Radio Broadcast (May-Oct 1926)

What's New at the Radio Shows A PreView of the New the Radio Set, While ] Fundamental Circuit erent m BY EDGAR H. FELIX BEAUTY ATiD UTILITY COMBINED The new Bosch "Cruiser" receiver, displayed in an unusual domestic setting. This is a two-control model with concentric \nob for onehand manipulation and typifies the sort of receiver offered the 1927 purchaser N "O MATTER what special features the visitor to the radio show may seek, he will find receivers which, apparently, have been designed to fit his particular needs. The broadcast listener, who uses his radio for the musical entertainment and pleasure it gives him, will appreciate particularly the improvements in fidelity of reproduction attained by better audio coupling methods, shielding and power tubes, the flexible volume controls which do not introduce distortion, the many convenient single and dual-tuning control receivers and the better power supply devices which reduce his maintenance duties to a minimum. The long distance enthusiast will find his requirements met by a large selection of highly sensitive and selective receivers with as many as four stages of radiofrequency amplification, so precisely synchronized that single and dual-control is feasible. In deference to the lady of the house, manufacturers have incorporated significant advances in ease of control, beauty of appearance and simplicity of maintenance. Several makers are showing receivers having a single tuning control with an illuminated indicator, calibrated by stations or wavelengths, taking the guesswork and uncertainty out of tuning. She will also be pleased with the advances made in appearance, not only of the set cabinet itself, but in the complete sweep which has been made of unsightly accessories, such as B batteries, storage batteries, chargers, and loud speakers. In the heller grade re ceivers, there is adequate space for every element necessary to the operation of the set. The engineer, visiting the radio shows, will sigh with relief at the disappearance of the "revolutionary circuit" fairy tales which, in past years, have circulated at the beginning of each season. 1927 ushers in design improvements instead of discoveries in circuit design which are claimed to be millenial. The industry has finally settled down to making its product a better performer by painstaking design and workmanship rather than seeking the attainment of the impossible by a mere rearrangement of parts in new combinations. RECEIVER DESIGN AND WORKMANSHIP HAVE IMPROVED THE technical expert finds the 1927 receiver a real advance in refinement of design and workmanship. Thoroughly shielded radio-frequency stages improve selectivity and stabilize operation. Precisely calibrated radio-frequency tuning represents a degree of precision manufacture entirely new to the industry. Adequate power tubes with a choice of effective coupling methods between stages have provided the 1927 purchaser with audiofrequency amplification of remarkable fidelity and flexibility. Loud speakers, combined in self-contained sets, are greatly improved and contrast pleasingly with the cramped, inadequately small sound projectors of earlier vintages. So much for generalities as to the year's improvements. We will consider the products of various manufacturers and how they have incorporated these and other improvements. We regret that mention of many meritorious products is necessarily omitted because data was not received in time to be incorporated in this article. Single tuning-control receivers arc considered first only because they represent the most striking, if not the most important tendency of the season. Although the future predominance of the single-control receiver is by no means established, many manufacturers are building at least one model of that kind. A few which have come to our attention are the Ail-American, Apex, Atwater Kent, Bosch, Cardinola, Chelsea, Crosley, A. C. Dayton, Diva, Distantone, Elkay, Federal, Freed-Eisemann, Ferguson, Franklin, Garod, Hunt, International, Kodel, Kolster, Magnatone, Magnavox, Mazda, Melodyne, Metro, Midwest, Mohawk, Morton, Murad, Okay, Operadio, Penna, Perlesz, Pfanstiehl, Priess, Radiola, Ray Isler, Rodgers, Showers, Simplex, Splitdorf, Shamrock, Stewart-Warner, United, Wilcox, and Windsor. From the foregoing, one should not conclude that these single-control sets predominate at the shows. In fact, it is probable that there are more two-control receivers than one-control being offered to the public. Having two hands, the user is expected to be able to manipulate both controls simultaneously and in synchrony. In so doing, these manufacturers contend, they obtain greater efficiency because the radio-frequency circuits are thereby more accurately tuned than they would be if operated by a single control. StrombergCarlson, for instance, the pioneers in quantity manufacture of multi-stage, shielded radio-frequency receivers, is concentrating its output upon two-control re THE PFANSTIEHL MODEL 20 An excellent single-dial receiver, calibrated directly in wavelengths. The dial is illuminated from the rear. Utter simplicity marks this handsome model. Price $125.