Wireless Telegraph Construction For Amateurs :: PREFACE TO THE THIRD EDITION.

PREFACE TO THE THIRD EDITION.

The success of the previous editions of this book has made a new and third one necessary.

There have not been any startling changes or new discoveries made in the field of wireless telegraphy since the first edition was published, but the art has undergone a number of small changes and improvements which have increased the efficiency and selectivity of the apparatus.

Since then a federal law restricting and controlling wireless telegraphy has been passed. Its effect has been to place wireless telegraphy upon a more certain basis, and to give a recognized standing to the amateur experimenter.

This new law has been included in this edition in the form of an appendix. The amateur will do well to read it carefully. Compliance with its regulations will prove beneficial rather than a hindrance.

A fully illustrated chapter explaining exactly how to comply with the law and how to build the apparatus required has been added. Complete descriptions of several new types of detectors are also included.

All old matter has been thoroughly revised and several illustrations replaced by ones more up-to-date and of direct interest.

ALFRED P. MORGAN.

UPPER MONTCLAIR, N.J.

May, 1913.

PREFACE.
PREFACE TO THE THIRD EDITION.
CHAPTER I. INTRODUCTORY.
- The Transmission and Reception of Electric Waves.
CHAPTER II. THE APPARATUS.
CHAPTER III. AERIALS AND EARTH CONNECTIONS.
CHAPTER IV. INDUCTION COILS.
CHAPTER V. INTERRUPTERS.
CHAPTER VI. TRANSFORMERS.
- Construction of a 2-K.W. Transformer.
CHAPTER VII. OSCILLATION CONDENSERS AND LEYDEN JARS.
CHAPTER VIII. SPARK GAPS OR OSCILLATORS.
CHAPTER IX. TRANSMITTING HELIXES.
CHAPTER X. KEYS.
CHAPTER XI. AERIAL SWITCHES AND ANCHOR GAPS.
CHAPTER XII. HOT WIRE AMMETER.
CHAPTER XIII. OSCILLATION DETECTORS.
- "UNIVERSAL" DETECTOR.
- ELECTROLYTIC DETECTORS.
- TANTALUM DETECTOR.
- CRYSTAL DETECTORS.
- LEAD PEROXIDE DETECTOR.
- THE MARCONI MAGNETIC DETECTOR.
CHAPTER XIV. TUNING COILS AND TRANSFORMERS.
CHAPTER XV. RECEIVING CONDENSERS.
CHAPTER XVI. TELEPHONE RECEIVERS AND HEADBANDS.
CHAPTER XVII. OPERATION.
- ELECTRICAL TERMS AND DEFINITIONS.
CHAPTER XVIII. THE AMATEUR AND THE WIRELESS LAW. WHAT IT IS; HOW TO COMPLY; HOW TO SECURE A LICENSE.
- APPARATUS REQUIRED IN MANY INSTANCES IN ORDER TO COMPLY WITH THE WIRELESS LAW.
- Receiving Apparatus.

Frontispiece. Plate I. Electrical Conventions.
Fig 1. Hertz Oscillator and Resonator.
Fig. 2. Hydraulic Oscillator.
Fig. 3. "Hydraulic" Transmitter and Receptor.
Fig. 4. Simple Wireless Telegraph Transmitter and Receptor.
Fig. 5. Electric Waves and Lines of Strain.
Fig. 6. Resonance Tube.
Fig. 7. Lag and Lead.
Fig. 8. Tuned Hydraulic Transmitter and Receptor.
Fig. 9. Tuned Wireless Telegraph Transmitter and Receptor
Fig. 10. Long-distance Receiving Set.
Fig. 11. Murdock Receiving Set.
Fig. 12. Clapp-Eastham Receiving Set.
Fig. 13. Prague Receiving Set.
Fig. 14. Receiving Set.
Fig. 15. Receiving Set.
Fig. 16. Murdock Transmitting and Receiving Set.
Fig. 17. United Wireless Portable Outfit.
Plate II. Aerial Systems.
Fig. 18. Electrose Insulators.
Fig. 19. Guy Insulator.
Fig. 20. Insulating Tube.
Fig. 21. High-tension Cable and Insulator.
Fig. 22. Flat-top T Aerial.
Fig. 23. Ground Clamp.
Fig. 24. Switch for Lightning Protection.
Fig. 25. Diagram of an Induction Coil.
Fig. 26. Induction Coil Core.
Fig. 27. Theoretical and practical form of secondary.
Fig. 28. Layer Winding for Small Coils.
Fig. 29. Section Winder.
Fig. 30. Impregnator for Silk Covered Wire.
Fig. 31. Methods of Connecting the Secondary Sections.
Fig. 32. Coil Case.
Fig. 33. Simple Interrupter.
Fig. 34. Independent Interrupter.
Fig. 35. Details of Magnets.
Fig. 36. Details of Moving Parts.
Fig. 37. Details of Standard and Screws.
Fig. 38. Diagram of Connections for an Independent Interrupter.
Fig. 39. Construction of a Paper Condenser.
Fig. 40. Wenhelt and Simon Electrolytic Interrupters.
Fig. 41. Construction of Electrolytic Interrupters.
Fig. 42. Details of Electrolytic Interrupters.
Fig. 43. Electrolytic Interrupter.
Fig. 44. Assembly and Dimensions of Core.
Fig. 45. Fiber Head and Separator.
Fig. 46. Section Form.
Fig. 47. Methods of Connecting Sections.
Fig. 48. Assembly of Leg.
Fig. 49. Transformer with One Secondary removed.
Fig. 50. Wiring Diagram.
Fig. 51. Clapp-Eastham 1/4-K.W. Transformer.
Fig. 52. United Wireless Motor-Generator set for supplying Alternating Current to the Transformer.
Fig. 53. Simple Condenser.
Fig. 54. Leyden Jar.
Fig. 55. "Aerial Switch."
Fig. 56. Amco Oscillation Condenser.
Fig. 57. Clapp-Eastham Oscillation Condenser.
Fig. 58. Methods of Varying Capacity.
Fig. 59. Spark Gaps.
Fig. 60. Spark Gap.
Fig. 61. Closely Coupled Helix.
Plate III. Transmitting Circuits.
Fig. 62. Prague Transmitting Helix.
Fig. 63. Closely Coupled Tuning Circuit.
Fig. 64. Loosely Coupled Transmitting Helix and Contact Clip.
Fig. 65. Loosely Coupled Transmitting Circuit.
Fig. 66. United Wireless Helix, Spark Gap and Condenser.
Fig. 67. Morse Key fitted with Extension Lever.
Fig. 68. Wireless Key.
Fig. 69. "United Wireless Type Key."
Fig. 70. Connections for Aerial Switch.
Fig. 71. Aerial Switches.
Fig. 72. Detail of Contacts.
Fig. 73. Details of Switch Parts.
Fig. 74. Method of Fastening Knife.
Fig. 75. "T" Aerial Switch.
Fig. 76. "United" Wireless Lightning Switch.
Fig. 77. Shoemaker Tuning Coil and Aerial Switch.
Fig. 78. "United" Wireless Anchor Gaps.
Fig. 79. Anchor Gap.
Fig. 80. Simple Hot Wire Meter.
Fig. 81. Meter with Case Removed.
Fig. 82. Glass Compensating Strip.
Fig. 83. Details of "Hot Wire" Supports.
Fig. 84. Details of Movement.
Fig. 85. Complete Movement.
Fig. 86. Side View of Hot Wire and Movement.
Fig. 87. United Wireless Hot Wire Ammeter.
Fig. 88. Universal Detector.
Fig. 89. Details of Universal Detector.
Fig. 90. Parts of Universal Detector.
Fig. 91. Bare Point Electrolytic Detector.
Fig. 92. Effect of Exposing too much Wire.
Fig. 93. Electrolytic Detector Circuits.
Fig. 94. Electrolytic Detector.
Fig. 95. Forming "Glass" Point.
Fig. 96. Shoemaker Detector.
Fig. 97. Shoemaker Detector Circuits.
Fig. 98. Lamp Detector.
Fig. 99. Simple Electrolytic Detector.
Fig. 100. Electrolytic Detector.
Fig. 101. Details of Electrolytic Detector.
Fig. 102. Increasing the Sensitiveness of an Electrolytic Detector.
Fig. 103. Tantalum Detector.
Fig. 104. United Wireless Carborundum Detector (horizontal type).
Fig. 105. United Wireless Carborundum Detector (vertical type).
Fig. 106. Clapp-Eastham Ferron Detector.
Fig. 107. Silicon Crystal in Cup.
Fig. 108. Silicon Detector Circuits.
Fig. 109. Perikon Detector Elements.
Fig. 110. Perikon Detector.
Fig. 111. Peroxide of Lead Detector.
Fig. 112. Marconi Magnetic Detector.
Fig. 113. Details of Transformer.
Fig. 114. Method of Joining Ends of Band.
Fig. 115. Pulley.
Fig. 116. Pulley Bearings.
Fig. 117. Circuit of Magnetic Detector.
Fig. 118. Fleming Oscillation Valve.
Fig. 119. Flame Audion.
Fig. 120. Circuit of Flame Audion.
Fig. 121. Double-slide Tuning Coil.
Fig. 122. Sliders.
Fig. 123. Double-slide Tuning Coil Circuits.
Plate IV. Receiving Circuits. (Straightaway Aerial.)
Fig. 124. Murdock Double-slide Tuning Coil.
Fig. 125. United Wireless Receiving Set.
Fig. 126. United Wireless Portable Receiving Set.
Fig. 127. Oscillation Transformer.
Fig. 128. United Wireless Receiving Transformer.
Fig. 129. Details of Receiving Transformer.
Fig. 130. Slider for Loose Coupler.
Fig. 131. Loosely Coupled Tuning Circuits.
Fig. 132. Combination Loosely and Closely Coupled Tuner.
Fig. 133. Clapp-Eastham Loose Coupler.
Fig. 134. A Highly Efficient Form of Loose Coupler.
Fig. 135. Potentiometer.
Fig. 136. Amco Potentiometer.
Plate V. Receiving Circuits.
Fig. 137. Tuning Circuit with and without an Adjustable Condenser.
Fig. 138. Tubular Condenser.
Fig. 139. Variable Condenser.
Fig. 140. Details of Variable Condenser.
Fig. 141. Sliding Plate Variable Condenser.
Fig. 142. Types of Permanent Magnets.
Fig. 143. Grinding Tool.
Fig. 144. Parts of a Holtzer Cabot Receiver.
Fig. 145. Holtzer Cabot Head Set.
Fig. 146. Adjustable Head Band.
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