Publication: Magyar Közlöny
Issue: MK-2003-40 (Year: 2003, Number: 40)
Era: 1990-2004
Section: a 23/2003. (IV. 24.) GKM rendelethez*
Paragraph Index: 424

g) Combined whistle systems If due to the presence of obstructions the sound field of a single whistle or of one of the whistles referred to in paragraph 1 f) above is likely to have a zone of greatly reduced signal level, it is recommended that a combined whistle system be fitted so as to overcome this reduction. For the purposes of the Rules a combined whistle system is to be regarded as a single whistle. The whistles of a combined system shall be located at a distance apart of not more than 100 metres and arranged to be sounded simultaneously. The frequency of any one whistle shall differ from those of the others by at least 10 Hz.

Source: https://magyarkozlony.hu/hivatalos-lapok/2e72167675ab9de53a766f2e8ff24eebb8b45c9c/dokumentumok/3fc892723f784b7239921e296e1ba2f32c28559e/letoltes