160 Metre Antenna for small gardens

Updated 02/03/2021

The antenna

The type of wire used in my antenna is 2mm diameter, using insulators to support the wire on the main mast at the bottom of the garden and the other leg supported on a convenient fir tree. The total length of the loop is 124 feet or about 38 metres in circumference. The length is fairly critical because anything sorter will require a higher capacitance tuning capacitor and the efficiency will reduce and anything longer you will not be able to tune the antenna for 160M. Picture 3 shows the radiation pattern.

Picture 1 shows the antenna arrangement in my garden. The white box contains the variable capacitor and motor to tune the capacitor shown in picture 2.

The tuning arrangement in figure 2 is how I configure the loop for Top Band. The wire length determines the exact frequency covered and the size of the capacitor, the size of capacitor I use is 30-200pf this tunes the loop from approximately 1.7MHz to 2.5MHz.

The ferrite core.

The ferrite core is an FT240-31.

The turns ratio in the input needs to be adjusted on the core to obtain the lowest S.W.R. on Top Band.

The motor and gear train.

The motor is a wormgear motor and both the motor and gears came from MotionCo


Diagram


Picture 1

 Loop


Picture 2


Box


Picture 3

Radiation patern


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