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Z and Q


"H. F. Resistance and Self-Capacitance of Single-Layer Solenoids", R G Medhurst (GEC Research Labs.). Wireless Engineer, Feb 1947 p35-43, Mar 1947 p80-92.

"Q of Solenoid Coils", M V Callendar, Wireless Engineer, (Correspondence) June 1947 p185.

"Q of Solenoid Coils", R G Medhurst, Wireless Engineer, Sept 1947 p281.

'Distrene' is a trade name for polystyrene.

The documents listed above are available in a zip archive from: www.classictesla.com (accessed 5th Jan 2016). The zip file is listed on the Classic Tesla downloads page . The references cited by Medhurst (at the end of the second part, March 1947, p92) are repeated below with corrections and, in some cases, abstracts.

References for Medhurst 1947

[1]  S. Butterworth. "Eddy-Current Losses in Cylindrical Conductors, with Special Applications to the Alternating Current Resistance of Short Coils."
Phil. Trans. Roy. Soc., 1922, A222, p. 57.

[2]  S. Butterworth. "Note on the Alternating Current Resistance of Single Layer Coils". Phys. Rev., 1924, Vol. 23, p. 752.

[3]  S. Butterworth. "On the Alternating Current Resistance of Solenoidal Coils." Proc. Roy. Soc., 1925, A107, p. 693.

[4]  S. Butterworth. "Effective Resistance of Inductance Coils at Radio Frequencies." Exp. Wireless & Wireless Engineer, 1926, Vol. 3, pp. 203, 302, 417 and 483.

[5]  S. Butterworth. "Designing Low-Loss Receiving Coils."
Wireless World, 1926, Vol. 19, pp. 754 and 811.

[6]  G. W. O. Howe. "The High-Frequency Resistance of Wires and Coils."
J.I.E.E., 1920, Vol. 58, p. 152.

[7]  C. N. Hickman. "Alternating Current Resistance and Inductance of Single-Layer Coils." Scientific Papers of the Bureau of Standards 1923, Vol. 19, P. 73.

[8]  W. Jackson. "Measurements of the High-Frequency Resistance of Single-Layer Solenoids," J.I.E.E., 1937, Vol. 80, p. 844.

[9]  A. H. Meyerson. "Coil Q Factors at V.H.F." Communications, May 1944, p. 36.

[10]  W. N. Tuttle. "Bridged-T and Parallel-T Null Circuits for Measurements at Radio Frequencies." Proc. I. R. E., 1940, Vol. 28(1), p. 23.
Bridged-T and parallel-T null circuits may, under some circumstances, be preferable to bridge circuits for radio-frequency measurements as no transformer is required and the generator and detector can have a common grounded terminal. An analysis of the circuits can be made in terms of the transfer impedances of the various possible component T networks so that the nature of possible null conditions becomes evident by inspection. The circuits considered include arrangements suitable for the measurement of resistance, reactance, and frequency, and of the power factor of dielectrics. Some of the circuits, particularly suited to high-frequency work, employ neither coils nor variable resistors.

[11]  D. B. Sinclair. "The Twin-T, A New Type of Null Instrument for Measuring Impedance at Frequencies up to 30 Mc." Proc. I. R. E. 1940, Vol. 28(7), p. 310.
A null instrument for measuring impedance at high frequencies is described. The circuit used is of the parallel-T, rather than of the conventional bridge type. The inherent adaptability of this circuit for use at high frequencies makes possible an upper frequency limit of 30 megacycles, which is considerably higher than that previously obtainable in commercial types of null instruments. The residual parameters causing error are noted and measures taken to minimize them discussed. Methods of measuring them and of correcting for their effects are given.

[12]  F. E. Terman. "Radio Engineers' Handbook."
McGraw-Hill Book Company, 1943.

[13]  C. R. Burch & N. R. Davis. "On the Quantitative Theory of Induction Heating." Phil. Mag., 1926, Vol. 1, p. 768.

[14]  A. J. Palermo. "Distributed Capacity of Single-layer Coils."
Proc. I. R. E., 1934, Vol. 22, p. 897.
The results of previous work done on the distributed capacity of single-layer coils are briefly outlined. Previous theory and experiment do not agree. The reasons for this disagreement are discussed. Two important parameters were omitted from previous theory. The theoretical part of the present paper yields a formula which includes these two additional parameters. This formula is substantiated by experimental evidence and gives the internal capacity of short single-layer coils. By a short single-layer coil, the author means one whose length of winding is, at most, of about the order of the diameter of winding. Any capacity due to leads or terminals should not be considered as part of the internal coil capacity but should be treated separately.

[15]  J. H. Morecroft. "Resistance and Capacity of Coils at Radio Frequencies."
Proc. I. R. E., 1922, Vol. 10, p. 261.

[16]  J. C. Hubbard. "On the Effect of Distributed Capacity in Single-layer Solenoids." Physical Review, 1917, Vol. 9, p. 529.

[17]  G. W. O. Howe. "The Calibration of Wave Meters for Radio-Telegraphy."
Proc. Phys. Soc., 1911, Vol. 24, p. 251 - 259.
Wave-meters consisting of a variable air-condenser and a set of coils can be calibrated approximately by calculation from the known capacity of the condenser and the inductance of the coils. The most probable source of error is that due to the capacity from turn to turn of the coil. This can be allowed for, with sufficient accuracy for all practical purposes, by finding the natural frequency of the coil alone and calculating its effective or self-capacity on the assumption that the whole steady current inductance of the coil is effective even when it is oscillating freely. This capacity is then added to the capacity of the air-condenser. Another method of finding the required correction by comparison of the results obtained on the overlapping portion of the ranges of two coils is also described. The correction can be made small by suitably designing the coils.

[18]  P. H. Massaut. "Distributed Capacitance Chart."
Electronics, March 1938, Vol. 11, p. 31.

[19[  G. W. O. Howe. "On the Capacity of Radio-Telegraphic Antennae." Electrician, 1914, Vol. 73, pp. 829, 859, 906.

[20]  G. W. O. Howe. "Inaugural Address to the Wireless Section."
J.I.E.E., 1922, Vol. 60, p. 67.

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