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where a conventional design has been augmented by replacing a single long conductor with several parallel wires, connected at their ends, and held in position by ring spacers or support struts mounted on a central mast (if any). The "cage" is either mounted around a central mast (either conducting or
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A cage can improve any antenna design by replacing a single wire in any section that carries large, unbalanced (radiating) current; the only issue is whether the improvement will be substantial enough to warrant the extra effort. The multiple parallel wires electrically simulate a single fat wire,
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When used as the main section of a vertical antenna, the cage is usually built to have a length one-quarter of the operating wavelength, and to surround the entire length of the central mast. If the tower is grounded, the cage wires must be electrically insulated from the tower for their entire
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height of the cage antenna is a bit less than 75 metres (250′) for the cage, plus about 2 metres (6′) to raise the lower end of the cage out of reach from the ground (depending on the details of the antenna feed, the lower end of the cage can carry a very high RF
223:". When configured as a folded unipole, the cage wires are instead called "skirt wires". A folded unipole might or might not obtain the wider bandwidth expected of a cage antenna, depending on how the unbalanced current splits between the mast and the skirt.
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length, and only optionally connected at the top, if at all. The cage wires are always fed at the ring connecting the cage's lower edge, with the other electrical side of the feedpoint always being the
148:, in 1922; a cage T-antenna 60 ft high by 90 ft long. The conductor is made of a "cage" of 6 wires held apart by wooden spreaders; this increased capacitance and decreased
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roughly equivalent to a wire with a diameter half as wide as the distance separating the cage wires, giving the modified antenna higher
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In the entirely optional case that the cage is electrically connected near the top of a mast and that mast's base is shorted to the
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152:. This antenna achieved transatlantic contacts on 1.5 MHz, at a power of 440 W.
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At 1,000 kHz the wavelength is 300 metres (1000′). Therefore, the minimum
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without as much weight and wind resistance as the equivalent fat wire would entail.
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Cage aerials have been built in different variants for broadcast stations in the
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172:non-conducting) or suspended from overhead wires.
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64:. Unsourced material may be challenged and
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128:Learn how and when to remove this message
144:Historic Radio Engineers Club station,
7:
62:adding citations to reliable sources
25:
711:Circularly disposed antenna array
529:Folded inverted conformal antenna
34:
1:
737:Radio frequency antenna types
351:Dielectric resonator antenna
758:
614:Regenerative loop antenna
609:Reflective array antenna
519:Corner reflector antenna
509:Collinear antenna array
691:Reconfigurable antenna
654:Yagi–Uda antenna
629:Short backfire antenna
366:Folded unipole antenna
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346:Crossed field antenna
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27:Type of radio antenna
663:Application-specific
554:Log-periodic antenna
426:Rubber ducky antenna
401:Inverted vee antenna
376:Ground-plane antenna
187:conductor resistance
183:radiation resistance
58:improve this article
574:Offset dish antenna
421:Random wire antenna
146:Riverhead, New York
716:Television antenna
564:Microstrip antenna
504:Choke ring antenna
499:Cassegrain antenna
396:Inverted-F antenna
308:Isotropic radiator
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701:Reference antenna
594:Parabolic antenna
514:Conformal antenna
436:Turnstile antenna
331:Biconical antenna
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16:(Redirected from
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742:Antennas (radio)
675:Corner reflector
489:Beverage antenna
451:Umbrella antenna
416:Monopole antenna
371:Franklin antenna
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619:Rhombic antenna
544:Helical antenna
534:Fractal antenna
479:AS-2259 Antenna
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391:Helical antenna
361:Discone antenna
341:Coaxial antenna
326:Batwing antenna
318:Omnidirectional
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524:Curtain array
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79: –
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77:"Cage aerial"
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73:Find sources:
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48:
43:This article
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37:
32:
31:
19:
634:Slot antenna
604:Quad antenna
589:Planar array
584:Phased array
559:Loop antenna
549:Horn antenna
456:Whip antenna
441:T2FD antenna
386:Halo antenna
381:G5RV antenna
335:
217:ground plane
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158:cage antenna
157:
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118:January 2009
115:
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98:
91:
84:
72:
56:Please help
44:
18:Cage antenna
484:AWX antenna
466:Directional
336:Cage aerial
165:cage aerial
731:Categories
256:References
202:mediumwave
185:, lowered
88:newspapers
677:(passive)
539:Gizmotchy
446:T-antenna
300:Isotropic
251:voltage).
191:bandwidth
45:does not
696:Rectenna
494:Cantenna
204:bands.
198:longwave
291:Antenna
244:
232:
227:Example
176:Purpose
167:) is a
162:British
102:scholar
66:removed
51:sources
670:ALLISS
246:
104:
97:
90:
83:
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649:WokFi
293:types
109:JSTOR
95:books
248:wave
200:and
81:news
49:any
47:cite
60:by
733::
241:4
156:A
283:e
276:t
269:v
238:/
235:1
160:(
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125:(
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116:(
106:·
99:·
92:·
85:·
68:.
54:.
20:)
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