摘要:

A description is given of a method of locating dry joints in telecommunication cables. The method is based upon the non-linear properties of dry connections and has been used successfully on both land and submarine cables.

DOI:10.1049/pi-b-2.1959.0320

出版商:IEE    

年代:1959

数据来源: IET

摘要:

The paper gives a simple theoretical approach to the problem of cross-modulation distortion arising from frequency pulling in, or in direct conjunction with, a frequency-modulated klystron. An expression for the distortion spectrum relative to the fundamental component is derived, and on the basis of this expression a family of curves illustrating the severity of the distortion is computed and plotted on a logarithmic scale. It is shown that even small mismatches on the far end of a relatively short feeder into which the klystron is working give rise to serious crosstalk which, if not remedied, sets a limit to the quality of the modulator unit.

DOI:10.1049/pi-b-2.1959.0321

出版商:IEE    

年代:1959

数据来源: IET

摘要:

The paper describes part of an investigation aimed at developing a multi-megawatt pulsed travelling-wave tube. To this end, a multistart helix structure which may be water cooled has been considered both theoretically and experimentally.Theoretical relationships have been determined for the axial series impedance of a sheath helix surrounded by a perfectly conducting cylinder, and for the phase velocity of the propagating modes. Results of experiments on four- and eight-start helix structures are found to give reasonable correspondence with the theoretical results for equivalent bounded sheath helices.

DOI:10.1049/pi-b-2.1959.0322

出版商:IEE    

年代:1959

数据来源: IET

摘要:

An improved bandwidth has been obtained from a six-cavity pulsed S-band klystron amplifier by the use of a double-tuned output circuit. The output power was greater than 2.5 MW over a 6.3% bandwidth when the drive power was optimized at each wavelength, and greater than 2 MW over a 5.5% bandwidth with a constant drive of 25 watts. The power in the electron beam was 10 MW.

DOI:10.1049/pi-b-2.1959.0323

出版商:IEE    

年代:1959

数据来源: IET

摘要:

The paper outlines the problem of the measurement of the Q-factors of resonators for the C.E.R.N. linear accelerator. The Q-factors involved are of the order of 105, and the resonant frequencies are in the range 200–300 Mc/s. The methods considered are briefly discussed, and the one which seems most suitable employs sinusoidal amplitude modulation. The accuracy depends on a low-frequency phase measurement, and, for this reason, accurate knowledge of the power law of the detector is not required. The modulation component undergoes a phase shift owing to the high Q-factor of the resonator. When this attains a magnitude of π/4 rad, the Q-factor is given by one-half of the ratio of the resonant frequency to the modulation frequency. Two alternative procedures are described. A mathematical treatment of the theory and some experimental results are included in Appendices.

DOI:10.1049/pi-b-2.1959.0324

出版商:IEE    

年代:1959

数据来源: IET

摘要:

If a tapered section is suitably matched at the transitions between two uniform waveguides, the electrical length of the taper is usually taken to be its physical length. It is shown here that a small correction is necessary on account of the cylindrical nature of the wave which propagates in the taper region, and a simple expression for the correction is found for a rectangular waveguide in the dominant mode.

DOI:10.1049/pi-b-2.1959.0327

出版商:IEE    

年代:1959

数据来源: IET