Marshall H Hollimon

45235066, Jun 18, 1985

Jan 23, 1984

6/572883

Marshall H. Hollimon - Cupertino CA

G10G 100
G09B 1500
G01R 2310

84454

An electronic, tempered scale tuning aid employs a transducer and signal processing means to detect and amplify a signal to the level required by digital logic circuits, which circuits are used to gate a precisely determined oscillator, which is arithmetically related to the operating range of the instrument through a counting and analyzing apparatus. By scaling the measured count, a display in musical notation of both absolute pitch and intonation error is obtained.

60496932, Apr 11, 2000

Jul 14, 1997

8/892090

Paul Baran - Atherton CA
George K. Bunya - Morgan Hill CA
F. Jud Heinzmann - Los Altos CA
Marshall H. Hollimon - Cupertino CA

Com21, Inc. - Milpitas CA

H04N 710
H04N 714

455 31

A plurality of intelligently-controlled frequency-domain filters or ingress noise blockers are disposed in serial connection to coaxial cable at feeder tap locations that connect each household node to the cable. Each filter is operative in the absence of upstream signals from the local node to block ingress energy in the upstream band and is responsive to energy produced by injected upstream signals in the upstream band only from the associated local node to unblock and thus pass information signals into the upstream band. The filter employs as its blocking/unblocking mechanism an active switch whose control signal, as well as power source, is the energy of the injected upstream signal, which may be largely the information-containing signal from the associated local node which is to be gated through to the head end. The switch is able to respond quickly to microvolt level signals. The active switch is preferably a depletion-mode-type field effect transistor (depletion mode FET).

60942118, Jul 25, 2000

Aug 15, 1996

8/699888

Paul Baran - Atherton CA
George K. Bunya - Morgan Hill CA
Marshall H. Hollimon - Cupertino CA
F. Jud Heinzmann - Los Altos CA

COM21, Inc. - Milpitas CA

H04N 710
H04N 714
H04N 521
H04N 5213

348 6

This invention permits the upstream transmission of short packets of information in a cable TV system, and blocking upstream noise at all other times, and does so without interfering with image quality of normal TV viewing. A remotely operable ingress noise blocking filter is placed at the terminating junction between a subscriber's coaxial drop cable and a corresponding feeder tap in a cable TV system. The ingress noise blocking filter contains a high pass filter to pass the normal TV band. This high pass filter is bypassed by a section containing low pass filters and a switch operated when receiving a control signal from a cable modem during those short durations the cable modem is authorized to transmit an upstream signal. Low pass filters isolate the switching elements so that switching transients cannot occur in the downstream TV band. The level of the amplitude of the downstream signal is unaffected whether the switching elements are open or closed.