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Displaying Results 1 - 8 of 8
• ### Migration of engineers

Publication Year: 1967
| PDF (102 KB)
• ### A hot electron, cold cathode, emitter

Publication Year: 1967, Page(s):347 - 352
| | PDF (796 KB)

A hot electron, thin-film, cold-cathode device is described which has an emission efficiency much higher than previously reported for similar cathodes. Measurements of the emission current and distributionat various voltages indicate the importance of a coherent scattering process, which if not considered in the design of the cathode will severely limit the emission efficiency. The important condi... View full abstract»

• ### Digital read-out echo sounder

Publication Year: 1967, Page(s):353 - 360
| | PDF (2059 KB)

The trend towards automation in hydrographic survey and oceanography calls for automatic read-out of depth from an echo sounder. A system of signal selection is described which includes an automatic time gate synchronized with the sea-bed echo. Automatic gain control is also used to maintain optimum amplitude discrimination throughout varying conditions. A recording echo sounder forms an integral ... View full abstract»

• ### Simultaneous use of sideways-looking sonar, strata recorder and echo sounder

Publication Year: 1967, Page(s):361 - 368
| | PDF (8934 KB)

In geological survey, the simultaneous operation of these three equipments on one vessel can have considerable merit. The sideways-looking sonar (known as the Transit SonarÂ¿) has a range of 600 yd and gives an approximately true plan of the sea bed on dry paper 6 in. wide when the ship moves at 5.7 (or 2.85) knots over the ground. The record produced by the Transit SonarÂ¿ may be readily correl... View full abstract»

• ### Television wired broadcasting systems

Publication Year: 1967, Page(s):369 - 383
| | PDF (2056 KB)

The paper outlines the growth of television wired broadcasting in the United Kingdom. After considering the fundamental problems involved in the use of video h.f. and v.h.f. frequencies, it describes the way these problems have been solved for h.f. and v.h.f. systems. Brief descriptions of practical h.f. and v.h.f. systems are given and this is followed by a comparison of the relative costs of the... View full abstract»

• ### An optical communication link for laboratory demonstration using microwave modulation of the light beam

Publication Year: 1967, Page(s):384 - 386
| | PDF (259 KB)

A simple system designed to demonstrate the possibility of transmission of information over an optical path, using a microwave sub-carrier, is described. It is shown that a satisfactory signal/noise ratio can easily be obtained under laboratory conditions, and the practical limitations of such a system are briefly outlined. View full abstract»

• ### A new sound velocity meter

Publication Year: 1967, Page(s):387 - 393
| | PDF (665 KB)

The design of a new instrument for measuring the velocity of sound in sea water with improved accuracy is described. A particular feature of the instrument is that it may be towed through the water without causing appreciable errors View full abstract»

• ### Conversion of a PAL Colour-Television Signal into a Symmetrical Dot-sequential Signal

Publication Year: 1967, Page(s):394 - 400
| | PDF (602 KB)

An N.T.S.C.-type colour-television signal can be converted into a driving signal for a one-gun display tube without full demodulation of the sub-carrier signal. With the adoption of the PAL system for colourtelevisionbroadcasts in many countries of Europe the question arises whether similar methods can be devised for transcoding a PAL signal into a driving signal for dot-sequential display systems... View full abstract»