Construction Details

3-El.-10m

4-El-10m

3-El-12m

4-El-12m

3-El.-15m

4-El.-15m

3-El.-17m

4-El.-17m

3-El.-20m

4-El.-20m

5-El-10m

3-Element-12-m-Yagi with 12.5 Ohm (Version 1)

Boom 3,50 m, narrow band version, high gain, high F/B (Version 2 see down)

Do not mount this Yagis with other antennas nearby. DK7ZB-match with 2x50-Ohm lambda/4 coax.

Short data for the Yagi at the begin, in the middle part and at the end of the band

Plot with the NEC-II-reference of YO7.2 by K6STI

The meaning of the data :

Frequency, gain, F/R, radiation resistance (impedance), SWR and loss against a theoretical defined maximum-gain- Yagi with the given boomlength. Remember, that this gain is only available with very low impedance and extrem low bandwidth!

 Elements of the 12-m-12.5-Ohm-Yagi, lengths for one element-half: 

 

20x1,5 mm

16x1,5 mm

12x1 mm

Position

Ref

1,00 m

1,00 m

1,05 m

0 m

Rad

1,00 m

1,00 m

0,945 m

1,235 m

Dir

1,00 m

1,00 m

0,785 m

3,50 m

Azimuth-diagram (horizontal pattern):

Elevation-diagram (vertical pattern):

Gain, SWR, F/R and Z versus frequency:

3-Element-12-m-Yagi with 12.5 Ohm (Version 2)

Boom 2,85 m, narrow band version, extreme high F/B

Gain 5,4 dBd

F/B > 30 dB

3-dB-angle hor. 64,6

3-dB-angle ver. 107,8

Do not mount this Yagis with other antennas nearby.

 DK7ZB-match with 2x50-Ohm coax.

Download EZNEC-Files

 Elements of the 12-m-12.5-Ohm-Yagi, lengths for one element-half: 

 

20x1,5mm

16x1,5mm

12x1mm

Position

Ref

1,00 m

1,00 m

1,10 m

0 m

Rad

1,00 m

1,00 m

0,965 m

0,725 m

Dir

1,00 m

1,00 m

0,74 m

2,82 m,

Needed lengths of the Aluminium tubes (remember: the middle and outer pieces need an additional part for overlap!)

  Tubes

20x1,5 mm

16x1,5 mm

12x1 mm

Reflector

1x 2,00 m 2x 1,20 2x 1,30 m

Radiator

2x 0,99 m

2x 1,20 m

2x 1,20 m

Director

1x 2,00 m

2x 1,20 m

2x 1,05 m