The Pip: the Russian marker that ticks once a second on 5448 kHz

What you hear

On 5448 kHz, in daylight, there is a signal that sounds like nothing at all until you listen for a minute: a short, high pip, about a second apart, hour after hour. There is nothing between the pips, no identification, no change in rhythm. It has been doing this since 1985, which makes it one of the oldest of the Russian channel markers after the Buzzer on 4625 kHz. Listeners abroad called it the Pip for obvious reasons, and the Russian nickname is the same word.

The pips are not the point. The point is what happens when they stop. Rarely, with no warning, the pipping breaks off and a man's voice reads a message in Russian: a callsign, groups of numbers, a code word, each part repeated. It lasts well under a minute, and then the pips come back as if nothing had happened. The message format is the same as the Buzzer's, and listeners who record both have noticed that one and the same message sometimes goes out over several markers at once. That is the strongest clue that they all serve the same system.

Who transmits and why

Nobody in a position to know has ever explained the station. What can be said from the signal itself is that it is a channel marker: a sound that keeps a frequency occupied, tells the intended listeners that the channel is alive, and makes any intruder obvious. The transmitter is in the Rostov region in the south of Russia, and by all signs it is the marker of a military net of the Southern Military District, in the same way that the Buzzer is thought to serve the west of the country. The voice messages have the shape of military traffic. What the numbers mean and who writes them down at the other end is unknown, and will probably stay so.

The station transmits openly and in the clear; there is nothing to break, and all a listener does is receive it.

When and where to listen

The Pip follows the rule of shortwave at these frequencies: in daylight it uses 5448 kHz, and after sunset at the transmitter it switches to 3756 kHz, where the signal carries further at night. The changeover roughly follows dusk and dawn in Rostov, so from western Europe the day frequency is a daytime and early-evening signal, and the night frequency takes over for the European evening and night. The night frequency has its own page in this guide.

The Pip is loudest on receivers in eastern and south-eastern Europe, the Caucasus and Turkey. From central Europe it is usually a clear daytime signal on 5448 kHz when conditions are normal; from the west and north it is weaker, and the night frequency is the better bet. The pips show on the waterfall as a dotted line even when the sound is faint.

The transmission is AM-like, and upper sideband gives a clean, sharp pip with the carrier below the audio. If the pips sound hollow or doubled, try AM. As with the Buzzer, catching a voice message takes patience: leave the receiver on and keep half an ear on it.

In ShackDeck

The station is in Station catalogue → Mystery stations → The Pip. Click it and the program picks a public receiver that covers 5448 kHz, tunes it and sets USB; the dotted stripe of the pips shows on the waterfall before you turn up the sound. No receiver, antenna or account of your own is needed. After dark, use the entry for the night frequency, The Pip (night), which does the same on 3756 kHz.