摘要:

The paper reviews briefly the history of stereophonic reproduction. The principal basic systems with their underlying ideas are described and compared. Some account is given of the supposed mechanism of natural binaural listening from the viewpoint of direction localization.The principles and practice are discussed of a particular system for domestic use, derived from the early work of A. D. Blumlein, and characterized by the use of spaced loudspeakers driven in phase, to which the name ‘stereosonic’ has been given. The aims of this system are defined, and the mathematical theory involved in its use is developed. Limitations and sources of error in the results achieved are described.Equipment used in the making of master recordings and some of the problems of studio technique involved are described. Consideration is given to the form which a domestic stereophonic record should take, and the standards to which such a record should conform, together with the requirements which these impose on the reproducing equipment.

DOI:10.1049/pi-b-1.1957.0180

出版商:IEE    

年代:1957

数据来源: IET

摘要:

The paper describes a new analogue computer which has been constructed at the Atomic Energy Research Establishment. It is to be used for nuclear power studies and comprises three main sections, namely the reactor-kinetics section, the control-system section and the thermal-system section. The design of these sections and their interconnection is described in detail, and brief reference is made to some of the problems which will be studied with this new computer.

DOI:10.1049/pi-b-1.1957.0183

出版商:IEE    

年代:1957

数据来源: IET

摘要:

The process of xenon poisoning, and its relation to the operation of a high-flux nuclear reactor, are discussed. An analogue computer which gives the present value of xenon poisoning, and an associated predictor which can be used to plan future reactor operations, are described. This computer-predictor is to be used as a reactor operator's tool.

DOI:10.1049/pi-b-1.1957.0184

出版商:IEE    

年代:1957

数据来源: IET

摘要:

The paper describes the design and construction of the Medical Research Council fixed-frequency cyclotron, which is to be used for research in radiotherapy and radiobiology and for the production of radioactive isotopes for diagnostic, therapeutic and medical research purposes.The machine is designed to maintain an output of 200μA of 15 MeV deuterons in an external beam under routine operating conditions.Special care has been taken throughout the design to ensure ease of maintenance and reliable routine operation.

DOI:10.1049/pi-b-1.1957.0187

出版商:IEE    

年代:1957

数据来源: IET

DOI:10.1049/pi-b-1.1957.0190

出版商:IEE    

年代:1957

数据来源: IET

摘要:

Methods requiring only measurements of impedance are used to investigate the efficiency of resistance-type milliwattmeters at frequencies of 9.2 Gc/s and 3 Gc/s (wavelengths of 3.26cm and 10.0cm). For fine-wire bolometers the results agree with those obtained by calorimetric methods and are consistent with the few results previously available at lower frequencies. Accurate values of efficiency cannot be obtained by impedance methods, in their present form, for thermistors at microwave frequencies owing to the uncertainty regarding the precise impedance of the semi-conducting bead.

DOI:10.1049/pi-b-1.1957.0191

出版商:IEE    

年代:1957

数据来源: IET

摘要:

The capacitance between the anode and the control grid of a certain type of receiving pentode has been found to increase with life, the rate of growth being dependent on the operating conditions of the valve and on the material and processing schedule of the anode. It is shown that the phenomenon is due to the transfer of impurity carbon from the anode to the mica insulators.

DOI:10.1049/pi-b-1.1957.0192

出版商:IEE    

年代:1957

数据来源: IET

摘要:

Controlled measurements of the d.c. electric strength of certain pure liquid poly-dimethyl siloxanes or silicones are reported. The liquids tested were the four lower members of the D.C. 200 series of silicone fluids having viscosities of 0.65, 1, 1.5 and 2 centistokes. The measurements were made under conditions identical with those employed for earlier experiments on puren-paraffins which have a similar molecular structure, so that useful comparisons could be made. The use of a hydrogen-thyratron circuit to by-pass the discharge energy when breakdown occurred was found to be essential, since the discharge products, which probably included silica, were appreciably greater than for then-paraffins.Like that of then-paraffins, the strength of the silicones, which is of the order of 900kV/cm, was found to increase with chain length and with decreasing test-gap. The liquid of 0.65 centistokes viscosity was also tested over the temperature range −55°C to 85°C, and it was found that the strength increased with decreasing temperature, the increase being most marked at temperatures below about 20°C. This behaviour is similar to that of then-paraffins already tested and cannot be ascribed to density changes alone.

DOI:10.1049/pi-b-1.1957.0193

出版商:IEE    

年代:1957

数据来源: IET

摘要:

Measurements have been made to determine the effects of varying the argon content of glow-discharge stabilizer tubes on the striking and running voltages, the magnitudes and durations of the initial drifts, the running-voltage/temperature and running-voltage/current curves and the impedance/frequency and noise characteristics. Neon-filled and helium-filled tubes, with argon contents varying from zero to 3.5% and having cerium cathodes, have been specially manufactured for the investigations. The results of the work are presented here and discussed.

DOI:10.1049/pi-b-1.1957.0195

出版商:IEE    

年代:1957

数据来源: IET

摘要:

An equipment is described whose primary purpose is to display variations in the r.f. admittance of low-level detector crystal valves during the adjustment process. For this purpose the input power level must not exceed about 5μW. The method is not, however, limited to this application but may be applied to microwave transmission systems generally.Information relating to the r.f. admittance is derived from four detector probes mounted with spacings of 3λ/8 along a standing-wave detector carriage. This is utilized electronically to actuate the deflecting plates of a cathode-ray tube in such a manner that a direct display of the Smith diagram is obtained on the face of the tube.The above principles are incorporated in an equipment operating at 3.2cm, but with an appropriate 4-probe standing-wave detector this could be used at any wavelength.

DOI:10.1049/pi-b-1.1957.0196

出版商:IEE    

年代:1957

数据来源: IET