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4-Element- 12,5-Ohm-Yagi with 3,60m-Boom (A 4m long Yagi see down) Short data: Gain 8,2dBd, F/R >26dB, bandwidth 300KHz (50.0-50.3 MHz) at SWR < 1.5 This type is in use at the station DL8FAJ and was at DL8FBC, both worked WAC in 2000/2001 Picture shows the homemade Yagi by ZP5YW. |
Match with 2x lambda/4 50-Ohm-coax in parallel to a grounded socket, feedpoint impedance 50 Ohm.
An other construction for the radiator is a folded dipole with an impedance of 50 Ohm (4x12.5 Ohm). At the feedpoint use a toroid balun 1:1 (T 200-6) or a simple coax-choke to match the symmetrical load to the coax-cable.
Important: The antennas have extremly high gain and F/B for the given length, but bandwidth is small and the yagis needs a very free surrounding. You must mount the Yagi on a separate mast, not together with other antennas!
The table for 12-mm and 10-mm-elements (also radiator), no tapering
| Element | Position | Length (12 mm) | Length (10 mm) |
| Ref | 0 mm | 2980 mm | 2986 mm |
| Rad | 750 mm | 2818 mm | 2826 mm |
| D 1 | 2075 mm | 2746 mm | 2756 mm |
| D 2 | 3580 mm | 2686 mm | 2700 mm |
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4-Element- 12,5-Ohm-Yagi with 4,00 m-Boom Gain 8,5 dBd, F/B 24 dB High-Gain Design, small Bandwidth
Matching with 2x1,23 m coax Aircell-5 |
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The stacked array 4 over 4 built by Mich, ON8DM
The measurement below shows the SWR and the impedances of one Yagi. Built without any fine-tuning! |
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Compare the simulated and the measured data! Read the procedure for the fine-tuning of the radiator and D1 at the page "Construction Details".
The table for 12-mm, 10-mm and 8-mm-elements (also radiator), no tapering
Mounting with insulated clamps above the boom
| Element | Position | Length (12 mm) | Length (10 mm) | Length (8 mm) |
| Ref | 0 mm | 2948 mm | 2952 mm | 2954 mm |
| Rad | 860 mm | 2796 mm | 2802 mm | 2814 mm |
| D 1 | 2340 mm | 2730 mm | 2742 mm | 2755 mm |
| D 2 | 3970 mm | 2664 mm | 2670 mm | 2686 mm |
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