Category Archives: FM

Blackout in Chile: A Reminder of Radio’s Role When All Else Fails

Many thanks to SWling Post contributor Carlos Latuff, who writes:

Good morning, Thomas. I just translated this article from Chilean radio station “Canal 95”, published on February 26. Original in Spanish here: https://www.canal95.cl/magazine/apagon-redes-sociales-rinden-tributo-radio-pila

After the blackout, social media pays tribute to battery-operated radios

Social media users highlighted the importance of battery-operated radios as the only reliable source of information in emergencies, while critics pointed to the fragility of the current system.

After a large blackout left much of Chile without electricity last Tuesday, millions of people were affected and left without communication. All due the fact that the telecommunications and internet antennas service completely collapsed.

In this scenario, and in the absence of real-time information, social media users began to highlight the importance of having battery-powered radios to access news in emergencies such as, for example, the decision to declare a curfew.

“Will we have to go back to copper wire telephones? Cell phones ‘died’ in the emergency. Explanations are useless in the face of a serious incident. Earthquake, tsunami, flood, or power outage like yesterday. Totally incommunicado. Only the battery-operated radio worked ,” remarked the renowned journalist and radio personality, Sergio Campos.

Many also recalled that this device has been key during earthquakes and other disasters in the country, although there was no shortage of jokes.

“Serious question: does everyone really have a battery-operated radio?” asked one user of the X platform. “It’s always good to have one. My mother-in-law has one and it’s super old, but it works. And the radio too,” joked comedian Luis Slimming.

Although some users admitted not having a functional radio at home, implying that they had not previously considered it necessary due to the outdated technology, other users reinforced the importance of having one of these reliable devices that allow them to stay in touch.

The work of radio stations that continued to operate during the emergency was also highlighted. There was no shortage of criticism of telephone companies and the widespread use of smartphones that do not have integrated FM radio.

“I want to give a round of applause to Chilean radio stations. We would still be going around in circles if it weren’t for the fact that they continued to broadcast and report on what was happening. Every Chilean home should have a battery-operated radio ,” wrote @satoruswft .

It remains to be noted that Chile has historically faced natural events that disrupt basic services, but the current dependence on the Internet and cell phones has created a gap in preparation for blackouts.

So, keep this in mind: a battery-powered radio is still a must-have in an emergency.

RFI, FM Habits, and Jeff’s Tabletop Radio Temptation

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Many thanks to SWLing Post contributor Jeff McMahon for sharing a recent Herculodge post, where he battles radio frequency interference (RFI) while trying to enjoy his Tecsun PL-990—only to find his PL-880 unaffected. This led to a deeper reflection on FM listening habits and the temptation of tabletop radios like the Sangean HDR-18 and HDR-19. But with RFI always a threat, is a new radio the solution or just another problem in disguise?

Read Jeff’s full post here.

Dan Reviews the Radel RT-860

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Many thanks to SWLing Post contributor, Dan Van Hoy, who writes:

Because I [purchased a RT-470L last year], Radtel sent me news of their brand new RT-860. No need to mod the radio like a Quangsheng. It does LW/MW/SW with SSB/CW (rx only, of course) out of the box for less than $50! I just posted a short preliminary review of the RT-860 on YouTube:

Click here to view on YouTube.

Unlocking Rare DX Treasures with SDR-Console’s Powerful Data File Analyzer Tool

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Finding Rare DX with the Data File Analyzer

By Don Moore

Don’s DX traveling stories can be found in his book Tales of a Vagabond DXer.

I’ve been a real jack-of-all-trades in my over five decades of DXing. I began with SWBC (shortwave broadcast) but soon branched out to medium wave and voice utility. Later I added longwave beacons and more recently I’ve gotten into digital utility stations. My goal has always been to log lots of different stations from lots of different places. And the rarer they are, the better.

For SWBC and medium wave stations, as well as scheduled utility broadcasts such as marine and aeronautical weather reports, the DXing process is simple. You tune to a frequency at a time when a station is scheduled to be on the air. It’s either there or it’s not there. If it’s not there then maybe propagation isn’t right or maybe your antenna/receiver setup isn’t the best for that frequency band or the station’s power level. You tune away to find something else with plans to try again another day.

But it’s not always that easy. Most utility stations do not have fixed schedules and only come on as needed. The best example of that is two-way marine, aeronautical, and military voice communications.

In eastern North America, tune to 8906 kHz anytime from late afternoon until morning and set your receiver to USB mode. You’ll probably hear empty static at first but it’s unlikely that more than ten or fifteen minutes will pass before you’ve heard some aeronautical traffic. The frequency is assigned for communication on the North Atlantic and is heavily used by aircraft communicating with New York Radio, Gander Radio (Newfoundland, Canada), and Shanwick Radio (Shannon, Ireland). If you keep listening, the frequency will probably be occupied around 25% of the time. Wherever you are in the world, there are a few heavily used air frequencies like 8906 kHz and listening to them can be fascinating. But I want to log more than just a few easily heard stations.

Sticking to aeronautical DX, there are many assigned frequencies for different regions and air routes around the world. But propagation to those distant areas is unpredictable and less-used routes have fewer flights. Fewer flights mean less radio communication and more empty static. The most interesting frequencies may only see traffic a few times a week.

Hearing the rarest voice utility DX requires listening to lots of empty static just to get a brief DX catch. For years my process was simple. I would set my receiver to an interesting frequency and leave the tape recorder running while I sat nearby listening and doing something productive. I got some very good DX over the years that way. But I don’t want to think about how many long hours of empty static I listened to in order to get that DX.

SDRs offered some improvement. Instead of audibly monitoring a specific frequency I could now make a spectrum recording that included a band of interest, say the 8815 to 9040 aeronautical band. During playback I could visually monitor the SDR waterfall for interesting signals. That works. But watching an SDR waterfall scroll by for three or four hours gets tedious quickly.

(When I refer to SDRs, I mean ones consisting of a small box that is connected to and controlled from a computer using a software program. None of this applies to models such as the Malachite line or the Icom IC-R8600, which use SDR technology inside but mostly function as a traditional receiver.)

Finding a Better Way

That better way is, I think, one of the most exciting DX tools out there – the Data File Analyzer in the SDR-Console program. Since I learned about it a few years ago, the Analyzer has gotten me all kinds of catches that I probably wouldn’t have gotten otherwise. Let’s start with an overview and then dig into the how-to.

SDR-Console is one of the better-known SDR programs and it works well with most of the common SDR radios on the market, including the Airspy, Elad, Perseus, and SDR-Play models. Here’s what the main window looks like:

The Data File Analyzer is a second window that produces a scrollable waterfall display for the entire length of an SDR spectrum recording. The display is similar to a standard waterfall with frequencies along the bottom and times along the side. However, there is also a scroll bar on the right side for browsing through the entire length of the recording. Instead of watching a four-hour spectrum recording slowly roll by in real time, I can scroll through the window looking for DX.

And this is what makes the Data Analyzer really useful. When I spot an interesting signal, I click on it and that causes the main window to start playing at that time and frequency. Now going through a four-hour spectrum recording takes from a few minutes to around half an hour, depending on how much DX I find.

Here’s a closeup of part of that same screen of spectrum recording made on 24 October 2024 at a DXpedition in western Pennsylvania, USA.

“A” marks a short exchange between an aircraft and Ndjamena Radio in Chad on 8894 kHz. “B” is Niamey Radio in Niger on 8903 kHz. “C” is Gander Radio on 8891 kHz. Just to the left of that is a string of digital signals. “D” is New York Radio on 8918 kHz. Again, there is a string of digital signals just to the left. Finally, “E” is communication from Dakar Radio in Senegal and Sal Radio in the Cape Verde Islands on 8861 kHz. I caught four African aero stations in just four-and-a-half minutes. I could also show you long stretches of time when there was nothing interesting coming in. With the Data File Analyzer I was able to visually find and focus on the DX and not waste my time with the empty static.

Here’s another image taken at the same DXpedition. Notice the three transmissions between 8820 to 8845 that seem to be mirroring one other.

That turned out to be Flightwatch Brisbane, the Australian regional aeronautical network. It uses multiple transmitter sites on 8822, 8831, and 8843 kHz to cover the entire country. I had never logged it before and I doubt I would have found it if DXing in the traditional manner.

The How-To

Here I’m going to assume that you already have SDR-Console installed and know the basics of how to use it, including making spectrum recordings. (If not, see the links at the end.) This article was written using version 3.4 of SDR-Console. Some of the functionalities described are not in earlier versions, so upgrade if you are not up to date. And I should point out that while you can do this on a single monitor, it works more smoothly if you have a dual monitor setup and can put each window on a different screen. Continue reading →

SBC pulls the plug on FM radio

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Many thanks to SWLing Post contributor, David Iurescia, who shares the following news item via SwissInfo.ch:

Swiss Broadcasting Corporation pulls plug on FM radio (SwissInfo.ch)

The Swiss Broadcasting Corporation (SBC) switched off outdated analogue FM transmitters at 11:59pm on New Year’s Eve.

Connections to around 850 ultra-shortwave transmitters throughout Switzerland have come to an end.

Anyone wishing to continue listening to the radio stations SRF1, SRF2 Kultur und SRF3 in the new year, for example, will have to switch to the digital radio technology DAB+ or Internet radio. All other SBC programmes were previously only available via the Internet or DAB+.

SBC, SWI swissinfo.ch’s parent company, now only needs around 260 antennas for DAB+ broadcasting.

Around two dozen private radio stations in Switzerland will continue to broadcast via FM and will not discontinue the service until the end of 2026 at the latest. [Continue reading…]

Channel 6 FM Radio Stations

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Many thanks to SWLing Post contributor, Bob Colegrove, who shares the following guest post:

Channel 6 Radio Stations

By Bob Colegrove

Even after all these years, I still find occasional surprises while playing with radios. How did I miss this one? I recently did what I thought was a definitive audit of the available FM stations in my area. Then, just the other day I happened to tune down below 88.1 (FM Channel 201). At 87.7 MHz I came across some delightful Latin music in clear stereo and proceeded to park the tuning knob there for a listen. At first, I thought I might simply have some intermodulation from a strong local station, but the stereo signal was much too clear. So, I resorted to the internet to determine what was going on. Turns out, according to their website, I was listening to DC 88.7FM in Fairfax, Virginia – no call letters, just “DC 88.7FM.”

Further investigation indicated that the station is officially WDCN-LD a low-power operator, but you won’t find it listed on the FCC FM Query site. That’s because it is something of a legacy station, a carryover from analog TV days when the audio for Channel 6 was broadcast with the carrier centered on 87.75 MHz, within the range of most FM receivers. Having discovered this, I retuned the radio slightly to 87.75 MHz and found the signal strength peaked. Wikipedia describes the history of WDCN-LD at https://en.wikipedia.org/wiki/WDCN-LD.

Of further interest is the history of so-called “Channel 6 FM radio stations.” The evolution of present-day stations is long and involved. Over several years, the FCC formed committees, requested comments, held hearings, wrote reports, published proposals, rendered rulings, and ultimately granted waivers. For the full story, see https://en.wikipedia.org/wiki/Channel_6_radio_stations_in_the_United_States. What resulted are legacy stations dating back to analog TV days which continue to operate sans video as de facto FM stations. For all practical purposes, we have a modest extension of the FM band. There are, in fact, 14 such stations currently spread across the lower 48 states. It is unlikely that the circumstances which created these stations will ever result in more stations being added. As of July 20, 2023, an FCC report and order restricted these stations to those already licensed and current licenses untransferable.

Do you live near a Channel 6 FM radio station?

Just to complete the picture, there is also officially an FM Channel 200 at 87.9 MHz, which was established in 1978, but to my knowledge is not used. Does anyone have any information on FM Channel 200?

As an historical aside, the present-day FM band, 88 to 108 MHz, is located directly between analog TV Channels 6 and 7. In 1958, to foster FM use, Regency Electronics, Inc. marketed a converter, Model RC-103, in a handsome Bakelite case, which could be attached between the antenna (generally “rabbit ears”) and the TV set. The converter contained a single transistor and was powered by three AA batteries. By tuning the TV to Channel 6, turning on the TeleVerter to FM, and rotating its dial, one effectively detuned the Channel 6 audio frequency upward, and could listen to the entire FM band. As this converter was manufactured prior to the advent of stereo broadcasting, the sound was in mono, and fidelity was limited to the audio quality of the TV. My dad bought one of these. It was connected to our Arvin 12”, B/W tabletop TV, and it served as our first FM radio for a few years. There were only a few stations at that time, mostly classical as I recall. Thus “FM” came to stand for “fine music.”