Abstracts of Bell System Technical Papers Not Appearing in this Journal (01 April 1928)

The Action of Fluxes in Soft Soldering and a New Class of Fluxes for Soft Soldering.3 R. S. DEAN and R. V. WILSON. This is a report of basic studies of soldering fluxes undertaken by the authors. It was found that the fluxing action depends on the evolution at soldering temperatures of HC1 gas or other halogen acid gases which have been found to be effective soldering fluxes. Based on this discovery soldering fluxes have been found among the organic compounds and the way opened for the development of a truly non-corrosive flux. Certain Topics in Telegraph Transmission Theory. 4 H. NYQUIST. 

The author gives results of theoretical studies of telegraph systems which have been made from time to time. Among other things he points out that although the usual method of determining the distortion of telegraph signals is to calculate the transients of the system an alternative method is based on the steady state characteristics. For the first method the telegraph wave is taken as a function of t and for the second as a function of CJ. 

A discussion of the minimum frequency range required for transmission at a given signaling speed is also included in the paper. Experiments and Obseroations Concerning the Ionized Regions of the Atmosphere.5 R. A. HEISING. Experiments are described in which a virtual height of the reflecting ionized region was measured using time lag between radio signals arriving over a direct and the reflected path. Heights were found of 150 to 400 miles with vertical movePhys.