Tag Archives: Interval Signal

Mystery Solved: Readers identify curious interval signal

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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China Radio International: China’s first sound trademark

CRI-China-Radio-International(Source: China Radio International via David Iurescia, LW4DAF)

A state-owned radio station’s signature tune is about to be approved as China’s first sound trademark.

The State Administration for Industry and Commerce (SAIC) said on Sunday that it has reviewed the application from China Radio International and plans to approve it.

A sound trademark is a sound that is used to perform the trademark function of uniquely identifying the commercial origin of products or services. Famous examples include the Nokia tune and the “I’m lovin’ it” jingle of McDonald’s.

China’s top legislature revised the Trademark Law to allow sound to be registered as a trademark in 2013.

The SAIC had received 450 applications for sound trademarks by the end of January since starting to accept such applications in May 2014.

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Between Broadcasts-Exploring Interval Signals

Lately, I’ve been listening to a plethora of shortwave broadcasts as I’m about to review several new radios. I’ve noted so many great interval signals that are still in use. The following is a reprise of a previous post–from over two years ago–about interval signals. If you’ve never heard of interval signals, this post offers an introduction. 

What are interval or tuning signals? Often the most recognized sounds in the shortwave bands are the repetitive tones and musical interludes heard between broadcasts, known as interval signals. These are simply characteristic  musical phrases that broadcasters play between programs.  In fact, for me, nothing is more nostalgic than to hear the interval signals of some of my favorite broadcasters from my youth. Here are a few classic examples of interval signals:Analog Radio Dial

Interval signals usually include station and program identification, and are often in multiple languages. Not only do they help identify the station, but in the days of crowded international broadcast bands, interval signals helped listeners tune in and adjust their radios prior to program commencement.

Broadcasters have been using interval signals since the 1920s, but there has been a decline with the advent of digitally tuned radios which, unlike analog tuners, take the guesswork out of tuning into a specific frequency.

So, in this digital age, are interval signals still around? Sure. Many broadcasters believe an interval signal is still the best way to announce station and program identification; one might say their interval signals have become audio “logos.”

Here is an audio clip I recorded on April 23, 2009, of the interval signal for the new Happy Station Show: [Click here to listen]

For comparison, listen to this audio clip of the Happy Station Show from Jan 20, 1980, when it was a part of Radio Netherlands: [Click here to listen]

Listening for Signals

Where can you hear interval signals today?  Fortunately, they can be heard all over the shortwave broadcast spectrum. The best times to hear interval signals are on the top of the hour and sometimes at the half or quarter hour.

Another great place to hear interval signals are on the web. There are several interval signal databases where you can listen to a wide variety of interval signals. One of my favorites is the Interval Signal Database. This site is in German and English and is well categorized and searchable. In fact, Bernhard, the webmaster of the Interval Signal Database, gave me permission to publish several of his audio clips above. [Danke, Bernhard!]

Here is a list of interval signal websites:

Since he’s somewhat of an interval signal guru, I asked Bernhard for his favorite interval signal recording. He pointed out this one from the Cold War era:  it is a recording of a special low-power (1kW) training station of the Austrian military. Bernhard informed me that in times of crisis, this station was to serve as a back-up for the Austrian Radio ORF.

Leave a comment:  What is your favorite interval signal, and why?

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On a side note–Bernhard also pointed out one of his favorite non-interval signal recordings.  In this recording, the news reader started the German language news by reading the frequencies, then noticed that the studio door was open.  You can clearly hear her getting up to close the door in the recording.

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