摘要:

The performance characteristics of some television pick-up tubes that have been used in practice in the past are reviewed critically. This review covers the Emitron, Super-emitron and orthicon. In the light of the experience gained in actual use of television cameras, an attempt is made to draw up a specification for an ideal pick-up tube.The C.P.S. Emitron (cathode-potential-stabilized Emitron) is then described. This description covers the general design of the tube, the technique of manufacture, the method of operation and the details of its performance characteristics. These are discussed with reference to the specification of the ideal tube and the performance of the actual tubes that have been described in this paper.

DOI:10.1049/pi-3.1950.0073

出版商:IEE    

年代:1950

数据来源: IET

摘要:

The design of a portable television camera and associated equipment for B.B.C. use is described. Electrically, the design was governed by the choice of the C.P.S. Emitron as the pick-up tube: mechanically, the chief consideration was suitability for use in a van specially fitted up as a mobile control room.A general description of the complete equipment is given, portions of particular interest, especially the signal-amplifier chain, being treated subsequently in greater detail.Methods of testing the overall performance, under the headings of sensitivity, resolution, hum pick-up and geometrical distortions are described.

DOI:10.1049/pi-3.1950.0074

出版商:IEE    

年代:1950

数据来源: IET

摘要:

Among the possible applications of Babinet's principle proposed by C.E.G. Bailey and H.G. Booker was the “folded slot,” the slot analogue of the well-known folded dipole. The paper describes modified forms of folded slot designed to exhibit reactance compensation, so that the variation of impedance over a wide band of frequencies is small. Calculation of the input impedance is facilitated by considering an equivalent circuit which applies to certain types of 3-terminal network. The bandwidth of an aerial for multi-channel f.m. broadcasting has been improved by the use of folded slots.

DOI:10.1049/pi-3.1950.0077

出版商:IEE    

年代:1950

数据来源: IET

摘要:

Periodic variations in the field intensity across a radiating aperture are investigated, and it is shown that they may alter the shape of the radiation pattern and reduce the power gain of the aperture. The way in which such variations arise in the distribution existing across the outer surface of a microwave lens is discussed.

DOI:10.1049/pi-3.1950.0078

出版商:IEE    

年代:1950

数据来源: IET

摘要:

A very compact high-voltage X-ray tube is described, in which the accelerating voltage is developed in a resonant cavity excited by a high-power magnetron operating at a wavelength of 25 cm. A mean current of 70 μA has been obtained at a peak voltage of 1.1 MV. Two points of interest are that the focal spot is very small (approximately ½ mm in diameter) and that, because the output is pulsed, the tube may be used as a stroboscope for the radiography of moving machinery. The limitations which apply to this method of acceleration are discussed.

DOI:10.1049/pi-3.1950.0079

出版商:IEE    

年代:1950

数据来源: IET

摘要:

Transfer standards have been developed for calibrating, at frequencies from 200 kc/s to 60 Mc/s, an admittance bridge which measures 0–100 millimhos and −150 μμF to +150 μμF. The standards have been used to give the bridge accuracies of about ± 2% ± 0.05 millimho in conductance, and between ± 0.2 μμF and ± 4 μμF in capacitance, depending on the conductance that is being measured at the same time. Suggestions are made for a new type of conductance standard that should make possible accuracies of better than ± 1 % in conductance, and better than ± 1 μμF in capacitance.

DOI:10.1049/pi-3.1950.0082

出版商:IEE    

年代:1950

数据来源: IET

摘要:

The paper is a collection of solar data derived from optical observations, and originally compiled for use in “solar noise” studies. An elementary description of the solar atmosphere is followed by mean values of electron density, electron temperature and magnetic field as functions of height in the chromosphere and corona. An assumed general magnetic field, and magnetic fields due to sunspots, are each treated. The data are finally presented in terms of plasma, gyro and collision frequencies, which quantities are fundamental to the magneto-ionic theory. Levels of zero refractive index and their significance are discussed and the effect of prominences is considered.

DOI:10.1049/pi-3.1950.0083

出版商:IEE    

年代:1950

数据来源: IET

DOI:10.1049/pi-3.1950.0091

出版商:IEE    

年代:1950

数据来源: IET

DOI:10.1049/pi-3.1950.0092

出版商:IEE    

年代:1950

数据来源: IET