Radio today (Sept 1935-Dec 1936)

A NEW DIRECT MAIL SERVICE IN RADIO TWTANY advertisers have found ■*-"■* difficulty in getting a really efficient mailing service. The demand has been for mailings to supplement or intensify trade paper campaigns, to run independently, to make special announcements or to send out literature giving greater detail than is usually given in space advertisements. Knowing of RADIO TODAY'S new technique in building lists for circulation purposes, these advertisers have wanted a corresponding efficiency in their direct mail work. Now, through an affiliation with the W. P. Woodall Company, RADIO TODAY is able to offer a comprehensive radio mailing service. W. P. Woodall is a direct mail specialist. He organized and managed the McGraw-Hill direct mail department for 10 years and recently resigned to establish his own company to specialize in radio mailing service. In conjunction with that work, the Woodall company will manage and operate the direct mail division of RADIO TODAY. In providing this additional approach to the radio market, the Woodall company will use strictly up-to-date lists of worth-while concerns, all classified so as to permit the selection of desired groups, and to omit all unwanted groups. The service is available to manufacturers, jobbers and others desiring to reach any division of the radio field with direct mail advertising. In selectivity and coverage, it will match precisely the sales effort of the advertiser, whether that effort is directed to vocational groups, or territorially, or both. Full information on new lists and breakdowns, mailing rates, etc., may be obtained through this publication. RADIO TODAY 480 Lexington Ave. New York, N. Y. SERVICE NOTES {From, page 53) No implication is intended by the use of the term "equivalent" that the tubes so indicated are interchangeable. Where two or more types are listed together in any one of the group columns, it is indicated that, while there exists differences in characteristics, nevertheless the general function and classification of these two or more types are the same. Note : The information contained in the tabulation is intended for the convenience of the serviceman in familiarizing himself with new tubes and should not be used in replacement work. PROTECTING ANTENNA TRANSMISSION LINES * Service note from Philco suggests using a short section of braided loom at the top nail-it-knob insulator to keep the transmission line from breaking due to swaying (see illustration). Loom prevents Jerks from being applied at any single point and eliminates sharp angles in the transmission feeder. The braided loom can be purchased at any electrical supply house. IMAGE FREQUENCIES— HOW TO USE THEM IN ALIGNING SETS * While alignment of the oscillator and r-f. circuits of all-wave superhets is practically the same for all bands, on the high frequencies care must be taken to align the oscillator at the correct frequency. Theoretically the oscillator frequency can be either above or below the signal frequency of the 1st detector, but for proper operation it must be the frequency for which the manufac(To page 56) CAPACITOR ANALYZER and RESISTANCE BRIDGE 6, 'APACITY, power factor, leakage, resistance, directly on the panel! The highly sensitive No. 6E5 Cathode Ray Tube is used for balancing. Dials are color-coded to match settings. A refined and extended Wien bridge, built into instantly useful form for laboratory, shop and field work. Jobbers In All Leading Cities SOLAR MFG. CORP. 599-601 Broadway, New York, N. Y. PERFORMANCE PLUS This Practical "CHANGEABLE" FEATURE SPEAKERS by OXFORD • Hear one of these new Oxford "Changeable Field" Dynamic Replacement Speakers! Then see how easily and economically you can change the field to suit your needs! Universal transformer matches any tube. Voice coil remains centered. Ideal for Service Men and Amateurs ! Available in 6", S" and 11" Models. Ask your Jobber — or write Now for Bulletin 361T EXPORT DIVISION: 1 5 Laight Street, New York, N. Y. Cable: "ARLAB" "ACCEPTED BY SOUND JUDGMENT" OKFORD-THRTHK WESSEEMiaMSBEaiA 54 Radio Todax