Category Archives: DX

DX Central’s MW Frequency Challenge: Week 11 Results and Week 12 Announcement

Guest Post: Following the Ethiopian war over shortwave radio

Many thanks to SWLing Post contributor and political cartoonist, Carlos Latuff, who shares the following guest post:

Carlos Latuff at Catacumba Park in Rio de Janeiro, monitoring Ethiopian broadcasts.

ETHIOPIA: A WAR THROUGH RADIO

by Carlos Latuff, special for The SWLing Post

We just entered 2022 and the civil war in Ethiopia has already completed 1 year. On the one hand we have the Tigray People’s Liberation Front (TPLF) guerrillas from northern Ethiopia and its allies, and on the other hand we have the armed forces of Ethiopian government and its allies. The dead are piling up, accusations of war crimes from both sides, local and international political interests at stake, and no perspective for a peaceful solution. Without going into the reasons for this new war in Ethiopian territory, I’d like to focus on the use of radio waves by both parties of this conflict.

I monitored shortwave broadcasts from Ethiopia and to Ethiopia between October 21, 2021 and January 4, 2022. The receivers were Tecsun PL-606 and XHDATA D-808, using both the telescopic antenna and a long wire. In all cases, listening was carried out in Brazilian cities.

Carlos at Catacumba Park monitoring and recording clandestine Ethiopian broadcasts.

The monitored stations were: Continue reading →

Guest Post: An Introduction to DXing the MF Marine Bands

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Many thanks to SWLing Post contributor, Don Moore–author of Following Ghosts in Northern Peru–for the following guest post:

Monitoring the MF Marine Bands

By Don Moore

For me, DXing has always been about the challenge of receiving difficult-to-hear radio stations, regardless of the type of station or frequency range. In my five decades in the radio hobby I’ve logged a lot of different kinds of stations – shortwave broadcast, medium wave, shortwave utility, longwave beacons, etc. But some of my favorite catches have been in the upper end of the medium frequency range.

Technically speaking, medium frequency (MF) is the range from 300 to 3000 kHz and includes the standard medium wave (AM) broadcast band. The upper end of the MF band, from 1600 to 3000 kHz (except for a small portion reserved for amateur radio), has always been assigned to various types of utility uses including broadcasts and other voice communications from regional maritime stations. And while digital modes and satellites have done a lot to change the nature of communication with ships at sea, there is still a lot of good human-voice DX to be heard.

Several dozen stations, mostly in Europe and North America, broadcast regularly scheduled marine information broadcasts in the MF range. These broadcasts are usually between five to ten minutes in length and include weather forecasts, navigational warnings, and other notices to keep ships at sea safe. On occasion it’s possible to hear two-way voice communication here between ships and shore stations, although that’s much less common today.

The Equipment

Nothing special is needed to DX the marine MF band other than a receiver that covers the frequency range and can receive USB mode (which all these broadcasts are in). However, for reasons explained below, I highly recommend using an SDR to make spectrum recordings of the entire band to go through later. Continue reading →

Guest Post: Don targets rare Norwegian stations during Newfoundland DXpedition

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Photo by the Bjørnøya Meteorologiske Stasjon

Many thanks to SWLing Post contributor, Don Moore–author of Following Ghosts in Northern Peru–for the following guest post:

The Rarest DX?

By Don Moore

In mid-October I received an invitation to attend the annual DXpedition in Cappahayden, Newfoundland with Jean Burnell, John Fisher, and Jim Renfrews. It didn’t take long for me to say yes. Newfoundland is one of the best places in the world to DX from and all kinds of amazing stuff has been heard there. I was excited at the prospect of great medium wave DX and being able to log low-powered European private and pirate shortwave broadcasters.

But something else was at the top of my try-for list. One of my many DX interests has always been logging coastal marine stations in the 1600 to 3000 kHz range. In preparation I started checking online sources to update my spreadsheet of schedules. In going through a recently added section on Marine Broadcasts in the DX Info Centre website I came across listings for twice-daily weather broadcasts from Hopen Island on 1750 kHz and Bjørnøya (Bear Island) on 1757 kHz.

I didn’t remember ever seeing anything about broadcasts from these remote islands in the Norwegian Arctic before. Were these stations actually on the air, I wondered. And if they were, could I hear them in Newfoundland? Continue reading →

Gary DeBock’s XHDATA D-808 loopstick model

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Many thanks to SWLing Post contributor, Gary DeBock, who shares the following:

The 7.5 inch (19cm) loopstick XHDATA D-808 model was designed to be the ultimate AM-DXing (or Longwave DXing) travel portable, and can be built for a construction cost of around $30 US. It has already been used by numerous DXers to track down transcontinental and transoceanic AM-DX during overseas travel, and the orange plastic loopstick frame allows full operation of the whip antenna for FM and Shortwave reception.

The modification procedure isn’t difficult, and the full construction article is posted at

https://dreamcrafts.app.box.com/s/5d0pi85jfptgmrj4pd0jsmaybgb6gteh

A video demonstration of its daytime DX performance (compared to the stock model) has been posted on YouTube:

Build one, and join the fun!

Many thanks for sharing this, Gary! Your ultralight DXing creations are simply amazing!

Guest Post: A synchronous detector crash course!

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Many thanks to SWLing Post contributor, 13dka, who shares the following guest post:

Revisiting the Belka’s “pseudo-sync detector”: A sync detector crash course!

by 13dka

“It’s usually hard to assess whether or not a sync detector helped with a particular dip in the signal or not, unless you have 2 samples of the same radio to record their output simultaneously and compare.”*

That’s what I wrote about the “pseudo sync detector” in my review of the Belka DSP last year.

Since I was recently upgrading to the Belka DX in order to pass on the Belka DSP to a friend, I had briefly two examples of almost the same radio on the table at the dike. I tuned them to the same stations and recorded some audio clips with one radio on sync detector, the other in regular AM mode, to answer the question whether or not sync has “helped with a particular dip in the signal”. Then I thought that demonstration would be an opportunity to try an explanation on what exactly (I think) sync detectors are all about anyway, hoping to find a middle ground between “technical” and “dumbed down beyond recognition”.

The trouble with sync detectors

Perhaps no component of a shortwave receiver is surrounded by so much misconception and confusion as sync detectors. Full disclosure: Until quite recently, I had an, at best, vague concept on what they do myself. It seems it’s not so much that people don’t know how they work, what they actually do when they work is where the ideas often diverge. Continue reading →

The Icom IC-705: Is this really a new holy grail SWL/BCL receiver?

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Many thanks to SWLing Post contributor, 13dka, who shares the following guest post:

The Icom IC-705: Is this really a new holy grail SWL/BCL receiver?

by 13dka

When Thomas got wind of its development in 2019 he immediately asked “could the Icom IC-705 be a shortwave listeners holy grail receiver?”. I usually wince a little when I hear “holy grail” because it means very different things to different people, it’s also a moving target with many people aiming at the spot where it was decades ago. But Thomas certainly had a very level-headed assembly of technical performance, quality and practicality requirements in mind when he used that term, and I thought he might be onto something!

There are some excellent, trustworthy reviews of the IC-705 out there. The following is not one of them, I just want to share an opinionated breakdown on why I think this is an interesting radio for SWLs/BCLs indeed, also deliberately ignoring that it’s actually a transceiver.

Jumping shop

While the era of superhet/DSP-supported tabletop holy grails ended with the discontinuation and sell-off of the last survivors more than a decade ago, powerful PC-based SDR black boxes were taking over the mid-range segment and it became very slim pickings for standalone SWL receivers: Thomas just recently summed up the remaining options here.

Between the steady supply of inexpensive yet serviceable Chinese portables, upgraded with a least-cost version of DSP technology, and the remnants of the high end sector there’s very little left to put on the wish list for Santa – that doesn’t need to be paired with a computer that is.

No surprise that SWLs/BCLs in search of new quality toys with tangible controls are taking a squint over the fence to the ham transceiver market: Hams are still being served the best and the latest in radio technology in all shapes and sizes, and even entry-level rigs usually come with feature-rich general coverage receivers. But transceivers never had SWLs much in their focus in the past decades, and particularly not BCLs: Frontend adaptation, additional AM filters, switches and functions would’ve meant increasing costs and so transceivers were never perfected for that purpose. DSP and SDR technology allowed for improvements on that without actually adding (much) hardware and so some interesting alternatives surfaced in the past years, but most of them still come with little downers, at least for BCLs.

Continue reading →