In Switzerland it is possible to sell mini transmitters in the VHF band (87.5 – 108 MHz (Very High Frequencies)) subject to certain conditions. The choice of the transmission channel, limited power, break in transmission in the absence of a signal are some of the basic rules with which these mini transmitters must comply so that their sale and use are authorised.
It is possible to offer, put on the market and operate mini transmitters in the VHF frequency bands (87.5 – 108 MHz) in Switzerland according to the CEPT (European Conference of Postal and Telecommunications Administrations) recommendation on the use of short-range equipment (ERC/REC 70-03).
Equipment which does not meet the requirements described below cannot be offered, put on the market or operated.
In accordance with the Law on Telecommunications, mini transmitters are radiocommunication equipment . They must therefore meet the requirements of the decree on telecommunications equipment.
In addition to passing a conformity assessment (a check that the essential requirements are met) and meeting the other conditions for placing on the market (declaration of conformity, marking of the equipment and user information), mini transmitters must comply with the technical parameters and requirements described in the interface regulations RIR1013-19. These mainly concern the following requirements:
- The user must be able to freely choose a transmission channel over the entire VHF band (88.1 – 107.9 MHz);
- The maximum radiated power must not exceed 50 nW e.r.p.;
- The equipment must possess an integrated antenna without a connector;
- The equipment must cease all transmission in the minute following the absence of a signal at the audio input.
VHF mini transmitters make it possible to listen to an audio signal on any VHF receiver located within a radius of a few metres without using wires. The audio signal (mono or stereo) originating, for example from an MP3 player or a hands-free set for a mobile telephone, is then played through the receiver's speakers.