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:
Jul. 20, 1976
Filed:
Dec. 19, 1974
Wayne J Bates, Des Plaines, IL (US);
Walter L Berenson, Palatine, IL (US);
William H Euchner, Jr, Arlington Heights, IL (US);
James H Grigg, Chicago, IL (US);
Morton Stern, Skokie, IL (US);
Ronald W Taylor, Arlington Heights, IL (US);
Motorola, Inc., Schaumburg, IL (US);
Abstract
A modem having a transmitter portion including a first modulator connected to receive audio frequency signals and supplying an output signal through a single sideband filter to a second modulator providing an output signal at a unique channel frequency, a receiver portion including a first demodulator connected to receive transmitted signals and supplying an output signal to a second demodulator through a single sideband filter with the second demodulator providing audio frequency output signals, a carrier switch supplying a small amount of the carrier to the second modulator during operation of the transmitter and a carrier level switch associated with the carrier switch for supplying the carrier at high and low levels, and a crystal controlled channel oscillator connected to the second modulator of the transmitter portion and the first demodulator of the receiver portion with removable, plugin crystals connected thereto for controlling the channel frequency of the modem.