313:
325:
277:
62:
174:. The charge on the capacitor flowed rapidly back and forth between the capacitor plates, through the coil and spark gap, creating a radio frequency oscillating current. The two spiral coils formed an air-core transformer. The oscillating current from the capacitor passed through the near coil (the
643:
613:
169:
In operation, the transformer charged the capacitor to a high voltage. When an electrode on the spark wheel passed a stationary electrode, a spark would jump, completing the circuit between the capacitor and coil, making a
339:
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
33:
142:
consisting of parallel metal plates separated by phenolic cloth, immersed in a container of insulating oil to prevent corona discharge losses, an air core RF
190:. Each time an electrode on the rotating spark wheel passed the stationary electrode, the spark would generate a brief burst of radio waves. These
335:
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
73:
417:
of copper strip. The foreground one is connected to the capacitor and spark gap, while the rear one is connected to the antenna and ground
41:
158:
driven by a motor, which rotates next to a stationary electrode. The two cylinders on the lines coming from the top of the transformer
128:
era. from 1900 to the early 1920s. This was a small transmitter made for hobbyists, claimed to be 95% efficient. It consists of a
194:
repeated at an audio rate, from several hundred to a thousand sparks a second, so the radio signal sounded like a buzz or whine in a
642:
637:
544:
527:
182:). The ends of the secondary coil were attached to the transmitting antenna, a long wire suspended in the air, and a
340:
336:
344:
117:
670:
The following pages on the
English Knowledge (XXG) use this file (pages on other projects are not listed):
623:
674:
125:
612:
607:
32:
183:
81:
171:
492:
Chokes to prevent radio-frequency current from tuned circuit from passing through transformer
221:
198:. A telegraph key was used to turn the transmitter off and on, to spell out text messages in
302:
195:
301:
occurred prior to
January 1, 1929, and if not then due to lack of notice or renewal. See
653:
289:
297:. This applies to U.S. works where the copyright has expired, often because its first
68:
191:
186:
connection. When the antenna was excited by this oscillating voltage, it radiated
166:
to prevent the RF current from the tuned circuit from getting into the transformer.
129:
121:
298:
224:
Radio
Amateur News" (Experimenter Publishing Co., New York), October 1919, p. 181
199:
187:
294:
151:
136:
414:
143:
210:
163:
580:
Click on a date/time to view the file as it appeared at that time.
413:
Inductively coupled output transformer consisting of two spiral
271:
222:"Efficient Amateur Radio Transmitter" in Hugo Gernsback, Ed.
178:), inducing a higher oscillating voltage in the far coil (the
56:
323:
311:
275:
135:
which steps the 120V power line voltage up to 25,000 V. a
383:
Rotary spark gap driven by electric motor behind wheel.
100:
80:
Commons is a freely licensed media file repository.
46:(700 × 450 pixels, file size: 135 KB, MIME type:
61:
8:
582:
507:
251:
146:consisting of two spiral strips of metal
672:
558:
542:
525:
522:
503:
496:
312:
276:
7:
154:consisting of a toothed metal wheel
660:User created page with UploadWizard
571:
516:
511:Rotary spark gap radio transmitter
510:
407:
377:
334:
285:
110:
93:
39:
515:
501:
106:Rotary spark gap transmitter.jpg
60:
42:Rotary_spark_gap_transmitter.jpg
21:
498:
408:
378:
111:
36:No higher resolution available.
14:
497:
26:
1:
467:Step-up transformer, 25,000V
341:Knowledge (XXG):Public domain
523:Items portrayed in this file
120:, an obsolete type of radio
118:spark gap radio transmitter
691:
345:Knowledge (XXG):Copyrights
287:This media file is in the
572:
140:(black rectangle, center)
16:
500:
337:rule of the shorter term
305:for further explanation.
67:This is a file from the
659:
629:
233:
216:
209:
206:
103:
71:. Information from its
442:Glass-plate capacitor
328:
317:
281:
74:description page there
675:Spark-gap transmitter
638:10:44, 29 August 2013
327:
315:
279:
148:(background, right)
126:wireless telegraphy
329:
318:
282:
156:(right foreground)
663:
625:Materialscientist
608:14:08, 3 May 2021
509:
356:
355:
349:
347:for more details.
270:
269:
244:
243:
220:Downloaded from
89:
88:
69:Wikimedia Commons
682:
650:
620:
412:
382:
350:
333:
326:
314:
278:
272:
266:
263:
260:
257:
252:
240:
212:
172:resonant circuit
124:used during the
115:
107:
101:
85:
64:
63:
57:
51:
49:
690:
689:
685:
684:
683:
681:
680:
679:
671:
664:
656:
648:
626:
618:
574:
573:
570:
569:
568:
567:
566:
565:
564:
563:
561:
551:
550:
549:
547:
536:
535:
534:
533:
532:
530:
514:
513:
512:
495:
494:
489:
486:
483:
480:
477:
474:
470:
469:
464:
461:
458:
455:
452:
449:
445:
444:
439:
436:
433:
430:
427:
424:
420:
419:
418:
405:
402:
399:
396:
393:
390:
386:
385:
384:
375:
372:
369:
366:
363:
360:
348:
332:
324:
307:
264:
261:
258:
255:
250:
245:
238:
228:on Google Books
167:
150:, and a rotary
105:
98:
91:
90:
79:
78:
77:is shown below.
53:
47:
45:
38:
37:
12:
11:
5:
688:
686:
678:
677:
669:
668:
667:
662:
661:
658:
654:
651:
645:
640:
635:
632:
631:
628:
624:
621:
615:
610:
605:
601:
600:
597:
594:
591:
588:
585:
578:
577:
562:
559:
557:
556:
555:
554:
553:
552:
548:
543:
541:
540:
539:
538:
537:
531:
526:
524:
521:
520:
519:
518:
517:
506:
505:
502:
499:
490:
487:
484:
481:
478:
475:
472:
471:
465:
462:
459:
456:
453:
450:
447:
446:
440:
437:
434:
431:
428:
425:
422:
421:
406:
403:
400:
397:
394:
391:
388:
387:
376:
373:
370:
367:
364:
361:
358:
357:
354:
353:
351:
330:
320:
319:
309:
283:
268:
267:
249:
246:
242:
241:
239:Unknown author
237:Unknown author
235:
231:
230:
218:
214:
213:
208:
204:
203:
196:radio receiver
108:
99:
97:
94:
92:
87:
86:
65:
55:
54:
35:
31:
30:
29:
24:
19:
13:
10:
9:
6:
4:
3:
2:
687:
676:
673:
665:
657:
652:
646:
644:
641:
639:
636:
634:
633:
627:
622:
616:
614:
611:
609:
606:
603:
602:
598:
595:
592:
589:
586:
584:
583:
581:
575:
546:
529:
493:
468:
443:
416:
411:
381:
352:
346:
342:
338:
331:
322:
321:
316:United States
310:
308:
306:
304:
300:
296:
295:United States
292:
291:
290:public domain
284:
280:Public domain
274:
273:
259:Public domain
256:Public domain
254:
253:
247:
236:
232:
229:
226:
225:
219:
215:
205:
201:
197:
193:
189:
185:
181:
177:
173:
168:
165:
161:
157:
153:
149:
145:
141:
138:
134:
131:
127:
123:
119:
114:
109:
102:
95:
83:
76:
75:
70:
66:
59:
58:
52:
43:
34:
28:
25:
23:
20:
18:
15:
579:
576:File history
491:
466:
441:
409:
379:
288:
286:
227:
223:
192:damped waves
179:
175:
159:
155:
147:
139:
132:
112:
82:You can help
72:
40:
22:File history
299:publication
188:radio waves
130:transformer
122:transmitter
104:Description
666:File usage
647:700 × 450
617:700 × 450
593:Dimensions
200:Morse code
48:image/jpeg
27:File usage
655:Chetvorno
590:Thumbnail
587:Date/Time
545:inception
415:inductors
410:English:
380:English:
303:this page
248:Licensing
180:secondary
152:spark gap
137:capacitor
113:English:
619:(135 KB)
504:Captions
144:inductor
116:A small
649:(80 KB)
604:current
599:Comment
528:depicts
508:English
293:in the
176:primary
160:(right)
96:Summary
44:
234:Author
217:Source
184:ground
164:chokes
133:(left)
265:false
262:false
162:were
596:User
560:1919
343:and
211:1919
207:Date
17:File
630:fft
488:450
485:700
479:121
476:119
463:450
460:700
457:250
454:131
451:176
438:450
435:700
432:288
429:185
426:149
423:174
404:450
401:700
398:317
395:326
389:352
374:450
371:700
368:184
365:186
362:169
359:374
482:67
473:69
448:23
392:35
202:.
84:.
50:)
Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.
