Category Archives: Mediumwave

Tom’s Recommendations: Earbuds and EQ Settings for Shortwave Listening

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

Earbuds for Shortwave Listening

by TomL

A few years ago I had bought the discontinued Sennheiser MM 50 earbuds for a cheap price on Amazon to use in my various radios. The portable radios in particular can use more fidelity because of their small, raspy speakers. I also like to listen without bothering others around me who might not want to listen. And earbuds are a LOT more comfortable for my ear lobes than any over-the-ear headphones I have ever used. Furthermore, the old Apple iPhone 4 earbuds were very harsh to listen to. However, a trade-off is that, generally, earbuds are somewhat fragile; one of the two pairs of MM50’s died through mishandling.

I was generally happy with them while listening to Shortwave broadcasters with a mix of news/talk and music. I especially liked them on Mediumwave listening; stations can sound surprisingly good when playing music. Then I tried using these earbuds on my Amateur Radio transceiver, a Kenwood TS-590S. I was impressed how clear they sounded with a lack of distortion, although there was too much bass. Fortunately, Kenwood supplies USB connected software with an TX & RX 18 band EQ (300 Hz spacing, not octaves).

Here is a frequency response chart I found from Reviewed.com for this model:

One of the notable things about these earbuds is the total lack of distortion. Most likely one of the reasons they sound so clear on Shortwave, which has many LOUD audio spikes.

I had not wanted to get Bluetooth earbuds. However, I had recently upgraded my cell phone and NO headphone jacks anymore! So, while I do not use Bluetooth yet for radios, I can see a time in the future to get a Bluetooth transmitter to plug into a radio with a headphone jack. I am reluctant since I do not like having to recharge my earbuds and I put in a lot of radio listening time. Am I supposed to buy two Bluetooth earbuds and swap while charging? Maybe in the future. And also, am I supposed to buy a Bluetooth transmitter for every non-Bluetooth radio I own? Not likely gonna happen.

In the meantime, I ordered cheap wired earbuds from Amazon. I had a $5 credit for trying Prime, so when I saw these Panasonic ErgoFit wired earbuds (RP-HJE120-K) for slightly over $10, I said to myself, “why not?”. Supposedly wildly popular, they are one of the most rated products on all of Amazon with 133,821 ratings/opinions (perhaps Russian bots?!?!?).

Here is a frequency response chart from ThePhonograph.com for these Panasonic earbuds:

You can see comparatively that the bass response in the very good Sennheiser MM50’s is much stronger, being good music earbuds. But for voice articulation, not as much, even though they have no distortion. The Panasonic ErgoFit’s have more modest bass, less of a dip in the lower midrange audio frequencies, and more importantly, has a peak near 2500 Hz and its harmonic 5000 Hz. The highest highs are also modest compared to the Sennheiser model. This general frequency response to “recess” the bass and treble frequencies and peak the 2500 Hz is very useful for voice intelligibility.

As described by the famous speaker-microphone-sound-system maker, Bob Heil relates what he learned from the scientists at Bell Labs many years ago. Speech intelligibility is enhanced when audio is compensated for our natural human hearing. Equalizing below 160 Hz, reducing the 600-900 Hz region, and peaking the 2000-3000 region centered at 2500 Hz will increase intelligibility dramatically. The story goes that Bell Labs was tasked by parent AT&T with finding out why the earliest phones in the 1920’s sounded so muffled and hard to understand. After many experiments, the scientists found the most important frequencies for our ears + brain to comprehend speech. In other words, our ears are not “EQ-flat” like a scientific instrument is. Continue reading →

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Radio Waves: 83 years of ABC Broadcasting, AM to New Zealand Northland, and Taliban blocks RFE/VOA/Radio Liberty

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Radio Waves: Stories Making Waves in the World of Radio

Welcome to the SWLing Post’s Radio Waves, a collection of links to interesting stories making waves in the world of radio. Enjoy!

ABC Radio Australia’s 83 years of broadcasting to the world (ABC)

This is the story of one of the ABC’s best kept secrets.

ABC Radio Australia was never intended to be a great secret. It was just the nature of the service that few Australians knew about it. When I hosted its breakfast program for nine years, I could count on one hand the number of people who knew what I was talking about when I told them I worked for RA.

Most people mistakenly thought it was the same thing as Radio National. I would have to explain, yet again, that this was our version of the BBC World Service, a worldwide broadcaster.

RA was founded at the start of the World War II by prime minister Robert Menzies as an antidote to the disinformation being broadcast by Australia’s new enemies, Germany and Russia. The idea of Australia Calling, as the service was initially named, was to provide an antidote to this propaganda, to counter that aerial bilge with factual, balanced and fair reportage.

So with a small team of English, Spanish, Dutch and French broadcasters, a minuscule budget and some tiny transmitters in antiquated shacks in Victoria and New South Wales, Australia joined the short-wave age in December 1939. [Continue reading…]

Boost for AM Broadcasting in NZ’s Northland Region (Content Technology)

Situated on the northwest tip of New Zealand’s north island, and home to the historically significant Waitangi Treaty Grounds, the Northland region is to receive a funding boost to strengthen its AM broadcasting infrastructure.

New Zealand’s Minister of Broadcasting and Media, Willie Jackson, and Minister for Emergency Management, Kieran McAnulty, have announced a NZD$1.48 million package to fund the repair and replacement of three transmission masts in Northland to ensure AM radio can stay on air in the region.

“This funding will secure the reinstatement of the Waipapakauri mast, which services Far North communities, and replace the masts at ?taika and ?haeawai which are on their last legs,” Willie Jackson said. “This will ensure that Northland communities retain their access to AM transmission in areas that are not serviced by FM frequencies.

“RNZ has already completed work to reinstate the Waipapakauri mast, which went back on air today.”

Minister for Emergency Management Kieran McAnulty said radio is a critical information channel to help reach New Zealanders in an emergency.

“When emergencies happen, the National Emergency Management Agency (NEMA) and local Civil Defence Groups work with the media to issue warnings and other critical information. We rely on radio as our number one emergency info channel as it is the most resilient and widely available form of public communication.

“Northland is especially reliant on AM radio due to its remote and rugged terrain, its exposure to hazards like tsunamis, and limited access to cellular service and other information sources,” Kieran McAnulty said. [Continue reading…]

Taliban Blocks Afghan Broadcasts By VOA, Radio Free Europe/Radio Liberty (All Access)

The TALIBAN has shut down several VOICE OF AMERICA RADIO ASHNA FM repeaters and has blocked RADIO FREE EUROPE/RADIO LIBERTY’s Afghan service RADIO AZADI, alleging that the U.S.-backed outlets are violating Afghani press laws and journalistic principles.

A statement from the VOA said that the move, which it noted broke a multiyear contract between the stations and the Afghan government, “is a blow to the large audience that turns to RADIO ASHNA for uncensored news and information. VOA broadcasts provided the people of AFGHANISTAN uncensored perspectives and hope. They gave ordinary Afghans a voice through call-in programs and discussion shows about subjects censored by domestic media. On VOA programs, topics ranged from the increasing isolation of AFGHANISTAN’s current government and the second-class status of women and girls as a result of the TALIBAN’s policies to the persistent economic failures that have diminished the quality of life in AFGHANISTAN since the TALIBAN takeover.”

“Many programs were anchored by women,” said Acting VOA Director YOLANDA LÓPEZ. “Removing VOA from the domestic airwaves will not silence us. It will only increase the importance of serving the captive audience inside AFGHANISTAN.”

The statement noted that the VOA reaches 7.3 million adults per week in the country, with almost half of those listening on broadcast radio; the service can also be heard via satellite TV, shortwave, AM, streaming, and social media and is “actively exploring additional ways to provide our content and fulfill our mission of serving our audience in AFGHANISTAN.” [Continue reading…]

Taliban hit Voice of America with broadcast ban (DW)

US-funded Voice of America said Taliban authorities pointed to “complaints” about their programing. Radio Free Europe was also banned by the Islamist regime.

Voice of America (VOA) and the AP press agency reported that Taliban authorities banned radio broadcasting from VOA and Radio Free Europe/Radio Liberty (RFE/RL) in Afghanistan from Thursday.

According to VOA, the Taliban authorities cited “complaints they have received about programming content” as reason for the ban.

However, there were no further details provided about the alleged complaints, VOA shared in a press statement.

Both VOA and RFE are funded by the US government, but “operate with journalistic independence and aim to provide comprehensive, balanced coverage,” the statement continued.

Whether or not the ban will be extended to other international broadcasters in Afghanistan remains unclear at this point.

In March, some parts of DW’s Afghan programing were stopped from being rebroadcast by Afghan partners, and BBC news bulletins in Pashto, Persian and Uzbek also taken off air.

Taliban say VOA and RFE ‘failed to show professionalism’
Afghanistan’s Foreign Ministry spokesman Abdul Qahar Balkhi told AP his country had laws regulating the media and any network that was “repeatedly contravening” them would be banned.

“VOA and Azadi Radio (Radio Liberty) failed to adhere to these laws, were found as repeat offenders, failed to show professionalism and were therefore shut down,” he said.

The Taliban regime has been cracking down on press freedom in the country by imposing restrictions on media and journalists since seizing power last year. [Continue reading…]

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Giuseppe experiments with mediumwave loop induction

Giuseppe upcycles and improves a homebrew MW antenna

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Many thanks to SWLing Post contributor, Giuseppe Morlè (IZ0GZW), who shares the following:

Dear Thomas and Friends of SWLing Post …

This is Giuseppe Morlè. As always, I try recycling what I have and improving upon antennas I’ve built in the past. This is one way we radio lovers can experiment. Many years ago, I made an antenna only for medium waves; by adding a circuit, I can now listen to short waves.

I took advantage of a small frame that I recovered from an old commercial FM / AM stereo receiver by removing its coils for medium waves and I wound around it only two coils sufficient to have a frequency range from 3.5 to 18 MHz.

I remember that the antenna in question also receives medium waves as it was born.

I chose this small frame because I wanted everything to be small in order to carry this compact antenna everywhere.

Unlike my other projects for SW and MW, which have a cable that carries the SW signal to the receiver, this time I used the induction that is created around one end of the loop, which I spiraled to get inside the stylus of my Tecsun PL-660 and which then transfers the signal to the receiver.

I did some tests on my balcony the day after a strong storm and I noticed that the propagation was absent but I still wanted to make sure that everything was working.

[Note that you can translate this video into your language via YouTube’s automatic subtitles. Click here to learn how to do this.]

I will keep you updated on other tests on more favorable days of propagation … I still invite you to follow me on my Youtube channel.

I wish everyone a good listening …
73. Giuseppe Morlè iz0gzw.

Many thanks, Giuseppe. I, for one, love all of your homebrewed and recycled antennas. This one is no exception! What a fun project. I love how you use what you have and aren’t afraid to experiment! Thank you for sharing.

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Don Moore’s Photo Album: Santa Bárbara, Honduras

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

Don Moore’s Photo Album: Santa Bárbara, Honduras

by Don Moore

I first set foot in Latin America in January 1982 when I arrived in Tegucigalpa to begin three months of Peace Corps training. Three months later I moved to my Honduran home, the town of Santa Bárbara in the western mountains. For the next two years I worked as a teacher and resource person at the Escuela Normal Mixta de Santa Bárbara, a specialized high school that trained its students to teach primary school.

Santa Bárbara had a shortwave station, La Voz del Junco on 6075 kHz but it was rarely reported because it broadcast irregularly and was usually blocked by big international broadcasters when it was on the air. I had never heard it but I met Miguel Hasbun, the owner-manager, on my first visit to Santa Bárbara when he picked me up hitchhiking north of town. He told me that the shortwave transmitter had been broken down for a while but that he was going to fix it ‘soon’. Over the next year I kept inquiring about the shortwave and he finally did fix it. After that the station broadcast irregularly for the next year or so, mostly in the morning. I served as volunteer veri-signer and issued around fifteen QSLs. I even issued one to myself.

Santa Bárbara had one other radio station, Ondas del Ulúa on 1140 kHz medium wave (later 1150 kHz). They also announced 4770 kHz shortwave in their canned IDs and station staff assured me they would be adding shortwave “soon”. It never did happen but the WRTH did list the frequency as future plans for several years.

Audio:

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Ondas del Ulúa 1982 sign-off announcement mentioning 4770 kHz.

The department of Santa Bárbara had one other radio station, Radio Luz y Vida on 1600 and 3250 kHz in the town of San Luis. The founder, manager, and veri-signer for Radio Luz y Vida was a missionary from Oklahoma named Don Moore. Needless to say, this caused a lot of confusion in the DX world as some people assumed he and I were the same person. On the map, San Luis is only about thirty kilometers from Santa Bárbara but getting there involved a five-hour journey on two buses. I only went once and the other Don Moore was out of town, so I never met him. I did meet two nurses who were working at the mission’s health clinic.

Photos

These pictures were all taken in 1982 to 1984 while I lived in Santa Bárbara [click on photos to enlarge].

La Voz del Junco’s yellow sign on main street in downtown Santa Bárbara. The small tower on the left was the corner of what had been an army post but was being used as a regional prison in the early 1980s. I once went there every day for a week to supervise student-teachers doing adult literacy classes for the inmates. It was not a pleasant place to be.

Entrance to La Voz del Junco. The girl is examining a poster for the night’s showing at the makeshift movie theater that Don Miguel operated nearby. Continue reading →

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AWA Presentation: A History of British Broadcasting

Radio physics explained: The Luxemburg-Gorky effect

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Get it while you still can: The Luxemburg-Gorky effect

by 13dka

The Radio Luxembourg longwave transmitter Junglinster in the 1930s [RTL Group]

“In radiophysics, the Luxemburg-Gorky effect (named after Radio Luxemburg and the city of Gorky (Nizhny Novgorod)) is a phenomenon of cross modulation between two radio waves, one of which is strong, passing through the same part of a medium, especially a conductive region of atmosphere or a plasma.” (Wikipedia)

That sounds pretty abstract, right? In my own words, imagine your radio is tuned to a station on let’s say 162 kHz, 500 miles away. Somewhere in the middle between your receiver and the 162 kHz transmitter is a station transmitting on a different frequency, let’s say 234 kHz. The Luxemburg effect is that you can hear the modulation of the 234 kHz transmitter in the middle, on the 162kHz station you are receiving. The effect is not depending that much on the frequency/wavelength though, the longwave station could affect medium wave stations and it has been created using shortwave frequencies far apart.

It was observed first in 1932, when listeners of the Swiss Beromünster 60kW medium wave station built just one year prior also heard a bit of Radio Luxemburg’s longwave transmitter (250kHz) on the Beromünster frequency (653kHz until 1934). Of course this was assumed to be some kind of crosstalk within the receivers and probably drove radio engineers insane until 1933, when Bernhard D.H. Tellegen, a Dutch electrical engineer and inventor suggested the true origin of the effect: The new (1932) 150kW Radio Luxemburg longwave transmitter in Junglinster was directly modifying the ionosphere hundreds of kilometers above, it “heated” the ionosphere in a way that it made the plasma’s charge and reflectivity follow the amplitude modulation of Radio Luxemburg, thus modulating waves of other wavelengths crossing this part of the ionosphere.

Practical demonstration

Even if you’re living in Europe, you may never have witnessed that effect and according to this article by Paul Litwinovich, chances to observe this in the US are rather slim, due to the relatively low power of the stations. I’m in Europe but never noticed it either – until recently: Continue reading →

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