Radio microphones

It is more than thirty years since radio microphones first appeared. Today they are in very widespread use in the audiovisual sector, as well as for conferences, public debates, concerts, etc… A radio microphone gives the speaker great freedom of movement. Generally low-power, they use different frequency bands. The use of such equipment is subject to the regulations on telecommunications.

Radio microphones saw the light of day with the appearance of transistors, which made it possible to miniaturise these devices. At that time, the technology enabled transmitters to be produced easily in the frequency ranges from 30 MHz to 200 MHz and the first radio microphones used those frequencies, sharing the frequency bands with other users.

Frequencies

Today, despite the efforts at harmonisation in Europe, the frequency bands allocated to the use of radio microphones are very often subject to national restrictions. European Radiocommunications Committee recommendation ERC/REC 70-03 concerning the use of short-range radio (SRD short-range devices) mentions the national restrictions for the 6 frequency bands available to radio microphones, together with the technical parameters, such as radiated power and the harmonised standards applicable in this area.

For Switzerland, the Federal Office of Communications (OFCOM) has adopted this document with its specific restrictions linked to the national frequency plan (NAFZ) and has issued a whole series of technical regulations.

The table below indicates the authorised power and the technical regulations for each frequency band (wireless microphones can be operated without a license):

Frequency band Maximum transit power Technical regulations Remarks

31.4 - 39.6 MHz

100 mW ERP

RIR1009-01

Use only in the channels indicated in RIR 1009-01

174 - 223 MHz

50 mW ERP

RIR1009-02

 

470 - 786 MHz 50 mW ERP RIR1009-10 The use of the 694-790 MHz frequency band could be limited after 2018
477 - 782 MHz 250 mW ERP RIR1009-11 Use only in the channels indicated in RIR 1009-11.

The use of the 694-790 MHz frequency band could be limited after 2018.

786 - 789 MHz

12 mW ERP

RIR1009-17

Use only possible until ca. end of 2018.
823 - 826 MHz 20 mW EIRP
(ca. 12 mW ERP)
RIR1009-18 100 mW EIRP (ca. 60 mW ERP) for wireless microphones carried on the body

826 - 832 MHz

100 mW EIRP
(ca. 60 mW ERP)

RIR1009-13

 

863 - 865 MHz

10 mW ERP

RIR1009-05

 

1785 - 1800 MHz 20 mW EIRP
(ca. 12 mW ERP)
RIR1009-09 50 mW EIRP (ca. 30 mW ERP) for wireless microphones carried on the body
1800 - 1804.2 MHz 20 mW EIRP (ca. 12 mW ERP) RIR1009-09

New frequency band from 1.1.2015

50 mW EIRP (ca. 30 mW ERP) for wireless microphones carried on the body

Notes:

  • The use of radio microphones in the bands 789 - 823 MHz and 832 - 862 MHz is forbidden.
  • Some frequency bands for non-specific applications may also be used for the operation of radio microphones. Technical regulations RIR 1008 define the frequency bands and radio parameters for these non-specific applications.

Frequency coordination for licence exempted PMSE users

Licence exempted PMSE users can register equipment on a voluntary basis to the database provided by a third party in order to coordinate frequency use at events.

Placing on the market

Radio microphones are subject to compliance with the usual conditions for placing telecommunication equipment on the market: conformity assessment procedure successfully passed, declaration of conformity, notification, marking and user information.

When radio microphones totaly or partly equiped with the frequency bands 789 - 823 MHz and 832 - 862 MHz (bands which cannot be used for radio microphones anymore) are placed on the market, the equipment class identifier must be applied to the instructions for use, to the packaging or on the device and the information that the radio microphone cannot be used on these frequency bands has to appear in the instructions for use. This will avoid disturbances of other services.
The equipment class identifier is represented by the following symbol:

Class identifier

Specialist staff
Last modification 04.07.2016

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