Tag Archives: Interval Signals

Dean solves second interval signal mystery

(Image source: Madrid.org)

In response to our second mystery interval signal challenge, SWLing Post contributor, Dean Bianco replies:

Mystery solved!

This is the “interval signal” (more accurately, a placeholder with a musical station identifier) for the Compañía Telefónica Nacional de España (CTNW) from Madrid, Spain.

They were a point-to-point HF radiotelephone terminal that provided overseas telephone and telegraph services in the days before satellites became common.

As a young SWL, I would receive all manner of strange musical identifiers for these utility stations. Most of these HF telecommunication services had gone to satellite by the early 1980’s. The HF bands were chock-a-block with signals, whether they be broadcast or utility services.

Glad to help!

To verify his claim, Dean shares the following embedded audio file made by Willi Passmann in the mid 1970s (via the excellent UtilityRadio.com website):

Well done, Dean! Thank you once again for coming to the rescue!

In case you didn’t know, dear readers, Dean Bianco is a force to be reckoned with in the shortwave radio world. 🙂 This year, he won the 3rd Annual Fest Trivia Quiz at the 2020 Winter SWL Fest! An impressive accomplishment, indeed. Not only that, but Dean’s an incredibly nice guy, great friend, and always willing to help out those new to the hobby!

Thank you, Dean!

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Let’s solve another interval signal mystery!

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Last month, we published a post asking SWLing Readers to help Brian (W9IND) identify an elusive interval signal. Turns out, the interval signal belonged to the Voice Mirror of the PTT Habana, Cuba station.

This month, SWLing Post contributor, David Crawford is asking for help to ID another interval signal which likely belongs to a utility station. David writes:

In follow-up to the La Habana utility mystery, here’s another one from the same era, 14985 kHz or thereabouts. Somewhere along the line I came to the conclusion that it might be El Salvador, but I don’t remember what led to that. The [recording embedded below] isn’t my own recording of it.

The tune is composed of individual DTMF tones, and when I was a bored youth I discovered that it could be played on an AT&T desk touch tone phone by pressing two keys at a time to remove the second tone. This one would repeat for hours at a time, interrupted by manually patched telephone calls.

Readers: Can you positively ID this interval signal? If so, please comment!

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Mystery Solved: Readers identify curious interval signal

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Yesterday, we published a post asking SWLing Readers to help Brian (W9IND) identify an elusive interval signal (click here to read that post).

We received dozens of replies–thank you so much!

Many readers immediately identified the tune as some sort of utility station placeholder for Point To Point communications. Turns out, they were correct.

Many thanks to Dean Bianco who was the first reader to solve the mystery.

Dean discovered that the interval signal was for the Voice Mirror of the PTT Habana, Cuba.

Dean verified it via Rainer Brannolte ‘s excellent website, UtilityRadio.com.

Here’s the audio clip from Rainer’s website:

Here’s a link to the PTT Habana Cuba page which also includes two other audio clips of the PTT service.

Rainer even includes a scan of his verification letter:

Click to enlarge (Source: Rainer Brannolte)

This morning, I received a number of responses from readers confirming PTT Habana–thank you so much!

Not only have we helped Brian ID the station, but now there’s also one less UNID audio sample on the Shortwave Radio Audio Archive.

In addition, I’m sure my friend Greg Shoom–who originally posted the recording–would be very pleased with this community effort.

Now I need to find some more shortwave archive mysteries to solve!

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Help Brian identify this 1970s era interval signal

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[Mystery solved! Click here to read the update.]

Many thanks to SWLing Post contributor, Brian (W9IND), who writes:

I want to thank you for stirring a memory that I never thought I’d relive – even though it still doesn’t solve the mystery of what the heck I was listening to in the first place!

Back in the early 1970s, I was a teenage SWLer with a curiosity for the worldwide signals that emanated from the speaker of my shortwave radio. Bitten by the SWLing bug after stumbling across Radio Nederland’s Bonaire relay station, I spent many a happy hour twirling the dial in search of fresh game to hear and QSL.

But on one such occasion (I’m going to guess it was in 1971), I was surprised and fascinated by what sounded like a snake-charming horn playing notes at random. Stranger still, the transmission would seemingly go off the air for a couple of seconds and then return to play the strange melody again. I chalked it up to one of the countless beeps, hums and other electronic noises that often appeared on utility frequencies in those days.

I never recorded it, I never had a clue what it was, and I never heard it again.

Until recently. On the Shortwave Radio Audio Archive.

A couple of weeks ago, while looking for old shortwave interval signals from the 1970s, I saw a recording marked “Unidentified interval signal 1” listed right after the interval signals of Deutsche Welle and Radio Nederland.

“OK,” I thought. “Sounds like a challenge. Maybe I can even help figure out what it was.”

Then it played … and I almost fell off my chair! I literally sat with my mouth open as the long-lost sounds of the “snake-charming horn” played again. Could it indeed have been an interval signal – and if so, for what station?

I wanted to contact the person who recorded it, but then I learned the sad news that Mr. Greg Shoom is no longer with us.

So I remain mystified, probably forever. But it sure was fun hearing that weird recording again! Thanks for the memories.

Let’s see if an SWLing Post reader can help, Brian!

I know of at least a dozen readers who are experts on all that is interval signals, so hopefully someone can listen and ID this one.

I’ve embedded audio from this SRAA recording below. Note that the unidentified interval signal can be heard between time marks 1:27 – 2:07 in the following recording:

Can you positively ID this interval signal? If so, please comment!

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Hobart Radio International’s three part interval signals specials

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Many thanks to SWLing Post contributor, Richard Langley, who writes:

While listening to my recording of yesterday’s Unique Radio broadcast over WINB, I noticed that the Radio Hobart International segment featured the second of a three-part interval signals special. Brought back many nice memories of long-gone shortwave stations. All three segments in studio quality can be found on the Radio Hobart International website:

http://www.hriradio.org/

Thank you for the tip, Richard! Kudos to HRI for putting these specials together. I’ve also embedded the audio from each episode below (email digest subscribers will need to view this on our site, or HRI):

HRI Interval Signals Special: Part 1

HRI Interval Signals Special: Part 2

HRI Interval Signals Special: Part 3

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The history of Deutsche Welle’s interval signal and signature tune

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(Source: Deutsche Welle via Mike Hansgen)

Beethoven on the air: the DW signature tune

When Deutsche Welle went on the air 65 years ago, the broadcaster opted for a melody from “Fidelio” for its signature tune. Ludwig van Beethoven’s opera is about an act of liberation.

A political prisoner is starved and nearly tortured to death because the prison’s military governor knows that the prisoner could incriminate him. The incarcerated man’s wife masquerades as a young man and, thus camoflaged, makes her way into the dungeon. When the governor attempts to stab the prisoner, the woman jumps between them and pulls out a pistol. At that very moment, trumpets sound out and the Minister, a higher authority, enters the scene. A friend of the prisoner, he recognizes what has been going on and sets the political prisoners free.

At this happy ending of the opera “Fidelio” by Ludwig van Beethoven, Minister Fernando sings the words “Es sucht der Bruder seine Brüder” (The brother seeks his brothers), and continues: “Und kann er helfen, hilft er gern” (And if he can help, he does so gladly.)

The melody to the words is anything but catchy; it is nearly ungainly in fact. Nonetheless, it was chosen as the signature tune when Germany’s international broadcaster began its shortwave radio transmissions on May 3, 1953.

The symbolism in the words

The choice not only had to do with the musical motif, but was also based on the symbolism in the words. Only eight years after World War II’s end, building new friendships and international relationships was no easy task for the new Federal Republic of Germany.

One sought to proceed in a “brotherly” manner with listeners and partners abroad through friendly exchange. Trust was to be built in a fair and impartial sharing of information.

For many years, the melody, played on a celesta keyboard, penetrated the constant ebb and flow of interference noise on the shortwave radio spectrum. It thus made its way to the speakers of shortwave radio sets around the world – often in endless repetitions leading up to the news at the top of the hour.

Click here to download a clip of the DW interval signal recorded on February 22,1982 at 1400 UTC. (Source: IntervalSignal Database)

The broadcaster then had its headquarters in Cologne, and the Beethovenfest classical music festival took place only sporadically in Bonn, 30 kilometers upstream the Rhine.

The move from Cologne to Bonn, and the media partnership with the re-established and much bigger music festival, had to wait until the new millennium. Then it seemed only fitting that Deutsche Welle should once again associate itself with Beethoven.[…]

Continue reading and listen to a number of “Fidelio” variations at Deutsche Welle.

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Interval Signals + Radio Astronomy = Bliss

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Yesterday, I spent part of the better part of the day at the Pisgah Astronomical Research Institute (PARI): a place that has begun to feel like a home away from home.

As you might imagine, radio astronomy observatories are places with very low levels of radio frequency interference. Since I had a few hours on the PARI campus to play radio, I used it as an opportunity to evaluate the CCRadio-EP Pro‘s AM/mediumwave performance.

For comparison purposes, I packed the CCRadio-EP Pro, Tecsun PL-660 and (for kicks) my Sony ICF-5500W.

Now isn’t the ICF-5500W a handsome boy?

I’ll post some of the CCRadio-EP Pro videos in my final review.

Though it was immense fun tuning through the AM broadcast band right through the gray line, being an SWL, I eventually turned to the shortwaves. The only shortwave radio I had on hand was the amazing little Tecsun PL-660. Conditions weren’t as bad as I had expected–propagation was decent and did I mention no noise?

After tuning around a bit, I happened upon one of my favorite interval signals: that of the Voice of Turkey.

Everything around me–all that was on my mind–simply took a backseat to the simple pleasure of listening to an interval signal on a cool, foggy spring evening surrounded by the beauty of PARI’s campus and those giant radio telescopes.

Though the feeling was nearly impossible to capture, I did make a recording to share with SWLing Post friends and readers from around the world. I hope you enjoy: