Category Archives: DX

SDR#’s Co-Channel Canceller Gets Additional Options

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In my earlier article, I introduced the Co-Channel Canceller, a unique feature in AirSpy’s SDR# program for the benefit of medium wave DXers.

Now only a day later, software author and AirSpy founder Youssef Touil expands the toolset of Co-Channel Canceller with I.F. Offset and Channel Bandwidth controls.

To download this latest release, click here to go to AirSpy’s downloads page.

It’s my hope that AirSpy will publish a tutorial or YouTube video(s) with step-by-step examples to help with using this unique feature. Until then, it’s certainly fun to try!

Guy Atkins is a Sr. Graphic Designer for T-Mobile and lives near Seattle, Washington.  He’s a regular contributor to the SWLing Post.

AirSpy SDR#’s New Killer Feature: the Co-Channel Canceller

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An example of an AirSpy SDR# software screen.

A version of AirSpy’s popular SDR# software, showing the dark mode interface introduced in 2019. SDR# is always evolving, and the latest new tool is the Co-Channel Canceller.

It’s easy to take for granted the magical math that happens in Software Defined Radio. Occasionally though a breakthrough occurs which really grabs our attention, thanks to the hard work and bright minds of the designers behind the receivers and the software.

On the software side, the first series of “wow” moments happened for me in 2007-2008 when Nico Palermo of Perseus SDR fame expanded the program’s alias-free bandwidth incrementally from a modest (but impressive for the time) 100 kHz all the way up to the current 1600 kHz coverage.

The top-end 1600 kHz bandwidth was a game changer which allowed  medium wave DXers the opportunity to record IQ-WAV files of the entire band for later review, analysis, and DXing. It’s even more impressive considering this expansion was done without any additional hardware or receiver updates.

What did Nico charge Perseus owners for this incredibly useful expansion of spectrum and waterfall bandwidth? Nothing! The program with its much improved features continued freely available to previous and new Perseus SDR owners.

Now in 2020, Youssef Touil, AirSpy’s hardware and software developer, brings  a “killer feature” to his own SDR program named SDR#, for the benefit of medium wave DXers: the Co-Channel Canceller. The cost for this innovative tool? Yep, it’s a free addition to SDR#.

What are the benefits of the Co-Channel Canceller? This question is best answered by listening to three examples published by Youssef on his Twitter feed.

Read the descriptions below and listen to the brief audio files. In each example the Co-Channel Canceller is turned on and off a few times:

For the first example above, I suspect the 594 kHz station is Saudi Arabia’s Radio Riyadh, and the off-channel 596 kHz signal is Al Idaa Al-Watania from Morocco. It’s impressive that the 50 kw 596 station can be uncovered to any degree, as Radio Riyadh is a whopping 2000 kw!

In the AirSpy Groups.io forum, Youssef clearly illustrates the steps needed to initiate the Co-Channel Canceller. I’ve reproduced his screenshots below:

I’ve only just begun to explore the possibilities of the Co-Channel Canceller tool, but it holds promise of helping to reveal and identify hopelessly buried co-channel or adjacent channel stations. Not only does it work “live” in real time reception, it functions well with recorded IQ-WAV files too! Checkout the newest version of SDR# and give this new feature a try. I can imagine situations where this tool could be highly useful at times for the shortwave DXer also.

Thanks, Youssef, for this brilliant tool, which you’ve included free with the newest SDR# !

I encourage radio hobbyists to support AirSpy’s efforts to advance the state-of-the-art. The diminutive AirSpy HF+ Discovery receiver is not only a reasonably priced SDR to use with SDR#, it’s a top performer and a recipient of the World Radio TV Handbook’s Best Value SDR award for 2020.

Guy Atkins is a Sr. Graphic Designer for T-Mobile and lives near Seattle, Washington.  He’s a regular contributor to the SWLing Post.

Giuseppe’s cross-loop experiments

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Many thanks to SWLing Post contributor, Giuseppe Morlè (IZ0GZW), who shares the following:

I’m Giuseppe Morlè from Formia, central Italy, on the Tyrrhenian Sea.

I wanted to share with you and friends of the SWLing Post community this antenna project of mine dedicated to those who do not have enough space on the roof or in the garden to install antennas.

These are two separate loops, with two different diameters, one 60 cm, the other 90 cm, each with two variables for tuning … the system is able to receive from 3 to 30 MHz.

I joined these two loops in an opposing way, better to say crossed that can communicate with each other due to the induction effect that is created between the two small coupling loops that are placed one under the other at the top.

In the videos you will be able to see how the antenna system receives. I can use one loop at a time, to detect the direction of the signal or I can use them together for a more robust signal and in an omnidirectional way.

I really like experimenting with the induction effect and you can see that even when closed at home the two loops do a great job.

From my YouTube channel:

I’m not a technician but I really want to experiment to try to listen as well as possible.

Thanks to you and CIAO to all the listeners of the SWLing Post community.

Giuseppe Morlè iz0gzw.

Very cool, Giuseppe! I must say I’ve never tried dual loop experiments like this where one can experiment with the induction interplay. I imagine this could give you some interesting nulling capabilities if you have an unwanted station interfering with a target low-band signal. Thank you again for sharing!

Gary Debock’s report from the 2020 Rockwork Ocean Cliff Ultralight DXpedition

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Many thanks to SWLing Post contributor, Gary Debock, who shares a short report he originally posted on Facebook from the Rockwork 2020 Ultralight DXpedition:

Rockwork 2020 started off with a monster session, with S9 signals from the likes of 320-AI (Aitutaki, Cook Islands), 352-RG (Rarotonga, Cook Islands), 558-Radio Fiji One, 603-Radio Waatea, 1017-Tonga, 1107-Magic Talk and the new 1503-Gold.

The session was kind of wild, with three different sets of visitors asking about my gear setup at Rockwork 4 (typically during critical moments of live DXing, of course :-). Despite this both Longwave and Medium Wave featured great propagation to New Zealand, with the long range beacon 238-KT (Kaitaia) opening up the fun around 1225. Switching back and forth between Longwave and MW in a live DXing format wasn’t exactly ideal, and no doubt my long time DXpedition partner Tom R. could have really cleaned up on the South Pacific beacons this morning with his SDR and broadband loop setup. As it was I came away with 238-KT, 320-AI (a monster signal), 352-RG and 366-PNI from across the equator, with 558-Radio Fiji One probably having its best session ever at the awesome ocean side cliff (extended S9+ periods between 1300-1330).

I promised long term “Cliffhanger DX” partner Craig Barnes that I would go all-out to receive some exotic DX in his honor, and the Cliff more than cooperated.

The Longwave and Medium Wave DX this morning [Auguest 5, 2020] was phenomenal, and there are still two more days before Tom gets here. Hopefully these conditions will stick around!

Audio samples

320 AI Aitutaki, Cook Islands Great signal but shaky sounding CW tone at 1239– best signal ever at the Cliff:

352 RG Rarotonga, Cook Islands In an S9 snarl with 353-LLD (Hawaiian mega-beacon) at 1256:

558 Radio Fiji One Suva, Fiji Overwhelming S9 signal and ID’s both before and after an island music song at 1312:

1017 A3Z Nuku’alofa, Tonga Female Tongan in an S9 snarl with DU sports co-channel (2KY?) at 1253:

More New Zealand monster signals from yesterday morning, courtesy of the “Kiwi Cliff.” This place’s preference for New Zealand signals is wacky to the extreme!

603 Radio Waatea Auckland, NZ 5 kW S9 Maori island music // 765 followed by a female Maori chant at 1309:

1107 Magic Talk Tauranga, NZ 10 kW Meltdown level Kiwi conversation between host and lady caller at 1255:

1503 Gold Wellington/ Christchurch, NZ 5/ 2.5 kW The old Radio Sports’ Yankee-accented English (from Fox Sports Network) has now been replaced by rocking oldies, such as Phil Collins with powerful strength at 1307:

73 and Good DX,

Gary DeBock (DXing at the Rockwork Ocean Cliff near Manzanita, OR, USA)
7.5″ loopstick CC Skywaves, PL-380 & XHDATA D-808
12″ Longwave FSL + three new 8″ Medium Wave FSL’s

Thank you so much, Gary, for allowing me to share your reports on the SWLing Post. Many of us would love to experience mediumwave DXing from your Rockwood perch, but we’ll have to live it vicariously through your excellent reports! We wish you excellent DX!

Giuseppe’s reception of the LRA36 test broadcast

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Photo from the Argentine Antarctic Base (LRA36) – Source: RAE

Many thanks to SWLing Post contributor, Giuseppe Morlè (IZ0GZW), who shares the following:

Dear Thomas

Here is the link of to video regarding the transmission of LRA 36 in USB mode Saturday July 25, 2020 from 17.00 UTC on 15.476 MHz.

A good result if I think it was almost impossible to listen to it with the sun still high … the place where I listen, in Formia, Italy, is really excellent.

73. Giuseppe Morlè iz0gzw.

Thank you for sharing this, Giuseppe! I’m always impressed with the DX you catch there at your location in Formia! Grazie e ciao!

Finally confirmed reception of LRA36 Radio Nacional Arcángel San Gabriel Antarctica

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For years now I’ve attempted to get decent reception of LRA36 Radio Nacional Arcángel San Gabriel in Antarctica. At times, I’ve been able to barely hear their AM signal here in North Carolina–at least, see it as a faint line on my spectrum display and barely hear audio rise above the noise. But in truth I could never confirm anything more than “male voice” and “music” thus never bothered with a report in good faith.

Recently, we’ve posted announcements for a series of test broadcasts from LRA36 in single sideband (SSB). Two weekends ago, I couldn’t receive a single inkling of their signal, but this past Saturday, I finally heard the station well enough to submit a detailed report and recording in confidence.

I had actually set my SDR to record 20 kHz of spectrum at home while I made my first CW POTA activation at the nearby Blue Ridge Parkway. A pop-up storm chased me away from the POTA site and it worried me that I had left my SDR running and connected to the antenna. Fortunately, none of the small thunder storms were directly over my home. Although there was heavy QRN due to local pop-up thunderstorms, their signal was there.

The following sample recording starts at 17:51 UTC  (July 25, 2020) on 15476 kHz.  It’s weak signal DX for sure, but interpretable. I made the recording with my WinRadio Excalibur SDR hooked up to a large Skyloop antenna. This clip starts with the song  Juana Azurduy by Mercedes Sosa:

I’m so chuffed to add the LRA36 QSL to my collection! Broadcasting in SSB made all the difference!

Have you successfully logged LRA36 from your home?  Please comment!

LRA36: Radio Nacional Arcángel San Gabriel test broadcast Saturday July 11, 2020

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Source: Base Esperanza – Antártida

Many thanks to SWLing Post contributor, Adrian Korol, who shares the following notice from the Argentine Antarctic station, LRA36:

Saturday, July 11, from 1400 to 1500 UTC, a test broadcast from LRA 36 Radio Nacional Arcángel San Gabriel on 15476 khz using USB.

Thank you for the tip, Adrian!