Author Archives: 13dka

Small Unidirectional Loop Antenna (SULA) Part 2: Construction Notes

Many thanks to SWLing Post contributor extraordinaire, 13dka, who brings us Part Two of a three part series about the new SULA homebrew antenna project. This first article describes this affordable antenna and demonstrates its unique reception properties. This second article focuses on construction notes. The third and final article will essentially be a Q&A about the SULA antenna. All articles will eventually link to each other once published.

This wideband unidirectional antenna is an outstanding and innovative development for the portable DXer. I love the fact that it came to fruition via a collaboration between Grayhat and 13dka: two amazing gents and radio ambassadors on our SWLing.net discussion board and here on the SWLing Post. So many thanks to both of them!

Please enjoy and share Part 2:


Part 2: SULA Construction notes

by 13dka

The drawing [above] has all you need to know. You basically need to put up a symmetrical wire diamond starting with a balun at the one end and terminating in a resistor at the other end of the horizontal boom, the sides are supposed to be 76cm/29.92″ long so you need to make yourself some…

Support structure:

I used 0.63″/1.6cm square plastic square tubing/cable duct profiles from the home improvement market to make the support structure. You can use anything non-conductive for that of course, broom sticks, lathes… The plastic profiles I used had the advantage of being in the house and easy to work on with a Dremel-style tool and everything can be assembled using the same self-tapping screws without even drilling. The profiles are held together with 2 screws, for transport I unscrew one of them and put that into an extra “parking” screw hole on the side, then I can collapse the cross for easy fit into the trunk, a rucksack etc.

These profiles are available in different diameters that fit into each other like a telescoping whip. This is useful to make the support structure variable for experiments and to control the loop shape and tension on the wire. The booms end up at 1.075m each, the profiles come in 1m length, so that’s 4 short pieces of the smaller size tube to extend the main booms by 37mm on each side

On the resistor end of the loop that smaller tube isn’t mounted in the “boom” tube but to the side of it in order to keep the wire running straight from the balun box on the other side.

Mast/mounting:

You can use anything non-conductive to bring it up to height. On second thought that is indeed bad news if you were planning on putting that up on your metal mast…and we have no data on what happens when you do it anyway. I don’t know if the smallest (4m) telescoping fiberglass poles would suffice for portable operation, but I’m a fan of just using the big lower segments of my 10m “HD” mast for the stiffness they give me (3 segments for the height, the 4th collapsed into in the base segment for easy rotation). Telescoping masts also give you easy control over…

Height:

The published patterns are for 3m/10′ feedpoint height over “average” ground. Increasing height further has no expectable advantage, instead it will deteriorate the favorable directional pattern of the loop. Flying it lower, or even a lot lower in windy weather on the other hand is causing a surprisingly moderate hit on performance.

Continue reading

Spread the radio love

Introducing the amazing SULA: An affordable unidirectional DX-grade loop antenna that you can build!

Many thanks to SWLing Post contributor extraordinaire, 13dka, who brings us a three part series about the new SULA homebrew antenna project. This first article describes this affordable antenna and demonstrates its unique reception properties. The second article will focus on construction notes. The third and final article will essentially be a Q&A about the SULA antenna. All articles will eventually link to each other once published.

This wideband unidirectional antenna is an outstanding and innovative development for the portable DXer. I love the fact that it came to fruition via a collaboration between Grayhat and 13dka: two amazing gents and radio ambassadors on our SWLing.net discussion board and here on the SWLing Post. So many thanks to both of them!

Please enjoy and share SULA Part 1:


Introducing the Small Unidirectional Loop Antenna (SULA) 1-30MHz

A small and simple, unidirectional and DX-capable loop “beam” for SWLs!

by 13dka

In early June, Andrew (grayhat), SWLing Post‘s resident antenna wizard suggested a variation of the “cardioid loop” on the SWLing Post message board: The original “cardioid loop” is a small loop receiving antenna deriving its name from a cardioid shaped (unidirectional) radiation footprint. The design is strikingly simple but it has a few downsides: It relies on a custom preamp, it needs a ground rod to work and it is unidirectional only up to 8 MHz.

Andrew’s version had the components all shuffled around and it did not only lose the ground rod, it also promised a nice cardioid pattern over the entire shortwave, from a small, diamond shaped loop. Wait…what? It can be made using parts available on Amazon and your DIY store:

You need some 3m wire and PVC tubes to create a support structure to hold the wire, a 530 Ohm resistor and a 9:1 balun like the popular “NooElec One Nine”. Since it’s a “lossy” design, adding a generic LNA like the NooElec “LANA HF” would help getting most out of it. When you put that all together you have what sounds like an old shortwave listener’s dream: a small, portable, tangible, and completely practical allband shortwave reception beam antenna with some more convenient properties on top, for example, it is a bit afraid of heights.

That sounded both interesting and plain crazy, but the .nec files Andrew posted were clearly saying that this antenna is a thing now. Unfortunately Andrew suffered a little injury that kept him from making one of those right away, I on the other hand had almost all the needed parts in a drawer so I ended up making a prototype and putting it through some of its paces, with Andrew changing the design and me changing the actual antenna accordingly, then mounting it upside down. Let me show you around:

  •  Small, diamond shaped wire loop (with 76cm/29.92″ sides), needing as little space as most other small loops.
  • Unidirectional with a ~160° wide “beam” and one pronounced minimum with a front/back-ratio of typically 20dB over the entire reception range 1-30MHz.
  • Moderate height requirements: It works best up to 3m/10′ above ground, where it gives you…
  • …a main lobe with a convenient flat takeoff angle for DX
  • Antenna is comparatively insensitive to ground quality/conductivity.
  • Wideband design, works best on shortwave and is pretty good up to 70cm.

A functional small beam antenna for shortwave reception that’s just as small and possibly even more lightweight (prototype:~250g/9oz) than your regular SML, that can be easily made out of easy to obtain parts and easily carried around for mobile/portable DXing and due to its cardioid shaped directional pattern also for direction finding, a “tactical” antenna that’s also doing DX? Unlike conventional, Yagi-Uda or wire beams it can achieve a low takeoff angle at only 3m/10ft height or less, the front/back ratio is typically better than that of a 3-element Yagi, with a particularly useful horizontal pattern shape. That it’s rather indifferent to soil quality could mean that more people get to reproduce the good results and being a real wideband antenna is making the SULA an interesting companion for multiband radios and SDRs. Really? A miracle antenna? Is it that time of year again? If I had a dollar for every….

Continue reading

Spread the radio love

Guest Post: 13dka Explores the International Beacon Project

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


In search of benchmark signals: The International Beacon Project

by 13dka

If you – like yours truly – like to tinker with antennas and radios to get the most out of them, you likely have your own set of reference stations. If this is a new concept for you – reference stations are whatever stations you deem apt to check propagation, the general function of your radio, when trying to improve reception or comparing radios… They are ideally always on when you need them and come in various strengths and distances on several bands from all over the world. Traditional sources for that are of course time signals and VOLMET stations on HF, even though the latter are giving you only two 5-minute slots per hour for testing reception from a specific region and the former have their own specialities here in Europe:

A typical scene on 10 MHz, captured at home 30 minutes after the full hour: BPM voice ID from China mixed with something else, then Italcable Italy kicks in on top of some faint murmur possibly from Ft. Collins, in winter some South American time stations may stack up on that together with splatter from RWM 4 kHz lower…

A reliable source of grassroots weak signals is particularly desirable for me because I enjoy proving and comparing the practical performance of radios at “the dike”, a QRM-free place on the German North Sea coast. In the absence of manmade noise and the presence of an ocean adding 10dB of antenna gain, finding benchmark stations with “grassroots” signal levels turned out to be a different challenge than it used to be: With somewhat sizeable antennas the stations tend to be (too) loud there, even with the baseline ionospheric conditions under a spotless sun in its activity minimum. In short, my old benchmark stations didn’t work so well anymore and I had to find something new. Continue reading

Spread the radio love

Guest Post: A synchronous detector crash course!

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

Spread the radio love

Guest Post: Dikeside Icom IC-705 RX action

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


The IC-705 in action at the dike

by 13dka

When I got the IC-705 in late October 2020, I didn’t get that much chance to enjoy it at the dike: After a couple of initial tests and 2 nightly “FYBO” MW DX sessions in November, a way too long and wet winter struck the German North Sea coast, with nighttime temperatures recovering to 2-digit Celsius figures only in the past few weeks. I took the opportunity to do more experiments with loops, preamps and a phasing unit to improve the RFI-stricken reception at home, so I could at least listen to European hams on 80 and 40m raving about their new 705s and start to write my own musings about that lovely little radio, recently posted here.

SSB DX

June 1st, 202

Finally, acceptable temperatures at night! But they come with a downside: When I connected the vertical around 8:00pm (local time), it was still almost 2 hours before sunset and a lot of thunderstorms in Europe made even 14 MHz very noisy, my hopes for some nice catches were immediately taking a dive. A short scan of the bands brought up nothing special, the only notable thing being the CB and 10m bands being moderately open. I should’ve known better: As soon as the sun splashed into the ocean, grayline propagation worked its magic!

Grayline while receiving Japan, June 1st

As the image probably hints, a couple of Japanese “big guns” produced some nice, comfy signals on the monopole, in addition to the South American and Carribbean stations usually booming in here!

Video: A short collection of ham stations heard around midnight

After midnight I noticed a residue signal of WWV on 20 MHz and still a few EU beacons on 10m. Both incredibly weak with QSB making them disappear but that’s where the 705 really shines – it’s not only picking up these grassroots signals just fine, it shows me that they’re there, or that they were there – a waterfall display keeps on proving that a perceived lack of activity on a band is often pure bad luck – you can tune across an entire band without hearing anything because on each frequency with some activity there’s the other (inaudible to you) station speaking right now, QSB is dipping the signal just when you tune past it…

June 5/6, 2021

That evening the Japanese stations were missing on 20m, I thought I picked one up on 17m, and like so often, the one odd Australian station came in on 20m. After midnight I noticed the 10m beacons again, there were even a few more of them. This time I brought my Belka DSP to the dike so I could compare it with the IC-705, after all the Belka proved to be my most sensitive portable before! The devastating result is likely owed to the fact that the Belka is pretty picky about passive antennas not being matched very well to its input (which is much optimized for the whip) but it picked up diddly squat. If it isn’t a testimony for the sensitivity of the IC-705, it might be one for its aptitude to cope with all sorts of antennas.

Then I tuned into the 10m SSB range and I was veeeery surprised to hear VO1FOG from St. Johns, Canada! This is the first time I heard a transatlantic signal on 10m in a solar minimum ever, but it was with condx only elevated enough for some daytime DX within the EU…and literally in the middle of the night! The signal was very unstable though, he later switched to the 12m band which worked better. Back to what I said about the waterfall display above: Without it, I could’ve missed this station with a pretty high probability simply because I didn’t expect any activity up there, so I wouldn’t have tuned across that band for very long, and without seeing the signal while the VFO is already somewhere else…

I also heard another new country (Ecuador) in SSB, the usual collection of Carribbean islands and some participants of the “Museum Ships Weekend Event” including NI6IW, which is the vanity call of the history-charged USS Midway in San Diego. The “Japanese” station JW4GUA turned out to be on Svalbard island, with the main town Longyearbyen being the northernmost town in the world, only 650 miles from the north pole, and I don’t hear stations from there very often!

Video: June 5th

June 10/11

The past days saw the SFI passing 80 and 11/10m becoming quite busy. By the time I parked the car at the dike, SFI had dropped to 73. That evening the grayline confined itself to colorizing the horizon. 10m and 11m were still full of signals, I could still hear 2 British chaps chatting on 27 MHz at 3:00 in the morning, but nothing really “extraordinary” was coming in – the one odd VK, more Carribbean islands, one Argentinian but not much from other parts of South America, it never gets boring how this all defies predictability. But as always I heard most of the North American continent, not booming in much that night but I followed 2 POTA activations for a while, which are usually at most 100W stations working a lot of other “barefoot” stations and I heard almost all of them. In the morning grayline window for the west coast I finally got one solid signal from Oregon. All my radio life, the US west coast has been a tough target for some reason.

The signal had that typical “over the pole” sound, a relatively quick phasing imprinted into the signal by the charged particles converging over the pole, causing northern lights in the region and that exiting feeling when observing really big, planetary scale physics in realtime, over here at my listening post. The magic of shortwave. 🙂

Broadcast bands

After the post touting the IC-705 as a SWL/BCL receiver, demonstrating it on the broadcast bands seems mandatory to me. However, capturing cool BC DX is a very different business than waiting on the ham bands for interesting stations coming and going and collecting spectacular (-ish) results in a single night this way. Broadcast schedules have to be studied, current “hardcore” DX targets identified… and I have to admit that I’m out of that loop currently. Just turning the knob and recording whatever is populating the bands, and doing that between 21-22:00 UTC, when all programs are directed towards anywhere except Europe turned out to yield pretty boring results. Here it goes anyway:

Video: Browsing the most important BC bands

CONDX and antenna:

The antenna I was using in these videos was a simple wire running up a 10m/33′ fiberglass pole, forming a very archetypical “monopole” or “Marconi” antenna, just a vertical wire, no counterpoise, no matching network, no un-un, transformer or flux capacitor. I planned on using this to make some experiments about the practical benefits (for reception) of all the components it’s now lacking, but it already demonstrates that the beauty of receive-only antennas is that they often don’t require crazy efforts: On the conductive soil at the dike it works pretty well (good signals all over the bands and sufficiently low takeoff angle) as it is.

The evening and the 2 full nights at the dike once again had condx that nobody would phone home about:

SFI, A and 3-hourly K-indices while I was at the dike.

It’s not that these numbers always fully explain actual and current condx but decreasing SFI and rising A/K-indices mean low expectations. Despite the condx still characterized by the solar minimum that way, the location is always delivering proper DX for my radios. Unless stormy or severely unsettled geomagnetic conditions give DX a day off, there’s almost always something to take home, be it a new country, a rare island, unexpectedly loud signals from the other end of the planet at unusual times and/or on unusual bands or other ionospheric mysteries.

Speaking of location: These videos demonstrate the properties of that listening post as much as the capability of the IC-705 to harvest them, and they don’t put that into relation to other radios, so you have to rely on my word on this: Compared to what I brought to that place so far it’s jaw-droppingly good, but a big contributor to that is that only few of my other radios can really cope with the antennas I like to use out there in first place. A radio like the IC-705 is sure making the most out of location and antenna, but it’s not the key component because a low-noise location is everything, it always was and it is today more than ever. Without it, radios and antennas can’t really play their jokers.

Spread the radio love

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

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

Spread the radio love

Armed with loops, fences, and an Icom IC-705, 13dka battles transatlantic MW DX

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


Dipping my toes into transatlantic MW DX

by 13dka

Most of my SWLing life I wanted to dig into MW DX but never managed to make that really happen for some reason. Then last November, I fetched my first transatlantic station while I wasn’t even trying, in a rather surprising setting:

I have to explain that my home and neighborhood got so infested with a multitude of QRM sources that I did not put my outdoor antennas back up after a storm blew them out of the trees in winter 2018/19. I just used an ML-200 loop indoors, which also has to put up with my own additional QRM sources in my den, consisting of 3 computers running 24/7 and a couple of switching power supplies, a TV, LED lighting… allowing for very basic reception as long as my neighbors don’t watch TV or use the internet. On top of that, medium wave is badly beaten by a mowing robot’s boundary wire here, making reception on several portions of the band completely impossible.

I never expected receiving any US stations on MW in that noise, but I couldn’t sleep that night and scanned the bands a bit with the IC-705 hooked up to my new YouLoop hanging over my bed for testing. I had seen the characteristic transatlantic carriers on MW many times before on my SDRs, but for some reason I never picked up anything intelligible on them in any winter season, now a lot of these carriers were there again but on 1130 there was actually modulation and it wasn’t the only station!

Small bedside loop: SWL’s dreamcatcher!

Bloomberg Radio 1130 came in with almost enjoyable quality at times, but Bloomberg is also kind of a surefire station for MW DX over here. I also picked up a station on 1120 and another one on 880 which was briefly so strong that it surmounted the strong interference from BBC Radio Wales on 882 kHz. 1120 was confirmed the next night to be KMOX in St. Louis, 880 kHz was *not* KCBS in NY – I checked that immediately, I have a KiwiSDR set to that frequency booknarked on my cellphone in case I have a craving for the 1-877-Kars-4-Kids commercial. Powerwise likely candidates for that would be CHQT (50kW) in Edmonton, CKLQ (10kW) in Manitoba or KRVN in Nebraska (50kW class B station) but this may be hard to verify due to the dominance of the BBC on that frequency. Anyway, KMOX wasn’t a bad catch for a small, passive indoor loop, that’s 7,150km or 4,440 miles from here!

Bloomberg Radio on the YouLoop:


Here’s KMOX:


This was A) quite encouraging for nighttime DXpeditions to the dike (brrr…cold!), B) a testimony for the YouLoop’s good performance on MW and C) a testimony for the IC-705 having pretty much all one could wish for in a capable MW DX radio – notch filter, passband tuning on AM, stable ECSS, waterfall display to detect stations and last but not least loads of sensitivity to make the most out of low-output antennas down on MW.

Going to the dike

Of course I just had to put on some long johns and drive to the dike around 3:00am local a few nights later, to try my luck with my ML-200 (lacking a better idea) with an 80cm diameter rigid loop. I was mildly surprised that reception wasn’t that much better than with the YouLoop at home. The overall yield wasn’t exactly outstanding compared to other people’s logs but a lot of stations were hidden in the frequency ranges that are submerged in QRM at home. My log has US/Canadian stations on 20+ different frequencies, unfortunately most of them UNID. Here are some recordings I made that night, hunting for unambiguous station IDs from North American broadcasters:

ML-200, Nov. 16th, 2020

1130 Bloomberg Radio on the ML-200:


Presumedly WABC 770 in NYC: In MW DX, never think you ID’d something properly just because you heard a city name and the frequency has a clear-channel station located there!


This is more unambiguously 1010 WINS in NYC (with a twist described later)


1030 WBZ Boston, MA – the first part of the clip is showing how it sounds when the signal is good, the second part demonstrates how reliably propagation is taking a rest while a station identifies itself.


The grandpa of AM broadcasting, 1020 KDKA:


Moving away from the east coast, this is WHAS 840 in Louisville, KY:


760 WJR Detroit, MI


Here’s a tough one, the religious content I heard with a great signal before doesn’t warrant a proper ID alone, and as per usual the station ID’d while fading out. I could ID this only with a set of big, closed headphones, which is a mandatory accessory for all extreme DX (CHRB 1140 in High River, Alberta):


Of course I was occasionally checking other bands too and got some serviceable signals from Brazil:

Clube do Para on 4885 kHz:


VOA Pinheiro from Belem, Brazil on 4960:


Going to another dike, this time it’s personal!

Time to try something completely different: A ~1,000m/3,000′ straight (and preliminary considered continuous) stretch of mesh fence along the dike heading ~345° (NNW), pointing roughly to mid-/western mainland North America. I had briefly tried its aptitude for being a “natural” Beverage antenna before – with mixed but encouraging results: Due to the fence not being terminated at the far end it may be kind of bidirectional, and according to my latest insights a Beverage style antenna doesn’t work well over very good (conductive) ground, probably even less so close (maybe 200′) to the ocean. Also, I forgot to pack the 9:1 balun I prepared for that purpose, so I just had some wire with alligator clip to connect the fence to the radio. Boo.

Accordingly, what I saw on the waterfall display didn’t look so much different than what I got from the ML-200 before – there were clearly more stations visible (as a carrier line on the waterfall) but nothing was really booming in. However, I managed to log a few more stations, such as WRKO in Boston and (the highlight of the night) 1650 KCNZ “The Fan” in Cedar Falls, IA which has only 1kW to boot at night to make the 6,940 km/4,312 mi to my dike. This may or may not be an indication that the “Beverage sheep fence” isn’t so bad after all!

“Fence”- reception, Nov. 18th, 2020:

VOCM 590, St. Johns, New Foundland, Canada’s easternmost blowtorch is like Bloomberg an indicator station for European MW DXers:


680 WRKO, Boston, MA:


1040 kHz, presumed to be WHO, Des Moines, IA: No ID, only a matching frequency and a commercial for “Jethro BBQ”, which has locations only in and around Des Moines:


Here’s 1650 KCNZ, Cedar Falls, IA with 1KW:

 

To put that into some relation, this is what 1KW sounds like on a very quiet 40m band in SSB (K1KW from Massachusetts on 7156 kHz producing a 9+20 signal that morning on the “Fence antenna”):


BTW, interesting bycatch – not the first time I caught WWV and WWVH on the same frequency but that morning was the first time I could hear both on 5 MHz:

 

So where have you been all my life, American AM stations?

A question remains – how could I miss the existence of these stations forever, then in modern SDR times see the carriers on the spectrum scope and still miss the modulation on these carriers? Or the other way around – why did I hear them now?

To begin with, when I started out with the radio hobby many decades ago, the reason for the occasional whine and whistle on some stations (particularly past midnight) wasn’t obvious to me: The last thing I suspected was that this could be interference from across the pond, with the pitch of the whine (or “het”) having a direct relation to the 9kHz vs 10kHz difference in channel spacing. Of course these stations were there all my life! Then, with just some regular radio you’d have to pick one of very few frequencies where a strong station from across the pond coincides with a nice silent gap in the local channel allocation. But until this millennium, European medium waves had no such gaps and a lot more local blowtorches.

Since that time many MW stations were turned off and demolished and whole countries abandoned MW here in Europe, so we’re in a much better spot now for transatlantic DX. Unfortunately the opposite is true for listeners on the left side of the pond, you guys still have a very crowded AM band but less potential DX targets in Europe. On the bright side, the remaining European stations are often not restricted to 50kW and you have another ocean with very distant and rewarding DX stations that are very, very hard to catch in Europe!

Wrong time, wrong place

Another bunch of factors are – of course – propagation, season and location/latitude. The MW DX season is roughly fall to spring nights (when TX and RX are in the dark) with a period of increased absorption in the middle (the “mid-winter anomaly”), signals are potentially stronger at lower latitudes and weaker at higher ones but the distance to the noisy equator and a lack of stations interfering from the N can be a huge advantage for using over-the-pole paths on higher latitudes. The big showstopper is solar activity: Good condx on shortwave can be rather bad for skywave propagation on medium wave, so a solar minimum is the long-term hotspot for (transatlantic) medium wave DX.

I’m glad that I learned how intense that relationship is right away: When I discovered that Bloomberg is pretty good on my indoor YouLoop at home, condx were pretty down with SFI in the low 70s and very little excitement of the auroral zones. 2 weeks later the SFI was only slightly higher in the 80s-100, many of the carriers were missing on the waterfall and Bloomberg could be heard only in much bigger intervals.

Speaking of which – even with favorable condx, a proper radio and a half-proper antenna, patience is key! In my very fresh experience the fading cycles on those over-the-pond signals are long! So far I have seen everything fading in and out over the course of a few minutes to half hours or more, with less favorable conditions or a worse antenna it may take much longer until it sticks out of the noise for a while. So you may have to park on a frequency for a long time to not miss the station coming up so much that it becomes readable at the right time to ID it. Multiple DX stations on the same channel can make identification difficult unless one station really dominates the other and that all may take hours or days until it happens. Here’s a lucky example on 1010 kHz:

Lucky because in this case one station is already known – it’s WINS but it often has another station underneath and I was curious what that station might be. On this occasion, the station ID’d itself as “Newstalk 1010” (which is CFRB in Toronto, 0:05 in the clip) just in a short talking break on WINS. Again, this can’t be heard on my laptop speakers but on headphones:

 

Waiting for a moment like this to happen isn’t exactly fun, that’s why spectrum recordings are incredibly valuable particularly on MW – you won’t miss a possible station ID on frequency A because you were listening to frequency B, but a part of me thinks this is taking a bit of the challenge away, like blast fishing. 🙂

Fancy equipment

The IC-705 fits snuggly-wuggly into my steering wheel for extra-comfy tuning!

Fun fact: While Bloomberg NY on 1130 was (kind of) booming in at home so I knew for sure it was there, I could hear it even on the XHDAtA D-808 with its tiny loopstick and only average sensitivity on the AM band! So for “easy”, loud and undisturbed stations some persistence and a simple portable radio may suffice to catch some transatlantic DX. But most of the stations will be hit by interference from closer stations, then the radio needs at least to be capable of stable sideband reception, with a corresponding narrow filter and proper suppression of the unwanted sideband – luckily this isn’t an unusual feature on inexpensive portables anymore. So if you already have an SSB capable radio that’s all you need to address the most common issue with transatlantic DX, US and EU stations being too close in frequency. Of course passband tuning and notch filters are most helpful assets in a radio for this, rescuing reception in even more severe interference situations and the spectrum/waterfall display on an SDR helps a lot with finding the carriers and SDRs also have all the nice tools but with some more patience you may find stations with many conventional receivers.

Of course antennas are the crucial component again: If conditions are excellent, even a loopstick may bring the first stations into the log, some small magnetic (wideband) loop could dig up some more stations, from there it’s quickly going a bit esoteric – AFAIK there are no commercial offers for multi-turn (tuned) loop antennas nor are FSL antennas easy to come by, you can’t buy EWE et al antennas either and Beverage antennas for MW are quite a project – not that hard to get a kilometer of wire and there are even kits to buy but it could be much harder to find a place to roll it out in the direction you’re interested in, in an area that doesn’t have electric fences or high voltage power lines within a radius of at least several miles. I guess once you become addicted, you’ll stop asking yourself whether or not it’s worth the effort.

So it’s pretty clear what happened: For catching TA DX stations, the ionospheric conditions must be good, to receive that with a loopstick they must be ideal and that’s what they are currently – it’s winter in what’s still a deep solar minimum and on top of that, some of my radios are very apt for MX DX and I was lucky to listen on the right time on the right frequency. When I started writing this article, my enthusiastic bottom line was supposed to be something like “MW DX isn’t rocket science”, which is certainly true but I think my history with it shows that it’s not exactly trivial either. Maybe that’s why it’s so rewarding, it sure is some hardcore DX challenge that complements the shortwave activity quite nicely and may give you something to look forward to when solar activity is down.

Spread the radio love