Stephen L Hoffman

US Patent:

20020025791, Feb 28, 2002

Filed:

Mar 20, 2001

Appl. No.:

09/812793

Inventors:

John Englert - Carmel IN, US
Stephen Hoffman - Carmel IN, US

International Classification:

H04B001/26

US Classification:

455/196100, 455/140000

Abstract:

A preferred embodiment of the present invention generally comprises a hand-held two-way radio employing digital selective calling. The hand-held two-way radio further comprises a VCO operative to modulate the radio signal frequencies of a guard channel such that the guard channel can be changed by changing the output of the VCO. In addition, the present invention comprises a hand-held two-way radio comprising circuitry operative to function according to the digital selective calling international standards, and a VCO operative to modulate the radio signal frequencies of a guard channel such that the guard channel can be changed by changing the output of the VCO. A fourth embodiment of the present invention comprises a hand-held two-way radio comprising circuitry operative to send and receive GPS data, and a VCO operative to modulate the radio signal frequencies of a guard channel such that the guard channel can be changed by changing the output of the VCO.

US Patent:

39965228, Dec 7, 1976

Filed:

Nov 17, 1975

Appl. No.:

5/632473

Inventors:

Richard C. Koch - Denver CO
Stephen J. Hoffman - Indianapolis IN

Assignee:

Regency Electronics Inc. - Indianapolis IN

International Classification:

H04B 134

US Classification:

325471

Abstract:

A signal-seeking radio receiver is disclosed which has two different types of local oscillator circuits. One type of local oscillator includes two transistors, the emitter of the first connecting to the base of the second and having a capacitor connecting between the emitter of the second and the base of the first. A large number of diode switched crystals can be connected to the base of the first transistor of the local oscillator without introducing an instability in the oscillator circuit. The second type of local oscillator is of the same general design as the first type except that it additionally includes a third transistor connected to the second transistor in a fashion similar to the first transistor. In this second oscillator configuration, the circuitry used to step among the channels also is used to alternately make either the first or third transistor operative in the local oscillator circuit.