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-17-m-Yagi with 28 Ohm (Version 1)

Boom 5,00 m (Broadband-Yagi for mounting with other antennas nearby)

(A second Yagi with 3,85 m Boom and 12,5 Ohm see down)

Dave, M0TAZ, and his team have built the Yagi and tested it on a fieldday.

The beam construction really was a team effort and was made possible by Chris G8OCV, George M1GEO

Peter G0IAP, John  M0UKD and Dave  G7UVW.

Links to the steps of building the yagi:       Part 1     Part 2

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 17-m-28-Ohm-Yagi, lengths for one element-half:   

 

30x2mm

25x2,00mm

20x1,5mm

16x1,5mm

Position

Ref

0,50m

1,35m

1,25m

1,165m

0m

Rad

0,50m

1,35m

1,25m

0,945m

2,19m

Dir

0,50m

1,35m

1,25m

0,675m

4,95m

Azimuth-diagram (horizontal pattern):

Elevation-diagram (vertical pattern):

3-Element-17-m-Yagi with 12,5 Ohm (Version 2)

Boom 3,85 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 lambda/4 coax.

Download EZNEC-Files

 Elements of the 17-m-28-Ohm-Yagi, lengths for one element-half:   

 

25x2 mm

20x1,5 mm

16x1 mm

12x1 mm

Position

Ref

1,00 m

1,00 m

1,00 m

1,305 m

0 m

Rad

1,00 m

1,00 m

1,00 m

1,125 m

1,00 m

Dir

1,00 m

1,00 m

1,00 m

0,83 m

3,83 m