70cm Ground Plane Antenna
- about 90cm of 1mm silver steel rod
- one luster terminal with at least two
- 50Ohms coax cable
- glass fibre mast
lead guides beeing able to carry 2mm leads
Construction & DesignSketches or drawings are IMHO not necessesary because of the extreme simplicity of the "design". Cut 19cm off the rod, and bend 2cm at one end by an angle of 90°. This will be the radiator, 17cm straight up in the air. It will directly go in one whole of the luster terminal. Watch out, that the terminal´s skrews are pointing downwards, elsewhise you will later have problems with water and corrosion. The radials are made of two rods with a length of 34cm. Stick both through the other whole of the luster terminal, centered. You might now bend each rod to an angle of 90°, with the luster terminal in it´s centre. To give it the correct feed-point impedance the radials should be twisted slighly downwards.
Connect the coax cable to your little aerial, using again the abilities of the terminal. BTW, I used RG174 (lossy!) for the last meter, to reduce the weight.
In the middle of modern luster terminals there are wholes, to mount the terminal wherever it should go to. This whole (3mm) is perfect to stick the mast through. At the very top mine has a diameter of 2.8mm. This makes the ground plane to rest only 12cm below the top.