Abstract :
It is known that the phase velocity in continuously-wound delay lines changes with frequency, at high frequencies, owing to various causes. The effect of the self-capacitance of the winding on the velocity and on the characteristic impedance is here determined by a simple method. A direct treatment is given of the decrease in the inductance per unit length which occurs when the wavelength along the coil is not very large compared with the winding diameter. The two effects have opposite influences on the velocity, and a fair degree of cancellation can be attained if a certain relationship between the parameters is satisfied.
