Radio Broadcast (May 1929-Apr 1930)

~z_ RADIO BROADCAST Here's the Answer to every question about the principles, methods, or apparatus of radio transmitting and receiving. THE RADIO MANUAL A Complete Course in Radio Operation In a Single Volume A Handbook for Students Amateurs Operators Inspectors For the first time an entire course of training in one book — the most complete and up-to-date work on radio. Developed sim ply and clearly from the elementary stage right through all phases of principles, practise, and apparatus so that a beginner with no knowledge of electricity ay get all he needs either for amateur operation or to qualify for a government license as operator or inspector. Prepared by Official Examining Officer The author, G. E. Sterling, is Radio Inspector and Examining Officer, Radio Division, U. S. Dept. of Commerce. The book has been edited in detail by Robert S. Kruse for five years Technical Editor of QST., the Magazine of the Radio Relay League. Many other experts assisted them. Id ChnntoYQ Cnriov Elementary Electricity JO ^napierS UOt/er. and Magnetism; Motors and Generators; Storage Batteries and Charging Circuits; The Vacuum Tube; Circuits Employed in Vacuum Tube Transmitters; Modulating Systems; Wavemeters; Piezo-Electric Oscillators; Wave Traps; Marine Vacuum Tube Transmitters; Radio Broadcasting Equipment; Arc Transmitters; Spark Transmitters; Commercial Radio Receivers; Radio Beacons and Direction Finders; Radio Laws and Regulations; Handling and Abstracting Traffic. JVr*...) f«fAinMA<?/in never before available such New information as a comp]ete description of the Western Electric s Kilowatt Broadcasting Transmitter; description and circuit diagram of Western Electric Superheterodyne Radio Receiving Outfit type 6004-C; Navy Standard 2-Kilowatt Spark Transmitter; etc, etc. Every detail up to the minute. Free Examination "The Radio Manual" has just been published. Nearly 700 pages. Profusely illustrated. Bound in Flexible Fabrikoid. The coupon brings the volume for free examination. If you do not agree that it is the best Radio book you have seen, return it and owe nothing. If you keep it, send the price of $6.00 within ten days. Order on This Coupon i D. Van Nostrand Co., Inc., 8 Warren St., Mew York Send me THE RADIO MANUAL for examination. Within ten days after receipt I will either return the volume or send you $6.00, the price in full. (Radio Broadcast 7-29) Name SL&No City and State The Radio Broadcast LABORATORY INFORMATION SHEETS By HOWARD E. RHODES T^HE aim of the Radio Broadcast Laboratory Information Sheets is to present, in a convenient form, concise and accurate information in the field of radio and closely allied sciences. It is not the purpose of the Sheets to include only new information, but to present practical data, whether new or old, that may be of value to the experimenter, engineer, or serviceman. In order to make the Sheets easier to refer to, they are arranged so that they may be cut from the magazine and preserved, either in a blank book or on 4" x 6" filing cards. The cards should be arranged in numerical order. Since they began, in June, 1926, the popularity of the Information Sheets has increased so greatly that it has been decided to reprint the first one hundred and ninety of them (June, 1926-May, 1928) in a single substantially bound volume. This volume, Radio Broadcast's Data Sfieets, may now be bought on the newsstands, or from the Circulation Department, Doubleday, Doran & Company, Inc., Garden City, New York, for $1.00. Inside each volume is a credit coupon which is worth $1.00 toward the subscription price of this magazine. In other words, a year's subscription to Radio Broadcast accompanied by this $1.00 credit coupon, gives you Radio Broadcast for one year for $3.00 instead of the usual subscription price of $4.00. — The Editor. No. 288 Radio Broadcast Laboratory Information Sheet Index July, 1929 (June 1928 to May 1929) SUBJECT SHEET NO. Acoustics, Effect of 266 A. C, r.m.s. Vs. Peak Volt age Amplification Constant Ammeters, How They Work Audio Amplifiers: By-pass Condensers in I mpedance-Coupled Input Circuits of Preventing Howling Preventing Distortion in Television Antennas, Received Power Audio Transformers: Primary Inductance High-Freguency Operation Balancing Radio Receivers Band-pass Circuits, Width Bass Notes, Importance of Battery Sets, Electrification Books on Radio Broadcast and Short-Wave Set Capacity-Inductance Prod ucts 278, 279 Current, Direction of Flow 199 Drill Sizes 219 Dynamic Loud Speakers 236 Bucking Coils in 274 244 197 222 252 231 282 194 242, 243 247, 248 208 227 234 233 255 269 265 224 MONTH March December June September January October May June December December July October November October January March March September SHEET NO. 238, 239 November May June September November April Coupling Transformers Used 251 January Field Circuits of 228 October Ear, Characteristics of 280, 281 May Effective Resistance 203 July Equalizers, Reason for Use 212, 213 August Equalizing Wire Lines 207 July Farm-Lighting Systems 202 July Filament Voltages, Importance 272 March Filter Circuits, Analysis of 258, 259 February Filters, Various Types 230 October Galvanometers, Design of 205 July Graphs, Types of 264 February Grid Bias from Power Units 275 April Grid-Bias Resistances 225, 226 October Harmonics, Power in 267 March Heater Connections 257 February Hi-Q Receiver, Circuit 215, 216 August Hum, Origin of 261 February Hum Voltage 284, 285 May Impedance-Coupled Amplifiers 231 October Inductance-Capacity Products 278, 279 May Kilocycle-Wavelength Chart 263 February Line Voltage, Effect on Tube 201, 204 July Measuring Instruments 214 August Meters, Protection of 283 May No. 289 Radio Broadcast Laboratory Information Sheet Index (Continued) July, 1929 Milliammeter, as a Voltmeter 217 Motorboating, Prevention of 193 Neutralizing r.f. Circuits 273 Power Output: Amount Beguired ( 245 j 256 Effect of Impedance on 237 Formulas for 270 Various Tubes 246 Operation on 2?0 Volts A. C. 241 Push-pull Amplifiers: Preventing Howling of 194 Testing for Faults in 271 Dual 262 Radio Receivers: Balancing of 233 Servicing of 218 Radio Transmission 223 Rectifier Tubes, Protection 210 Resistance-Coupled Amplifi Distoriion in Filter Circuits for Screen-Grid Tubes in 242, 243 249, 250 I 195, 196 1 206 Voltage Gain of 260 Resistors, Determining Size 200 R. F. Screen-Grid Amplifier 198 Roberts Four-Tube A. C. Set 220, 221 Room Acoustics. Effect of 266 Screen-Grid R. F. Amplifier . 198 September June April December January November March December December June March February October September September August December January June, July February June June September March June Screen-Grid R. C. Amplifiers 195, Selectivity, R. F. Amplifier Servicing Radio Receivers Shielding, Use of Short-Wave and Broadcast Set 238, Soldering Irons, Care of Tap Sizes Telephone Set 276, Telephone Transmission Units Television Amplifier 247, Television, Data on Television, Frequency Band Tubes: Grid Bias Resistance of A. C. 225, Effect of Filament Voltage Effect of Voltage on Life 201, Heater connections to A. C Hum Voltage of A. C. 284, Power Output of Tuned Circuits: Effective Resistance of Mathematics of Voltage Gain of R. C. Amplifiers Voltmeters, How They Work Voltmeter, Milliammeter as a Wavelength-Kilocycle Chart Wire Linos, Equalizing 196 206 209 218 253 239 211 219 277 229 248 240 235 226 254 204 257 285 246 203 268 260 232 217 263 207 June July August September January November August. September April October December November November October January July February May December July March February October September February July nil • • JULY 1 9 29 •