1935 Patio Man's Guide PUBLISHED BY [RN A E DI WS O SHORT WAVE RADIO 1935 RADIO MAN'S GUIDE CO NTENTS RADIO SET BUILDING 3 Radio Symbol Charts 2 The Pelham (1-Tube Short-Wave Set) 3 The Skyscraper (3-Tube T.R.F. Short-Wave Receiver) 5 The "Skyscraper" Power Pack (For Small S. W. Sets) 8 LS2 The Trophy Winner (4-Tube Short-Wave Set) 9 An A.C.-D.C. Midget (4-Tube Broadcast Receiver) 9 Radio Prieto, Buenos Aires The All-Star Senior (6-Tube All-Wave Receiver) 11 A High-Fidelity Receiver (8-Tube T.R.F. Broadcast) 13 SERVICING AND LABORATORY INSTRUMENTS 15 This book is dedicated to the tens Ohmmeter Design 15 of thousands of radio men, lo- A Portable Tube Checker 17 cated throughout the world, who A Direct-Reading Slide-Wire Bridge 20 read RADIO NEWS each month. A Vacuum Tube Voltmeter (All-Purpose, A.C. Operated) 21 The 1935 Radio Man's Guide has A 100-22,000 Kc. Signal Generator 24 been compiled and edited from RADIO TROUBLE SHOOTING 28 the works of many outstanding Part One—Symptoms of Defective Receivers 28 radio experts and the editors feel Part Two—Service Procedure 31 certain that it will prove to be Tube Characteristic Chart 32 one of the year's outstanding radio publications. Your com- DX AIDS 39 ments will be appreciated. Fundamentals of Short-Wave Radio 39 International Call Letters 41 Foreign Broadcast DX'ing 41 "Double-Doublet" Antenna System 42 • World Time Conversion Chart 43 World Distance Maps 46/ ' Edited by "HAM" NOTES 47 Radio Amateur Abbreviations 47 ,Laurence M. Cockaday "Q" Readability System 47 "R" Audibility System 48 "T" Tone System 48 Associate Editors Hints on R. F. Amplifiers (For Amateur Transmitters) 48 Walter H. Holze PUBLIC ADDRESS SYSTEMS 52 William C. Dorf A Powerful 6-Tube P. A. System 52 A Rack and Panel Amplifier 54 .EXPERIMENTAL RADIO DATA 56 • Charts For aperimenters 56 A Simple Electronic Alarm 56 Capacity, Frequency and Inductance Chart 57 Copyright 1935 Resistance and Capacity Chart 58 Ohm's Law Chart 59 Teck Publications, Inc. STATION LISTS 60 461 Eighth Avenue U. S. Broadcast Stations (By Call Letters) 60 New York, N. Y. U. S. Broadcast Stations (By Frequencies) 62 Foreign Broadcast Stations 63 Printed in the U. S. A. Municipal Police Radio Stations 63 State Police Radio Stations 64 World's Leading Short-Wave Stations 64 2 1935 RADIO MA N'S (;t711;7. RADIO NE WS SY M B OL CH ART DOUBLEPo LE- — 0 WIRES - 1 - ° — HALF- WAVE 01 ( DOUBLE CRYSTAL 0 CONNECTED I RECTIFIERS 0 THRO W — 0 c.— MICROPHONE - SWITCH (8I 84 ETc) WIRES SIN GLE 0 0 FULL- WAVE 0 NOT DEC K ra i M ULTI- 0 c. M AGNETIC RECTIFIERS CONNECTED POINT PICKuP (80,25Z 5 ET C.) S WITC H 0 MULTIPLE ,5 .3 . FIXED DECK- 0\ 0 TRIODES RESISTOR M ULTI- ° CR YSTAL 0 a POINT PIC K U P re (04A,27 ETC) SWiTCH VARIABLE -4A)441 44- SCREEN I I SINGLE A GRID AERIAL RESISTOR CELL H TUBES (22,24 ETC.) 0 0 1 1 POTENTIO- DOUBLET 1 BATTERY A lli PENTODES ilifSk , 0 M ETER II H r (47, 2A5,ETC.) 0 PENTODE OR TR PLE FIX E D .1. GRID TUBE INDIRECTi LOO P LY HEATED.WITH CON DEN SER F USE CVAJO 7 SUPPRESSDR GRID • • PRONG. 57.58,6D6,6C6 ETC.' VA RIABLE OPEN i I( v---o CON DENSER T. 1... GROUN D 1--,_ CIRCUIT DOUBLE DIODE -,T JA C K • TRIO DE (55,75 ETC) ELECTROLYT I C I+ 7--- \ DOUp,kiTODDIOEDE CON DENSE R I_ 0 PHONEs 0 0 RECTIFIE R al 7 (2137, 6B7 ) AIR CORE i M AGNETIC 0 PENTAGRID INDUCTANCE .0.'" SPEAKER 1 M ETERS 0 ‘0. TUBES (4A6 ,6A7) 0 — Qs — COUPLE D g. E R.F. DYN A MIC ___L'e _ PO WER -4\...,•-\.,,N, TRIODE le ) COILS SPEAKER G C LINE PLUG4' : PENTOD E 10001 flaISIII 6 F7 HALF-WAVE VARIO- it < RECTIFIE R 0 CRYSTAL 'l DOUBLE GRID TUBE COU PLER COL D DIRECTLY SPEAK ER CATH O DE, HEATE D GAS EOU S. 49,46. : CARBO N FULL-WAVE VA RIO- MICROPHONE 114 RECTIFIE R FULL -W AVE II C OLD CLASS B M ETER SIN GLE oil= _ C ATH O D E, TU BES _ BUTT O N GASE OU S (49, 53, ETC.) • ei IRON CORE COIL (A.F. [ C ARBON CHOKE ) rMICROPHONE NE ON * )1].4 (GLO W) W U N DE RLIcH AU TO- DOU BLE TU BE TRANS- BUTTON FOR M ER TRANS- 0) f_, CONDENSER I FOR M ER PIL O T 0 '5 ,---- MICROPH ONE I TRIPLE T WIN ...k ‘.. LA M P — 1 e 2B6 SINGLE POLE 1 VELOCIT Y " I SINGLE THRO W MI K E . PH OTO RECTIFIER- S WITC H . CELL (RIBB O N) ' PO wER- PENTODE 4 2 A7 ' 1935 RADIO MAN'S GUIDE 3 Radio Set Building OST Americans really enjoy doing things to set-building during the past year. RADIO NEWS with their own hands and co-ordinating their has specialized in the better designs incorporating rnworkmanship with their own individual brain these latest principles. Our technical staff maintains power. That is why Americans have always been inter- steady contact with America's foremost designers in ested in radio construction. Recently set-building has the "How to Build" field. been growing in popularity, in leaps and bounds; at Herein we are giving to our readers a number of least, that is how it is with RADIO NEWS readers. designs in different fields, some simple and some In fact, set-building as a hobby seems to have more complicated. The Editors feel that these de- engaged the interest of more radio fans recently than signs are the finest that have been put before the at any time since the popular home-construction days set-building public for some time and that they offer of 1924. People, young and old, are turning to the set-builder the chance he has been waiting for to set-building at home to enable them to listen in to build a receiver really worth while and one that will short-wave transmissions from all over the world. produce results in both distance reception and in It is true that the increase of activity on the short high quality of reproduction. waves has had a lot to do with this revival of inter- RADIO NEWS' policy of putting out blueprints of est, but it is also true that people want to build not its main designs will also be found to be a help to only short-wave sets, but sets that will bring in the set constructors, and as the list of available blueprints regular broadcast-band transmissions. grows, the Editors promise that efficient receivers Realizing these needs of a large number of radio for any kind of use and fitting any pocketbook will experimenters who have been "steady customers" in be adequately covered. Follow RADIO NEWS designs the more experienced set-building field as well as , in your experimental set-building, and you cannot the thousands of new recruits who have been turning go far wrong! The Pelha m (1-Tube Short-Wave Set) ' T HE circuit shown in Figure 1 is results. The switch SW is the lower positive terminal. In the building of a modern version of the "Junk central control on the panel and is this set, these four terminals are Box" circuit, made so famous by used for turning the set "on-and-off." brought out to binding posts on the RADIO NEWS in 1928, and found to be, The tube used is a type-30 three- back edge of the baseboard, as are by thousands of fans, one of the element tube in the plate circuit of also the two terminals for the antenna most popular single-tube short-wave which is found a choke coil, RFC, and and the ground. This may be seen sets. a condenser, C5, which act as a filter clearly in the photographic illustra- It uses a standard set of triple- to keep redio-frequency currents out tions, Figure 2 and 3. Two more bind- winding, short-wave coils shown as of the 'phone circpit so that the set ing posts are used for the phones. Li, L2 and L3. It has an antenna con- will not have "hand capacity." In building the set, the first job is denser, Cl, for adjusting the antenna Going back to coil Li, this is the to make the frame, consisting of front frequency. This is placed on the base- antenna coil, while L2 is the grid coil panel and baseboard. Details and sizes board. Another condenser, C2, the left- and L3 is the feed-back coil. , of this framework are shown in hand control on the panel, is used for The set is powered by dry cells and Figure 4. tuning. It is very sensitive to adjust. all that is necessary is two ordinary After the framework has been put The third condenser, C3, which is the bell-ring batteries, connected in series together with a good grade of glue right-hand control on the panel, is across the two terminals marked A and small screws and given a coat of used for controlling volume through (plus) and A (minus), where A (plus) shellac (if desired), the next job is to regeneration. The condenser, C4, is goes to the positive terminal and A mount the parts in their proper places.