Tag Archives: MW

Chuck’s re-capped GE Superadio II might set a new AM BCL benchmark

I recently took delivery of a better-than-new classic solid-state portable broadcast receiver: the venerable GE Superadio II.

This Superadio II was generously given to me by SWLing Post contributor, Chuck Rippel (K8HU), who has–in his spare time–been re-capping and restoring all three of the GE Superadio series models and bringing them back to life. Chuck wanted to send me one of the units he’d recently finished, knowing that it might help me when doing AM reception evaluations. He insisted “no strings attached.”

Besides thank you, all I can say is…

Wow–!

Note angels singing in the background.

When I received the Superadio II a week or so ago, I removed it from the box and it looked brand new; even sporting the original “Headset Capable” grill sticker.

This is a case, however, of a refurbished radio likely out-performing the original.  Here’s a list of the main modifications:

  • All of the original dry capacitors replaced with Nichicon Audio Grade components
  • FM AFC and AM and FM IF and RF sections have been aligned
  • Rebuilt the volume control

I’m sure there are other modifications Chuck didn’t mention.

Chuck told me each radio takes a full day to restore. Some of the alignment, rebuilding, and re-capping is surprisingly tricky and varies with each of the three models. Why is he doing this?

Chuck told me, “My enjoyment comes from giving these radios a new lease on life.”

A new lease on life, indeed!

Last weekend, we had a break in the weather–and I had a short break in my schedule–so I took the GE Superadio II, GE 7-2990A, C.Crane CCRadio3, and Panasonic RF-2200 outdoors for some fresh air.

It was late afternoon and, frankly, I didn’t have the time to do a full comparative session, but having spent the better part of an hour tuning around and comparing the characteristics of each radio, I decided to make a short video to share.

The video features the GE Superadio II, but I speak to some of the pros and cons of each model. Keep in mind, this is very much a casual/informal comparison:

Click here to view on YouTube.

The SR-II not only has the best audio fidelity in this bunch, but it’s also extremely stable and has no noise floor to speak of. No doubt, this is the result of those Nichicon Audio Grade components and a skilled technician.

Side note: Chuck is well-known in the radio world because he used to restore the Collins R390A which must be one of the most mechanically-complicated receivers ever made.

I haven’t even properly tested the SR-II on FM yet because I couldn’t pull myself away from the mediumwave dial that afternoon!

I asked Chuck if he would consider refurbishing GE Superadios for other people and I think he would.  If interested, contact me and I’ll put you in touch. Else, Chuck might leave details in the comments section of this post.

He does currently have a restored GE Superadio II on eBay. I just checked and in his listing, you’ll see a full description of the modifications made.

Click here to view on eBay.

Chuck, thank you once again for sending me this SR-II. It’ll become a permanent addition here at SWLing Post HQ. Again, I’m simply amazed at the audio fidelity of this 1980s era receiver. Honestly, I don’t think there’s anything made today that can even compare.

And thanks for doing your bit to refurbish these classic portables!

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CBC Yukon features Finnish DXer who logged their station from 7,000 km away

Image Source: CBC/Google Earth

(Source: CBC Yukon)

From Yukon to Finland: CBC’s radio signal heard from afar

Host Elyn Jones heard saying ‘this is Yukon Morning,’ about 7,000 kilometres away

A keen listener has managed to hear CBC Yukon’s radio broadcast from about 7,000 kilometres away.

Jorma Mäntylä lives in Kangasala, Finland.

On Oct.15 he was scanning the airwaves and came across the signal from Dawson City, Yukon, broadcasting CBC’s Yukon Morning show.

The signal lasted about an hour.

“It was clear to hear your Yukon Morning program led by a female journalist and the morning news,” he said.

The host that day was Elyn Jones in Whitehorse.

Upon hearing the signal Mäntylä sent an email with an attached audio clip asking for confirmation.

CBC Yukon wrote him back to confirm what he’d heard. We also scheduled an interview by videoconference to speak about his hobby.

No ordinary radio

Mäntylä doesn’t have an ordinary radio. He’s part of the Suomen Radioamatööriliitto, the Finnish Amateur Radio League.

He started listening to signals in 1967.

He uses custom-built equipment to scan for shortwave and AM radio signals.

Sometimes it takes a while, through the crackle, to determine the language being spoken and from where the signal is broadcasting.

The game is to discover new stations, identify them, and then send an email to confirm the reception.

“I very often listen to foreign radio stations. That has been my hobby for 50 years,” he said. ‘It’s given me interesting moments learning about other cultures and nations,”

Hearing a signal from Yukon is rare. Mäntylä says on Oct. 15 he also heard broadcasts from radio stations in Anchorage and Fairbanks, Alaska.

Click here to continue reading the full article.

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Video: Uncovering a Buried Co-Channel Station with the New AirSpy SDR# Tool

AirSpy’s Youssef Touil shares a video from YouTube author “PY3CRX&PY2PLL” which dramatically demonstrates the extent to which the Co-Channel Canceller tool can uncover a much weaker signal beneath a powerful one:

Youssef commented on the video that It only needs some tweaking to the lock/offset to get a perfect decode. So, presumably the result could be even better than heard here.

For more information on the Co-Channel Canceller, see my original article here, and the follow-up piece.

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

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SDR#’s Co-Channel Canceller Gets Additional Options

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.

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

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.

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KJJR DX Test on Saturday (May 2, 2002)

Many thanks to SWLing Post contributor, Paul Walker, who shares the following announcement:

KJJR 880 Whitefish, MT(Kalispell) will test for 1 hour at 10kw non directional Saturday May 2nd 12:01am to 1am mountain time. It will consist of morse code, sweep tones, along with various telephone sound effects

There will be no paper QSL’s issued for this test. Only emailed confirmation. Send an email to walkerbroadcasting@gmail.com with “KJJR 880 DX Test” in the email (You MUST put that in that subject line so I don’t accidentally delete it thinking it’s spam!). The reply will likely be a simple email reply with details of the station and confirming the details of what/when you heard it. You WILL get a reply from me in due course, please give me some time!

This is done on short notice and being kept simple as to not burden anyone involved. Thanks to Les Rayburn for creating the test material and Todd Clark for generously offering up the station. I’ve already seen communication between him and the station, asking them to block out an hour from the logs, so he can tinker around with things at the tower site.

Thanks for the heads-up, Paul! Here’s hoping a few MW DXers can log this test.

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A Compact RSPdx & Wellbrook Loop Kit for the Beach — My Approach

I have enjoyed three to four medium wave and shortwave DXpeditions per year since 1988, to sites on the Washington and Oregon coasts. I love the chance they give to experiment with antennas in a (hopefully!) noise-free location, and concentrate on catching stations that might not be heard from home.

All of my DX trips have been via car–until now! I’ve just returned from nine vacation days in Hawaii (Waikoloa Beach, on the Big Island), and I thought others might like to see the radio related items I chose to take along for air travel. I’m pleased to report that everything worked as planned, and I have five days of SDR IQ WAV files of the MW band for review, all recorded in the time frame surrounding local dawn.

My goal was not the smallest, most compact portable setup, but one with high performance and modest size. Fitting everything into a day pack was another requirement. A simple wire antenna and an even smaller Windows tablet or laptop than the one I’ve used (and a smaller SDR like the HF+ Discovery, for that matter) would make a much smaller package. However, the items I’ve assembled worked excellently for me during my enjoyable Hawaii vacation. The directional loop antenna provided nulls on medium wave of 30 dB during preliminary tests indoors, a less-than-ideal test situation.

Waikoloa Beach–just one of a zillion picturesque scenes in Hawaii.

Here is a list of what I’ve put together for my DXing “kit”:

    • SDRPlay RSPdx receiver
    • Short USB cable for receiver<>PC connection, with two RFI chokes installed
    • Lenovo X1 tablet— a Windows 10 device with magnetically attached keyboard; this model is a competitor to Microsoft’s Surface Pro tablet
    • Wellbrook Communications’ ALA1530 head amp module, modified for female SO239 connectors enabling use of large diameter LMR-600 coaxial cable as a 2-turn loop element. My antenna setup is similar to Wellbrook’s commercial flexible loop
    • Wooden base for the antenna (ALA1530 is bolted to the base)
    • 20 feet of lightweight RG-174 coax
    • Wellbrook DC interface module for the ALA1530
    • 3.0 Ah LiFePO4 rechargeable battery for the Wellbrook antenna
    • 15 foot long section of high grade “Times Mfg.” LMR-600 coax cable with PL259 connectors (bought from Ebay already assembled/soldered)
    • Fold-up beach mat
    • Small day pack to hold everything

All the contents of this DXing setup fit a standard size day pack.

You’ll note the absence of headphones in the list. This is because my intent from the start was to record all the DX (MW band) as SDR WAV files for DXing post-vacation. That said, I did have headphones in my travel luggage for later spot checks of a few frequencies. That’s how I found 576 kHz Yangon, Myanmar lurking at their 1700 sign-off with national anthem and English announcement. The remainder of the DX to be uncovered will have to wait until I’m back home near Seattle!

The LMR-600 is a very thick and stiff coax cable, whose diameter approaches that used in the standard aluminum tubing ALA1530 series from Wellbrook. It has the benefit of being self-supporting in a 2-turn configuration and will also coil up into an approx. 12-inch package for transport. It just barely fits within the day pack I’m using. As I understand it, magnetic loops with tubing or large coax as the active element, versus simple wire, are more efficient in operation. Whether or not this holds true in practice remains to be seen.

I fashioned a wooden disc 3/4″ thick to attach the ALA1530 head amplifier, as I didn’t want to bring along a tripod or other support stand. The Wellbrook antennas all work well near or at ground level, so I was able to get great reception with the antenna right on the beach. The diameter at two turns of the coax is only a few inches smaller diameter than Wellbrook’s aluminum tubing loops. Three strips of strategically placed Velcro straps help keep the turns together when deployed as well as during storage.

In theory a two-turn loop should give 5 dB less gain than a single turn version; however, my older ALA1530 module has 5 dB more gain than the newer “LN” type, according to Andrew Ikin of Wellbrook Communications. The net result is that my two-turn antenna should have equal gain to the larger one-turn variety. Future experimentation with this DIY coax loop antenna is in order!

The Wellbrook loop antenna, RSPdx receiver, and Windows 10 tablet on the beach in Waikoloa, Hawaii.

Another view of the DXing position. Being this close to the water with my radio gear was unnerving at first, but the wave action on a calm Hawaii beach is totally different from the Oregon/Washington beaches with waves that can move in and out by a hundred feet or more.

The Wellbrook “DIY FlexLoop” works fine at beach level, and is less conspicuous this way, too.

The ALA1530 module is bolted to the 11-inch wooden disc for support. I’ve modified the module’s sockets to securely hold SO239 female connectors.

The commercial Wellbrook FLX1530LN is a fine product, and worthy of your consideration as a compact and high performance travel antenna. Full details can be found at this link.

SDR WAV Files for Download

One of my goals from the start for my Hawaii trip was to bring back SDR “IQ” WAV files for sharing with others. These approx. 900 Mb files cover the entire medium wave band as heard from my beach location in Waikoloa.

The overall page is: https://archive.org/details/@4nradio   Clicking on any of the entries will bring you to a details page. From there just right click on the “WAVE” link, and choose “Save as…” to download. For a few of the recordings I also posted the file that precedes the one that goes across the top-of-the-hour, because things seemed a bit more lively prior to 1700 (which  was at local sunrise, give or take a couple of minutes).

The IQ WAV files are only playable with suitable SDR radio software: SDRuno is first choice (but you need a RSP receiver connected). The files are also is compatible with HDSDR and SDR-Console V3. It may also play on Studio 1 software.

I hope other DXers enjoy the chance to tune through the MW band, as heard from the Big Island of Hawaii.

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

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