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.
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 →
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 →
One of my favorite DXing locations was this little cottage at the El Rancho Hotel just outside San Ramon, on the edge of the Amazon jungle in Peru. At $18/night, including breakfast, the hotel was a bargain, and there was plenty of room for my delta loop.
A Guide To Vagabond DXing
By Don Moore
Ever since I served as a Peace Corps volunteer in Honduras in the early 1980s, Latin America has been my primary focus for both DXing and traveling. So when I retired in 2017, my main goal was to begin taking long annual trips . . . and I do mean long. From October 2017 to May 2018, I traveled through Peru, Ecuador, and Colombia visiting about fifty different towns and cities. This year, I’m on a five-month trip through southern South America. In Latin America you can get just about anywhere cheaply and easily by bus, so that’s how I get around. It’s also a great way to meet people and to see the countryside. But luggage can become a burden, so I limit myself to a single mid-sized wheeled suitcase and a large knapsack. And that means that my mobile DX shack has to be very carefully planned.
Your plans may not include multi-month odysseys like mine, but I think my experiences will help you prepare to DX on your next trip, wherever it might be. Of course, what makes a good mobile DX shack depends on what your DX interests are. I consider myself a station collector, in that I want to make loggings of lots of new and different stations and to build up an understanding of radio broadcasting in different regions. So on my travels I concentrate on the medium wave broadcast band and longwave beacons, with maybe little bit of shortwave utility DX. (There’s not much on shortwave broadcast that I can’t also hear at home.)
Take the DX Home With You
For years my standard DX travel gear was a Sony ICF-2010, a cassette recorder, and an old Radio West ferrite loop antenna. But listening time was always limited since it was a vacation. There were other activities on the agenda and I was generally too tired to get up early for DXing. I always went home with some interesting loggings and audio recordings, but once I left for home the DXing was done.
SDRs have changed all that and now my first rule of travel DX now is take the DX home. The best souvenir of a trip is the hundreds of hours of DXing that I take home with me. In a 2016 trip to central Colombia, I made about 300 MB of recordings of the medium wave band. While listening to them later I logged over 400 stations from twenty countries (and I still have about half the files to go through). I never would have even gotten close to that many stations listening on my Sony like an ‘old-fashioned’ DXer, hi!
Lately, I’ve been accumulating SDR files much faster than I could possibly go through them, so it’s a fair question to ask what the point is. When will I ever listen to them all? Like most DXers, I’m not fortunate enough to live in a perfect DX location. When conditions are mediocre, I’d rather spend my DXing time going through some more interesting SDR files. And, I know I’ll have lots of good DX waiting for me years from now when I’m no longer able to travel the way that I do now. For me, SDR recordings make much better souvenirs that some cheap tourist trinkets that will gather dust on a shelf. It doesn’t matter whether your travels take you to a nearby park or to a distant continent. SDRs can preserve the DXing experience for years to come.
My Mobile DX Shack
This is my typical DXing setup with the Afedri. The rooftoop terrace at the Hotel Rosa Ermila ($10/night) in Cascas, Peru was the most elegant place I’ve ever DXed from, but reception was only average with the PA0RDT dangling from the railing.
The centerpiece of any DX shack is the receiver. On my 2017-18 trip, I had an Afredri SDR-Net with an SDRPlay RSP1 as a backup, but this year I replaced the Afedri with an Elad FDM-2. Together, my two SDRs are smaller than all but the smallest portable receivers. Of course I also need a laptop, but I’m going to take one anyway. An important consideration in selecting a travel SDR is to get something that is powered off the laptop’s USB connection so that it is easy to DX totally off battery power if line noise becomes an issue.
The other vital component of DXing is the antenna. A good on-the-road antenna for SDR DXing has to be small, easy to erect, broadband, and versatile. That sounds like a lot to ask, but the perfect DX travel antennas do exist.
For compactness and ease of use, nothing can surpass the PA0RDT mini-whip. How good is it? That’s what I used to log over 400 medium wave stations in Colombia in 2016. I just attached the unit to my coax and threw it about three meters up into a short tree. The antenna works best when mounted away from nearby structures, but sometimes I’ve gotten decent results placing the PA0RDT on balconies and windowsills of tall buildings. It’s mostly a matter of luck as to how bad the local noise levels in the building are and how much the building itself may block signals. Using a short support, such as a broom or a hiking pole, it may be possible to mount the unit a meter or so away from the building.
While it’s best to mount the PA0RDT away from obstructions, the antenna might give good results anywhere, even on the neighbor’s roof. (Just make sure it’s not likely to get stuck. Pulling the unit out of a stubborn papaya tree is no joke.)
The biggest drawback of the PA0RDT for serious MW and LW DXing is that it is non-directional. For a directional antenna, a Wellbrook loop is great if you’re traveling by car, but that one-meter diameter aluminum loop doesn’t fit in my suitcase. Fortunately, a few years ago Guy Atkins and Brett Saylor told me about an alternative: buy a Wellbrook ALA-100LN unit and attach it to a large homemade wire loop. Now my travel kit includes two nine-meter lengths and one eighteen-meter length of #18 stranded copper wire. The wires can be spliced together for loops of 9, 18, 27, or 36 meters circumference, according to what fits in a location. Erection of a wire loop is easy enough with a suitable tree branch. I just throw the wire over the branch and then form it into delta (with the bottom running just above the ground) using two tent stakes and some short cord to hold the corners. The ALA-100LN unit goes in the bottom center.
Items that go in my suitcase, left to right: tent stakes and wire for the Wellbrook loop, a small box with more adapters, another battery box, 50 foot coax, 12 foot coax, and my hiking pole. The pole doubles as a support for the PA0RDT sometimes.
The loop doesn’t have to be in a delta; that’s just often the easiest to erect. I’ve successfully used squares, rectangles, trapezoids, oblong diamonds, and right angle triangles. Any balanced shape with the ALA-100LN in the bottom center should be bi-directional in a figure-eight pattern. Non-balanced shapes will work equally well but with unpredictable directionality. Just keep the wire in a single plane and place the ALA-100LN unit someplace along the bottom.
Both the PA0RDT and the Wellbrook require a 12V power supply. The North American version of the Wellbrook comes with an excellent noise-free 110V power supply, but that’s of no use in 220V countries and also I want to be able to DX totally off battery power when necessary. Fortunately both antennas use the same size power connector, so I carry three eight-cell AA battery packs for remote power.
Contents of the DX box, clockwise from upper left: the two pieces of the Wellbrook ALA-100LN, the two pieces of the PA0RDT mini-whip, two 8xAA battery boxes and a set of batteries, USB and coax cables, a passive 4-way antenna splitter, battery tester, various adapters and cup hooks (for securing wires), 4TB hard drive, the SDRPlay RSP1, the Elad FDM-2, and more short patch cords.
My mobile DX shack is rounded out with everything that is needed to connect the parts together. I have at least four of every adapter and patchcord, since I know they won’t be easy to replace on the road. For lead-ins, I have 12-foot and 50-foot lengths of lightweight coax with BNC connectors. I also have a few F-to-BNC adapters so I could buy some standard TV coax if needed. A 4 TB hard drive provides plenty of space the SDR recordings I plan to make. (Before leaving, I fill it with videos that I can delete after I watch them or when I need space.) For DX references, I download various station lists online so that I have them available even if I don’t have an Internet connection. It’s also important to keep those lists with the SDR files from the trip so that if I’m listening to the files years from now I’ll have references which were current at the time.
A common concern for traveling DXers is getting through airport security. When I went to Colombia in 2016, I wrapped my DX gear in clothing for protection and then stuffed everything into my backpack. Security didn’t like what they saw and I had to empty the bag so that every single item could be examined and swabbed for explosive residue. The TSA lady was very nice about it, but I wanted to minimize the chance of that happening again.
At an office supply store I found a plastic storage box that fits inside the main pocket of my backpack. My SDRs, antenna components, and hard drive get wrapped in bubble wrap and all placed together in the box along with small cables, adapters, etc. Larger items – the wire, coax, and stakes for the loop – get packed in my checked bag.
The DX Box packed and ready to go.
At the airport, I slide the box out of my backpack, place it into a cloth shopping bag, and then send it through the X-Ray machine on its own so that the agent can get a close look at the contents. So far in about a dozen security checks in the USA, Peru, and Mexico, the box of gear hasn’t caused so much as a pause on the conveyor belt. And, if the box would get pulled for a closer look, at least I won’t have to empty the entire backpack again.
Most of my equipment fits in this plastic box which slides into my backpack.
Where to DX
A mobile DX shack isn’t worth anything without a suitable place to DX from. Hotels may work if you have a balcony where you can put a small antenna, but more likely than not there’ll be problems with RF noise. The best hotels are ones that are a collection of cottages or bungalows or that otherwise have an open yard-like space for an antenna. My favorite place to find possible DXing sites is on AirBnB. It’s often easy to find AirBnBs that are on the edge of town or even in the countryside with lots of space. Of course, since I don’t have a car, I need to make sure I can get there using public transportation.
While visiting Huanchaco, Peru with DX friends Karl Forth and John Fisher, we had a beach-front apartment with an adjoining rooftop terrace. We had excellent results with an oblong loop and the ALA-100LN on the terrace.
The key to selecting a DX location is to examine all the photos very carefully. Is there open space for the antennas? Are there trees or other potential supports? Is there a gazebo, terrace, or other space that could be used for DXing? Google satellite view and Google street view can be very helpful in scouting out a location (And it’s surprising how much of South America is now on Google Street View.) And, I always look for possible noise sources. One place I almost rented in Colombia turned out to have high voltage power lines running next door when I found it on Street View.
I always tell the hotel staff or AirBnB host what I’m doing so that they understand why the gringo has wires running around. And I make sure not to put my antennas or coax anywhere that might interfere with the employees or other guests. Most of the time I’m able to erect the antenna near my room and run the lead-in into my room through a window. Then I can leave my laptop running all night to make scheduled SDR recordings. That’s the Holy Grail of DXing – catching the overnight DX while you sleep. But if my room turns out to have too much RF noise (as has been the case a few times), then I head out to the gazebo or terrace to DX using battery power. That does mean I have to stay up late or get up early since I can’t leave the laptop outside on its own. But, some of the best DX that I’ve had has come from running off full battery power in gazebos.
My delta loop had plenty of space at the Posada de Sauce ($25/night with breakfast) in the jungle near Tarapoto, Peru. The lodge was totally powered by solar panels and was one of the quietest places I’ve ever DXed from.
Antenna security is another consideration. At one place I stayed I wasn’t comfortable leaving my expensive antenna components unattended outside all night. And then there was what happened on my first trip to Colombia in 2010. I knew that a place I would be staying at for two nights had an open field right behind it, so on that trip I took 500 feet of thin insulated wire for a mini beverage-on-the-ground. DXing was great the first night but terrible the second. When I went out the next morning to wind up the wire I learned why. The worker who had been weed-wacking the hotel gardens the previous day had also done the field, and in doing so he had cut my wire in three places. He had, however, very nicely tied the wires back together.
Share the DX
DXing off battery power in the gazebo in the Mauro Hilton Hostel in the mountains above Manizales, Colombia. The antenna was the PA0RDT thrown in a tree. I had great DX with the loop from my room, but I came here to enjoy the views one evening.
Finally, if you take an SDR on a trip and get some good DX, make a selection of your files available for download. Other DXers will enjoy hearing what the band sounds like somewhere else. Several dozen of my files from Peru, Ecuador, and Colombia are available for download in a shared Google Drive folder. If you see something you want, be sure to download it now. The winter DX season is just starting here in deep South America and in the coming weeks I’ll be replacing some of those older files with ones made in Argentina and maybe in Uruguay and southern Brazil. I’ve found a lot of places to stay that look to be perfect for a vagabond DXer.
The PA0RDT miniwhip – see the email address at the bottom of the article for ordering information. I highly recommend getting the original PA0RDT. There are several cheaper versions for sale, but DXers have reported quaility control problems with those.
Don, thank you so much for sharing your travel DXing expertise. This article is absolutely brilliant and so informative for anyone who wishes to make SDR field recordings. I love how carefully you’ve curated and distilled your portable setup and have given priority to having antennas for all occasions. I also think carrying spare parts and, especially, a spare SDR makes a lot of sense.
Post Readers: As we mentioned in a previous post, Don is an author and has recently published “Following Ghosts in Northern Peru: In the Footsteps of 19th Century Travelers on the old Moyobamba Route” which is available in Kindle and print formats via Amazon.
(Note: A more extensive set of photos from Radio Tarma, and other Peruvian radio stations, can be found at Don’s website. The website also contains details of the Peruvian travelogue book he recently wrote and published.)
Radio Tarma building
Shortwave stations in South America are few and far-between these days, but those of us who have been tuning the bands for a few decades remember the days when the tropical bands were filled with Latin American broadcasters from dozens of scattered mountain and jungle towns. One such place was Tarma, a picturesque but chilly city of about 50,000 nestled in a narrow valley in the central Peruvian Andes at 3,000 meters above sea level. Tarma has been an important commercial center since colonial times and archaeological findings indicate that the region was heavily populated long before the Spanish came. Today it sits at the junction of two major trade routes, so it continues to be a bustling place.
View of northern Tarma from the Radio Tarma transmitter site
While wandering around central Peru in April 2018, I made a point of stopping in Tarma so as to visit the town’s namesake broadcaster, Radio Tarma, one of the few Peruvian stations still on shortwave. Radio Tarma’s frequency of 4775 kHz has been a fixture on the sixty meter band for over four decades. What I didn’t know was that this would turn out to be the best of the over one hundred Latin American station visits that I have made in my travels.
Radio Tarma Frequencies
When I first stopped by on Monday afternoon, everyone was busy and no one had time for a visiting gringo. By chance I had arrived on the station’s sixtieth anniversary and they were preparing for a big celebration that night. I was invited to come back in the evening when there would be a huge street party with live music. That evening I got to talk to several members of the station staff and was introduced to owner-manager Mario Monterverde, who invited me to come back for a tour in two days after the celebrations and ceremonies were over.
Radio Tarma’s 60th Anniversary Party
The Radio Tarma Party Band
Radio Tarma Owner/Manager Mario Monteverde
The reason for Radio Tarma’s continued presence on the sixty meter band is Mario Monteverde, Radio Tarma’s energetic owner-manager.
Mario Monteverde in the old record library.
Running radio stations is his passion, and that includes reaching distant listeners on shortwave. Don Mario remembers what shortwave used to be like in Peru and he can rattle off station names and frequencies from past and present as good as any serious DXer. We spend a lot of time talking about stations I used to hear and the ones that I visited in my 1985 trip to Peru. We mostly talk in Spanish, although he speaks English well. He studied in Lima and later in the United States for several months. In the 1980s, he lived in San Francisco for a year while working as a DJ at a Spanish language FM station.
Don Mario thinks that it’s unfortunate that there is so little use of shortwave in Peru today, but other radio station owners think he is crazy to continue to use shortwave. The only listeners to shortwave in Peru are peasants in jungle settlements and remote mountain valleys. That may be a suitable audience for a religious broadcaster, but these listeners have no value to commercial stations, such as Radio Tarma, as they are mostly outside the money economy and of no interest to advertisers. But Don Mario doesn’t care and so Radio Tarma continues to broadcast on shortwave several hours every morning and evening for whoever might happen to tune in.
Studio for Radio Tarma
And, Radio Tarma can afford to broadcast as it sees fit. Don Mario’s Grupo Monteverde is one of the most professionally run and profitable communications companies that I have visited in Peru. In addition to Radio Tarma (on MW, FM, and SW), the company operates two television stations in Tarma, the local cable network, the local FM repeater for Radio Programas del Peru (Peru’s radio news network), and Radio Tropicana, a chain of FM music stations in Tarma and three nearby towns.
Founded in 1958 by Mario’s father, Radio Tarma was the first radio station in this city. Using two homemade 500 watt transmitters, the station initially broadcast on both medium wave and 6045 kHz shortwave, but the shortwave went off the air after about a year. Then in 1978, Mario’s father dusted off the old shortwave transmitter and applied for a new license. He was granted 4770 kHz, but that was soon changed to 4775 kHz, where Radio Tarma has been ever since. In the past four decades, Radio Tarma has been logged by thousands of DXers all over the world and, although it’s hard to believe, when I visited Tarma in April 2018 they were still using that original 500 watt transmitter that Mario’s father built sixty years before. However, a new one-thousand watt solid state transmitter was currently in Lima being tested by the Ministry of Transport and Communications. It should be on the air by now.
Studio for Radio Tropicana’s Tarma station
Don Mario starts by giving me a tour of the station building and its well-equipped offices and studios. He shows me the closet where the transmitter for the studio-to-transmitter-site link is and then takes me upstairs to the record library. Radio Tarma has one of the largest and oldest collections of vinyl records in the Peruvian Andes and includes numerous rare recordings. Many of the disks are EPs, or extended-play, which was once a very common format in the Andes. These records are the size of a 45 but recorded at 33 rpm so that there are two songs on each side. Don Mario keeps the records for their value but they aren’t used on the air anymore as Radio Tarma and its sister stations are all fully computerized. When there’s time they work on digitizing the better historical recordings from their collection.
Radio Tarma mountaintop transmitter site
After seeing the studio, we get in Don Mario’s four-wheel drive SUV for the trip up a steep and winding dirt road that leads to the mountaintop transmitter site. For most of the station’s history, Radio Tarma broadcast from a field on the north side of town.
Radio Tarma’s pre-2012 transmitter site was in the large field in the center of this photograph.
Then in 2010 Don Mario decided to modernize by buying a modern 3000 watt solid-state transmitter for the medium wave frequency and by building a modern transmitter facility on a ridge overlooking town. The new site, which was inaugurated in 2012, is at 3,600 meters elevation (over 600 meters higher than Tarma) and located about 1.5 kilometers south of the old site. (If you’ve logged Radio Tarma both before and after 2012, I think it’s fair to count these as two different transmitter sites.)
Radio Tarma’s mountaintop transmitter plant.
Another view of Radio Tarma’s mountaintop transmitter plant.
Radio Tarma MW and FM masts
The transmitters and antennas for all the Grupo Monteverde stations in Tarma (MW, FM, SW, and TV) are housed in the gray fortress-like cement building covered with a jungle of antennas and satellite dishes, for both receiving and transmitting. All of Peru’s main cellular services have towers nearby, as do several other FM and TV stations in Tarma, but Radio Tarma has the best location, right at the end of the ridge overlooking all of the town. For shortwave, Radio Tarma uses a dipole antenna strung between two masts.
Radio Tarma’s shortwave dipole
The transmitters and other technical equipment are all housed in a large room that takes up most of the first floor of the building. Upstairs there is a small apartment, complete with a living room and kitchen, for the technician who lives here plus another small apartment where Don Mario comes to stay when he feels like escaping to the quiet mountaintop for a night or two.
Radio Tarma SW and three MW transmitters
Radio Tarma transmitter room
Don Mario takes pride in showing me the original 500 watt medium wave and shortwave transmitters that his father made. Normally the shortwave service is shut down for several hours in midday when the frequency won’t propagate, but he turns on the transmitter so that I can see the tubes come to life. The three medium wave transmitters – the original 500 watt one, its 1978 1000 watt replacement, and the new 300 watt solid-state one – are lined up against the wall adjacent to the shortwave transmitter.
Mario Monteverde and Radio Tarma’s original 500 watt shortwave transmitter
Alfonso, transmitter operator at Radio Tarma
Don Mario tells me that the two older medium wave transmitters are regularly maintained so that they could be used at a moment’s notice if needed. He then proceeds to show me that he means just what he says, and shuts down the solid-state transmitter. Once that’s down, he powers up the original Radio Tarma MW transmitter that his father made, and we watch the old tubes light up. Then when it’s operating fully, he turns his father’s transmitter off and switches on the 1978 transmitter for a few minutes before finally returning the signal to full power on the new transmitter. One wonders just what his listeners thought was happening with all this on-and-off transmitting on a beautiful sunny day barely a cloud in the sky!
View of southern Tarma from the transmitter site
Radio Tarma and the Grupo Monteverde are a model operation for radio in smaller cities in the Peruvian Andes. Getting to know both the city and the station was one of the highlights of a seven-month journey through the northern Andes in South America.
Don Mario’s father built the foundation and Don Mario turned Radio Tarma and its sister stations into the small but professional media group that they are. He’s now in his mid-sixties and plans to run the radio operations for several more years. But he is beginning to think of the future. He never married and has no children, his siblings live in Spain and Lima, and all his nieces and nephews are in the United States. It’s not likely that anyone in the family would return to Tarma to run a radio station. He is investigating options of how to set up the corporation so that Radio Tarma and its sister stations would continue as locally-owned and operated radio broadcasters. Whatever he works out, let’s hope it includes a commitment to continue broadcasting on shortwave for many years to come!
Many thanks to SWLing Post contributor, Don Moore, who writes:
I’ve been traveling through northern Peru and I’ve made some SDR recordings along the way – medium wave, long wave, and some shortwave meter bands. I hope to eventually get through them all!
I have also uploaded some recordings to a shared Google drive so that other DXers can hear what the bands sound like in northeastern Peru, on the edge of the Amazon jungle. Maybe some of the blog readers would be interested in this. You will need the below link to see the SDR files and an explanatory document. I plan to add a few more once I get another hotel with a good Internet connection again.
Fantastic, Don! Thank you for sharing your spectrum recordings!
Post readers: If you don’t already have HDSDR installed on your PC, you’ll need to grab it here. HDSDR is free and can playback these spectrum recordings. Once installed, simply press the “play” button on the HDSDR console and point HDSDR to the downloaded spectrum file. You’ll be tuning through Peruvian spectrum in no time!
Noted DXer and South American radio enthusiast Don Moore (USA) is travelling again and posting fascinating photos & commentary of DXing and life in Colombia.
The focus is MW. My postings include photos and local recordings of stations from southernmost Colombia including the cities of Pasto and Popayan. I’m currently in Cali (the third largest city) for two weeks. I’ll also get a complete band scan completed in the next few days.