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13 lip 2023 · I show you how to make an End Feed Half Wave (EFHW) on bands 10 - 40. I will go over cutting and tuning the antenna for each wave. Then we will put...
An 80-10 end-fed half-wave antenna can be a very good performing part of an HF station. But its performance depends heavily on a well-designed and carefully constructed 49:1 unun, which matches the long wire impedance to within tuning range of operation. But the perfor-mance of an end-fed antenna is also very dependent on height above ground.
27 sty 2017 · A shortened multi-band End-Fed Half Wave (EFHW) antenna for 80-10m. This is a shortened multiband antenna, about 23m long, for 80m-10m that offers low SWR (1.3:1) on 80m and 40m, and below 3:1 on 20, 15 and 10m. The antenna has almost 300kHz bandwidth on 80m between 3:1 SWR points.
To fix the mismatch we need an impedance matching transformer, but before looking at the transformer in detail, you may wonder why move the feed point to begin with? The answers are many and varied, but moving the feed point to the end allows much greater flexibility in deploying the antenna, both as a portable antenna or a base antenna.
6 maj 2020 · Currently the antenna is resonate at about 7.7 Mhz. You would like it to be resonate at 7.1 Mhz. Take the old resonate frequency divided by the new resonate frequency and multiply by the original length, (7.7/7.1)*65 = 70.5 or so.
26 wrz 2018 · End Fed Half Wave (EFHW) Antenna Upgrade Part 2 - The Loading Coil. Once I had upgraded the matching transformer for my EF-10/20/40 MKII "EndFedz" (see Part 1) my thoughts turned to the loading coil. The original coil is designed for low power portable applications.
4 sie 2020 · There are some changes if you want to do a 160m EFHW antenna. First, you need 260 feet of wire and no coil on the antenna. The transformer should be 3 - 43 mix cores with 3 primary and 21 secondary windings (up to 30 depending on SWR).
