Tag Archives: Software Defined Radio

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

45 Replies

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 →

Spread the radio love

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

6 Replies

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 →

Spread the radio love

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

2 Replies

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 →

Spread the radio love

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

10 Replies

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.

Spread the radio love

Radio Waves: Insomnia-Fueled Pirate, Cold War & High-Tech Tactics for Russia, PL-660 Panadapter, Women-Run Radio in Somalia, and Building an SDR Transceiver

3 Replies

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!

Meet the 68-year-old ‘bad-boy nerd’ behind this North Side pirate radio station (WBEZ)

If you’re driving through the greater Ravenswood area and tune your radio dial to 87.9 FM, you might just enter a sort of radio twilight zone. On tap? Old timey, crime-thriller radio dramas, complete with sleuthy melodramatic music, damsels in distress and classic radio sound effects – footsteps, doors slamming, the gun going off.

There are no call letters or DJs, just “audio noir” floating out over a two-square-mile sweet spot on Chicago’s North Side.

It’s all broadcast illegally out of a nondescript two-flat on a residential block. There’s a spindly antenna on the roof, visible mainly from the alley, and a 50-watt transmitter in the upstairs apartment. And there’s Bill, a retired computer and audio engineer who’s been operating this illegal station for some 15 years. He asked us not to use his last name for fear of “FCC prison.”

“People on the lakefront up in the high rises can hear it,” said Bill. “And they used to listen at Lane Tech somewhere on an upper floor. So it gets out a little ways, but not that far.”

Bill got into noir not because it’s gripping radio, but rather because it’s not. He has insomnia, and the plot lines from Dragnet and Yours Truly, Johnny Dollar help him fall asleep. [Continue reading and listen to this piece at WBEZ.]

U.S. and Ukrainian Groups Pierce Putin’s Propaganda Bubble (NY Times)

U.S.-backed news outlets and Ukrainian activists use Cold War techniques and high-tech tactics to get news about the war to Russians.

WASHINGTON — Using a mix of high-tech and Cold War tactics, Ukrainian activists and Western institutions have begun to pierce the propaganda bubble in Russia, circulating information about the Ukraine war among Russian citizens to sow doubt about the Kremlin’s accounts.

The efforts come at a particularly urgent moment: Moscow appears to be preparing for a new assault in eastern Ukraine that could prove devastatingly bloody to both sides, while mounting reports of atrocities make plain the brutality of the Kremlin’s tactics.

As Russia presents a sanitized version of the war, Ukrainian activists have been sending messages highlighting government corruption and incompetence in an effort to undermine faith in the Kremlin.

Radio Free Europe/Radio Liberty, a U.S.-funded but independent news organization founded decades ago, is trying to push its broadcasts deeper into Russia. Its Russian-language articles are published on copies of its websites called “mirrors,” which Russian censors seek out in a high-stakes game of whack-a-mole. Audience numbers have surged during the war despite the censorship. Continue reading →

Spread the radio love

HFDY vs. Fire Brothers: Dan compares two Chinese Malahit SDR clones

10 Replies

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

Two Chinese Clones:   A Look at Noise Levels

Arriving recently here in the radio shack, were a Chinese clone under the name of “Fire Brothers” and another under the name HFDY.  I thought it would be constructive to note the key differences between these two clones, both of which are running Malahit 1.10c firmware, and post some video of a brief comparison.

A note in advance of any comments – I am primarily a HF listener so these comparisons do not cover frequencies above 30 MHz.  For those whose focus is on higher frequencies I recommend looking through the many comments on the Malahit Facebook group and Telegram by those who use these receivers in those ranges.

HFDY

  • Constructed of metal-like material (a correction from my previous articles that this is fiberglass of the kind used in printed circuit boards – thanks to Georgiy of Malahiteam for pointing this out)
  • Front speaker grille is gold color and appears to be metal but may be fiberglass as well – audio is quite good
  • Two top-mounted antenna jacks, one 50 ohm, the other Hi-Z (makes switching between HF and FM/VHF reception easier) with in-use LED indicators
  • Two high quality right side mounted black metal encoder knobs with large power button (clear printed Frequency/STDBY/Volume printed on panel)
  • Cabinet held together with TORX screws
  • 1.10c firmware
  • Receiver is elongated left to right to accommodate left side front-firing speaker, but is thinner overall and could be easily placed in a pocket though not recommended to prevent damage
  • Like every one of these SDRs, suffers from body sensitivity to touch which reduces signal levels unless some sort of additional ground is attached to cabinet
  • Internal flat-type Lithium battery of 3300 mAh though apparently capable of fitting up to 8000 mAh

Continue reading →

Spread the radio love

Dan adds updates to his Malahit SDR and variant reviews

2 Replies

Many thanks to SWLing Post contributor, Dan Robinson, for the following update to his previous post regard the DSP-2 and HFDY Malahit SDRs:

HFDY clone of the Russian-made Malahit SDR

Malahit and HFDY Updates

by Dan Robinson

HFDY CLONE:  As noted by a reader in comments, the Chinese-made HFDY leaves out a large portion of the military AIR band, with no coverage from 250MHz to 400MHz, or about 150MHz, whereas the Russian-made DSP2 only loses 20MHz from 380MHz to 400MHz.  This may be of concern for some readers, others not.

RUSSIAN DSP-2:  As users of the Russia-made DSP-2 may or may not have noticed, the current firmware shows SIX memory bank pages when there are only 5.  This appears not to have been discussed much on the Malahiteam Telegram group or elsewhere.  In response on this, Georgiy of Malahiteam says this “is normal and for our future features” so clearly there are future plans that we are not aware of.

CHINESE-MADE FIRE BROTHERS CLONE:  On September 21st, I took delivery of another China-manufactured clone, with a heavy metal cabinet, a vertical format with controls on top, and twin front-firing speakers.  Obtained via Alibaba, and branded as “Fire Brothers” this has a thick built-in telescopic antenna and a separate SMA jack which the maker describes as “[supporting] a better external shortwave antenna”

On Alibaba, prospective buyers of this receiver are given two options:  Type 1: 50KHz-2GHz without firmware updates supported, and Type 2 with support for updates.   The unit did arrive with 1.10c Malahit firmware with a 160 kHz bandscope width.

As noted above, this China-manufactured clone also blocks 200 mHz – 400 mHz and shows the Msi001 chip and STM32h743 and a claimed blocking figure of 85dB and  sensitivity up to 250MHz of 0.3?V = 10dB.  The battery is described as 5000 mAh and presumed to be flat type Lithium Ion.

The only thing included with this clone, which arrives in a plain black box marked “Fire Bros.Radio” is a USB-C cable.  That’s in stark contrast with the HFDY clone which comes in a high quality fabric zipper case, flexible whip antenna, USB-C cable, and a small metal stand.

The Fire Brothers manufacturer highlights the “high quality speakers” which not only fire out the front of the receiver, but also wrap around with openings on left and right sides of the radio.  My first tests show that audio is indeed quite nice, certainly equal to the Russia-made DSP-2, possibly an improvement on the HFDY clone which has a single front-firing speaker.

I’ll have more on this Chinese clone and some comparisons with the DSP-2, HFDY, and Afedri SDRs, in future articles here on SWLing Post.

Spread the radio love