Raymond W Clark

US Patent:

45568537, Dec 3, 1985

Filed:

Sep 28, 1984

Appl. No.:

6/655529

Inventors:

Raymond N. Clark - Cherry Hill NJ

Assignee:

RCA Corporation - Princeton NJ

International Classification:

H01P 5103

US Classification:

333 26

Abstract:

A coax-fed slotted-cylinder (pylon) antenna for UHF television operation at power of 200 kW and above has a coaxial feed which is large enough to propagate higher TE. sub. 11 mode as well as the desired fundamental TEM mode. The power fed to each slot and as a consequence the antenna array factor may be perturbed by the higher modes. It is important to reduce losses in the feed of the high-power signals from the transmitter or high power amplifier up the tower to the antenna. For lowest loss, a waveguide is used for the run up the tower. A waveguide-to-coax transition is used for adapting the waveguide to the coaxial antenna feed while suppressing the undesired TE. sub. 1,1 mode. The transition has two short semicircular waveguides opening into the waveguide feed from the transmitter. The semicircular walls of the two waveguides are coupled to the outer conductor of the coax antenna feed. The semicircular waveguides have a common flat wall, the center of one core of which is coupled to the center-conductor of the coax antenna feed.

US Patent:

46022279, Jul 22, 1986

Filed:

Jul 30, 1984

Appl. No.:

6/635926

Inventors:

Raymond N. Clark - Cherry Hill NJ
Anthony N. Schmitz - Mt. Laurel Township, Burlington County NJ

Assignee:

RCA Corporation - Princeton NJ

International Classification:

H01P 516
H03H 748

US Classification:

333109

Abstract:

A television broadcast transmitter includes two power amplifiers or transmitters, a dummy load and an antenna. A noncontacting switching arrangement includes directional couplers or hybrids operated as controllable phase-shifters under the control of pairs of variable reactive terminations. Signals arriving at the antenna or load port by two paths combine in-phase to couple signal to that port, or combine out-of-phase to cancel signal. If the out-of-phase condition is inaccurate, cancellation may be incomplete, resulting in crosstalk. To avoid the need for accurate positioners to position the variable reactive termination at the position providing the desired phase-shift, a particular structure of the reactive termination is used. The reactive termination is a short-circuited coaxial line with an axial gap in the center conductor at a position less than one quarter operating frequency wavelength from the short circuit. The center conductor is hollow around the gap and lined with insulating material, and an elongated conductive slug is actuated to selectively occupy one or two positions within the center conductor, one position remote from the gap whereby a minimum series capacitance results, and the second position straddling the gap, whereby the series capacitance increases.

US Patent:

44918712, Jan 1, 1985

Filed:

Dec 6, 1982

Appl. No.:

6/447142

Inventors:

Anthony N. Schmitz - Mount Laurel NJ
Raymond N. Clark - Cherry Hill NJ

Assignee:

RCA Corporation - New York NY

International Classification:

H04N 538
H04N 540
H04N 704

US Classification:

358186

Abstract:

A television transmitter uses a diplexer to combine the signals from a visual power amplifier and an aural power amplifier. The diplexer uses hybrids coupled together by transmission lines, and the transmission-lines have aural-frequency cavities which reflect the aural energy from the aural input port to the antenna output port. In the event that the aural power amplifier fails, it is desirable to revert to multiplexed operation, in which the visual amplifier amplifies combined visual and aural signals. This mode of operation is accomplished by switching the low-level aural signal for combining with the low-level visual signal and by simultaneously switching the tuning of the aural cavities.