MERVIN LEE GRINDAHL
Pilots at 5 Ave, Otisco, MN

6684080, Jan 27, 2004

Apr 10, 1998

09/058687

Keith W. Barnes - Waseca MN
Rory A. Smith - Waseca MN
Mervin L. Grindahl - Waseca MN

Transcrypt International/E. F. Johnson Company - Burnsville MN

H04B 700

455515, 455519, 455509

A system for channel assignment in a trunked transmission communication system including a plurality of subscribers. A plurality of subscribers is provided home channel assignment to reduce collisions. A home channel alias is provided for home channel coverage where a designated home channel is unavailable. A system for call grouping is provided to avoid talk group splitting. A first check is used to determine if other channels are conducting communications with identical home and talk group information. A second check is available after a temporary channel assignment. In one system both the home channel aliasing and call grouping are performed.

6374115, Apr 16, 2002

Apr 10, 1998

09/058678

Keith W. Barnes - Waseca MN
Rory A. Smith - Waseca MN
Mervin L. Grindahl - Waseca MN

Transcrypt International/E.F. Johnson - Waseca MN

H04Q 720

455520, 455426, 455524

A trunked radio repeater communication system capable of use in a networked system includes a plurality of distributive switches and a unique signaling protocol and a switching protocol for interconnecting the trunked transmission communications systems into a wide area network that provides an expanded feature set of radio communications capabilities. The trunked radio repeater system including a protocol supporting communications for repeaters and/or subscribers conducting communications using existing protocols, such as the Logic Trunked Radio (LTR) protocol and supporting additional special functions.

6529486, Mar 4, 2003

Apr 10, 1998

09/058345

Keith W. Barnes - Waseca MN
Rory A. Smith - Waseca MN
Mervin L. Grindahl - Waseca MN

Transcrypt International/E.F. Johnson Company - Waseca MN

H04Q 728

370327, 370341, 370350, 370389, 455 15, 455518

A trunked radio repeater communication system capable of use in a networked system includes a plurality of distributive switches and a unique signaling protocol and a switching protocol for interconnecting the trunked transmission communications systems into a wide area network that provides an expanded feature set of radio communications capabilities. The trunked radio repeater system including a protocol supporting communications for repeaters and/or subscribers conducting communications using existing protocols, such as the Logic Trunked Radio (LTR) protocol and supporting additional special functions.

6804529, Oct 12, 2004

Feb 2, 2001

09/776416

Keith W. Barnes - Waseca MN
Rory A. Smith - Waseca MN
Mervin L. Grindahl - Waseca MN

Transcrypt Internationall E. F. Johnson Company - Burnsville MN

H04B 700

455515, 455519, 455509

A system for channel assignment in a trunked transmission communication system including a plurality of subscribers. A plurality of subscribers is provided home channel assignment to reduce collisions. A home channel alias is provided for home channel coverage where a designated home channel is unavailable. A system for call grouping is provided to avoid talk group splitting. A first check is used to determine if other channels are conducting communications with identical home and talk group information. A second check is available after a temporary channel assignment. In one system both the home channel aliasing and call grouping are performed.

4799059, Jan 17, 1989

Mar 14, 1986

6/839889

Mervin L. Grindahl - Waseca MN
Quentin S. Denzene - Waseca MN

EnScan, Inc. - Minneapolis MN

G08C 1700

34087003

An improved automatic/remote RF instrument monitoring system including a plurality of transponders configured to operate with one of a plurality of parameter sensing instruments remotely located from an interrogate/receiver. The interrogate/receiver transmits RF transponder activation signals in the form of a tone modulated onto a carrier. In response to the activation signals, the transponders "wake-up" and transmit an RF transponder signal which is received and processed by the interrogate/receiver. The transponders include a transmission enable circuit which initiates transmission of the RF transponder signals at random times after receipt of the activation signals. The RF transponder signals are formed by a plurality of spaced transponder information packets. Transponder information packets of the transponder signal are transmitted at pseudorandom frequencies as a Manchester encoded bit stream including a preamble field of predetermined preamble data, an instrument parameter field of data sensed by the instrument, an instrument identification field of instrument identification data, and an error control code field of BCH error control code data.

4786903, Nov 22, 1988

Jun 1, 1987

7/058636

Mervin L. Grindahl - Waseca MN
George Rosar - Owatonna MN
Mark Kodet - Waseca MN

E. F. Johnson Company - Waseca MN

H04Q 700, H03B 512

340825540

A radio frequency transponder is provided that combines high signal sensitivity in the receive mode and variable frequency capability in the transmit mode in a low component and power efficient design. A single tuned amplifier acts as the externally quenched oscillator of a superregenerative receiver when the transponder is operated in the receive mode, and as the carrier frequency generator when the transponder is operated in the transmit mode.

4733169, Mar 22, 1988

Apr 15, 1986

6/852155

Mervin L. Grindahl - Waseca MN

E. F. Johnson Company - Waseca MN

G01R 2310

324 79D

A frequency detector completely implemented with digital logic circuitry is disclosed. The frequency detector hereof employs a unique phase locked loop digitally implemented with asynchronous ripple counters, and a digitally implemented amplitude comparator and signal integrator. The detector is especially adapted for implementation in CMOS hardware, or similar hardware having low current drain characteristics. The selectivity of the detector can be set to a narrow bandwidth for excellent noise discrimination characteristics.

5212714, May 18, 1993

May 18, 1989

7/355089

Mervin L. Grindahl - Waseca MN
Philip M. Wala - Waseca MN

E. F. Johnson Company - Waseca MN

H04L 2500

375 5

A high speed data interface unit that is fully compatible with existing, trunked, land mobile voice transceivers is provided. Data rates of up to 4800 baud using bilevel modulation are achievable without the use of dedicated data transceivers, or the designation of a dedicated data channel. The data interface includes a microprocessor based modem having data pulse formation, data recovery, and pulse filtering circuits that optimize available channel bandwidth for communication of digital data.

7626920, Dec 1, 2009

Apr 1, 2005

11/097736

Mervin L. Grindahl - Waseca MN, US
Vladimir Z. Kelman - Eagan MN, US
J. Eric Dunn - St. Paul MN, US
Stuart A. Froelich - Plymouth MN, US
Keith W. Barnes - Waseca MN, US

NextNet Wireless, Inc. - Burnsville MN

H04J 11/00

370208

A fixed wireless access system generally comprises a consumer premise equipment (CPE) unit, that is connected via an Ethernet interface to a personal computer or local area network, and a base station unit that is connected via an Ethernet interface to a network. As such, the CPE unit is preferably easily user-installed while the base station unit is preferably tower-mounted within a 1-5 mile range of the CPE unit. Both the CPE unit and base station unit preferably incorporate an integrated data transceiver/switch that enables a radio frequency air link operating in the 2. 5-2. 686 GHz range. Orthogonal frequency division multiplexing is used in the uplink and downlink transmissions between CPE units and base station units.

4876700, Oct 24, 1989

Apr 16, 1986

6/852539

Mervin L. Grindahl - Waseca MN

E. F. Johnson Company - Waseca MN

H04L 2706

375 87

A unique data recovery circuit which is able to recover transmitted digital data with a data clock embedded therein. No initial timing signals are required for operation of the data recovery circuit. Instead the data clock is recovered from the received data and used to synchronize the flow of data through the circuit. Noise pulses and other anomalous transients are rejected by the circuit so that the data output accurately corresponds to the data transmitted. Operation of the invention is achieved through a number of expedients which include a random access memory delay line which delays interpretation of the data until the data clock has been recovered. A uniquely integrated delay switching network is utilized to switch recovery of the clock from the received data to the delayed data. A phase locked loop and an integrate, sample and dump circuit are also employed, both of which use asynchronous ripple counters to achieve the primary objective of the invention which is to recover the data transmitted.