Construction Details

2-El.-12,5-Ohm (0,40 m)   

2-El.-28-Ohm (0,60 m)

3-El.-12,5-Ohm (1,90+2,20 m) new

3-El.-28-Ohm (1,90 m)

3-El.-28-Ohm (2,50 m)

4-El-12,5-Ohm (2,90 m)

4-El-12,5-Ohm (3,60 + 4,00m)

5-El.-28-Ohm (4,50 m)

5-El-12,5-Ohm (6,00 m)

5-El-18-Ohm (6,00 m)

6-El.-28-Ohm (7,20 m)

7-El.-28+50Ohm (9,20+7,75 m) 8-El.-28-Ohm (12,30 m) 9-El.-28-Ohm (14,00 m)
4-El-28+50-Ohm (2,20 m) 5-El-50-Ohm (4,30 m) new 6-El-50-Ohm (6m+7,20 m) new

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

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 

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!

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