(19)

(11)

EP 0 248 871 A1

(12)

(43) Date of publication: 16.12.1987 Bulletin 1987/51 (21) Application number: 87900184.0 (22) Date of filing: 05.12.1986

(51) International Patent Classification (IPC):  H03L 7/ 093( . ) H03L 7/ 183( . ) (86) International application number: PCT/GB1986/000742 (87) International publication number: WO 1987/003760 (18.06.1987 Gazette 1987/13)

(84) Designated Contracting States: DE IT NL (30) Priority: 06.12.1985 GB 19850030168 (71) Applicant: PLESSEY OVERSEAS LIMITED Ilford Essex IG1 4AQ (GB)	(72) Inventor: BRENNAN, Paul, Victor Woodford Green Essex IG8 9PT (GB)