{"product_id":"sirio-thunder-27-antenna-cb-senza-piano-di-massa","title":"Sirio Thunder 27 CB Antenna","description":"\u003ch2\u003eSirio Thunder 27 – CB Base Antenna Without Ground Plane\u003c\/h2\u003e\n\n\u003cp\u003e\n\u003cstrong\u003eSirio Thunder 27\u003c\/strong\u003e is a CB antenna designed for \u003cstrong\u003efixed base installations without a ground plane\u003c\/strong\u003e. It is ideal for mast mounting where a ground plane is not available, offering reliable performance for CB radio users and 10-meter amateur radio applications.\n\u003c\/p\u003e\n\n\u003cp\u003e\nThe antenna uses a \u003cstrong\u003e¼-wave design with helical loading\u003c\/strong\u003e, providing \u003cstrong\u003eomnidirectional radiation\u003c\/strong\u003e and \u003cstrong\u003evertical linear polarization\u003c\/strong\u003e. No tuning is required, allowing immediate operation across the supported frequency range.\n\u003c\/p\u003e\n\n\u003ch2\u003eElectrical Performance\u003c\/h2\u003e\n\n\u003cp\u003e\nSirio Thunder 27 operates across the \u003cstrong\u003e25–29 MHz\u003c\/strong\u003e frequency range, covering the CB band and the \u003cstrong\u003e10 m HAM band\u003c\/strong\u003e. Its wide bandwidth ensures stable operation with \u003cstrong\u003eSWR ≤ 2\u003c\/strong\u003e over at least 5 MHz.\n\u003c\/p\u003e\n\n\u003cp\u003e\nThe antenna supports up to \u003cstrong\u003e100 W continuous CW power\u003c\/strong\u003e and up to \u003cstrong\u003e300 W CW for short periods\u003c\/strong\u003e, making it suitable for fixed stations using medium-power transceivers.\n\u003c\/p\u003e\n\n\u003ch2\u003eConstruction and Installation\u003c\/h2\u003e\n\n\u003cp\u003e\nBuilt from \u003cstrong\u003ealuminium, copper, galvanized steel and nylon\u003c\/strong\u003e, the Sirio Thunder 27 offers high mechanical strength and long-term durability in outdoor installations. The antenna is designed for \u003cstrong\u003emast mounting\u003c\/strong\u003e and features a \u003cstrong\u003eUHF female connector (SO-239)\u003c\/strong\u003e for compatibility with standard coaxial cables.\n\u003c\/p\u003e\n\n\u003ch2\u003eTechnical Specifications\u003c\/h2\u003e\n\n\u003ctable\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003cth\u003eType\u003c\/th\u003e\n\u003ctd\u003e¼ λ with helical loading\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eRadiation Pattern\u003c\/th\u003e\n\u003ctd\u003eOmnidirectional\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003ePolarization\u003c\/th\u003e\n\u003ctd\u003eLinear vertical\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eFrequency Range\u003c\/th\u003e\n\u003ctd\u003e25–29 MHz (no tuning required)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eSupported Systems\u003c\/th\u003e\n\u003ctd\u003eCB, 10 m HAM\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eGain\u003c\/th\u003e\n\u003ctd\u003e0 dBd \/ 2.15 dBi\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eBandwidth\u003c\/th\u003e\n\u003ctd\u003e≥ 5 MHz @ SWR ≤ 2\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eMaximum Power\u003c\/th\u003e\n\u003ctd\u003e100 W CW continuous \/ 300 W CW short term\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eConnector\u003c\/th\u003e\n\u003ctd\u003eUHF female (SO-239)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eMaterials\u003c\/th\u003e\n\u003ctd\u003eAluminium, copper, galvanized steel, nylon\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eHeight\u003c\/th\u003e\n\u003ctd\u003eApprox. 960 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eWeight\u003c\/th\u003e\n\u003ctd\u003eApprox. 700 g\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eMounting Type\u003c\/th\u003e\n\u003ctd\u003eMast mount\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e","brand":"Sirio Antenne","offers":[{"title":"Default Title","offer_id":49447432257875,"sku":"SI2107902.00","price":39.0,"currency_code":"EUR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0890\/6516\/1043\/files\/sirio_thunder_27_cb_antenna_omnidirezionale_polarizzazione_lineare.jpg?v=1769092417","url":"https:\/\/mhzoutdoor.com\/en\/products\/sirio-thunder-27-cb-base-antenna","provider":"MHzOutdoor","version":"1.0","type":"link"}