(1) The requirements of Regulation 6 below shall, subject to paragraph (2) below, be complied with if any apparatus is used by any person unless it—
(a) complied with the said requirements at the date of its manufacture, assembly or importation; and
(b) is maintained in reasonable working order; and
(c) is not likely to cause undue interference with any wireless telegraphy used for the purposes of any safety of life service or for any purpose on which the safety of any person or of any vessel, aircraft or vehicle may depend.
(2) The provisions of paragraph (1) above shall not apply to the use of apparatus which is sold or let on hire before the date of the coming into force of these Regulations by a person who in the course of business manufactures, assembles or imports such apparatus and which is not likely to cause undue interference with any wireless telegraphy.