Tag Archives: Mediumwave

Bob’s Radio Corner: Where it Began – The AM Medium Wave Broadcast Band

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Copilot Radio, Model Unknown
The dial certainly has some problems, but the rich, Bakelite, art deco cabinet is superb.

By Bob Colegrove

One of the great attractions of the radio hobby is that it has so many different areas on which to specialize.  As examples, one can focus on a particular band, collect or restore radios, DX or just listen.  With so much to choose from, one can impulsively skip from one area to another.  I have tuned the shortwave bands for many years, but I also like the AM medium wave band.  If there is a purpose to this post, it is simply to bring some occasional attention to AM listening and DXing.  There is nothing new in what follows.

What’s in a Name?

To start with, this subject is somewhat confusing by calling it what we do.  There are at least three common terms for the electromagnetic spectrum between 530 kHz and 1700 kHz: 1) AM, 2) broadcast band, and 3) medium wave.  This poses an identity dilemma; that is, none of these names are exclusive.  AM defines a form of modulation, amplitude modulation, which is used in other portions of the spectrum.  The same may be said of broadcast band.  There are several international broadcast bands within the shortwave spectrum.  That leaves us with medium wave.  But that term lacks precision.  What exactly are the boundaries of medium wave?  Shortwave bands have relatively precise names related to their wavelength, 80 meters, 31 meters, etc.  Should we call medium wave the 176-thru-943-meter band, instead?  Let’s just stick with any of the old familiar terms.

In the Beginning

I’m sure many readers share the experience related here.  Even before shortwave there was medium wave.  Our initial encounter may have been with the monolithic, multi-band console radio in the parlor.  However, the house was likely home to one or more less pretentious table radios, which were limited to the medium wave broadcast band.  It all began with curiosity about what lurked in the relative space between the few local stations that played so clearly along the dial.  We likely found less listenable stations poking through in the inter-station space.  These were stations like our own in neighboring communities.  Then, at night, a strange thing happened.  Like stars in the sky, more stations appeared, some hundreds of miles away.  At the same time, some of the stations we heard during the day disappeared, maybe even a local station or two.

Well, one thing led to another, and soon we were keeping track of stations that we heard.  We took note of where they were located and their position on the dial using a new term called kilocycles.  The fastidious among us kept daily logs with dates, times, and reception conditions.  So, our DXing career began.

I came along a full generation after the advent of AM radio broadcasting.  In my early years, it was still the mainstay of public information and entertainment.  Television stations were beginning to pop up across the country one by one, and FM radio’s popularity was still a decade away.  Like any imposing distraction, there was curiosity in what was being heard and, in the case of radio, where it was coming from.

Our house was home to perhaps three or four AM radios.  At the age of seven, I was gifted of a 4-tube Sears Silvertone – mine to keep in my own room.  But the radio that really got me going came along several years later and belonged to my father.  This was a General Electric Model P755A, five-transistor portable.  Shaped somewhat like a lunchbox, including the handle, it was the quintessential portable radio that the world had been waiting for.  It ran for many hours off a single, but pricey 9-volt carbon-zinc battery.  There was purposely no provision to run it from AC power.  Also, it used an internal ferrite core antenna.  There was no jack or terminal for an external antenna.  Besides the tuning knob and volume control, it had a jack for a single earplug.  It was truly portable in all respects.  For all its simplicity, it did its job very well, and I borrowed it whenever the occasion presented itself.

Left: Silvertone Model 132.818-1, Sears, Roebuck & Co (1949, $11.95)
Right: General Electric Model P755A Transistor Portable (1957, $19.95)

As an only child, I was the sole recipient of any goodies that came along, and it wasn’t too long before I had my own comparable Westinghouse portable.  But the GE was really the one that got things started.

A Plethora of Stations

I have recently wondered whether shortwave use has contracted about as far as it can go.  This is not the case with AM, at least not yet.  The graph below shows the total number of AM radio stations in the US throughout history, 100 years.  The total has remained relatively stable since 1960, albeit with a slight downward trend from the peak around 1990.  Stations occasionally come and go.  Some rebrand with a different format or fresh call letters.  Note that the steepest rate of decline, 217 stations, occurred over the past five years, amounting to 4.7%.  Whether this rate of attrition will continue is a matter of speculation.

Medium wave DXing is a lot different than shortwave.  The density of stations will vary depending on what part of the world you live in.  Here on the East Coast of North America, the AM band is saturated with signals.  That is, with a suitable antenna, one can at least detect a station on each of the 118 available channels – certainly at night and possibly even during the day.  On the other hand, some years ago, I had an opportunity to visit Honolulu, Hawaii.  With little time to listen, I only heard a few of the islands’ stations but imagined what possibilities nighttime Dxing held.

Despite the density of stations on the East Coast, there will still be limits on the number of stations logged.  My experience is that initially the log grows quickly, then tapers off steadily as you go along.  Your time is eventually spent locked in on a local or regional frequency, waiting for something you’ve heard to fade out and something you haven’t heard to fade in.  In a previous posting, I worked the lower end of the band rigorously for some time, coming up with a fair number of catches.

Ten-kHz channel separation is the convention in Region 2, the Americas.  There have been some occasional anomalies.  Several years ago, there was a handful of so-called “split-channel” nonconformists, who placed their carriers midway between channels and presented an opportunity to log some hard-to-hear countries.  It was also possible to pull in a few very high-power European and North African stations.  This took advantage of the 9 kHz vs. 10 kHz channel spacings between Region 1 (east) and Region 2 (west).

Seasonal changes are also important.  Winter is the best.  Propagation is generally better and more consistent.  Atmospheric noise is minimal.  Local stations limited to daylight operation have shorter hours.  The gray hours around sunup and sundown can produce unusual DX conditions.

Programming

Programming has changed since the 1950s.  As the go-to medium for public information and entertainment, content was original and competitive.  Mornings were often filled with local DJs playing occasional songs and generally keeping listeners apprised of news and weather.  Traffic helicopters were still in the future.  The genre of soap operas was born and consisted of 15-minute, serialized dramas one after the other during the middle of the day.  Faithful audiences followed these melodramas for many years.  DJs took over the airwaves again in mid-afternoon and continued through dinner time.  Prime time lasted throughout the evening hours with regular drama, comedy and variety shows which were networked throughout the country. Continue reading →

Check Your Time with the LM Chime

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by Dan Greenall

Shades of the 1970’s.  Commercial AM radio (in English) the way it used to be. Heavy on nostalgic music from the 1960’s to the 1990’s, plenty of good old style jingles, and of course, the LM chime every hour.

Decades ago, the “LM” used to stand for Lourenco Marques Radio as the station was based in this city in Mozambique. Today, it is Lifetime Memories Radio, and broadcasts to Maputo and the surrounding area, where it can be heard on 87.8 FM. The station also broadcasts on 702 kHz medium wave from a transmitter near Johannesburg, South Africa, and can be heard worldwide via Kiwi SDR or online stream here   https://lmradio.co.za/

In addition to the live stream, be sure to read about the rich history of the station that began in 1936. The station was shut down in 1975 when Mozambique gained independence, but has re-emerged in the 21st century.  A visit to the LM Radio museum is well worth the trip.  https://lmradio.co.mz/history/

In 1973, I was able to hear Radio Clube de Mocambique on 4855 kHz shortwave from here in Canada.  If you listen closely, you can hear the LM chime.

Give them a listen, but first, check out these sample recordings made between November 27 and December 8, 2025, through a Kiwi SDR located near Johannesburg:

2025-11-27:

2025-11-28:

2025-11-28:

2025-11-29:

2025-12-04:

2025-12-08:

Paul Reviews the Radtel RT-880G

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by Paul Jamet

Looking for a versatile radio?

Which radio listener hasn’t dreamed of owning a portable multi-band receiver allowing them to explore the widest possible radio spectrum?

For nearly a year now, walkie-talkies have appeared on the market which, beyond the classic VHF–UHF functions, also allow listening and transmitting on CB (27 MHz) as well as listening to LW/MW/SW bands (LSB/USB/CW). The RADTEL RT-860 has won over those who have tested it.

Read here: Dan Reviews the Radel RT-860

The arrival of the Quansheng TK-11 — available in three versions — has caused quite a stir on social networks. Then, almost at the same time, the RADTEL RT-880 and RT-880G (G for GPS) appeared, also sold under other names such as iRadio UV98.

Among all these available models, I chose — as a radio listener, especially when I’m traveling — the RADTEL RT-880G. My choice is explained mainly by its antenna connectors (SMA-Female and SMA-Male), its large color display, its GPS module, its thousand memory channels, and the possibility of simultaneously monitoring three VHF/UHF frequencies. This device is highly customizable, but its user manual would deserve to be much more detailed and explicit.

The RT-880G comes with a “standard” 18 cm antenna for VHF-UHF bands, which is also used for FM station reception. I haven’t yet tested the device on the 27 MHz (CB) band, for which a dedicated antenna is preferable. No antenna is provided for LW/MW/SW listening.

For listening to LW/MW/SW bands, the device is often shown with small donut-type loop antennas (10 cm diameter).

However, for easier transport, I simply chose this small telescopic SMA-Male antenna, 48 cm long (weight: 20 g): to which it is possible to clip a wire antenna, such as the SONY AN-71, which can prove very useful.

I also used an antenna normally intended for CB, the ABBREE 27 MHz telescopic antenna (130 cm), admittedly heavier (weight: 78 g) and bulkier, but which gives very good results for the HF band.

The purpose of this contribution — which concerns only listening — is to arouse curiosity among mobile (or stationary) listeners, to invite those who own this walkie-talkie to come here and share their experience, and to collect your comments. It is therefore not a full review of the RT-880G, but simply an illustration of what it offers for listening to LW/MW/SW bands.

For LW/MW/SW bands, the RT-880G allows you to set the:

  • step to 1 – 5 – 10 – 50 – 100 – 500 – 1,000 – and 9 kHz],
  • bandwidth [0.5 – 1.0 – 1.2 – 2.2 – 3.0 – 4.0],
  • AGC (Automatic Gain Control)
  • BFO – (Beat Frequency Oscillator) – used for fine tuning SSB reception (the minimum step being 1 kHz).

Sample Recordings

Local park where some of the recordings were made.

Here are a few audio files that will help you form an opinion.  The recordings were made with a smartphone placed near the receiver.  The recordings were made using a smartphone placed near the receiver. The sound quality is quite good, even surprising. Continue reading →

Preserving Radio History in Your Community

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Many thanks to SWLing Post contributor Dan Greenall, who writes:

I have lived in southern Ontario, Canada my entire life, have been DXing since the late 1960’s and have held the amateur radio call sign VE3HLC for over 50 years.  Most of this area’s AM broadcast stations had been considered “pests” over the years as I searched for more distant targets, until recently, when many of these began quietly slipping from the airwaves.  While this opened up some new frequencies to DX, I soon began to feel that I had lost some old friends, many that I had known since childhood.

When I retired in 2018, I decided to spend a little time trying to preserve some radio history of stations in southern Ontario communities that have played a part in my life. This might include audio clips, QSLs, station booklets, and other types of ephemera, and I would try to place this information where it could be easily accessed by future historians or anyone else who is interested.  In the end, I chose to use the Internet Archive (archive.org), where most uploaded information can be viewed (or heard) and downloaded for free.

CFPL, London, Ontario   980 kHz (still on the air)

“Communications in the Community” is a hardcover limited edition (2000 copies) souvenir book printed in 1966 by the Special Printing Unit of The London Free Press in London, Ontario, Canada.  It includes historical information about the London Free Press (newspaper) and CFPL radio and television.  I was lucky to find this item at a church rummage sale nearly 20 years ago.

CFPL began its life as CJGC in 1922. I acquired one of their QSL cards from 1925 through an eBay purchase a few years ago.

The above and more can be found by clicking on this link.

https://archive.org/details/page-16

CKOC, Hamilton, Ontario 1150 kHz (still on the air)

CKOC radio in Hamilton also started up in 1922.  My parents met while working at the station in the late 1940’s.  My brother and I (both radio amateurs), along with a few friends were given permission to operate on “Field Day” weekend in 1985 from their old abandoned transmitter site at Elfrida, Ontario.

This area has long since been developed to build homes and shopping areas.

“This is Hamilton, Ontario and the story of broadcasting station CKOC” is an undated booklet (I am guessing circa 1950) that I was able to purchase on eBay.  Also found on eBay were two verifications, one from 1931 and the other from 1983.

You can find these scans and more by following this link.

https://archive.org/details/page-13_202209

CKNX, Wingham, Ontario 920 kHz (still on the air)

This station began in 1926 using the unusual call sign 10BP.  It would remain that way until 1935.  I managed to secure this QSL from 1932 through eBay, signed by its founder W.T. “Doc” Cruickshank.

Interesting stories of how the station began can be found at this link.

https://www.communitystories.ca/v1/pm_v2.php?id=story_line&lg=English&fl=0&ex=386&sl=2541&pos=1&pf=1

CKCR, Kitchener-Waterloo, Ontario 1510 kHz  (no longer on the air)

In 1924, this station began briefly in nearby Brantford, Ontario. It quickly moved to Kitchener-Waterloo and existed until 1965 when it became CKGL.  The CKCR call sign was picked up later in 1965 by a station in Revelstoke, BC.

Another eBay purchase, I found this QSL with a not-to-scale map of southern Ontario from 1934.

More Ontario QSL’s can be found in my broadcast band gallery at this link: https://archive.org/details/ckoc-hamilton-on-1983

I would encourage others to save parts of the local radio history in their city, state, province or country and give back to the hobby that we have enjoyed for so many years.   I would also be happy to hear about any efforts you have made!

Giuseppe’s Ingenious Recycled Antenna Board for SW & MW Listening

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Screenshot

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

Dear Thomas,

I’m Giuseppe Morlè, IZ0GZW, from Formia, in central Italy on the Tyrrhenian Sea.

I’d like to show you my antenna board for shortwave and mediumwave listening with portable receivers like the Tecsun PL-660.

The board has two distinct circuits:

      • A small-diameter loop with two turns for shortwave reception (3.5–18 MHz).
      • Three ferrite rods with 30 turns each, plus a four-turn link coil that carries the signal to the receiver for mediumwave reception.

In the video, you’ll see how the board works on its own, and then how performance improves when I connect a 15-meter wire and throw it over the balcony of my house. In that case, the signal becomes much stronger.

Tuning is done with a 900 pF variable capacitor. To listen to mediumwave, I simply disconnect one side of the shortwave loop. With just that single variable capacitor, I can tune all of the bands.

It’s a surprisingly effective antenna for small portable receivers, and it’s built entirely from recycled materials—at no cost.

I hope you enjoy it. Greetings to all the friends of the SWLing Post.

73, Giuseppe Morlè, IZ0GZW

Click here to view on YouTube.

Many thanks, Giuseppe, for once again sharing your creativity with us. I’m always impressed by the antennas you design and by the performance you achieve—especially considering they’re largely homebrewed from recycled parts. That’s radio at its very best!

[Note that his video is in Italian, but you can turn on subtitles for your preferred language.]

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:

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.