Hvorfor anvender repeatere ikke rundstrålende cirkulært polariserede antenner?

Hvorfor anvender (danske) VHF/UHF-repeatere ikke rundstrålende cirkulært polariserede antenner?

Den vigtige fordel er, at det er underordnet om en vandret eller lodret polariseret antenne anvendes i den anden ende.

Følgende er også en nyttigt effekt:

GBPPR Tech Bulletin #2 - Advantages of Circular Polarized FM Repeater Antennas:
https://www.qsl.net/n9zia/cir_pol_rpt.html
backup:
https://web.archive.org/web/20211006121156/https ://www.qsl.net/n9zia/cir_pol_rpt.html
Citat: "...
The improvement afforded by circular polarization is primarily a reduction in mobile flutter. The flutter on a mobile signal is cased by reflections from large buildings (in urban settings) or other terrain features. These reflections cause measureable polarization shifts, sometimes to the point where a vertically polarized signal at the transmitting site may appear to be primarily horizontally polarized after reflection.
...
In both described situations described here, circular polarization can offer considerable improvement.
..."

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Forslag til rundstrålende cirkulært polariseret antenne - den kan garanteret redesignes til ikke at anvende printplade, hvilket ihvertfald er nyttigt ved VHF-frekvenser:

10% BB
The Pagoda antenna is an omnidirectional circularly polarized antenna design that I created. My main design goals were:
https://www.maartenbaert.be/quadcopters/antennas /pagoda-antenna/
Backup:
https://web.archive.org/web/20210402073634/https ://www.maartenbaert.be/quadcopters/anten nas/pagoda-antenna/

Pagoda-2 testet af:
Example 6: LHCP Omnidirectional FPV Antenna:
https://antennatestlab.com/antenna-examples/exam ple-6-lhcp-miniature-fpv-omnidirectional -antenna
Backup:
https://web.archive.org/web/20210319142025/https ://antennatestlab.com/antenna-examples/e xample-6-lhcp-miniature-fpv-omnidirectio nal-antenna

Python designfil:
https://files.maartenbaert.be/quadcopters/pagoda 3-design-files/pagoda3-design-files.zip
Backup:
https://web.archive.org/web/20210402074506/https ://files.maartenbaert.be/quadcopters/pag oda3-design-files/pagoda3-design-files.z ip

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145MHz:

36,55 faktor @ 5300MHz/145MHz. Ønsket præcision lig eller bedre end 36,55x0,1mm ca.= 3,6 mm
ca. 63,7cmØ (estimeret 17,445mm@5300MHz)
16cm = D2
42,5cm = D1

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435MHz:

12,18 faktor @ 5300MHz/435MHz. Ønsket præcision lig eller bedre end 12,18x0,1mm ca.= 1,2 mm
ca. 22,2cmØ (estimeret 17,445mm@5300MHz)
5,35cm = D2
14,2cm = D1

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Forslag af en anden rundstrålende cirkulært polariseret antenne - men den har lidt ringere data end Pagoda-antennen. Den kan fysisk anskues som værende en "krøllet" big-wheel antenne:

Make a DIY Cloverleaf Antenna:
https://oscarliang.com/make-diy-cloverleaf-anten na/
backup:
https://web.archive.org/web/20220212063712/https ://oscarliang.com/make-diy-cloverleaf-an tenna/

435MHz 5 PETAL CLOVER LEAF ANTENNA
435MHz 5 Petal Cloverleaf tower mounted antenna. November 2016
https://vk6ysf.com/435mhz_5_petal_cloverleaf_ant enna.htm
backup:
https://web.archive.org/web/20200223160734/http: //vk6ysf.com/435mhz_5_petal_cloverleaf_a ntenna.htm