![]() For example a high impedance antenna of 2500 ohms could be fed by 50 ohm feedline if you had a transformer with an impedance multiplication of 50. If the antenna impedance is not close to the impedance of the feedline in use, some means of transforming the impedance of the antenna to that of the feedline must be used. However ferrite cores have limits to their power handling and also they have ideal frequency ranges outside of their ideal range the inductance doesn’t have the same increase. Using ferrite cores allows for reduced number of turns, which means lower losses. The purpose of the ferrites is to increase the inductance of the wires passing through the cores, to allow them to operate as a transformer at a lower frequency than would be possible if the cores were say, cardboard or plastic. The impedance ratio is the square of the turns ratio. From the turns ratio an impedance transformation can be derived. Put that is the “antenna theory” …lets say… behind this design?Īssuming that you meant “But what is the antenna theory”, it’s a transformer with a specific turns ratio between primary and secondary.
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