Monthly Archives: June 2020

SigDigger: A free digital signal analyzer app for MacOS & Linux from EA1IYR

Many thanks to SWLing Post contributor, Ferrie, who recommends the SigDigger digital signal analyzer written by Gonzalo Carracedo (EA1IYR). According to the project’s Github page:

SigDigger is a graphical, digital signal analyzer I wrote in Qt5 for Unix systems like GNU/Linux or MacOS. Unlike existing alternatives, SigDigger is not based on GNU Radio. Instead, it uses its own DSP library (sigutils) and a realtime signal analysis library (Suscan) that exploits multicore CPUs to distribute load. Also, SigDigger supports most SDR devices in the market thanks to SoapySDR. Sigutils, Suscan and SigDigger are software libre, licensed under the terms of the General Public License version 3.

[…]SigDigger works in x86-64 CPUs running MacOS or GNU/Linux. In terms of performance, it can beat Gqrx by a factor of 20% (measured as saved CPU usage).

There are plans to port SigDigger to additional operating systems and architectures. Both Suscan and Sigutils have been successfully built and run in armhf Linuxes (i.e. Raspberry Pi) in the past, but official support is on its way.[…]

Current features

  • MacOS & GNU/Linux support.
  • Both realtime and replay analysis modes
  • Analog mono audio playback (AM, FM, LSB and USB)
  • Baseband recording (full spectrum and per-channel)
  • Per-device gain presents
  • Dynamic spectrum browsing
  • ASK, FSK and PSK inspection
  • Gradient-descent SNR calculation
  • Different spectrum sources (cyclostarionary analysis, signal power…)
  • Symbol recording and visualization
  • Doppler analysis
  • Filename-based raw file parameter guessing
  • Transition analysis
  • Interactive Panoramic Spectrum view
  • Waveform inspection window, including burst detection and limited off-line demodulation support
  • Signal source decimation
  • Bandplan information
  • Audio channel recorder
  • Blind parameter estimation
  • Network broadcast of demodulated channel
  • UDP broadcast of received samples and demodulated symbols
  • Spectrum integrator (for radioastronomy enthusiasts like me!)

Check out SigDigger’s Github page for full build instructions and pre-compiled binary release links.

Many thanks to Ferrie for the tip!

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Credit Card Crystal Radio

Many thanks to SWLing Post contributor, Paul Evans, who shares this article from Hackaday that highlights a crystal radio built completely on a smart chip credit card by Billy Cheung.

Hackaday notes:

This is possible because the smart chip on many credit cards contains a diode. It’s then a simple matter of hooking up the right pads on the credit card to the rest of a crystal radio circuit, and you’re all set. Of course, [Billy] goes the whole hog, building the entire radio on a single credit card. Other cards are cut up to create bobbins for winding coils to form a variable inductor, used to tune the radio. Doing this allows for a much cleaner, thinner design, rather than using a variable capacitor which is comparatively hard to find. Turning the dial allows stations to be tuned in, and with a high impedance earbud hooked up, you’re listening to AM radio. Oh, and don’t forget an antenna!

Cheung documented the whole process and even shares templates via links in the description of his YouTube video.

Many thanks to Paul and Hackaday for sharing this fun project!

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FTIOM & UBMP, June 7-13

From the Isle of Music, June 7-13:
This week, special guest Rodrigo García helps us present Ceda el Paso’s innovative new jazz fusion album Te estoy llamando. In the second half, we listen to part of a new tribute to Orquesta Aragon’s 80 years by Maraca, Orquesta Aragón and others.
The broadcasts take place:
1. For Eastern Europe but audible well beyond the target area in most of the Eastern Hemisphere (including parts of East Asia and Oceania) with 100Kw, Sunday 1500-1600 UTC on SpaceLine, 9400 KHz, from Sofia, Bulgaria (1800-1900 MSK)
If you don’t have a shortwave radio or are out of range, you can listen live to an uplink from a listening radio in the Netherlands during the broadcast at
http://websdr.ewi.utwente.nl:8901/?tune=9400am
2. For the Americas and parts of Europe, Tuesday 0000-0100 on WBCQ, 7490 KHz from Monticello, ME, USA (Monday 8-9PM EST in the US).
If you don’t have a shortwave or are out of range, you can listen to a live stream from the WBCQ website here (choose 7490): http://www.wbcq.com/?page_id=7
3 & 4. For Europe and sometimes beyond, Tuesday 1900-2000 UTC and Saturday 1200-1300 UTC on Channel 292, 6070 KHz from Rohrbach, Germany.
If you don’t have a shortwave radio or are out of range, you can listen live to uplinks from various websdrs in Europe.
Our Facebook page is https://www.facebook.com/fromtheisleofmusic/
Our Patreon page is https://www.patreon.com/tilford

Uncle Bill’s Melting Pot, June 7 and 9:
Episode 168 honors guitarist and cofounder of Malo, Jorge Santana, who passed away in May, with an hour of music from Malo’s early recordings.
The transmissions take place:
1.Sundays 2200-2300 (6:00PM -7:00PM Eastern US) on WBCQ The Planet 7490 KHz from the US to the Americas and parts of Europe
If you don’t have a shortwave or are out of range, you can listen to a live stream from the WBCQ website here (choose 7490): http://www.wbcq.com/?page_id=7
2. Tuesdays 2000-2100 UTC on Channel 292, 6070 KHz from Rohrbach, Germany for Europe.
If you don’t have a shortwave radio or are out of range, you can listen live to an uplink from different web SDRs in Europe
including a live uplink from a listening radio in the Netherlands at http://websdr.ewi.utwente.nl:8901/?tune=6070am
Our Facebook page is https://www.facebook.com/UncleBillsMeltingPot/
Our Patreon page is https://www.patreon.com/tilford

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Radio Waves: Radio Stations in the Movies, Opposition to ABC Budget Cuts, Numbers Stations, and Student Repairs Vintage Radios

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 Tracy Wood, Michael Bird, and David Shannon for the following tips:


How accurately have radio stations been portrayed in TV and movies? Alan Cross rates them (Global News)

Over the last century, radio stations have been the subject and the setting for a number of TV shows and movies. This, for better or worse, is how the general public perceives how real-life radio works. I’ve rated this selection of radio-centric shows and scenes through the years.

1. WKRP in Cincinnati (1978-1982)

Authenticity Rating: 3/5

Every time people of a certain age hear that I work in radio, they inevitably ask “Is it anything like WKRP?” The answer is both yes and no.

The show’s creator, Hugh Wilson, did come from a radio background, serving time as a sales rep at WQXI, a top 40 station in Atlanta, so he was certainly well qualified. His characters were slight caricatures of the real thing: the general manager who was often clueless about what was happening with his station; the harried program director; the burnout morning man; the trippy nighttime DJ; the sleazy salesperson; the squirrely newsman; the naive copywriter; and the receptionist who secretly runs the place. I’ve worked with each of those people multiple times.

The show was groundbreaking in its use of music. Up until WKRP came along, no one used real music in the soundtrack. It was all stock stuff, soundalike material made up by studio players. But viewers of WKRP heard actual songs from bands they recognized — something that eventually created endless licensing headaches when it came to syndication and issuing the show on DVD. That remains the reason why the show isn’t streamed anywhere. (Hugh Wilson explains the music issues here.)[]

Australians overwhelmingly oppose ABC budget cuts (ABC Friends National)

According to a new survey, 76% of Australians oppose any further cuts to the ABC’s budget and 49% believe it should get more Federal Government funding

The findings of a Roy Morgan national opinion poll serve as a warning to the Government that voters have had enough of budget cuts to the national broadcaster. Successive Governments have reduced ABC funding by a total of $783 million since 2014.

Read the survey here [PDF].

The survey shows Australians overwhelmingly turn to the ABC in times of crisis, underlining the national broadcaster’s critical role in the bushfire crisis and the COVID-19 pandemic. ABC Friends commissioned the opinion poll, which was carried out by the independent research group, Roy Morgan.[]

What is number station and story behind it? (US Updates)

Fictional novels about number stations have been created in the minds of most people. Many people think of the number station as a ghostly, creepy, mysterious or supernatural symbolic message. But are the messages fictional novel about numbers stations  at the number station really mysterious? In today’s discussion we will know what number station is and why somebody finds it fictional novel about number station?

We all listen to the radio more or less. There are basically two types of radio listeners, such as FM radio stations and radio stations broadcast from the Internet. There are also radio stations of other frequencies and their different names. Such as high frequency or shortwave, extra high frequency, ultra high frequency limit through which there is also satellite signal and police scanner report.

Amateur radio, pelagic and air stir are also included in these frequencies. Today we will learn about high frequency i.e. shortwave radio station which is also known as fictional about number station. This number is used to send symbolic messages to various intelligence agencies and the military. This number station has been in found since the First World War and has been the center of attraction for many years. For many years some of journalists have tried to decipher the mystery of this number station.[]

Coronavirus: Student repairs vintage radios during lockdown (BBC)

A teenager who restores and repairs old radios says he loves the “unexplained charm” and history of the wireless.

Diogo Martins, from Oadby, Leicestershire, has been able to spend more time on his hobby during the coronavirus lockdown and has added to his collection of vintage radios.

“Without a doubt many of these radios have a family history where families have gathered around to listen to music and information, and it’s that history which I find so endearing,” he said.

The 19-year-old electrical engineering student said in restoring them he is “continuing their legacy”.

Video journalist: Harris Millar


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Can you help Adi identify the radios in this video?

Many thanks to SWLing Post contributor, Adi, who writes:

i just finished watching this BBC piece:

In the background are two “blurred” receivers, they are unrelated to the story as far as being told or shown.

They look as top $$$$ type but what are they?

Post Readers: Can you ID the commercial-grade rigs in the background?  Please comment!

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The SDR.hu web SDR portal is no more, but we have several excellent alternatives

In January, András Retzler–owner of the SDR.hu KiwiSDR portal–started requiring registration and a ham radio license in order to access their extensive online database of SDRs.

Today, we learned of the site’s closure.  Here’s the message posted at SDR.hu:

The SDR.hu project has been finished

I’d like to say a big thanks to everyone who joined my journey with this project!

I hope you had a good time listening on the site, and learnt some things about SDR. The purpose of this site was to provide a technological demonstration for amateur radio operators about Software Defined Radio, and I hope this goal has been reached. As this website was a one-person hobby project, with my tasks and responsibilities growing, and my focus moving to other projects at which I hope to make a greater positive impact, I’m unable to further develop SDR.hu and protect it from abuse.

Furthermore, I think this site has some good alternatives now. Nevertheless, in my opinion amateur radio receivers should be shared with strict access control in the future.

If you have more questions, feel free to consult the FAQ.

73!

Andras, HA7ILM

SWLing Post contributor, Mark Fahey, shared the following message sent by Andras to all KiwiSDR owners in the database this morning:

Hello,

You are receiving this e-mail because you were listing a receiver on SDR.hu in the last 3 months.

I wanted to let you know that the SDR.hu project is discontinued.
This is because I have to focus on my PhD and unfortunately I don’t have enough time anymore to maintain the website and protect it from abuse.
If you have questions, there’s a FAQ on the front page: https://sdr.hu/
For KiwiSDR users there is another listing service available on the KiwiSDR website: http://kiwisdr.com/public (I’m not involved with this one.)
Thank you very much for having participated in the project!

VY 73!

Andras, HA7ILM

Alternative KiwiSDR Portals

Fortunately, there are a number of other KiwiSDR portals that do not require registration or a call sign. Here’s a list:

If you prefer another KiwiSDR portal, please comment with a link.  I’ll try to update this post with any new additions!

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