Search results
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.
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.
31 gru 2022 · UN-UN 49:1 QRP – transformator impedancji anteny EFHW. Budowa anteny End Fed Half Wave (EFHW), czyli pólfalowego monopola zasilanego na jednym z jego końców, oferuje szereg zalet czyniąc tą konstrukcję bardzo atrakcyjną jeśli myśli się, na przykład, o pracy terenowej lub wielopasmowej z użyciem jednej anteny.
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.
For those that enjoy the LNR and Hy Endfed antennas, but want to run more power, Balun Designs now offers an excellent alternative. Built with the same craftsmanship as all our other units, this new model will allow you to either replace your current matching unit or construct a new higher power end fed half wave antenna.
For it's simplicity and small dimensions is very popular for portable or SOTA activities, and also as a static-mobile antenna. This Mini 49:1 UnUn can be used also as the base point of a vertical dipole antenna with its half wave length. MULTIBAND ANTENNA.
Figure 2 shows the complete schematic view of a typical EFHW antenna system. Briefly, the 100pf/2kv cap across the primary of the impedance matching transformer is there to allow better tuning in the 10 meter band. The transformer is a step-up with an impedance ratio of 49:1, and wound on a type 43 toroid core.
