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.

Date of Patent:
Dec. 07, 1982

Filed:

Mar. 02, 1981
Applicant:
Inventors:

Abram Froese, North Vancouver, CA;

Larry Y Onotera, Surrey, CA;

Muhammad J Ahmed, New Westminster, CA;

Alvin Liebelt, Vancouver, CA;

Assignee:

AEL Microtel, Ltd., Burnaby, CA;

Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H04B / ; H04B / ;
U.S. Cl.
CPC ...
455 42 ; 455 67 ;
Abstract

The baseband input to a frequency modulation transmitter is switchably connectable to a square wave generator, the amplitude of the square wave output being adjusted to provide a predetermined deviation of the FM radio transmitter. The output frequency of a pilot oscillator is also applied to the baseband input and it is subjected to phase modulation because of group delay which exists in the system and which adversely affects the signal during transmission through the system. At the receiving end of the radio system, the receiver output obtains the pilot signal which has been phase modulated by the group delay slope in the system, because of the square wave test signal. This phase modulation is detected in a phase lock loop, amplified, rectified and applied to a meter so as to provide an indication of the group delay slope in the system.


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