527:
310:
86:
38:
654:
347:), Mainland China (50 years p.m.a., not Hong Kong or Macao), Germany (70 years p.m.a.), Mexico (100 years p.m.a.), Switzerland (70 years p.m.a.), and other countries with individual treaties.
723:
203:
Dr. George C. Southworth and his assistant A. E. Bowen of Bell
Telephone Labs show how extremely short electric waves can be guided through a flexible metal pipe
265:
magazine would have the copyright renewed in 1966. Online page scans of the
Catalog of Copyright Entries, published by the US Copyright Office can be found
52:
48:
42:
97:
65:
163:
of different modes. He demonstrated that they could pass through the 25 ft flexible metal waveguide and be detected by a receiver consisting of a
325:
323:
because it was published in the United States between 1929 and 1963, and although there may or may not have been a copyright notice, the
254:
180:
he showed that waves would not propagate through a waveguide that was under a certain diameter, that is, each waveguide had a
224:
690:
585:
568:
344:
145:
340:
517:
187:
A brass grating in one orientation could block the waves but in perpendicular orientation allowed them through
681:
The following pages on the
English Knowledge (XXG) use this file (pages on other projects are not listed):
653:
648:
56:
37:
194:
149:
105:
269:. Search of the Renewals for Periodicals for 1965, 1966, and 1967 show no renewal entries for
181:
330:
167:
coupled to an amplifier and galvanometer. He demonstrated further properties of the waves:
173:
Using an electric field probe he demonstrated the E field structure of the different modes.
664:
319:
164:
343:
for US works (depending on the date of the author's death), such as Canada (70 years
92:
507:
498:
453:
471:
160:
489:
480:
462:
444:
435:
426:
417:
408:
399:
390:
381:
372:
363:
354:
141:
339:
Note that it may still be copyrighted in jurisdictions that do not apply the
685:
334:
266:
213:
229:
magazine, Popular Book Corp., New York, Vol. 8, No. 12, April 1938, p. 669
273:. Therefore the copyright was not renewed and it is in the public domain.
708:
159:
were several vacuum tube oscillators producing 1.5 GHz (8 inch, 20 cm)
232:
621:
Click on a date/time to view the file as it appeared at that time.
190:
The propagation velocity was less than that of waves in open air.
304:
80:
525:
193:
A soft rubber rod could also conduct the waves, forming a
170:
Using a metal paddle reflector he created standing waves.
144:
before the
Institute of Radio Engineers by the inventor,
552:
Add a one-line explanation of what this file represents
508:
499:
713:
454:
124:
104:
Commons is a freely licensed media file repository.
472:
490:
481:
463:
445:
436:
427:
418:
409:
400:
391:
382:
373:
364:
355:
526:
70:(810 × 620 pixels, file size: 94 KB, MIME type:
225:"Four inch waves turn science topsy-turvy" in
85:
176:By using progressively smaller diameter pipe
8:
623:
548:
516:
284:
701:The following other wikis use this file:
683:
599:
583:
566:
563:
544:
537:
130:Southworth demonstrating waveguide.jpg
309:
7:
671:User created page with UploadWizard
612:
233:http://www.americanradiohistory.com
557:
551:
315:
134:
117:
63:
556:
542:
308:
84:
31:
21:
539:
329:. For further explanation, see
135:
14:
538:
223:Retrieved March 28, 2015 from
26:
1:
140:Demonstration in 1938 of the
709:Lankide:Urkokoko/Proba orria
564:Items portrayed in this file
691:Waveguide (radio frequency)
742:
720:Usage on ru.wikipedia.org
705:Usage on eu.wikipedia.org
335:the copyright renewal logs
613:
530:Flag of the United States
326:copyright was not renewed
271:Short Wave and Television
263:Short Wave and Television
227:Short Wave and Television
155:. Behind the blackboard
146:Bell Telephone Laboratory
16:
541:
341:rule of the shorter term
178:(seen at right on floor)
91:This is a file from the
724:Микроволновое излучение
670:
249:
238:
219:
212:
209:
127:
95:. Information from its
531:
98:description page there
41:Size of this preview:
529:
649:14:50, 29 March 2015
331:Commons:Hirtle chart
317:This work is in the
195:dielectric waveguide
150:George C. Southworth
455:português do Brasil
261:This 1938 issue of
47:Other resolutions:
532:
697:Global file usage
674:
550:
536:
535:
520:
303:
302:
277:
276:
258:
255:Reusing this file
113:
112:
93:Wikimedia Commons
32:Global file usage
733:
661:
528:
521:
312:
311:
305:
299:
296:
293:
290:
285:
252:
245:
215:
182:cutoff frequency
139:
131:
125:
109:
88:
87:
81:
75:
73:
60:
57:810 × 620 pixels
53:627 × 480 pixels
49:314 × 240 pixels
43:783 × 599 pixels
741:
740:
736:
735:
734:
732:
731:
730:
695:
682:
675:
667:
659:
615:
614:
611:
610:
609:
608:
607:
606:
605:
604:
602:
592:
591:
590:
588:
577:
576:
575:
574:
573:
571:
555:
554:
553:
510:
501:
492:
483:
474:
465:
456:
447:
438:
429:
420:
411:
402:
393:
384:
375:
366:
357:
353:
350:
348:
297:
294:
291:
288:
283:
278:
243:
205:
129:
122:
115:
114:
103:
102:
101:is shown below.
77:
71:
69:
62:
61:
46:
12:
11:
5:
739:
737:
729:
728:
727:
726:
718:
717:
716:
711:
699:
698:
694:
693:
688:
680:
679:
678:
673:
672:
669:
665:
662:
656:
651:
646:
642:
641:
638:
635:
632:
629:
626:
619:
618:
603:
600:
598:
597:
596:
595:
594:
593:
589:
584:
582:
581:
580:
579:
578:
572:
567:
565:
562:
561:
560:
559:
558:
547:
546:
543:
540:
534:
533:
523:
338:
313:
301:
300:
282:
279:
275:
274:
259:
247:
246:
244:Unknown author
242:Unknown author
240:
236:
235:
221:
217:
216:
211:
207:
206:
200:
199:
191:
188:
185:
174:
171:
132:
123:
121:
118:
116:
111:
110:
89:
79:
78:
40:
36:
35:
34:
29:
24:
19:
13:
10:
9:
6:
4:
3:
2:
738:
725:
722:
721:
719:
715:
712:
710:
707:
706:
704:
703:
702:
696:
692:
689:
687:
684:
676:
668:
663:
657:
655:
652:
650:
647:
644:
643:
639:
636:
633:
630:
627:
625:
624:
622:
616:
587:
570:
524:
522:
519:
515:
511:
506:
502:
497:
493:
488:
484:
479:
475:
470:
466:
461:
457:
452:
448:
443:
439:
434:
430:
425:
421:
416:
412:
407:
403:
398:
394:
389:
385:
380:
376:
371:
367:
362:
358:
351:
349:
346:
342:
336:
332:
328:
327:
322:
321:
320:public domain
314:
307:
306:
292:Public domain
289:Public domain
287:
286:
280:
272:
268:
264:
260:
256:
251:
248:
241:
237:
234:
230:
228:
222:
218:
208:
204:
198:
196:
192:
189:
186:
183:
179:
175:
172:
169:
168:
166:
165:silicon diode
162:
158:
154:
151:
147:
143:
138:
133:
126:
119:
107:
100:
99:
94:
90:
83:
82:
76:
67:
66:Original file
58:
54:
50:
44:
39:
33:
30:
28:
25:
23:
20:
18:
15:
700:
620:
617:File history
513:
504:
495:
486:
477:
468:
459:
450:
441:
432:
423:
414:
405:
396:
387:
378:
369:
360:
352:
324:
318:
316:
270:
262:
226:
202:
177:
156:
152:
136:
106:You can help
96:
64:
22:File history
482:slovenščina
128:Description
677:File usage
658:810 × 620
634:Dimensions
601:April 1938
491:українська
437:македонски
250:Permission
214:April 1938
161:microwaves
148:scientist
72:image/jpeg
27:File usage
714:Uhin gida
686:Microwave
666:Chetvorno
631:Thumbnail
628:Date/Time
586:inception
473:sicilianu
446:português
281:Licensing
201:Caption:
142:waveguide
137:English:
545:Captions
410:italiano
392:français
660:(94 KB)
645:current
640:Comment
569:depicts
549:English
464:русский
383:español
374:English
365:Deutsch
356:العربية
157:(right)
120:Summary
68:
512:
503:
494:
485:
476:
467:
458:
449:
440:
431:
422:
413:
404:
401:galego
395:
386:
377:
368:
359:
345:p.m.a.
239:Author
220:Source
153:(left)
298:false
295:false
231:on
637:User
509:繁體中文
500:简体中文
333:and
267:here
210:Date
17:File
518:+/−
428:한국어
419:日本語
337:.
55:|
51:|
45:.
514:∙
505:∙
496:∙
487:∙
478:∙
469:∙
460:∙
451:∙
442:∙
433:∙
424:∙
415:∙
406:∙
397:∙
388:∙
379:∙
370:∙
361:∙
257:)
253:(
197:.
184:.
108:.
74:)
59:.
Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.
