Category Archives: Software Defined Radio

A “knobs and switches” oldster investigates the SDRplay RSPdx . . . Wow!

By Jock Elliott, KB2GOM

It is hard to imagine a less spectacular looking piece of radio gear than the SDRplay RSPdx. It is literally a black box. Aside from the printing on top of the box, the most exciting thing about the RSPdx are the two red plastic covers on the antenna connectors on the side. There are no switches, no knobs . . . you can’t do anything to it except connect an antenna (or antennas) on one side and a USB cable on the opposite.

But once you connect the USB cable to your laptop and fire up the SDRuno software (that you have previously downloaded and installed), you are now in command of a listening post that covers from 1 kHz to 2 GHz.

We’ll get to the important stuff in just a minute, but first a little background.

For an oldster retrocrank like me, a proper radio has knobs and switches . . . preferably a knob or switch for every job. Lately, however, I have noticed that a lot of DXers and ordinary listeners are reporting good success with SDRs – software-defined radios. So I started to wonder about them.

There are three elements to a software-defined radio like the SDRplay RSPdx: the SDR box itself, which is the part of the system that actually receives the radio signals; a Windows computer (laptop or desktop), which provides the command and control for the SDR; and whatever antennas are required to receive the signals that the listener would like to hear. And, just to be absolutely clear, you need all three elements for the SDR system to work at all.

With my curiosity about SDRs rising, I inquired of Thomas, SWLing’s Maximum Leader, whether SDRplay – one of SWLing Post’s sponsors – might like me to take a look at one of their SDRs. Their answer was an emphatic Yes, and I had an RSPdx in my hands just a couple of days later at no cost to me or the SWLing Post.

I have to admit I had some trepidation about the process of bringing the RSPdx online because any time you have three different elements from three different sources that must work together for a system to function properly, there is always the possibility that some of the elements might not “play well together.”

Installation is easy and fast. Connect the RSPdx to the computer using a USB A-male to B-male cable (which the user must supply; often called a printer cable), then connect the antennas using the appropriate cable. In my case, I connected an MFJ 1886 Receive Loop to the Antenna C connector and an off-center fed dipole to the Antenna A connector.

To SDRplay’s great credit, they have produced an excellent video for first-timers and folks not familiar with SDRs — https://youtu.be/Oj_-dOLVzH8 . I recommend watching it, perhaps a couple of times, before you get started.

When you first fire up the SDRuno software, you will see the main panel:

Click on the “RX” button, and the Receive panel will be displayed. After you slide it over, it will look something like this:

Click on SP1 or SP2 in the main panel, and one of the peak displays will appear:

Finally, click on the PLAY button in the main panel, and whatever frequency you have selected will begin to play. Continue reading →

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Loop-On-Ground Antenna Part 3: Tom’s low-noise, low-profile, portable antenna evolves

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Loop on Ground Antenna Part 3

(using multiconductor wire)

by TomL

It dawned on me recently, perhaps due to sloppy thinking or unintended distractions, that I never wrote about my modified Loop on Ground (LoG) receive antenna that I use at parks and such. For over a year now, I have been using 3-conductor rotor wire bought cheap at the local hardware store and have wired the conductors in series. Grayhat (Andrew) was the inspiration when he decided to create a folded dipole along the side of his house.

The usual construction of a LoG antenna for shortwave is a single wire of about 60 feet in circumference in order to not go above one wavelength for 20 meter band usage. If you recall, going above one wavelength will start creating weird lobes in the reception pattern. See – Loop-On-Ground Antenna Part 2.

However, I did not like this 19 foot diameter wire on the ground in public parks just waiting to be tripped over. Like, the time when a horse got loose from its owners and almost tripped over my 60 foot wire. I don’t think I would have liked the resulting lawsuit!

So out of fearful necessity I took some leftover RCA 3-conductor rotor wire, about 29 feet of it, and wired a loop with the conductors in series. This gives about 81 feet of total conductive length. But since it is folded onto itself, there is an undetermined loss of resonant length. Callum (M0MCX) of DXCommander fame has experimented and found folded dipoles need three times more length in the folded section to reach resonance, so my loop is probably around 69 feet (electrically). See – Fold the end of a Dipole Back – What’s Happening?.

In the picture below, the black wire with Ring Terminal at the bottom goes all the way around to the other side, soldered to the green wire, which goes around and is soldered to the red wire, which goes around to the Ring Terminal at the top, plus tie-wraps to hold the wires together.

The next picture is how the Wellbrook Medium Aperture preamplifier is connected to the loop with BNC cable that goes to the 12V power injector. I have had this Wellbrook unit for maybe 6+years with no signs of problems. WARNING – do NOT use the Wellbrook preamplifier in the presence of high powered RF energy like your Amateur Radio antenna pumped with 1000 watts from a linear amplifier; the Wellbrook premap might just overload and get damaged! I did use this loop and preamplifier at last year’s 2022 ARRL Field Day and was able to get away with it because we were only using 100 watts per station. Listening to the 9pm 3916-net trivia group was fun but I still needed to keep it away from the transmitting antennas. Continue reading →

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Radio Waves: Shively Labs Broadcast Antennas, Fedora SWL, F-150 Lightning AM, and Young Listeners on the Decline

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Radio Waves: Stories Making Waves in the World of Radio

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 contributor Dennis Dura for the following tips:

Public radio engineers await fate of major antenna maker (Current)

The potential sale of one of the country’s only major manufacturers of high-power FM broadcast antennas is causing concern among public radio engineers who have long depended on the company for challenging projects such as directional antennas and multistation combiner systems.

Antennas and combiners made by Shively Labs carry the signals of many major stations, from Boston’s WBUR to Dallas’ KERA/KXT to Seattle’s KUOW. Shively’s headquarters in Maine boasts one of the few test ranges needed to fully prepare complex directional antenna systems for real-world performance.

Founded in 1963 by former RCA engineer Ed Shively, the company has been owned since 1980 by Howell Laboratories, an engineering firm that now has a wide range of product lines. Those include water purification systems, dehydrators and an increasing amount of contract work for the U.S. Navy.

While its military and commercial marine business has grown, broadcast antennas have become a smaller piece of the company’s portfolio, said Shively VP Angela Gillespie. [Continue reading…]

How to become a Shortwave listener (SWL) with Fedora Linux and Software Defined Radio (Fedora Magazine)

Catching signals from others is how we have started communicating as human beings. It all started, of course, with our vocal cords. Then we moved to smoke signals for long-distance communication. At some point, we discovered radio waves and are still using them for contact. This article will describe how you can tune in using Fedora Linux and an SDR dongle.

My journey

I got interested in radio communication as a hobby when I was a kid, while my local club, LZ2KRS, was still a thing. I was so excited to be able to listen and communicate with people worldwide. It opened a whole new world for me. I was living in a communist country back then and this was a way to escape just for a bit. It also taught me about ethics and technology.

Year after year my hobby grew and now, in the Internet era with all the cool devices you can use, it’s getting even more exciting. So I want to show you how to do it with Fedora Linux and a hardware dongle. [Continue reading…]

Did AM Radio Just Get Hit By “Lightning”? (Radio World)

There’s something missing from the newest F-150 Lightning truck

These days, the auto industry is as disrupted as broadcast radio. Like the radio companies – a group of independent operators, each moving down a different pathway – automakers are highly individual companies. Continue reading →

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Radio Waves: Radio Martí, SDRs for Ukraine, Military Morse Code Innovation, and RFE/RL Opens Riga Bureau

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Radio Waves: Stories Making Waves in the World of Radio

Welcome to the SWLing Post’s Radio Waves, a collection of links to interesting stories making waves in the world of radio. Enjoy!

Radio Martí news: Migrants land by Keys broadcasting tower promoting Cuban democracy (Miami Herald)

Washington maintains a waterfront radio tower in the Florida Keys to broadcast programming aimed at encouraging democracy and press freedom in Cuba, and on Sunday that area in Marathon was the landing spot for a group of migrants fleeing the island. A boat of 25 migrants arrived on the shores of Sister Creek, home to a Radio Martí transmission station on Sunday morning, said Adam Hoffner, assistant chief patrol agent for U.S. Customs and Border Protection’s Miami operations. The landing was one of two known migrant arrivals in the Keys on Sunday, with another 28 Cubans arriving on private property in Key Largo. While the government-run broadcasting agency targets Cuban listeners with Spanish programming, Radio Martí reports typically discourage the kind of voyage that reportedly landed some Cubans on or near Martí property, said Tomás Regalado, the former Miami mayor who also recently ran the agency that oversees Radio and TV Martí. “Historically, the migrant situation was something that was treated as news,” Regalado said. “But with the caveat that it’s a very dangerous trip and not recommended.” [Read more here…]

Ukraine Uses Off-The-Shelf Electronics To Target Russian Communications (Forbes)

A nonprofit organization based in the U.S. is supplying Ukrainian forces with advanced electronic warfare gear assembled from simple off-the-shelf components. The secret is a new technology known as Software Defined Radio (SDR) which can locate Russian radio emitters, from command centers to drone operators. Previously this sort of capability required expensive, high-grade military equipment.

Serge Sklyarenko says his organization, American Ukrainian Aid Foundation, based in New York, is supplying Ukrainian intelligence with a number of the versatile SDR radio kits.

“The beauty of them is they are software defined, meaning they can be reprogrammed in the field to suit a multitude of use cases,” Sklyarenko told me.

In a traditional radio set, the signal from an antenna is processed by dedicated hardware – amplifiers, filters, modulator/demodulators and other components. This means that each radio set is dedicated to one particular type of radio signal, whether it is a 5G cellphone, AM radio, digital television or WiFi. In Software Defined Radio, the only dedicated hardware is the antenna. All the signal processing is carried out digitally with a computer. Simply by changing the programming, an SDR can extract the signal for cellphone, radio, Bluetooth, or any other defined waveform. One device can do everything. [Continue reading…]

Innovation on Morse Code for the US Military (SOFREP)

On January 10, 1991, the U.S. Army Intelligence School Devens (USAISD) introduced the Basic Morse Mission Trainer to the 98H Morse intercept operator and 98D emitter identifier/locator advanced individual training courses. This system revolutionized the training of Morse code copying skills for both students and instructors, reducing course attrition, and turning out better trained operators faster. Continue reading →

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Mario shares a short review of the Airspy HF+ Discovery SDR

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Many thanks to SWLing Post contributor, Mario Filippi (N2HUN), who shares the following guest post:

Author’s Airspy HF+ Discovery (small black box to the left of the laptop)

A Short Review of the Airspy HF+ Discovery SDR

by Mario Filippi (N2HUN)

I recently purchased an AirSpy HF+ Discovery. As a SWL for over 60 years who’s owned many shortwave radios by manufacturers such as Drake, Yaesu, Icom, Zenith, Kenwood, Panasonic, Sony, Radio Shack, Grundig, CountyComm, MFJ, Sears, AOR and have used a number of different SDRs such as the RTL-SDR.com, HackRF, NooElec and many other rudimentary inexpensive first generation SDR dongles, I feel the AirSpy was an excellent choice. It cost $169 plus shipping.

For LW/MW/HF reception, I use a 30’ ground mounted vertical with about 50 buried radials in different stages of decomposition hihi. For VHF, a roof mounted 2m/70cm SlimJim antenna is used, but I haven’t done much listening in that portion of the spectrum yet except for occasional foray into the aero, 2m ham, NOAA satellite and public service bands. Note that the AirSpy also covers 60 – 260MHz.

An older Dell Inspiron laptop and SDR# are used in conjunction with the AirSpy. For decoding, MultiPSK, FLDigi, MTTY, Yand (for NAVTEX), along with VB cable are the accompanying software to make the digital modes intelligible.

So far I’ve logged a few local LF aeronautical beacons and some DGPS beacons on longwave but will be in a better position to judge its performance when winter sets in. As for the medium (520 – 1710 kHz) wave AM broadcast band, the AirSpy easily brings in both local stations during daytime and distant stations at night with no adjacent channel interference whatsoever. Even low powered community Emergency Alert Stations in the 1600 – 1710 kHz portion of the band can be heard daily from this QTH. A rotatable loop would certainly improve reception though.

As for shortwave listening the AirSpy HF+Discovery is, in my opinion, great for listening to both shortwave broadcasts and utility stations though I tend to concentrate on UTES mostly such as VOLMET, WEFAX, RTTY (the few that remain unencrypted), CW marker stations (e.g. XSG and XSQ from China) NAVTEX (519 kHz), aero/maritime SSB, time signal stations (WWV, CHU) and many of the other esoteric digital utility signals populating the band. As for SW broadcast stations, WRMI, Radio Exterior, RFI, R. Marti, BBC, WWCR and Radio Algerienne, to mention a few have been received. The Frequency Manager (memory storage) in SDR# has quickly filled up with intercepts using the AirSpy.

As a ham and CB operator (yes, the two can mutually coexist in the same human body), I’ve found the AirSpy HF+ Discovery to be a trouper on all the HF ham and CB bands. One of my favorite hangouts is the 28.100 – 28.300 MHz slice of 10m where domestic and international low power CW beacons transmit their callsigns (and at times their grid squares and power output) into the ionosphere and achieve great distances. Recently, beacons from 5, 6 and 7 land in the US along with DX prefixes ED4, PY4 and XE1 were logged. If you’re into 10m FM operation you can also tune the AirSpy to hear local and distant repeaters on 29.62 – 29.68 MHz. When the band is open, .62 and .64 seem to be the most active here in Central NJ.

If you’re a CB (aptly named the Citizen’s Band) op, the AirSpy HF+ Discovery does a stellar job on Channels 1 – 40 which is especially exciting when the band’s open. While domestic (USA) CB’ers are limited to frequencies from 26.965 – 27.405 MHz you’ll nonetheless hear DX ops below our (USA) channel 1 and above channel 40 conversing in French, Spanish and German in LSB/USB. Add to this mix the fact that the FCC dropped the 150 mile limit for US ops a few years back and now the advent of the FM mode operation in the US, you’ll find the AirSpy won’t disappoint. In my opinion the AirSpy HF+Discovery was an excellent choice and I’m more than satisfied with its performance.

In the matter of honesty and full disclosure, I purchased the AirSpy HF+ Discovery completely on my own in an effort to upgrade my station. My choice was based on information gathered from the Internet and YouTube video reviews. The performance of this receiver was based on my experience using the vertical antenna described earlier, the hours spent at my QTH (location) listening to stations of interest to me and my six decades experience as a SWL. No test equipment to assess sensitivity, selectivity or other empirical methods to measure performance was used. That information can be found on the Airspy website. The main purpose of this article was to craft a rudimentary review for those interested with the caveat that reception will vary depending on many factors such as location, antenna, ionospheric conditions, feedline quality, computer/software variations, QRN, QRM, and operator experience. The results presented in this article are typical for my location; others may experience different results. Thanks very much.

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Radio Waves: Maverick-603 SDR for FT8, EC-130J Commando Solo Final Broadcast, WRTH Survey, and Railways On The Air

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EC-130J Photo By Staff Sgt. Tony Harp | An EC-130J Commando Solo aircraft from the 193rd Special Operations Wing performs a flyover during Community Days at the Lancaster Airport in Lititz, Pennsylvania, Sept.17, 2022. (Source: DVIDS)

Radio Waves: Stories Making Waves in the World of Radio

Welcome to the SWLing Post’s Radio Waves, a collection of links to interesting stories making waves in the world of radio. Enjoy!

RadioStack’s Maverick-603 Is a Fully-Functional Open-Silicon Software-Defined Radio for FT8 (Hackster.io)

Built using open tools and readied for manufacturing at SkyWater using the Efabless platform, the chip on this SDR is something special.

New Hampshire-based RadioStack is looking to launch a piece of amateur radio equipment with a difference: the Maverick-603 is powered by free and open source silicon, built using the Efabless platform at a SkyWater fab.

“Maverick-603 is the first affordable FT8 receiver board built around an RF receiver chip that was designed using fully open source tools and fabrication,” its creators explain. “It is capable of acquiring FT8 signals between 7MHz and 70MHz. With this frequency range, you will be able to receive signals from around the world with high accuracy. The use of our Low Noise Amplifier (LNA) will also give the chip the ability to amplify very low-strength signals, which is necessary for an effective FT8 receiver.” [Continue reading…]

EC-130J Commando Solo performs final broadcast (DVIDS)

MIDDLETOWN, PA, UNITED STATES
09.17.2022
Story by Master Sgt. Alexander Farver
193rd Special Operations Wing

Airmen from the 193rd Special Operations Wing here, who operate the only flying military radio and TV broadcast platform in the U.S. military, transmitted their final broadcast today to spectators at the Community Days Air Show at Lancaster Airport, Lititz, Pa., bringing to close a 54-year chapter in unit history.

The EC-130J Commando Solo mission has helped keep this Air National Guard unit’s aircraft and its Airmen at the tip of spear for nearly every major U.S. military operation since the Vietnam War. Before bombs dropped or troops deployed in the Global War on Terror following the attacks on Sept. 11, 2001, this specially modified aircraft was already over the skies of Afghanistan broadcasting to America’s enemies that the U.S. military was bringing the fight to them.

“Any world event or crisis that our military has responded to in recent history, our 193rd Airmen – and Commando Solo – were likely key components in that response,” said Col. Eric McKissick, 193rd SOW vice commander. “As we prepare to open a new chapter in our history, we thank those who have enabled us to be among the very best wings in the Air National Guard.”
The genesis for this airborne information operations platform can be traced back to 1968 when the 193rd Tactical Electronics Warfare Group received its first aircraft, called the EC-121 Coronet Solo. In the late 1970s, the aircraft were replaced by the EC-130E before finally being replaced by the current aircraft in 2003. Throughout its history, it was instrumental in the success of coordinated military information support operations, earning the wing the moniker of “the most deployed unit in the Air National Guard.”

These deployments included: Operation Enduring Freedom, Operation Iraqi Freedom, Operations Odyssey Dawn/Unified Protector in Libya, Operation Inherent Resolve, Operation Resolute Support/Freedom’s Sentinel, Operation Secure Tomorrow and Operation Unified Response in Haiti.

Although this unique mission has earned the wing many prestigious accolades, Lt. Col. Michael Hackman, 193rd Special Operations Squadron commander, believes the mission’s success and legacy lies in winning the hearts and minds of adversaries and providing vital information to allies, refugees and victims in times of crisis.

“This capability has been an essential tool in our nation’s inventory, from the battlefields to assisting hurricane and earthquake-ravaged nations,” Hackman said. “During this time, thousands of Pennsylvania Air National Guard volunteers fulfilled their call to duty in this unique capacity, leveraging this capability against U.S. adversaries and supporting allies while always fulfilling the unit tenet of ‘Never Seen, Always Heard.’”

Aside from sporting an impressive operational record, the aircraft holds another distinction with having completed over 226,000 hours of accident-free flying.

“Having that many thousands of hours of accident-free flying is a testament to the excellence of our maintainers, to the operators and anybody who has touched that aircraft. Thank you for leaving that foundation and setting that example that we’re building from,” said Col. Jaime Ramirez, 193rd Special Operations Maintenance Group commander.

McKissick believes the success of the 193rd in operating the Commando Solo mission over the past few decades has led to Air Force Special Operations Command selecting the wing to be the first and only ANG unit to operate the MC-130J Commando II. The Commando II flies clandestine, or low visibility, single or multiship, low-level infiltration, exfiltration and resupply of special operations forces, by airdrop or airland and air refueling missions for special operations helicopters and tiltrotor aircraft, intruding politically sensitive or hostile territories.
“Today we honor the men and women, past and present, who have served this unit and mission with unparalleled distinction,” said McKissick. “The Airmen who came before us created an enduring culture and spirit of hard work, innovation and grit. We thank them for that, and we will do our best to carry this forward.”

The final broadcast of the EC-130J was transmitted to the ground and played at the Community Days Air Show at Lancaster Airport. In the transmission, the wing thanked the local community for their support over the past 54 years before broadcasting the Santo and Johnny song, “Sleepwalk.” The transmission ended with the phrase, “Commando Solo, music off.” [Read the full article here…]

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Railways On The Air (Southgate ARC)

The South Eastern Amateur Radio Group (EI2WRC) will be active from The Waterford and Suir Valley Railway station Kilmeaden, Co. Waterford for the ‘Railways On The Air‘ event on Sunday, the 25th of September.

WSVR is a community heritage project. The project has enabled the magic of rails golden age to be brought to life in Kilmeaden. A heritage narrow gauge railway runs along 17 kilometres of the abandoned Waterford to Dungarvan line.

The South Eastern Amateur Radio Group would like to thank the manager Maria Kyte and all the staff of The Waterford and Suir Valley Railway for all their help and allowing us access to the station to do this event again this year. For more information about the WSVR please see www.wsvrailway.ie .

The September meeting of the South Eastern Amateur Radio Group EI2WRC will take place on Monday, the 26th of September 2022 at 8.00 p.m. sharp at The Sweep Bar, Adamstown, Kilmeaden, Co. Waterford, Eircode X91 H588. New members or anyone interested in learning more about amateur radio or the group are as always very welcome to attend.

For anyone that wishes to find out more about the South Eastern Amateur Radio Group and their activities you can drop them an email to southeasternarg /at/ gmail.com or please feel free to go along to any of their meetings. You can check their website www.searg.ie and you can also join them on Facebook and follow them on Twitter.

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How Jake configures SDR# to listen to Encore classical music

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Many thanks to SWLing Post contributor, Jake Brodsky (AB3A), who shares the following guest post:

How I Listen to Encore on Radio Tumbril

Listening to Classical music on shortwave is a challenge. It has loud and soft parts to the music. There may be selective fading. It isn’t a simple thing.

Also, configuring a software defined radio such as the highly configurable SDR# is not trivial. Note to readers: SDR# has been updated a lot recently and the noise reduction features are vastly improved. Kudos to Youssef Touil for all the hard work on this software. He continues to impress me with every update.

So I have some suggestions for those who are interested in listening:

First, get a decent set of over-the-ear headphones. Don’t rely on laptop speakers. They’re usually not designed for audio fidelity.

Set the radio for DSB reception with Lock Carrier and Anti-Fading checked. I also set the bandwidth to cover about 11 kHz or thereabouts.

On the Audio tab I uncheck the Filter Audio option. I’m going to rely on IF filtering to do my work for me.

Next, find an empty channel on the band where you will be listening to the program. Enable the IF Noise Reduction feature, set it to HiFi, and then set the threshold so that the noise floor is reasonably low. If you set the threshold too high, you’ll lose the higher frequency audio and there will be artifacts from the noise floor that I find unpleasant. A little bit of noise reduction is good, but more is not better.

I also enable the IF Filter/notch processing window to handle any stray birdies from switching mode power supplies. However, if not needed, I turn that feature off.

I turn off the AGC. And then I set the volume level to something reasonable, not too loud, not too soft, but just barely able to hear the noise floor.

Then I tune in the program. I was listening to the Sunday Evening (Monday 0200 UTC) broadcast from WRMI on 5950 kHz. There was some fading going back and forth. However, I took the atmospherics in stride, as if it were part of the experience. The broadcast from this evening
ended with the Pastoral Symphony from Beethoven. There were a few fades and there were a few swells, all due to atmospherics as the signal faded to the noise floor and emerged from it. But there was very little distortion. (thanks to the excellent engineers at WRMI).

The experience was actually sublime.

This is why I listen to shortwave broadcasts.

73,

Jake Brodsky, Amateur Radio Station AB3A

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