Category Archives: Mediumwave

Simple Wire Antenna: Giuseppe’s Mediumwave DXing Adventures from the Tyrrhenian Sea

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Many thanks to SWLing Post contributor, Giuseppe Morlè (IZ0GZW), who writes:

Dear Thomas and Friends of SWLing Post,

I am Giuseppe Morlè from Formia, Central Italy, on the Tyrrhenian Sea.

This time, I want to share a very simple antenna setup for listening to and attempting extreme DX on Medium Waves.

I first saw this antenna in several videos, and many DXers have used it during various expeditions.

For my setup, I used a 15-meter-long wire. At around 11 meters, I formed a small coil with 8 turns, then continued the wire for another 3 meters.

I began with some tests on my balcony by laying the wire flat along the ground for its entire length. I used my small Sony SRF-37V as a receiver. By placing the receiver within the coil of turns, I immediately noticed a significant difference compared to the built-in ferrite antenna.

In the early afternoon, I tuned into a Chinese language broadcast on 1377 kHz. You can watch a video of this experiment on my YouTube channel:

Encouraged by the excellent results, I decided to head to the tourist port of Caposele di Formia the next day in the early afternoon. I set up on the pier overlooking the sea. This time, I laid the wire in an eastward direction — towards the night, where the sun had already set, while it was still high for another two hours on my side.

Once again, I achieved amazing results.

I was able to hear the same Chinese station on 1377 kHz, but this time with much clearer audio than from my balcony, where electrical noise interfered. By the sea, the signal was clean and strong.

After a while, I tuned into VOA broadcasts from Thailand on 1575 and 1395 kHz, both with surprisingly good audio quality. You can see this second experiment here:

Sometimes, all it takes is a bit of wire and a small coil to create an excellent, ground-level antenna — in this case, oriented eastward.

I also tried using my loop cassette and a Tecsun PL-660 but couldn’t hear anything. Yet the little Sony SRF-37V proved itself to be a true “DX killer” on AM — truly impressive.

I even caught a segment of the VOA program “World Today,” discussing the Chinese economy and Southeast Asia.

As the sun set, the DX signals faded, making way for closer European and Asian broadcasters.

I will definitely return with a longer wire to see if this surprising setup can be improved even more.

A warm greeting to all the Friends who follow SWLing Post and to you, Dear Thomas.

73, Giuseppe IZ0GZW

More Reception Videos:

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Don Moore’s Photo Album:  Guatemala (Part Four) – To the Western Highlands

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Many thanks to SWLing Post contributor Don Moore–noted author, traveler, and DXer–for the latest installment of his Photo Album guest post series:

Lago de Atitlán con el pueblo de Panajachel de fondo (Photo by Larissa Gomez via Wikimedia Commons)

Don Moore’s Photo Album:
Guatemala (Part Four) – To the Western Highlands

More of Don’s traveling DX stories can be found in his book Tales of a Vagabond DXer [SWLing Post affiliate link]. If you’ve already read his book and enjoyed it, do Don a favor and leave a review on Amazon.

If anyone deserves recognition as the first tourists to visit western Guatemala it would be the American John Lloyd Stephens and Englishman Frederick Catherwood. In the 1820s and 1830s, Stephens traveled extensively in Europe and the Middle East and published several books about his journeys. On one of those trips he met Catherwood, an accomplished artist who traveled around the Mediterranean making drawings of archaeological sites.

The pair decided to visit Central America after coming across accounts of ruins in the region by the Honduran explorer Juan Galindo. Their trip received official support when U.S. President Martin van Buren appointed Stephens as a special ambassador to Central America.  The two men wandered the region for several months in 1839-40 visiting known Mayan sites and rediscovering many others. Stephens wrote two books about their travels, Incidents of Travel in Central America, Chiapas and Yucatán and Incidents of Travel in Yucatán while Catherwood published a book of his drawings, Views of Ancient Monuments in Central America, Chiapas and Yucatan. All three books became immediate bestsellers.

Frederick Catherwood’s 1840 lithograph of the central plaza in Quetzaltenango, Guatemala. 

The three books introduced the Mayan civilization to the rest of the world for the first time, bringing new visitors to the region. Some came to do serious research. Others were just curious adventurers. But the numbers that came were small as only a few wealthy people had the time and money to journey to exotic places.

Then the 1960s brought a new kind of tourist – the hippie. Many young people in Europe and North America saw flaws in the materialism of their own societies and became interested in experiencing non-western cultures. The Mayan region of Guatemala was a perfect destination. It was exotic, relatively easy to get to, and cheap.

That qualification of cheap was especially important. The hippies weren’t big spenders staying in classy hotels and eating at pricey restaurants. They found rooms in basic hospedajes and ate everyday local food cooked by indigenous women at roadside comedores. In many ways that was better. The money went directly to local working people instead of to the wealthy owners of fancy establishments.

The 1960s and 1970s became the era of hippie tourism in Guatemala. Most of visitors went to the area around Lake Atitlán, drawn by the lake’s natural beauty and the region’s year-round springlike climate. The epicenter of it all was the little lakeshore village of Panajachel.

Clouds of War

To anyone wandering the shoreline of Lake Atitlán in the mid-1970s, Guatemala seemed to be a peaceful place. In reality, a guerilla war was raging just a hundred kilometers away. In 1954, a CIA-sponsored coup overthrew Guatemala’s elected government and ushered in a long period of repressive military regimes. With the military showing no signs of relinquishing power, around 1965 a few leftist activists went into the remote mountains of northern Huehuetenango and Quiché departments with hopes of repeating Fidel Castro’s success in Cuba.

By all appearances, this should have been a minor footnote in Guatemala’s history. The would-be revolutionaries, after all, were city people without the skills to survive in the remote mountain highlands. But they recruited a few Mayans to their movement and then a few more until the Mayans dominated the guerilla movement. Yet the Mayans were never guided by ideology. The guerilla movement was a way of fighting back against centuries of repression, discrimination, and poverty. As one observer put it, “They’re Communists because of their stomachs, not because of their heads.”

As the guerilla movement grew the combat zone gradually moved south and into other regions. And the war became less a political revolution than an ethnic conflict. The military was dominated by Spanish-speaking ladinos who knew nothing of Mayan culture or the Mayan languages. All Mayans were seen as potential enemies, as was anyone who attempted to improve the Mayans’ lives. That lead to the formation of military-run death squads which targeted small town mayors, teachers, social workers, church leaders, and anyone else who dared to speak up. By 1981 over two hundred non-combatants were being kidnapped, killed, and dumped by the side of the road every month.

In 1976 the Lake Atitlán region had been seen as a peaceful place. A few years later the combination of active military death squads in the villages along the lake and a widening guerilla war elsewhere had put an end to that image. The era of hippie tourism in Guatemala was over. Continue reading →

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Bob’s Radio Corner: Pairing a Phone or Tablet with a Radio

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Pairing a Phone or Tablet with a Radio

By Bob Colegrove

The Internet is full of resources for radio listeners and hobbyists.  There are numerous examples of general information, frequency, and schedule lists.  There are also WebSDR sites, which allow you to compare reception experiences from around the world.  All of these can be accessed quickly and easily by having them loaded on your phone or tablet operating side-by-side with your radio and having Wi-Fi or cellular access.  We never had any of this when I was starting out.

I realize there are other ways to go about what I have described below, for example, merging station listings with SDR.  This posting is for folks like me who are SDR-challenged.  I listen to plain old radios.  My modern-day experience with newfangled technology has been limited to hitchhiking on WebSDR sites for the last few years.  It has served me well.

Ideally, I would like to generalize this topic to simply cover all phones and tablets.  In truth, my experience has been limited to an iPhone and Kindle Fire tablets.  They have worked very well as I shall explain.  Perhaps you have paired a different phone or tablet with your radio, in which case, feel free to share your experience.

The choice of a phone or tablet is yours.  Either works well.  Your decision will be affected by what you have available and what is easier to use.  If you intend to buy a new device and associate it with your radio, cost will be an additional factor.

A noteworthy device (the one I tend to favor) is a Kindle Fire.  Mainly, they are cheap.  The regular price of a 7-inch model is just under $60 and can often be purchased for less during Black Friday and Prime Day sales.  It is versatile, possessing all the usual functions except for cellular access.  Perhaps most importantly, it is virtually noise-free.  For a while I struggled using Internet sources on a laptop computer.  Even a good one located about 10 feet away from the radio antenna generates noise.  On the other hand, I have taken a 7-inch Kindle Fire in hand and placed it against the resonant coil of a loop antenna.  This abuse generated no more disturbance to the antenna than if it were a block of pinewood.  I have noticed some slight noise from the 11” Kindle when the antenna is exposed this way, but when that tablet is held at arm’s length from the antenna, all is well.  Recently, I have expanded this application to my iPhone and found its noise immunity matches that of the Kindle Fire 7.

Broadcast Schedules

The most useful Internet resources are the broadcast schedules.  These are the comprehensive frequency-time-station listings that tell us where and when to tune.  There are many good ones.  My favorites are the EiBi listing http://www.eibispace.de/, and Dan Ferguson’s https://groups.io/g/swskeds/topics.  For the latter you will need to request membership.  SWskeds merges EiBi, Aoki (https://www1.s2.starcat.ne.jp/ndxc), HFCC (https://new.hfcc.org/index.php), as well as other sources into a single list.

Processing

The EiBi listing comes as a CSV-formatted text file, which can be imported into a spreadsheet. I have done some processing using spreadsheet functions to produce a customized listing.  Processing the frequency-time-station lists is most conveniently done using a computer rather than the phone or tablet.   Processing includes selecting, arranging, or filtering the downloaded data tailored to your needs.  This might include adding a filterable column to indicate only stations that are on at the current time.  Some users might favor filtering by country or station. The heavy lifting processing is done automatically whenever a new listing is published by simply dropping the new file into the existing spreadsheet.  No, the functionality of a spreadsheet and ease of editing are not as good on a tablet as with the mouse and keyboard of a computer.  My processing on the computer includes measures to optimized the screen view to the most essential information thus minimizing the amount of scrolling on the tablet.

After the files are downloaded and processed, they can be loaded on the phone or tablet in a couple of different ways.  They can be directly transferred over a USB cable, or they can be transferred using a cloud server.  The USB cable-transfer method may be difficult on some devices, particularly iPhones.  The Kindle seems to be the more convenient device.  Being an obedient Microsoft customer, I can also transfer the files from my computer to OneDrive, then pick them up on the Kindle or iPhone using the OneDrive and Microsoft 365 apps which are available for both phone and tablet.

Examples

The screenshot below shows an EiBi example at 0014 UTC.  Although the “ON” column filter is set to show only transmissions currently “ON,” it had not been manually updated on the Kindle for a couple hours and thus includes listings from a previous time.  The EiBi database does not include transmitter power or beam information.  However, the identification of countries and transmitter sites is extensive.  These are determined by downloading and printing the README.TXT file on the EiBi site.

The SWSkeds listing is available in both CSV and Excel formats.  It contains several additional data fields, very importantly including transmitter power and beam direction when available.  For this list, I make the simple conversion of the existing Excel data range tab, “COMBINED” to a table so I can easily apply filters.  The screenshot below shows an example at 1750 UTC with the “ON” column filtered to “ON.”

Not to be left out, the complete medium wave broadcast station list for Region 2, the Americas, is easily downloadable at https://www.fcc.gov/media/radio/am-query.  The entire database is formidable and contains nearly 600 pages in a printable format.  Much of this bulk is due to the doubled size necessitated by giving both daytime and nighttime power separate entries for each station.  A number of marginally useful data columns can be eliminated in spreadsheet processing.  I have added formulas to calculate the azimuth heading and distance from my listening post (blanked out in the example below).

A variation of the downloadable file format is the direct-query site, SHORT.WAVE.INFO.  Here you can simply enter queries by station, language, frequency, or band, and produce listings which match your criteria.  Any listings which are currently on the air will be highlighted in red.

WebSDR

Finally, I would like to mention the WebSDR sites.  While not used explicitly for broadcast schedules, these sites are great for anyone wanting to compare how well they are receiving signals relative to what others are experiencing.  Granted, location and time of day are big factors that affect reception, but it is still useful to make these relative comparisons.

Home base is http://websdr.org/ which presents a catalog of many WebSDR sites by location.  At the bottom of the page is a world map which pinpoints the location of each site.  Most of these sites cater exclusively to hams; however, The University of Twente, Enschede, Netherlands (http://websdr.ewi.utwente.nl:8901/) covers 0.000 to 29.160 MHz unabridged.  The screenshot below shows the tablet/phone version of the U. of Twente site.  There are also two sites on the US East Coast which cover some non-hamband portions of the SW spectrum:  http://na5b.com:8901/ in the Washington, DC area and http://websdr.k3fef.com:8901/ in Milford, Pennsylvania.  The SHORT.WAVE.INFO and WebSDR sites can be directly accessed and queried over the tablet’s browser and a Wi-Fi or cellular connection.

Using the System

In my relentless pursuit to log the Nibi-Nibi Islands, I will load up one of the frequency-time-station listings and start my DX session.  This typically includes a scan of a particular band, checking signals I can receive against the lists.  If my interest peaks on a particular catch (usually a weak one), I will switch the tablet over to a WebSDR site to see how it is being received in Europe or along the East Coast of NA.

In summary, ready access to these Internet resources using a phone or tablet next to the radio has notable advantages:

  • The frequency-time-station listings provide quick, reliable signal identification in most cases.
  • The WebSDR sites confirm that my antennas are doing their job.

Am I done?  I hesitate to stop here.  The process of discovery is a marvelous human experience.  The foregoing are merely starting points.  Other applications might include sunrise-sunset calendars or maps or propagation forecasts.  There are certainly other ways to do all this depending on your druthers.  I know I am erring by omission and neglecting many other good resources.  Let’s hear about yours.

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Don Moore’s Photo Album:  Guatemala (Part Three)- Guatemala City Continued

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Many thanks to SWLing Post contributor Don Moore–noted author, traveler, and DXer–for the latest installment of his Photo Album guest post series:

Photo Source: Dennis Sylvester Hurd via Wikimedia Commons

Don Moore’s Photo Album:
Guatemala (Part Three) – Guatemala City continued

by Don Moore

More of Don’s traveling DX stories can be found in his book Tales of a Vagabond DXer [SWLing Post affiliate link]. If you’ve already read his book and enjoyed it, do Don a favor and leave a review on Amazon.

When I started DXing in 1971, and for several decades afterwards, the most widely logged Guatemalan shortwave station by DXers was Radio Cultural on 3300 kHz. It was also known as TGNA, the call letters of that 90-meter-band frequency. The medium wave outlet on 730 kHz was TGN. The station also used 5955 kHz and 9505 kHz, but those frequencies were always harder to hear because of interference from more powerful international broadcasters.

Back then this Evangelical broadcaster was owned and operated by the Central American Mission of Dallas, Texas, but only received a portion of its funding from the CAM. Additional funding came from local donations in Guatemala and another important source was selling time to American Evangelical preachers to air their prerecorded English language religious programs. These programs were broadcast late at night, when propagation into North America and Europe was best, and were always preceded by an English station identification. That made it an easier log for DXers who didn’t understand Spanish.

TGNA was the station I most wanted to visit when I arrived in Guatemala City in June 1983. But Guatemala DX Club members informed me that the station had been temporarily closed down because of “philosophical disagreements” with the government. They were off the air and would remain so for several weeks. I made four more visits to Guatemala City over the next year but somehow never found the time to visit the station. It wasn’t until my visit in December 1987 that I finally stepped inside their front door. That visit became the subject of the first article I wrote for Monitoring Times magazine in June 1988.

Wayne Berger, station manager and chief engineer, and missionary Bob Rice gave us a very long tour of the station. Wayne and Bob had built or rebuilt most of the station’s technical equipment and even some of the infrastructure. On the day we arrived they were welding a broken door back on its hinges. Wayne had built the 3300 kHz transmitter, shown in the next picture, out of spare parts.

Main studio control room at TGNA in 1987.

At the time of my visit, TGNA had two pennants. The larger one was mostly reserved for local listeners. The smaller one was sometimes included with QSLs to lucky DXers.

But neither of those compared with these traditional handmade weavings given by listeners for the station’s 37th anniversary in August, 1987. (I just wish my color photos had survived.)

English ID from Radio Cultural, 3300 kHz, as heard in Pennsylvania 23 November 1979 at 0427 UTC:

Audio Player

Radio Cultural, 3300 kHz, as heard in Michigan 23 March 1989 at 1101 UTC:

Audio Player

Easter in Guatemala

Of all the things I’ve seen in my travels, the Easter processions of Guatemala certainly rank near the top. I am fortunate to have been in Guatemala twice for the holiday, in 1982 and 1984, and I plan a return trip in the next few years. Processions take place all over Guatemala during Easter week, but the most elaborate take place on Easter Thursday and Good Friday in Guatemala City and, especially, in Antigua, the old capital twenty kilometers to the west. There are several processions both days in each city and each procession takes several hours. Continue reading →

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Carlos Visits the Studios of UFRGS Radio

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Visiting the studios of the University Radio of Rio Grande do Sul, Porto Alegre, Brazil

by Carlos Latuff

On the morning of Thursday, February 27, 2025, I visited the studios of the radio station of the Federal University of Rio Grande do Sul (UFRGS in Portuguese) in Porto Alegre, Brazil. Founded in 1950, it’s the first broadcaster in Brazil operated by a university, which currently broadcasts on medium wave (AM) and over the Internet (streaming): https://www.ufrgs.br/radio/ao-vivo/

Headquarters of the UFRGS radio studios in Porto Alegre, Brazil.

The programming focuses mainly on classical music, but it also has programs of other musical styles. Despite the technical, bureaucratic and financial difficulties (a typical scenario of state radio stations in Brazil), the UFRGS Radio has been operating thanks to the efforts of its team. One of the things that catches my attention at this station is the news bulletin, broadcast on weekdays at 12:00 p.m. local time, presented by Mrs. Claudia Rocca.

News bulletin from UFRGS Radio, voiced by Mrs. Cláudia Rocca.

The bulletin is 10 minutes long and brings local, national and international news, some of which are suitable for my already traditional illustrated radio listening.

According to the station’s director, Mr. Claudio Roberto Dornelles Remião, the UFRGS radio station, like most AM radio stations in Brazil, will migrate to FM, but there’s still no set deadline.

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Beyond DXing: Analyzing Medium Wave Propagation During the 2023 Annular Eclipse

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The following article dives into medium wave (MW) radio propagation during the 2023 annular solar eclipse, building upon insights from the 2017 total solar eclipse when DXers made broadband radio recordings of the whole MW band for the first time. Unlike that previous study, the 2023 research took a methodical approach, with standardized data collection, stable receivers, and GPS-synchronized frequency locking. Thirteen radio enthusiasts across North America and Europe contributed to the study, capturing 10 Terabytes of SDR data. Using Carrier Sleuth software, researchers pinpointed key signal strength variations, with some regions experiencing remarkable boosts in signal during the eclipse. These findings highlight how eclipse-induced propagation effects are not the same as those seen during typical sunrise and sunset transitions. The study opens doors for further exploration into whether these effects are symmetrical and how they might relate to ionospheric thinning along specific signal paths.  The article ends by asking assistance from DXers to help ID enhanced signals in the 2023 eclipse data sets.  

Medium Wave Monitoring During the 2023 Annular Solar Eclipse—Not Just About DXing

By Nick Hall-Patch, VE7DXR

Background        

The 14 October 2023 annular solar eclipse was the first one to cross the continental United States since the total eclipse of 17 August 2017. From a DXing standpoint, 2017 was the first eclipse in which there was widespread use of software defined radios (SDRs) to record the entire medium wave (MW) band throughout the duration of the eclipse.  Therefore, it was possible to study eclipse receptions after the fact rather more than had been the case during earlier ones. Several IRCA members recorded the 2017 eclipse on their SDRs, and in the months after the eclipse, data files from several locations were examined. It was therefore possible to evaluate the varying signal strength of KSL-1160’s carrier from four different locations in western America, all from outside the path of totality, and to speculate upon the differences in the responses at each site.

That study of KSL’s strength variations during the eclipse led to a presentation at the St. Louis IRCA/NRC convention in 2018, and eventually to an IRCA Technical column (now IRCA Reprint G-096 at  http://dxer.ca/images/stories/2019/irca-reprint-index.pdf) which proved to be of interest to HamSCI, an amateur radio citizen science group that had already been using amateur radio communications as a way to study that eclipse’s effects upon the ionosphere. A version of the article appeared on HamSCI’s website and the SDR files referenced by the article were also hosted by the HamSCI community on zenodo.org, along with SDR data from three further locations in eastern America. (Go to zenodo.org, and search on the phrase “Solar Eclipse 2017 recordings” to examine this data for yourself.)   Zenodo is a long-term open repository for scholarly work, and these data sets have since been downloaded hundreds of times.

Why would these 2017 SDR files have been of interest to an organization studying radio wave propagation?  Unlike the short duration communications found on the amateur radio bands, medium wave (MW) AM broadcasters, assigned between 525 and 1705kHz, provide continuous signals, many for 24 hours a day. Their carrier frequencies are like steady RF beacons.  Any changes in that beacon’s amplitude or frequency at a receiver are likely to have been caused by changes in the path between transmitter and receiver. By using suitable hardware and software, either monitoring a single frequency or the entire medium wave broadcast band using SDRs, the resulting files can allow us to characterize the propagation induced changes that these carriers undergo over time, including variations in signal strength and apparent shifts or spreading in the frequency of each carrier.   During a solar eclipse, the brief period of darkness along the path of the eclipse can allow AM broadcasters’ signals to temporarily travel much further than they would normally in the daytime, and it is possible to study variations that occur even more quickly than those occurring daily during sunrise and sunset.

Preparation for the 2023 Solar Eclipse

From a DXing standpoint, the 2017 eclipse SDR files were more than functional, but a closer examination revealed gaps in the data, changes of antennas when it suited the DXer, and receivers that had not been properly warmed up, resulting in recorded carriers that appeared to be drifting.  From the standpoint of a scientist, this was “found data” requiring judicious handling and compensation.  In addition, the data had been transferred many months after the recording had taken place, and sometimes it was no longer clear how the receivers and antennas had been set up for the recording.

Nearly a year before the 2023 eclipse, HamSCI had decided that it would be interested in examining more MW SDR data, but this time asking that the recording of the data be approached in a more professional fashion.  In other words, participating DXers would be asked to think a bit more like scientists for the duration of the recordings.  Making recorded IQ files of optimum use to propagation researchers would include the following:

  • Documenting receiver, software and antenna used, with as many details as possible.
  • Not making changes in receiver or antenna configuration during the recording period; if absolutely necessary, recording that change in detail, especially the time that it occurred.
  • Warming up the receiver for several hours before recording in order to minimize apparent carrier drift in recorded signals.  Better yet, encouraging participants to use SDRs that were locked to a frequency standard such as the Bodnar GPS reference clock, because a frequency locked SDR’s data would display frequencies with stability and accuracy, and allow characterization of any carrier Doppler shifts.
  • Making sure that timestamps in their recorded data were as accurate as possible, at a minimum setting the computer clock accurately immediately before recording, and preferably to use a network time protocol (NTP) time client on the computer that would be recording the SDR IQ files.
  • Starting recording well before maximum totality in their area, until well after that time; one hour before the start of the partial eclipse to one hour after the end of the partial eclipse were suggested as a minimum.
  • If possible, making additional SDR recordings of, for example, the period from two hours before and after sunset and sunrise on the day of the eclipse, and also making a reference recording of the eclipse time period on another day.

Figure 1 shows the path of the 2023 eclipse and the times of maximum obscuration.  Efforts were made to involve monitors in both North and South America, and in the end, 13 participants were involved in the experiment, using 14 sites in Canada, the USA, Mexico and Portugal.

Figure 1

  • 12 sites also included data from local sunrise (LSR) and/or local sunset (LSS)
  • 12 sites also recorded data from the same time as the eclipse period on another date in order to provide a reference of a normal day’s reception conditions
  • 6 sites produced data using an SDR locked to a frequency standard that was disciplined using GPS signals. Three of the remaining sites included a signal from a frequency standard in their data recording.
  • 10 sites recorded using computers that had their clocks updated using Network Time Protocol (NTP); others set computer time manually

About 10 Terabytes of SDR recordings were submitted for analysis, which is one heck of a lot to poke through in order to find signals fading up and down for a few minutes during the course of the eclipse. Fortunately, it was possible to pre-process all of the files using Carrier Sleuth software which allowed visualization of hours of data at a time from each MW channel, all available to 0.1Hz resolution over an 80Hz span centered on each broadcast channel.  It was then a fairly quick process to scan through each of the 117 channels of the AM broadcast band for each data set, searching for unusual carrier enhancements appearing during the eclipse time period.

An example is shown in Figure 2, portraying 1650 kHz as logged during eclipse enhancement in Phoenix, AZ by Burke Baumann KF7NP. The thin lines representing various carriers are represented in “hotter” colors when signal strength increases.

Figure 2

Because Carrier Sleuth can rapidly generate a chart for signal strength vs. time for each individual carrier, it was decided arbitrarily that a carrier that increased in strength by at least 10dB during the duration of the eclipse at that site would be deemed to have been influenced by the passage of the moon’s shadow.  By that metric, six sites indeed reported that during the eclipse, different broadcast signals appeared from those normally received in the daytime.  However, other sites did not, or received only a few traces of carriers during the eclipse period.

Figure 3 shows the various sites that submitted SDR data, indicated by pale blue circles, and within each circle is the number of AM broadcast band channels on which eclipse effects were noted, even if it was just a carrier.

Figure 3

From Figure 3, it can be seen that locations in Canada’s west and in the south and west of the USA were likely to have been influenced most by the passage of the eclipse. In contrast, it appears that those who were in locations of less than 50% of totality were unlikely to have seen much effect from the passage of the eclipse. Continue reading →

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Carlos’ Illustrated Radio Listening Report and Recording of Radio 2 (February 19, 2025)

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Many thanks to SWLing Post contributor and noted political cartoonist, Carlos Latuff, who shares illustrated radio listening report of a recent Radio 2 broadcast.

Carlos notes:

Trump designates Mexican cartels as terrorists, Radio 2, Rosario, Argentina, 1230 kHz AM.

Click here to view on YouTube.

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