Category Archives: Software Defined Radio

Check out the new scheduler functionality in SDRuno V1.41

Many thanks to Jon Hudson with SDRplay who shares the following information about the latest release of SDRuno on the SDRplay blog:

Try out the new features in SDRuno V1.41 released today

SDRuno V1.41 was fully released today.  It includes the much requested full scheduler facility which allows you to set up numerous recording events for your RSP.  As well as providing all the expected calendar options (time of day, date, start and stop times, repeating options and so on), you can also set the ‘profile’ for each recording – this allows you to pre-set frequencies, bandwidths, demodulator options (AM/FM/USB/LSB etc.), choice of filters and antenna port selection.  Additionally you can choose the settings for connectivity to other third party software or the running of a specific plugin.

• New Scheduler panel which replaces the old “Recorder” panel (launch using the SCHEDULER button in the main panel).
• A new autolayout to include the scheduler (for screen resolutions of 1920×1080 and above).
• Backup and Restore of the ini file settings (access via the main panel OPT menu)
• Screenshot button has been added to the SP1 title bar
• IQ wav files can now be used in plugins
• Autolayouts now take account of the taskbar location and size.
• Autolayouts have been improved to take account of higher resolutions.
• Saved workspace notification moved to the status bar.
• Memory Panel will now prompt to save any changes made when switching to another memory
• Decimation and the LOLOCK state are now correctly saved and recalled within a profile.
• Main panel version tooltip now displays correct information.
• The step size could be set incorrectly when using non-FM modes and pressing any of the FM sub
mode buttons.
• ADS-B/DAB mode now handles when in both band-framed mode and also when the LO is locked.
• Bugs associated with wav file playback
• When loading a profile, the last used memory bank field will update correctly
• Saving a profile will now update the displayed loaded profile field correctly
Known Issues
• SP2 CWAFC drift issue (Zoom/window size/freq display)
• IF output mode disabled SP1 spectrum mouse clicks
• Occasionally if SDRuno is closed whilst a plugin is still running, it may not close properly. This may
necessitate a PC reboot to fix it.

You can find this latest version of SDRuno on our downloads system :

Click here to continue reading this post on SDRplay’s website which also includes a number of tutorial videos.

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Guest Post: Mediumwave DXing in Botswana

Many thanks to SWLing Post contributor, Peter Wilson, who shares the following guest post and recordings from his listening post in Botswana:

Peter’s receiver is a Airspy HF+ Discovery SDR using SDR Console V3

MWDX from Australia and the USA received in Botswana

by Peter Wilson

Hello Thomas.

I moved my 16.2 metre random wire slightly farther away from the house, and installed a binocular balun and connected 20m of RG58 at the far end, not the “house end”.

Peter’s random wire antenna with binocular balun

Reception examples:

1500 USA WFED Washington DC 12790km

1152 AUS 6PB
ABC NewsRadio Busselton 8469km with ABC News ID

1600 B Radio Nove de Julho ID 7234km
Sao Paulo. Brazil. ID,
Web Address and jingle. Rinsed and repeated.
Portuguese: Radio Nove de Julho [English: Radio 9th July]

1026 kHz MOZ Emissor Provincial de Manica Chimoio 1057km.
A bit parochial but features the radio Mozambique song.

850 USA WTAR Norfolk, Virginia Fox Sports Radio ID 12700km

1296 6RN ABC Radio National. Wagin, Australia 10kW 8644km

558 AUS 6WA ABC Great Southern WA Wagin 8644km

Impressive reception from your home in Botswana! Thank you so much for sharing these recordings, Peter. You’ve certainly made the most of your random wire antenna!

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Radio Waves: Old Gen FM Radio, Radio Burst Model Challenged, Iceland WebSDR, and Ida Destroys WZRH/KVDU Tower

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, Troy Riedel, Dan Van Hoy, and the Southgate ARC for the following tips:

FM Radio, the choice of an old generation (Hackaday)

Had the pandemic not upended many of this summer’s fun and games, many of my friends would have made a trip to the MCH hacker camp in the Netherlands earlier this month. I had an idea for a game for the event, a friend and I were going to secrete a set of those low-power FM transmitters as numbers stations around the camp for players to find and solve the numerical puzzles they would transmit. I even bought a few cheap FM transmitter modules from China for evaluation, and had some fun sending a chiptune Rick Astley across a housing estate in Northamptonshire.

To me as someone who grew up with FM radio and whose teen years played out to the sounds of BBC Radio 1 FM it made absolute sense to do a puzzle in this way, but it was my personal reminder of advancing years to find that some of my friends differed on the matter. Sure, they thought it was a great idea, but they gently reminded me that the kids don’t listen to any sort of conventional broadcast radio these days, instead they stream their music, so very few of them would have the means for listening to my numbers stations. Even for me it’s something I only use for BBC Radio 4 in the car, and to traverse the remainder of the FM dial is to hear a selection of easy listening, oldies, and classical music. It’s becoming an older person’s medium, and it’s inevitable that like AM before it, it will eventually wane.

There are two angles to this that might detain the casual hacker; first what it will mean from a broadcasting and radio spectrum perspective, and then how it is already influencing some of our projects. [Continue reading…]

New observations challenge popular radio burst model (Sky and Telescope)

Strange behavior caught by two radio observatories may send theorists back to the drawing board.

Fourteen years ago, the first fast radio burst (FRB) was discovered. By now, many hundreds of these energetic, millisecond-duration bursts from deep space have been detected (most of them by the CHIME radio observatory in British Columbia, Canada), but astronomers still struggle to explain their enigmatic properties. A new publication in this week’s Nature “adds a new piece to the puzzle,” says Victoria Kaspi (McGill University, Canada). “In this field of research, surprising twists are almost as common as new results.”

Most astronomers agree that FRBs are probably explosions on the surfaces of highly magnetized neutron stars (so-called magnetars). But it’s unclear why most FRBs appear to be one-off events, while others flare repeatedly. In some cases, these repeating bursts show signs of periodicity, and scientists had come up with an attractive model to explain this behavior, involving stellar winds in binary systems.

However, new observations by European radio telescopes may rule out this model.

Astronomers knew that FRB 20180916B, located in a galaxy some 475 million light-years away, produces multiple bursts about every 16 days, during a ‘window’ that lasts for a few days. “The idea was that the magnetar is part of a binary system with a 16.29-day period,” says Inés Pastor-Marazuela (University of Amsterdam), the first author of the new paper. If the companion star had a thick stellar wind that absorbs radio waves, the bursts would only be visible when the magnetar was on ‘our’ side of the orbit, she explains. [Continue reading…]

New WebSDR in Iceland (Southgate ARC)

Iceland’s IRA reports on August 24 Karl Georg Karlsson TF3CZ connected a new receiver over the internet covering 24-1800 MHz

A translation of the IRA post reads:

QTH is Perlan in Öskjuhlíð in Reykjavík. These are Airspy R2 SDR receivers for 24-1800 MHz (on VHF and UHF). The antenna is a Diamond D-190.

Karl Georg stated the following on FB:
The extension is not just for 2m, it can only be on one band at a time. So if one user switches, others who are connected also move between bands. (However, you can listen to each frequency within the same band). The receiver automatically tunes to APRS QRG 144.800 MHz, see the APRS website:

URL of the receiver,mod=usb,sql=-150

Thanks to Karl Georg for his valuable contribution. This is an important addition for radio amateurs who experiment in these frequency ranges, as well as listeners and anyone interested in the spread of radio waves.

IRA Board

Source Iceland’s national amateur radio society, the IRA

WZRH/KVDU Tower Destroyed By Hurricane Ida (Radio Insight)

The nearly 2000 foot tower utilized by Cumulus Media Alternative “Alt 92.3” WZRH LaPlace and iHeartMedia Variety Hits “104.1 The Spot” KVDU Houma LA was toppled by the winds of Hurricane Ida.

The 1999 foot structure was constructed in 1988 to host both signals. Only the bottom 150 to 200 feet remain standing. Both stations are licensed to operate with 100kW/591m, but have low powered auxiliary sites in downtown New Orleans. WZRH is located on the roof of Place St. Charles with 630w/200m. KVDU is on the Hancock Whitney Center with 1.2kW/220m.

In addition to KVDU, iHeartMedia Gospel 940 WYLD is silent at its cluster. The company reports that the remainder of its signals are now operational after all but 93.3 KQUE and 98.5 WYLD-FM were off the air on Monday.

Cumulus Media states that its entire cluster of WZRH, Adult R&B 102.9 KMEZ Belle Chasse, Country “106.1 Nash-FM” WRKN Picayune MS, and Hot AC “106.7 The Krewe” KKND Port Sulphur LA are off the air. [Continue reading…]


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Mike compares four active mag loop antennas

Many thanks to Jon Hudson who shared the following on the SDRplay Facebook page:

In this new video, Mike Harwood compares 4 different active mag loop antenna at various frequencies up to 52MHz using two SDRplay RSPduos which allowed simultaneous spectrum snapshots of the 4 loops in action with real signals.

These are loops from Bonito, Cross Country Wireless, LZ1AQ and Wellbrook.

This is the second of Mike’s antenna comparison videos. He welcomes comments which will help shape the content for future antenna experiments:

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Malahit DSP-2: Dan’s thoughts on external antennas, firmware, and purchase decisions

Many thanks to SWLing Post contributor, Dan Robinson, for the following guest post:

Additional Thoughts on the Malahit DSP-2 

  • Potential for Noise Reduction Using Non-Whip Antennas
  • Latest Firmware Changes

by Dan Robinson

After my last update on the Russia-made Malahit DSP-2, I thought it important to add something about the receiver, as it could well influence those who may be on the fence about purchasing one.

In a series of communications, Georgiy at Malahit team has stressed steps taken to attempt to deal with internal interference seen across the bands.  And he has asserted

that noise spikes lessen if the receiver is connected to a non-whip antenna.

Most of my tests have used whip antennas of various lengths, in various locations indoors and outdoors, because it’s my view that portability is a major attraction of these small SDR receivers.

Continue reading

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Malahit DSP-2 Review Update 3: Dan evaluates the latest hardware version

Many thanks to SWLing Post contributor, Dan Robinson, for the following guest post:

UPDATE NO 3: Malahit DSP-2 (August 18, 2021)

A few weeks ago, I wrote about my experiences with the Russia-made Malahit DSP-2 receiver, and made a recommendation that potential purchasers of the receiver hold off until the design team in Russia made some changes.

Weak points included the SMA antenna connector – specifically the short cable going from the antenna to the PCB board, and sharp noise spikes seen at numerous locations throughout the spectrum from mediumwave up to 30 MHz.

My particular DSP-2 unit went dead after an update to an early version of the 2.10TEST firmware.  At the time, I had spoken via Skype with Georgiy on the Malahit team and kept up a string of communications on the Malahit Telegram channel.

It was not clear to me whether the problem with the first DSP-2 was primarily due to SMA antenna issues or also due to a problem with the firmware update I had applied at the time (it was an early version of 2.10TEST).

My appreciation goes to Georgiy who decided to send a new DSP-2 to me.  This took about 3 weeks from the end of July until just recently when the receiver arrived (though the U.S. Postal Service made the end of that journey quite interesting).

Here are some observations that I hope will help current and prospective owners of the DSP-2: Continue reading

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