Spark_gap_wireless_station_1910.jpg
Summary
Description Spark gap wireless station 1910.jpg |
English:
A typical amateur
wireless telegraphy
radio station from 1910. It consists of a
spark-gap transmitter
(on right)
which generates radio waves with an electric spark, and a
crystal radio receiver
(on left)
, connected through a "transmit/receive" switch on the wall to a large outdoor wire antenna. When sending, the transmitter is turned off and on by the operator with a
telegraph key
on the table to produce different length pulses of radio waves, to communicate text messages in
Morse code
.
|
Date | |
Source | Retrieved December 5, 2008 from George Washington Pierce (1910) Principles of Wireless Telegraphy , McGraw-Hill Book Co., New York, p. 322, fig. 231 on Google Books |
Author | George Washington Pierce |
Licensing
Public domain Public domain false false |
This media file is in the
public domain
in the
United States
. This applies to U.S. works where the copyright has expired, often because its first
publication
occurred prior to January 1, 1929, and if not then due to lack of notice or renewal. See
this page
for further explanation.
|
||
This image might not be in the public domain outside of the United States; this especially applies in the countries and areas that do not apply the
rule of the shorter term
for US works, such as Canada, Mainland China (not Hong Kong or Macao), Germany, Mexico, and Switzerland. The creator and year of publication are essential information and must be provided. See
Wikipedia:Public domain
and
Wikipedia:Copyrights
for more details.
|
Annotations
InfoField
|
This image is annotated: View the annotations at Commons |
526
404
142
113
684
557
Induction coil steps up voltage from motor-generator to several thousand volts
494
136
80
89
684
557
Oscillation transformer
451
155
50
50
684
557
Spark gap in glass envelope
429
233
145
75
684
557
Glass plate capacitor in box forms tuned circuit with oscillation transformer
440
300
64
29
684
557
Headphones
384
25
123
70
684
557
Antenna loading coil, used to tune antenna to resonance at transmitter frequency
190
206
117
107
684
557
Crystal receiver
305
139
76
63
684
557
Transmit/receive antenna cutover switch
63
363
301
186
684
557
Motor-generator set which increases frequency of 60 Hz house current to 500 Hz to increase the spark rate giving the transmitter's signal a higher pitch in the receiver which cuts through interference better.
239
70
48
56
684
557
Hot-wire antenna current meter
386
283
48
31
684
557
Telegraph key