WebThis is 1:49 RF impedance Transformer designed for matching EFHW (End Fed Half Wave) antenna to 50 OHm The transformer is made of high quality components – 2pcs of Amidon FT240-43 core and military grade AWG 14 PTFE wire. The efficiency is about 98%. You will get – FT240-43 core’s winding with military grade AWG 14 PTFE wire WebJun 3, 2024 · If my transformer efficiency guess above is true, later models with higher power ratings may shrink the difference. ... Bear in mind the tests above were to …
Toroid windings for EFHW - Antennas - SOTA Reflector
WebFeb 28, 2024 · Our Low band transformers for 1.8-8Mhz such as MEF-105-5K, MEF-107-4K, and MEF-107-2K-Plus feature insertion losses of only 0.07-0.25dB. For increased power handling on digital modes such as … http://infotechcomms.co.uk/downloads/Multi_band_EFHW.pdf alessandro de boni
Does a 1/2 wavelength end-fed antenna need a good RF ground?
WebFeb 4, 2024 · EFHW transformer two ways; EFHW LNR Precision EF-10/20/40MKII Examination; Categories Antennas Tags 4nec2, autotransformer, dipole, EFHW, end … WebNov 1, 2024 · Hello Heinz, thanks for sharing, I’m glad to add this info to some previous references for a better understanding of the EFHW feeders. I am afraid that we will still see this bad toroid winding technique replicated for a long time, thus loosing efficiency and reducing the radiated power in the antenna… WebAug 12, 2016 · A 9:1 unun is a transformer that reduces the impedance at the input by a factor of 9. So, if you connect a length of wire that presents an impedance of about 450 Ω to the input, you’ll get an impedance of about 50 Ω on the output. In fact, the 9:1 unun that I built is actually an autotransformer. Here’s a video that talks a little bit ... alessandro deodato cardif