Train horn

A Makrofon (from Greek μακρός large, φωνή sound ) is a device on vehicles with a loud warning sound can be produced with a fixed frequency. It is used on emergency vehicles, trains and ships.

Makrofon the vibration is generated, which is in the range of audible frequency ( about 20 Hz to 20 kHz). In this case, compressed air is passed through a metal plate, the device to vibrate, thereby generating sound. She leaves the Makrofon then a horn which acts against the optimal acoustic impedance. Thus the largest possible part of the sound energy arrives at the receiver.

In today's rail vehicles, the Makrofon is used to warn people and other road users, for example, on platforms or before not technically secured crossings before the approaching train, and also for giving a Zugpersonalsignals or Rangiersignals. The Makrofon this replaced the pipe, which was used in older rail vehicles. It is similar to the horn of a motor vehicle, but much louder. Moreover, usually two Makrofone with different frequencies (e.g., Series 101: 370 Hz and 660 Hz ) can be used, which are driven simultaneously. This results in a deliberately discordant and penetrating warning tone, from which it is hoped that a special signal effect. Often both Makrofone but can also be controlled individually.

When emergency vehicles also Makrofone two different frequency be used. But these are not the same, but used interchangeably.


  • Makrofon a locomotive of class 182? / I
  • Makrofon a train class 628 (from outside and inside )? / I
  • Audible signal device
  • Schienenfahrzeugtechnik