Tag Archives: Web SDRs

Radio Waves: Data RX via Web SDRs, Mystery Signals from Space, Public Media’s role in Democracy, and Pirates SPAM UVB-76

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 Marty, Troy Riedel, and Rich Cuff for the following tips:


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.

[…]A while back, I discussed how to receive data signals with a low cost shortwave radio (N&V May 2015). Now, the concept takes on a new dimension since we are using virtual radios not in our possession.

As astonishing as it seems, many of these Web based shortwave receiver data signals can be processed and decoded using just your PC and some free decoding software. Yes, some signals are encrypted, and can’t be decoded. Fortunately, there are plenty of unencrypted data signals around to keep us busy for a long time.

However, as will be discussed later on, it does require a special trick to allow you to pipe the streaming audio signals from the Web to the decoding software. In this article, I will show you how to use these Web based shortwave receivers to access data transmissions and to get started in this exciting hobby. [Click here to read the full article…]

Unknown objects at the heart of the Milky Way are beaming radio signals, then mysteriously disappearing (Business Insider)

Ziteng Wang found a needle in an astronomical haystack.

Wang, a physics PhD student at the University of Sydney, was combing through data from Australia’s ASKAP radio telescope in late 2020. His research team had detected 2 million objects with the telescope and was classifying each one.

The computer identified most of the stars, and the stage of life or death they were in. It picked out telltale signs of a pulsar (a rapidly rotating dead star), for example, or a supernova explosion. But one object in the center of our galaxy stumped the computer and the researchers.

The object emitted powerful radio waves throughout 2020 — six signals over nine months. Its irregular pattern and polarized radio emissions didn’t look like anything the researchers had seen before.

Even stranger, they couldn’t find the object in X-ray, visible, or infrared light. They lost the radio signal, too, despite listening for months with two different radio telescopes. [Continue reading…]

Do countries with better-funded public media also have healthier democracies? Of course they do (Nieman Lab)

But the direction of causality is tricky. Do a democracy’s flaws lead it to starve public media, or does starving public media lead to a democracy’s flaws?

There’s a new book coming out in the U.K. this week called The BBC: A People’s History, by David Hendy. Its publisher calls it a “monumental work of popular history, making the case that the Beeb is as much of a national treasure as the NHS…a now global institution that defines Britain and created modern broadcasting.”

Cross the pond: While Americans generally like PBS and NPR, I wouldn’t expect them to come up quickly if you asked someone on the street to begin listing national treasures. (I’m even more sure America’s health care system would go unmentioned, too.) Who “created modern broadcasting” in the U.S.? It certainly wasn’t the two public broadcasters that didn’t hit airwaves until 1970. And what TV network is a “global institution” that “defines” the United States abroad? Apologies to PBS Newshour, but that’s CNN.

No one says “Auntie Peebs.”

It’s obvious that the U.S. approached the new broadcasting technologies of the 20th century in ways wildly different from their European peers — and in ways that reflect on the countries themselves. American radio began wild and unregulated, experimental, a bubbling font of creativity — and then quickly became commercialized, optimized for mass audiences and massive profits. The BBC, which turns 100 this year, was more structured, more statist, more controlled — but has remained more central to residents’ lives, more civic-minded, and more beloved. [Continue reading…]

Pirates Spammed an Infamous Soviet Short-wave Radio Station with Memes (Vice)

The UVB-76 numbers station took a break from being a suspected communications tool of Russian intelligence to blast ‘Gangnam Style’

Pirates hijacked an infamous short-wave radio station, which dates from the Soviet era but is still online today, and used it to broadcast everything from Gangnam Style to audio that draws memes when inspected under a spectrum analyzer.

For decades the numbers station known as UVB-76 has emitted an enigmatic series of beeps and a voice reading numbers and names, in what people suspect is a long running communications method for Russian intelligence. Since the broadcast is public, pirates are able to use their software-defined radio (SDR) transmitters to effectively flood the frequencies with noise and memes.

The recent barrage of attacks on the station come as Russia prepares to invade neighbouring Ukraine, where radio enthusiasts speculate at least some of the pirate broadcasts originate. [Continue reading…]


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CATSync: Control web SDR tuning from your rig

Many thanks to SWLing Post contributor, Rob (PE9PE), who writes:

This is an interesting tool for those hams suffering from lots of local QRM.

https://catsyncsdr.wordpress.com/

Thanks, Rob! CATSync seems to allow control of a web-based SDR from any OMNI Rig-supported radio via CAT control (which is the majority of transceivers). It appears CATSync allows control of tuning and mode changes via your radio and from the web SDR interface back to your rig.

One interesting use of this would be to use a remote SDR for receiving while using your home antenna for transmitting. This could help those inundated with RFI at home. While this might not be an allowed practice for contesting (having your receiver and transmitter in two different locations) it’s certainly permitted if you want to check in with a net or chat with friends. You don’t need CATSync to do this–you can always manually tune a web SDR separately–it would simply facilitate keeping both your RX and TX on the same frequency.

CATSync has a free trial with limited control–you can purchase the full version for 9.95 EUR.

Click here to check out CATSync.

Thanks for the tip, Rob!

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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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RSGB 2018 Convention Lecture: DC to Microwaves on your smartphone

(Source: Southgate ARC)

The presentation by Noel Matthews G8GTZ on the Farnham WebSDR given to the 2018 RSGB Convention is now available on YouTube:

Click here to view on YouTube.

This presentation gives an overview of the Farnham WebSDR, available at http://farnham-sdr.com/ which currently covers the LF bands through to 10GHz.

The presentation describes the system architecture and antennas currently used on each band and how the team has used RTL dongle receivers, available for under £10, to give good RF performance on all bands from DC to 10GHz. There is a demonstration of the SDR in use on both PC and smartphone.

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Creating a global network of inexpensive remote SDRs

U_Twente_SDR

Many thanks to SWLing Post contributor, Mark Fahey, who replies to Ivan’s preliminary review of the V3 RTL-SDR dongle:

With Shortwave SDRs (the receiver dongle) now costing less than $20, the time has come for us to set up a global group of receivers that we can all log into at will!

RTL-SDR-RTL2832U-e1471375714199Have a look at SDR.hu – here you can put your SDR dongle on line and share it with anyone and they have full control of the receiver just as if it was in their own shack.

Imagine receivers scatted around the world – South America, Tropical Asia, Africa! The cost is now virtually nothing, all that is needed is the dongle, antenna (doesn’t have to be anything special – even a long wire or whip) and a small low cost CPU (Raspberry Pi for example).

Anyone else interested in this dream? Lets get together, get some receivers setup and then talk about our experience in a kick-ass presentation at the 2017 SWL WinterFest in PA!

Also… I am very soon to receive my KiwiSDR matched to a BeagleBone CPU. It will be online at SDR.hu and four remote listeners will be able to tune the full shortwave bands independently, its like my own Twente setup! Heaps of others are getting receivers online in the next few months with KiwiSDRs, this is going to be totally amazing!

I agree, Mark! While there is already quite a network of remote SDRs and receivers in the world, the barrier of entry keeps getting lower and lower. It’s hard to imagine that $25 can buy an SDR that natively covers the shortwave and mediumwave bands!

There’s only one other requirement for an online SDR that Mark didn’t mention: a decent Internet connection. Sadly, this is the only thing keeping me from hosting a remote SDR here at my home. I considered purchasing a KiwiSDR like Mark, but my upload speed (0.2-0.3 mbps) is so terrible and so unreliable that I could only host one listener at a time at best. You can bet that as soon as my ISP upgrades our service, I’ll launch a web SDR as well.

Of course, I’m willing to bet that most SWLing Post readers have more than enough bandwidth to host a $25 remote receiver! Let’s make Mark’s vision a reality!

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