The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 01, 1986
Filed:
Jun. 15, 1984
Applicant:
Inventors:
Lawrence M Ecklund, Wheaton, IL (US);
Charles J Marik, Richmond, IL (US);
Assignee:
Motorola, Inc., Schaumburg, US;
Attorneys:
Primary Examiner:
Int. Cl.
CPC ...
H04H / ;
U.S. Cl.
CPC ...
381 15 ; 455304 ; 455306 ;
Abstract
In an AM stereo system wherein a low frequency pilot tone is added to the difference channel signal before modulation of the carrier, 'image shifting' and audio distortion in a receiver, due to residual pilot tone signal, are removed by separating out a portion of the pilot tone after it has been filtered and phase shifed for enabling the stereo mode of operation. The separated signal is then inverted and delayed appropriately for each of the PLL and audio circuits.