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This project assembles a 49:1 ferrite-core (“FT”) type #43 transformer that matches 50 ohm input to 2500 ohm end fed antenna. It is optimized for 3.5/7/10/14 MHz but will work reasonably well on all amateur bands from 80 meters thru 10 meters with a 135 foot length of wire and a short connection to ground.
14 sie 2024 · Antenna Loop Calculator. Need help? Ask our AI assistant. Efhw Antenna Formula. The following formula is used to calculate the length of an End-Fed Half-Wave (EFHW) antenna. L = 468 / f L = 468/f. Variables: L is the length of the antenna (feet) f is the frequency (MHz) To calculate the length of an EFHW antenna, divide 468 by the frequency in MHz.
23 lut 2023 · I explain the basics of the End Fed Half Wave (EFHW) Antenna, and how i calculate the lengths of my antenna for my targeted bands. I also go over some harmonics and how this can be used to combine a couple of bands on a single antenna.
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.
EFHW | Experimental Multiband Antenna with 49:1 UnUn. I made my first multiband experimental version of the Multiband EFHW antenna with 49:1 UnUn transformer. In this first part I want to show you complete process of made this antenna.
22 lut 2021 · The following is a list of materials required to make a 49:1 unun impedance transformer for an end-fed half wave antenna. You will also need a half-wavelength length of wire (14 or 12 gauge typically) in order to construct an antenna radiator for whichever ham band you choose.
The 49:1 impedance transformer ( or 64:1 ) will help you bring down the high impedance of your resonant EFHW antenna to almost 50 Ohm. Let’s have a look at a few details on how to build a 49:1, or a 64:1 impedance transformer.
