{"id":104,"count":9,"description":"<p style=\"text-align: left\">These are our <strong>MEF (Multiband End Fed) transformers<\/strong> \u2014 high-ratio 49:1, 56:1, 75:1, and 81:1 UNUNs (~2500, 2800, 3750, or 4050:50 ohms) for EFHW antennas. Pick the model for your bands and power, add a half-wave wire, and you have a resonant multiband antenna: <strong>wire length in feet = 468 \u00f7 frequency in MHz<\/strong>. The average insertion losses \u2014 published with measured charts on every product page \u2014 run 0.1\u20130.5 dB, unmatched by any similar transformer on the market.<\/p>\r\n<p style=\"text-align: left\"><strong>Choosing your MEF is two decisions.<\/strong> First, your lowest band: <strong>MEF-130<\/strong> series covers 1\u201330 MHz including 160m; <strong>MEF-330<\/strong> covers 3\u201330 MHz (80m up); <strong>MEF-530<\/strong> covers 5\u201330 MHz (40m up); the <strong>MEF-104<\/strong> and <strong>MEF-107<\/strong> are the 160m low-band specialists; the <strong>MEF-307<\/strong> is the 80\/40m specialist. Second, your power: LP for portable and 100W-class, 1K-Plus and 2K-Plus with three 3-inch cores for high power, and 3K\/4K\/5K models for the biggest stations.<\/p>\r\n<p style=\"text-align: left\">Building your first end-fed? The full guide \u2014 theory, wire trimming, installation configurations, and SWR expectations \u2014 is in <a href=\"https:\/\/myantennas.com\/wp\/tech-info\/all-about-efhw-antennas\/\"><strong>All About EFHW Antennas<\/strong><\/a>, written by Danny Horvat, E73M\/N4EXA, who designs and measures every transformer on this page.<\/p>","link":"https:\/\/myantennas.com\/wp\/product-category\/balun\/efhw-xfrms\/","name":"EFHW-xfrms","slug":"efhw-xfrms","taxonomy":"product_cat","parent":41,"meta":[],"menu_order":0,"_links":{"self":[{"href":"https:\/\/myantennas.com\/wp\/wp-json\/wp\/v2\/product_cat\/104","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/myantennas.com\/wp\/wp-json\/wp\/v2\/product_cat"}],"about":[{"href":"https:\/\/myantennas.com\/wp\/wp-json\/wp\/v2\/taxonomies\/product_cat"}],"up":[{"embeddable":true,"href":"https:\/\/myantennas.com\/wp\/wp-json\/wp\/v2\/product_cat\/41"}],"wp:post_type":[{"href":"https:\/\/myantennas.com\/wp\/wp-json\/wp\/v2\/product?product_cat=104"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}