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

5-Element-18-Ohm-Yagi with 6m-Boom

A new Version of this Yagi see down (07/2014)

Short data: Gain 9.3 dBd, very good F/R >33dB, bandwidth 700 KHz (49.8-50.5 MHz) at SWR < 1.5

This Yagi has slightly less gain than the 12,5-Ohm-Yagi, but is not so critical and the pattern is excellent. You can mount the antenna 1,50 m above a roof or 2m above other Yagis for shortwave.

The Photo shows the Yagi built by  Manfred, DL8FBC.

On the top is a 7-Ele-DK7ZB-Yagi for the 2m-band.

Paco, EA5EF

has a very good solution for the transformation line. 

I used 60 Ohm-cable (old german type, today not available) 2x parallel. 

Paco used 3x93-Ohm-coax RG62 with good success.

To transform the 18 Ohm of the Yagi to the 50 Ohm for the feeding you need a 30 Ohm-quarter-wave-line.

The 5-El.-18-Ohm-Yagi by Paco, EA5EF with the 3x93-Ohm-coax-match

It is possible to use a parallel match of 50- and 75-Ohm coax (gives 30 Ohm), e.g. RG58 and RG59 parallel

(Hint from 9A1CBM, mni tnx!)

Radiator 2x400 mm 16 mm, end-pieces 12 mm, elements 12 mm

Element

Element-position (mm)

Element-length (mm)

R

0

2995

DE

995

2865

D1

2190

2725

D2

4340

2715

D3

5970

2625

 

5-Element-18-Ohm-Yagi with 6m-Boom

New Version July 2014

Boom 6,00 m

Gain 9,43 dBd

F/B 30 dB

SWR 50,0-50,3 MHz <= 1,25

More Gain, better Bandwidth

All elements 12 mm, radiator, too

Element

Element-position 

Element-length (12 mm)

R

0

2984 mm

DE

850 mm

2819 mm

D1

2165 mm

2695 mm

D2

4320 mm

2686 mm

D3

5970 mm

2624 mm