Category Archives: Radio History

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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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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The Birth of Radar Memorial

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Photo by Amanda Slater

Many thanks to SWLing Post contributor, Paul Evans, who writes:

Interesting article on the new monument to radar between Daventry and Towcester in Northamptonshire, UK.

https://www.atlasobscura.com/places/birth-of-radar-memorial

Legend has it that this was conducted around 25-28 MHz, which was the very top end of higher power RF at the time.

The location sits closer to Towcester, although the event is always quoted as having taken place at Daventry (the source, not the receiver).

It’s fascinating that Plessey Research Caswell was set up almost immediately, not very far away and was heavily involved in radar and other solid-state research through to the 1990s.

[Disclosure: the author (Paul) worked at Plessey Caswell and was Two Terminal device Manager at Plessey Microwave, Towcester in the 1980s]

Many thanks, Paul, for sharing this fascinating bit of history.

Radio Canada International at 75 years

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(Source: RCI.net via David Iurescia)

Today is an auspicious day for RCI. It was February 25, 1945 that the CBC International Service began shortwave broadcasting to Europe. It was designed at the time to provide accurate news to occupied areas in

English French and German, and to provide news from home for the huge contingent of Canadian military personnel serving and fighting in the Second World War.

Since then the “IS” has gone through a variety of changes, including the name which was changed to Radio Canada International in 1970. It has been through several moves, from its first location in a former brothel, to the converted Ford Hotel a few years later, to rented office tower space, to the main headquarters of the French service, Radio-Canada.

It has also gone through a number of language-service changes, from 14 languages during the cold war broadcasting to formerly free countries then under the control of Moscow, to its current five languages, Mandarin, Spanish, Arabic, English and French.

Other changes include the drastic cuts of 2012 which saw some 80 per cent of staff cut and the cessation of shortwave to become its current online operation.

Throughout it all RCI continues to inform on Canadian issues including political, scientific, cultural and societal and provide Canadian viewpoints and positions on world affairs.

Click here to read the full article at RCI.net.

Help Brian identify this 1970s era interval signal

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[Mystery solved! Click here to read the update.]

Many thanks to SWLing Post contributor, Brian (W9IND), who writes:

I want to thank you for stirring a memory that I never thought I’d relive – even though it still doesn’t solve the mystery of what the heck I was listening to in the first place!

Back in the early 1970s, I was a teenage SWLer with a curiosity for the worldwide signals that emanated from the speaker of my shortwave radio. Bitten by the SWLing bug after stumbling across Radio Nederland’s Bonaire relay station, I spent many a happy hour twirling the dial in search of fresh game to hear and QSL.

But on one such occasion (I’m going to guess it was in 1971), I was surprised and fascinated by what sounded like a snake-charming horn playing notes at random. Stranger still, the transmission would seemingly go off the air for a couple of seconds and then return to play the strange melody again. I chalked it up to one of the countless beeps, hums and other electronic noises that often appeared on utility frequencies in those days.

I never recorded it, I never had a clue what it was, and I never heard it again.

Until recently. On the Shortwave Radio Audio Archive.

A couple of weeks ago, while looking for old shortwave interval signals from the 1970s, I saw a recording marked “Unidentified interval signal 1” listed right after the interval signals of Deutsche Welle and Radio Nederland.

“OK,” I thought. “Sounds like a challenge. Maybe I can even help figure out what it was.”

Then it played … and I almost fell off my chair! I literally sat with my mouth open as the long-lost sounds of the “snake-charming horn” played again. Could it indeed have been an interval signal – and if so, for what station?

I wanted to contact the person who recorded it, but then I learned the sad news that Mr. Greg Shoom is no longer with us.

So I remain mystified, probably forever. But it sure was fun hearing that weird recording again! Thanks for the memories.

Let’s see if an SWLing Post reader can help, Brian!

I know of at least a dozen readers who are experts on all that is interval signals, so hopefully someone can listen and ID this one.

I’ve embedded audio from this SRAA recording below. Note that the unidentified interval signal can be heard between time marks 1:27 – 2:07 in the following recording:

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

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Dan shares memories of work at KGEI

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Many thanks to SWLing Post contributor, Dan Van Hoy (K7DAN), who shares the following comment in reply to our recent KGEI post. Dan writes:

It was my privilege to work at KGEI as a broadcast engineer and antenna rigger with FEBC from 1981-85. After that we went off to serve FEBC in Davao City in the Philippines. Never had any problems with the 50KW GE transmitter except one night when a driver tube failed. Nice to have a transmitter you could walk into! It was back on the air in about 45 min with a new tube. Mario Barahona was the main announcer most nights faithfully bring the Good News from the Voice of Friendship in Spanish.

I also painted the building tan with a dark brown trim while I was there. As I recall, I painted the KGEI name in dark brown too. The biggest project for me was helping install the TCI 16 folded dipole slewable array with reflecting screen stretched between two 365 ft tall towers. I was the only antenna rigger on the project.

The 250KW transmitter was primarily used for Russian broadcasts over the North Pole using the TCI antenna. The ERP was somewhere between 15-20 million watts depending on how the antenna was slewed. We were often heard loud and clear in a variety of home devices in nearby Foster City. I called the 250KW transmitter the worlds biggest Heathkit. It was ably maintained by an amazing radio engineer named Loch Gordon. Jack Brooks, WA6DBT, was the station manager. Hiley Rainer was the jack of all trades do it all engineer. It was one of the most enjoyable periods of my life.

Wow, Dan…I had no idea! Thank you for sharing those wonderful memories. I can’t imagine singlehandedly installing the antennas you did! I need to call you next time I have an antenna hanging party!

“German Archaeologists came across a Russian spy radio”

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Photo: Jürgen Vogel / LandesMuseum Bonn via the Southgate ARC

(Source: Southgate ARC via Jake Brodsky, AB3A)

Not an everyday find: Archaeologists from the Rhineland Regional Council were amazed when they came across a Russian spy radio instead of Roman traces in the Hambach open-cast mine during excavations. Hidden in a large metal box.

“When the box was opened, it hissed,” Dr. Erich Claßen, head of the LVR Office for the Preservation of Archaeological Monuments in the Rhineland, told journalists. In the container: a Soviet radio type R-394KM, code name Strizh, a digital HF spy radio.

It was developed in the early 1980s in the Soviet Union (USSR) and used by the countries of the Warsaw Pact in the final phase of the Cold War. It was the last model before the fall of the Iron Curtain in 1989 and the collapse of the Soviet Union in 1992.

The device has a digital news system and a digital frequency display. It was used by agents abroad as well as by special units and was available with Russian or English text on the front. The spy version is known by the Russian code name “Strizh” (English: Swift).

In the LVR-Landesmuseum in Bonn there is currently not only the mysterious radio to see. Under the title “Gods, Graves and Agents”, spectacular finds from the year 2019 are on display until 29 March:

https://bodendenk
malpflege.lvr.de//de/aktuelles/veranstaltungen/AusstellungAiR2019.html

Tom DF5JL

Click here to read the full article at the Southgate ARC.