Tag Archives: DX

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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Giuseppe catches the 40th Anniversary broadcast of LRA36

Many thanks to SWLing Post contributor, Giuseppe Morlè, who writes:

Ciao Thomas,
I’m Giuseppe Morlè, iz0gzw, from Formia, central Italy on the Tyrrhenian Sea … this is what I managed to hear about the 40 years of transmission of LRA 36 from the Antarctic Argentina to 15,476 …

I took two receivers and two different antennas to the sea … the Kenwood R1000 was connected to my tested “Simil beverage on salt Ground” with salt water tip and the Tecsun PL-660 to my Loop Mea Casali self-built …

Both antennas are directed to SSW where we find the LRA36 station …

The main problem was the boring and tragic Chinese Jammer that strongly raged on 15.470 until 15.00 UTC and then calmed down a bit so I could hear the last part of the transmission with fading and spoken female and male in Spanish …

On the Tecsun and the loop I have not found the station …but on my Kenwood R1000 and my similar beverage on salt grond I listened to about 13 minutes of final transmission.
You can watch the video on my YouTube channel at the link:

Thanks to you and a warm greeting from Italy.
Giuseppe Morlè iz0gzw.

Wow! Great catch, Giuseppe!  I understand the Chinese jammer made it difficult, but obviously your antennas did the trick. I tried to catch the same broadcast from home, but only received a very faint signal. Most of the audio was lost in the noise.

Thank you for sharing.

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Guest Post: Brazil’s newly-formed “15.61 Crew”

Many thanks to SWLing Post contributor, Martin Butera, who shares the following announcement for a new radio enthusiast group in Brazil:


The new 15 point 61 Crew

São Paulo is the largest city in Brazil, the Americas, and the seventh largest in the world, with a population of 11,300,000.

 

This was the stage for the meeting between Ivan Dias da Silva Junior (a recognized Brazilian radio listener with more than 27 years of experience and founder of the Regional DX) and his colleague, Martin Butera (a renowned amateur radio operator (LU9EFO – PT2ZDX), with 29 years of experience and currently a correspondent journalist for the British Dx Club, covering information from South America for the radio newsletter “Communication”).

The place of the meeting was not an accidental: we met in a noted coffee bar in the Republic Square–an iconic meeting point in São Paulo. Republic Square is located in the city center and is one of the most visited places in Brazil.

We founded the 15 point  61 Crew in São Paulo, on September 3, 2019.

The 15 point  61 Crew is not a DX club, nor a formal registered organization. We are just an informal group who like DXing.

What is the meaning behind our name? The number 15 is the dialing code of Sorocaba and  61 is the Brasília code, joining the two cities where the Crew founders are based–a distance of more than 900 km (Brazil is a huge country!).

The 15.61 Crew doesn’t have political or religious objectives. Our main objective is DXing, with an emphasis on organizing related activities: mainly DXcamps to be held in distant and exotic places, and bringing a new panorama of what is shared about DXing in our country.

We don’t have any kind of administration positions. The 15.61 Crew members are and always will be in equals.

To be a member of 15.61 Crew you just need to be active in our hobby, share information, write items, go with us to DXcamps, develop technical projects, etc.

As we aren’t a DXing club or organization, we will not have a website nor social media. We will share micro-books, especially about our activities through existing media, like the SWLing Post by our friend, Thomas Witherspoon, and by ourselves, because at the moment we are members of other radio related bulletin boards.

Our communication will be through an email address and a Paypal account for those who want to help us to continue developing our activities and also provide feedback on other projects (such as sharing content with other websites, thus creating a virtual collaboration for all).

For this purpose, we are currently developing several projects, such as a 15.61 Crew certificate program and different materials, such as caps, shirts, mugs, etc.

The 15.61 Crew members believe that there are so much things to be heard in the ether and we are prepared for it.

Ivan Dias da Silva Junior & Martin Butera

(15.61 Crew founders)

São Paulo, September 3, 2019


Thank you for sharing this Martin! I hope the 15.61 Crew enjoys some great success and champions a dynamic DX community! If you’re interested in joining this South American crew, contact Martin Butera.

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AirSpy HF+ Discovery: First Impressions on Medium Wave vs. Elad FDM-DUOr

The highly anticipated AirSpy HF+ Discovery SDR has been in the hands of early adopters for about two weeks–and I’ve seen nothing but positive comments!

After a long run (2007-2013) with a Microtelecom Perseus, my SDR of choice became the Elad FDM-S2, and more recently an Elad FDM-DUOr “hybrid” SDR receiver. The two Elads have the same core processing components and identical performance when the DUOr is connected via SDR software.

This week I’ve compared the HF+ Discovery ($169) against the FDM-DUOr ($899) using Studio 1 software and identical modes & settings. The following video features the radios’ performance on a crowded daytime medium wave band from suburban Seattle-Tacoma USA.

Click here to view on YouTube.

Notes:

  • Software used is two “instances” of Studio 1, version 1.06e
  • Antenna is an east-west oriented Wellbrook ALA1530LNP Imperium loop
  • Mode, filter bandwidth, AGC, etc. are the same for each radio
  • 768 kHz sampling bandwidth used for both receivers

Stations tuned are:

  • 1320 KXRO Aberdeen WA, 74 miles @ 5 kW (in-line with antenna)
  • 1110 Oak Harbor WA, 78 miles @ 500 watts (in antenna’s null)
  • 1040 CKST Vancouver BC, 147 miles @ 50 kW (in antenna’s null)
  • 1430 KBRC Mt. Vernon WA, 85 miles @ 5 kW (in antenna’s null)
  • 750 KXTG Portland OR, 118 miles @ 50 kW (in antenna’s null)

I purposely sought out signals difficult to hear in the presence of powerhouse stations. Only 1320 kXRO (in-line with my antenna) and 750 KXTG are what you might consider average or fair quality signals. Headphones are recommended for most of these, particularly 1040 kHz.

You’ll note that the pass band has been “pulled” over the edge of the carrier frequency by a few hundred Hertz. This is an excellent trick that can often reduce noise and/or improve intelligibility. It’s a feature unique to Perseus, Studio 1, and SDRuno software; it works in sideband modes and in selectable sideband Sync AM (SAM) mode.

After listening to the signal comparisons, what are your thoughts on the HF+ Discovery? Please leave your comments below.

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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Free Advice: Stop worrying about solar minimums and just play radio!

Lately we’ve been getting some pretty dismal news about the upcoming solar cycles and the potential for a pretty dismal trend according to some researchers.

We report this news on the SWLing Post because the sun and space weather play an important role in radio signal propagation and one’s ability to snag elusive DX.

After publishing news items like this, though, I always receive a number of emails and comments stating that these trends surely marks the end of all radio fun. After all, if there are no sun spots whatsoever, why bother!?!

Truth is, it’s sort of like saying, “the weather looks lousy, I don’t think I’ll be able to have fun.”

I lived in the UK for several years. If I let the potential for lousy weather stop me from having fun, I’d have never gotten anything done!

The same goes for space weather in our radio world.

A couple weeks ago, I made a Parks On The Air (POTA) activation running 15 watts with the Elecraft KX3 into a simple 20 meter vertical in SSB mode.  Even though propagation was poor, I logged a new contact, on average, once per minute over the course of 30 minutes! It was non-stop!

The GE 7-2990A (left) and Panasonic RF-B65 (right)

I also listened to the Midwinter Broadcast to Antarctica with two portable radios. Propagation was poor and I didn’t even use an external antenna…but I caught the broadcast and had a load of fun hanging out on the Blue Ridge Parkway!

My advice?

As I said in a post last year, use the sunspot low as an excuse to explore frequencies and modes you’ve never used before. Use this as an opportunity to improve your listening skills and the most important part of your listening post or ham station–your antenna system!

I often receive email from people who’ve found the SWLing Post and take the time to write a message to me complaining about the death of shortwave radio: the lack of broadcasters, the prevalence of radio interference and the crummy propagation. They wonder, “is it all worth it?”

My reply?

“Hey…sounds like radio’s not your thing!”

While this same person is moaning and complaining, I’ll be on the radio logging South American, Asian and African broadcast stations.

I’ll be working DX with QRP power, even though everyone tells me that’s not possible right now.

I’ll be improving my skill set and trying new aspects of our vast radio world.

You see: I’ve learned that the complainers aren’t actually on the air. They gave up many moons ago because someone told them it wasn’t worth it, or they simply lost interest. That’s okay…seriously…but why waste time complaining? Go find something else that lights your fire!

While these folks are complaining, I’ll be on the air doing all of the things they tell me I can’t do.

In the words of Admiral David Farragut: “Damn the torpedoes, full speed ahead!”

Go out there and play radio!

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Top 10 DX Of The Year Contest Results!

Many thanks to Istvan Biliczky, from the Top 10 DX Of The Year Contest who shares the following results from the December 2018 contest:

Click to enlarge results sheet.

Istvan tells me that the “certificates are printed, verified, t-shirts are done, and all packed, will be sent this week.”

Check these photos:

Brilliant news and congratulations to the many friends and SWLing Post readers I see in the winners circle! Thank you for sharing, Istvan and thanks for hosting this impressive DX contest!

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“Radio on the Edges”: Robert’s lifelong pursuit

(Photo source: All Things Radio by Robert Gulley)

SWLing Post contributor, Robert Gulley (AK3Q), recently published a post on his blog discussing the edges of radio reception and his pursuit of DX in all forms. I think this article speaks to many of us.

(Source: All Things Radio by Robert Gulley)

Radio on the Edges can mean a number of different things, depending on one’s perspective. For me, at the moment, it means distance. It means reaching the edges of where a signal can go.

One of the more intriguing aspects of radio is just how far a signal will travel. I have been a DX chaser for years, starting with AM Broadcast signals when I was a kid. The further the station, the cooler the signal in those days.

Then of course there was Shortwave radio. Now that was cool! That was real DX! Hearing countries from around the world was just the best! Well, that it, the best until I became an amateur radio operator and could send signals around the world! Whoo-Hoo! Hot Dog! Oh yeah, baby!!

Still to do on my DX list is to bounce a signal off the moon. Technically my signals have already gone into space, to the ISS and to orbiting satellites. But the moon so far has eluded me. Well at least, confirmation of bouncing off the moon back to myself or to another amateur has so far eluded me.

But Radio on the Edges also means a different kind of DX.[…]

Click here to continue reading on Robert’s excellent site, All Things Radio.

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