Donald J Palmer

US Patent:

52221490, Jun 22, 1993

Filed:

Nov 15, 1991

Appl. No.:

7/792841

Inventors:

Donald E. Palmer - Sunnyvale CA

International Classification:

H04B 300

US Classification:

381 94

Abstract:

In audio frequency high fidelity equipment, termination plugs for input ports and output ports of various types wherein the termination plugs include a conductive-film-covered ferromagnetic-core electrical damping element inductively coupled to potential signal carrying components. In an unbalanced configuration, an RCA-type plug may include a shorting loop between the center conductor and the shield wherein a loop or coil of conductively-clad ferromagnetic material is disposed around the shorting conductor forming a transformer circuit, the cladding being a shorted secondary. The cladding is a film of copper, gold or silver, which is preferably covered with electrical insulation. In a an embodiment for an output terminator plug for an RCA-type jack, the RCA-type plug includes an impedance matching load between the center conductor and the shell, the impedance matching load element being electrically coupled with a loop or coil of the cladded ferromagnetic material disposed around the impedance matching load element. In a still further embodiment, a balanced signal line connector may include a ferromagnetic loop or coil, appropriately clad in copper and insulated, wherein the loop is disposed to surround the entire shell portion, thereby enclosing both the shell and the balanced signal carrying lines. The signal carrying lines are preferably connected to ground through the shell and have in line a matched impedance load.

US Patent:

48855553, Dec 5, 1989

Filed:

Dec 21, 1987

Appl. No.:

7/135776

Inventors:

Donald E. Palmer - Sunnyvale CA

International Classification:

H04B 328

US Classification:

333 12

Abstract:

An apparatus for minimizing degradation of fidelity of a signal in a transmission line intended for carrying signals of wavelengths greater than the length of said transmission line and wherein the signals are of frequencies over several octaves, wherein a structure of ferromagnetic material is employed encircling a transmission line and the ferromagnetic material, preferably a toroid, serves as core to a transformer with a secondary having a termination in a substantially short circuited load whereby ringing signals in the transmission line are dissipated in the secondary circuit. Therefore, the invention causes the frequency response of a cable to be umimpaired for the desired signal, and it simultaneously and selectively couples the undesired reflection currents into a secondary circuit where they are dissipated.

US Patent:

49451898, Jul 31, 1990

Filed:

Aug 9, 1989

Appl. No.:

7/391768

Inventors:

Donald E. Palmer - Sunnyvale CA

International Classification:

H01B 1100

US Classification:

174 32

Abstract:

An interconnection cable for audio frequency high fidelity applications comprises a first and a second conductor which are disposed close to one another and connected at the ends, wherein the second conductor has an electrical length which is a least three times longer than the first conductor. The second conductor is helically wound about the first conductor. A third conductor may be included in the space within the helical winding, and in one embodiment may be connected at the ends of the first and second conductor. In another embodiment, the third conductor may be insulated from the first conductor and the second conductor for signal return.

US Patent:

50649663, Nov 12, 1991

Filed:

Oct 15, 1990

Appl. No.:

7/597140

Inventors:

Donald E. Palmer - Sunnyvale CA

International Classification:

H01B 1100

US Classification:

174 32

Abstract:

An interconnection cable for audio frequency high fidelity applications, such as loudspeakers, is provided wherein a first wire and a second wire extend between a reference end and a terminal end, the second or auxiliary wire being divided into two serial segments by a single electrical discontinuity separating each segment, wherein each segment is conductively terminated at its respective end in a signal common or ground with the first wire, and wherein the electrical discontinuity is at between 9/16 and 23/32 of the distance from a reference end. Multiple interconnection cables may be assembled into balanced transmission lines for a signal path and a signal return. It is preferable that the reference end be at the signal source and the terminal end is at the signal load.

US Patent:

49393154, Jul 3, 1990

Filed:

Dec 2, 1988

Appl. No.:

7/279391

Inventors:

Donald E. Palmer - Sunnyvale CA

International Classification:

H01B 1118

US Classification:

174 36

Abstract:

An interconnection cable for audio frequency high fidelity applications is provided wherein a conductive shielding is a sheath which is divided into two segments, wherein the sheath surrounds at least one signal-carrying conductive lead from which the shield is insulated, wherein the sheath has a single electrical discontinuity separating each segment of the sheath, wherein each segment of the sheath is conductively terminated at its respective end of the cable in a signal common or ground, and wherein the electrical discontinuity is at between 9/16 and 23/32 of the distance from a reference end and preferably at between 5/8 and 2/3 of the distance from the reference end. It is preferable that the reference end is at the signal source and the other end is at the signal load. High frequency distortion caused by radio frequency noise is minimized where the discontinuity is at the 5/8 distance from the reference end, and ringing in the lead due to coupling between the shield and the lead is minimized where the discontinuity is at the 2/3 distance. To minimize both ringing and r. f.

US Patent:

55480829, Aug 20, 1996

Filed:

Nov 22, 1994

Appl. No.:

8/343698

Inventors:

Donald E. Palmer - Sunnyvale CA

International Classification:

H01B 1102

US Classification:

174 34

Abstract:

A signal shielding structure for a cable, such as an audio cable, employs 1) a shielding sheath which is electrically insulated from and encloses the signal-carrying conductors in the cable and 2) one or two discrete inductors electrically coupled between selected discrete points of termination on the shielding sheath and selected ground points to provide a d. c. signal path to ground and to inhibit ground termination of r. f. signals. The shielding sheath floats and is preferably everywhere electrically isolated from direct-wire connection with all grounds and all signal sources except for the connection through the inductor or inductors.