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The analysis of structural return loss in CATV coaxial cables leads to the following conclusions: (1) SRL spikes (resonances) occur when the period length is equal to a half wavelength and integral multiplies of half wavelengths. (2) Maximum SRL spikes occur when the period is symmetrical. (3) The SRL spike due to the fundamental frequency can be of a lesser amplitude than spikes caused by the harmonic frequencies depending upon the asymmetry of the irregularity period. (4) The length of cable that can be effectively measured varies inversely with cable attenuation. It follows, therefore, that periodic impedance changes are more critical in low attenuation cables. (5) For a specific SRL value, the recent extension of requirements from 216 MHz to 300 MHz adds to the difficulty of meeting the requirement. (6) The recommended procedure for testing SRL is to match the cable average impedance by employing a variable bridge and termination. When a fixed 75 ohm bridge is used to measure cable whose impedance differs from 75 ohms, the voltage due to the mismatch may vectorially add to or subtract from the reflected voltage. By cutting a small length from the cable, the phase relationship of the unbalance voltage and reflected voltage may subtract to provide a better SRL reading. (Author), Prepared for presentation at the International Wire and Cable Symposium (17th), Atlantic City, N. J., 4-6 Dec 68.

The manufacture, storage and installation of long lengths of telephone cable is becoming increasingly desirable as handling and installation techniques improve. It is well known that electrical testing of long cable lengths is complicated by propagation effects which introduce errors into measured values. This paper presents a simplified method of determining low frequency true mutual capacitance on long cable lengths by one open circuit admittance measurement. (Author), International Wire and Cable Symposium (16th) Atlantic City, N. J., 29, 30 Nov-1 Dec 67.