7-Element-Yagis 28 Ohm+50 Ohm, 3.00/2.80-m-Boom
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New: 7-El.-Ultra-Wideband-Yagi 50 Ohm, 6 MHz SWR < 1,15 Boom 2,80 m Gain 10,2 dBd |
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The suppression of common waves is made with a 50-cm-loop of the coax-cable. After the 50 cm the cable
is fixed to the metallic boom. The capacitive coupling shortens the common waves to ground.
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7-Element-Yagi 28Ohm, 3.00m-Boom
The picture right shows the 2x7-El.-group of Patrick, TK5EP
On his page (in english language a lot of informations and pictures) This Yagi has slightly different dimensions with a gain of 10,6dBd, but greater bandwith. All details on the page of TK5EP.
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10,7dBd Gain F/B >30dB at 144,3MHz 3,00m-Boom, very clear pattern For SSB/CW-part of the 2m-Band Stacking distance 2,85m |
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The 2x7-El.-stacked by Knut, DM4KL
In the pictures below you see the measured data for the two antennas. You see slight differences, in practise you will have such effects. Click to enlarge! |
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4x7-El.-Yagi Stacking vertical French contest group F5LEN F5MBM F5RMY
Details: www.jn38.org
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The 4x7-El.-Group by Philippe, F1HQM
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Elementlengths and -positions, Radiator 12mm or 10mm diameter!
| Diameter | Ref | Rad | D 1 | D 2 | D 3 | D 4 | D 5 |
| 10mm | 1020mm | 968mm (12mm) | 941mm | 914mm | 898mm | 901mm | 873mm |
| 3/8'' | 1020 mm | 973 (3/8'') | 943 mm | 916 mm | 900 mm | 903 mm | 874 mm |
| 8mm | 1022mm | 972mm (10mm) | 949mm | 922mm | 906mm | 909mm | 881mm |
| 6mm | 1024mm | 974mm (10mm) | 956mm | 930mm | 914mm | 917mm | 889mm |
| Position | 0mm | 275mm | 465mm | 920mm | 1605mm | 2360mm | 2980mm |
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Patterns for 144,3MHz, above 145MHz increase the back lobes and the antenna has 0,1dB more gain
7-Element-Yagi 50Ohm, 3.00m-Boom
Narrowband-Versions for SSB 144-145MHz or FM 145-146MHz
Feeding with the 50Ohm-caox-choke
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Gain 10,7dBd 3dB-angles hor = 39,6°, ver =44,8° Stacking distance 2,85m (for a single antenna)
The Photo shows the 2x7-El.-Yagi built by Billy, PY2LCD
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Lengths and Spacing of the Elements
| Type | Diameter | Ref | Rad | D 1 | D 2 | D 3 | D 4 | D 5 |
| SSB | 6 mm | 1024 mm | 982 mm (6 mm) | 952 mm | 932 mm | 918 mm | 923mm | 894 mm |
| 8 mm | 1020 mm | 974 mm (8 mm) | 942 mm | 925 mm | 908 mm | 914mm | 884 mm | |
| 10 mm | 1018 mm | 969 mm (10 mm) | 935 mm | 918 mm | 900 mm | 906 mm | 876 mm | |
| FM | 6 mm | 1018 mm | 975mm (6mm) | 942 mm | 925 mm | 908 mm | 913 mm | 884 mm |
| 8 mm | 1014 mm | 965mm (8mm) | 932 mm | 915 mm | 898 mm | 904 mm | 874 mm | |
| Position | 0 mm | 320 mm | 460 mm | 935 mm | 1630 mm | 2385 mm | 2980 mm | |
