephone calls.

Readers: Can you positively ID this interval signal? If so, please comment!

Radio Red Zone: A Coronavirus station in quarantined Italy

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(Source: Aljazeera)

Radio Red Zone broadcasts from a town under quarantine and brings listeners useful health advice and sense of community.

Codogno, Italy – As the coronavirus grips Italy and stringent measures are taken to slow the spread of the infection, a local radio station is providing citizens with a sense of normality amid a quarantine.

The station broadcasts from Codogno, a town now known as the “Wuhan of Italy” under lockdown. Trains do not stop there, and the streets are empty.

“Good morning, Codogno!” says 82-year-old presenter Pino Pagani, starting his live broadcast from inside Lombardy’s red-zone area, where about 50,000 people have been under quarantine for almost two weeks.

Pagani then reads an inspirational message sent in from listener Diego Lazzanoni, an Italian living in Castiglione d’Adda town:

“We are here in our homes to fight with our childhood friends and families. Although we are on our knees right now, I feel the silent vicinity of my town. Even if the streets are empty, and no sound is to be heard, I know that when this nightmare is over, we will be partying as we alone know how. We don’t and won’t give up.”[…]

Click here to read the full article.

Tecsun PL-990 (pilot run) now on AliExpress

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Many thanks to SWLing Post contributor, Dan Robinson, who notes that the Tecsun PL-990 has now appeared on AliExpress.com.

The price is a steep $399 US shipped via DHL with an estimated delivery of late March. They claim to have about 900 units available.

You can check out the PL-990 on the AliExpress website, but it might require registration even via this direct link.

Frankly, I would wait until the PL-990 is available at Anon-Co since they’re an authorized Tecsun distributor, have proven customer service, and will likely have a more competitive price. I would also question if the AliExpress units are the new export version we’ve been waiting for, or simply the units that were available within China last year. The AliExpress page gives us no clear indication of the production version at time of posting.

UPDATE: Turns out, these are the pilot Chinese versions of the PL-990. I can’t recommend purchasing one–especially at this price.

I hope this might indicate that the PL-990 is close to release. Covid-19 has certainly stopped much production and development in China. Thanks again for the tip, Dan!

Radio Waves: Plant-powered Satellite Comms, BBC Pips, Filter Basics, and Replacing Shortwave

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

Many thanks to SWLing Post contributors Marty, Dennis Howard, Dennis Dura, Kris Partridge and Richard Langley and for the following tips:

Plant-powered sensor sends signal to space (Phys.org)

A device that uses electricity generated by plants as its power source has communicated via satellite—a world first.

[…]The device can inform farmers about the conditions of their crops to help increase yield, and enable retailers to gain detailed information about potential harvests.

It transmits data on air humidity, soil moisture and temperature, enabling field-by-field reporting from agricultural land, rice fields or other aquatic environments.

The extremely low power device sends signals at radio frequencies that are picked up by satellites in low Earth orbit. It was developed by Dutch company Plant-e and Lacuna Space, which is based in the Netherlands and the UK, under ESA’s programme of Advanced Research in Telecommunications Systems (ARTES).[…]

The eccentric engineer: a tale of six pips and how the BBC became the national arbiter of time (Engineering and Technology)

This edition of Eccentric Engineer tells the story of the BBC Time Signal and how, over the years, it has just got more complicated.

Every engineer needs to know the time, if only so as to not miss lunch. Since 1924, many Britons have been checking their watches against the BBC time signal, known affectionately as ‘the pips’.

The history of the ‘pips’ is almost as long as the history of the BBC itself. The first transmissions from what was then the British Broadcasting Company began in late 1922 and soon afterwards there were suggestions of broadcasting a time signal under the control of the Royal Observatory at Greenwich – then the arbiter of time in the UK.

No one seems to have seen a need for this degree of precision, but early broadcasts did use their own ad hoc ‘pips’, marking the 8pm and 9pm news programmes with a time signal consisting of the announcer playing the Westminster chimes on a piano and later a set of tubular bells. This proved rather popular with listeners, who could now adjust their clocks and watches daily, so the BBC decided to invest in some more high-tech clocks from the Synchronome Company. These provided audible ‘ticks’, which the announcer then simply counted down.[…]

What Is Replacing Shortwave? (Radio World)

A joint effort is necessary to bring the digitization of radio to a successful end

Analog shortwave will celebrate about 100 years of existence in 2028 when many hope 5G will have been properly defined, tested and applied, though broadcasting is low on its long list of perceived advantages.

It’s true that shortwave was typically a medium of the Cold War that peaked in 1989 and that afterward its listenership dwindled. Many international broadcasters gave up on it as the post-war transmitters got rustier and the energy bills kept mounting.

After all, when budget cuts are needed, no transmitter will go on strike or write to the press, as happened when the BBC World Service tried to unsuccessfully close its Hindi shortwave transmissions in 2011. In 2020 these broadcasts stopped, when committed BBC Indian listeners, writers and thinkers who opposed it in 2011 did not protest too much.

The slow death of shortwave has been blamed on the internet and satellite. As technology and content are inextricably linked, shortwave created its type of content that is no longer favored by the savvy FM listener, internet user and cellphone obsessed.[…]

Filter Basics: Stop, Block and Roll(off) (Nuts and Volts)

A casual observer might think that wireless systems consist primarily of filters connected by the occasional bit of circuit! Block diagrams of transceivers often include as many filters as any other function. This is true at the system level, just as it is at the circuit level — and many circuits behave in a filter-like way, whether intended to be a filter or not! That makes understanding filter basics important for wireless success.[…]

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Rescuing the Eton E1 from a sticky situation

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I’m back from a week of travels and the 2020 Winter SWL Fest. In short, is was another amazing Fest and so much fun. I hope to write more about it in the coming days, when I have a few moments to catch up and after I shake a nasty bug (chest cold) I picked up.

Although I had no intention of making purchases at the Fest beyond a few raffle tickets, I couldn’t resist snagging an Eton E1 (XM version) at a silent auction from the estate of our recently-departed friend, Tony Pazzola (WB2BEJ). Tim Moody kindly organized the silent auction.

Tony was an amazing friend to all and an avid radio collector, so there were some excellent radios offered up in the silent auction–I could have easily easy bid on each and every one of them! In the end, though, only one really caught my eye: the Eton E1 XM.

A small sampling of the radios from Tony’s estate.

Tony took amazing care of his radios, but his Eton E1 XM suffered from what all of those models eventually do: a sticky chassis.

Back in the day (roughly 2009 to 2013) Eton/Grundig covered a number of their radios models with a rubberized coating that unfortunately breaks down over time and becomes tacky or sticky to the touch.

I think this E1’s sticky coating put off potential bidders.

It was particularly nasty–if you picked up the radio, you had to immediately wash your hands.

The E1’s starting bid on Friday was $200–quite fair considering this unit is fully-functional and comes with all software, cables, manuals and a SiriusXM radio antenna. By Saturday, the starting bid had been decreased to $150. I resisted putting in an offer, but after seeing that it didn’t sell after all bidding had ended, I couldn’t resist. That E1 needed a good home, right? Plus the proceeds go to Tony’s family.

The sticky coating didn’t scare me. If you’ve been an SWLing Post reader for long, you’ve no doubt read our numerous posts about cleaning off this mess. There are a number of solutions, but I’ve heard the most positive long-term results by employing a de-greasing product called Purple Power (click here to read archived posts). Indeed, it’s the solution Eton Corporation recommends.

On the way home Monday, I stopped by a big box store and grabbed a bottle of Purple Power.

Tony still had the original plastic film on the large backlit display.

Sporting a pair of nitrile gloves, I grabbed a bunch of paper towels and a few cotton swabs, then started the cleaning process. I spent the better part of an hour carefully going over the entire body of the E1and trying to remove residue in every crevice without allowing the Purple Power solution to creep under buttons.

In short? I’m very pleased with the results and am now a solid believer in Purple Power.

As others have reported, Purple Power breaks down the sticky residue and allows it to be removed with a cloth or towels with very little scrubbing. Indeed, the process was much easier than I anticipate.

Now I have a super-clean Eton E1 XM to put on the air!

Now I have no excuse to finally remove the sticky residue from both my Grundig G6 and G3!

So far, I’m loving the Eton E1. It is, no doubt, a benchmark portable. Of course, another motivation behind snagging this E1 is so that I can compare it with the Eton Elite Satellit once it eventually hits the market.

Do you have an Eton E1? What are your thoughts about this receiver? Please comment!

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Tate Modern ISS installation doubles as ham radio antenna

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Photo by @helenleigh

Many thanks to SWLing Post contributor, Matthew, who shares the following tweet from Helen Leigh:

This sculpture at the Tate Modern blew my mind this week. It’s a wire sculpture inspired by the International Space Station that functions as an antenna for a ham radio.