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
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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. |
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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. |
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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 |
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DE |
995 |
2865 |
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D1 |
2190 |
2725 |
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D2 |
4340 |
2715 |
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D3 |
5970 |
2625 |
5-Element-18-Ohm-Yagi with 6m-Boom
New Version July 2014
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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 |
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D1 |
2165 mm |
2695 mm |
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D2 |
4320 mm |
2686 mm |
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D3 |
5970 mm |
2624 mm |
