3-El.-12,5-Ohm (1,90m+2,20 m) new
|4-El-12,5-Ohm (2,90 m)|
|5-El-12,5-Ohm (6,00 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|
3-Element-12,5-Ohm-DK7ZB-Yagi with 2,20m-Boom
Another Yagi with 1,90-m-Boom see down!
All you need is gain! This portable Yagi has lower weight and more gain than any comparable Yagi. Stacked array 3 over 3 with 10 dBd!
In the ISSUE 107 (May 2011) of the SIX-NEWS (UKSMG) was a report about this Yagi
Download as PDF-File
High-gain, narrow-band version
Gain 7.15 dBd
F/B 13 dB
The antenna was designed with 12,5 Ohm for 50.125 MHz. Without any tuning the measured SWR minimum was at 50,155 MHz with 1,04! You can correct the lengths of the elements 1-2 mm for SWR 1,0 at 50,150 MHz.
during the UKSMG-50-MHz-Contest 2011
1.st place single op/ portable
Powered with two solar panels (120 + 75 W)
and 180 Ah lead acid batteries
In 2017 first place in the UKSMG-6h-portable section with the 2x3-Ele. from JM49GT
The stacked Array 3 over 3
built by Mitch, ON8DM
Gain 10 dBd, stacking distance 4,50 m
The first measuring with the EZNEC-lengths without any correction:
Element mounting with the Nuxcom-clamps (see the page "construction details")
Element positions and lengths, all elements with the same diameter:
|Element||Position||Length (12 mm)||Length (10 mm)||Length (8 mm)||Length (3/8'')||Length (1/2'')|
|Ref||0 mm||2934 mm||2940 mm||2940 mm||2940 mm||2930 mm|
|Rad||910 mm||2790 mm||2798 mm||2808 mm||2800 mm||2788 mm|
|Dir 1||2170 mm||2708 mm||2720 mm||2734 mm||2724 mm||2702 mm|
The stacked array 3 over 3 with a gain of 10 dBd in free space
3-Element-12,5-Ohm-DK7ZB-Yagi with 1,90m-Boom
Bandwidth 500KHz (49.9-50.4 MHz) at SWR < 1.5
Updated dimensions (18-July-2006) for a little bit more bandwidth, new antenna built and tested :
|Element||Element-position||Element-length (12mm)||Element-length (10mm)|
|Rad||600mm||2820mm (see text below)||2820mm (see text below)|
Middle part of the radiator for 12mm and 10mm parasitic elements 2x150mm of 16x1,5mm, outer ends 12x1mm, length tip to tip. Fine-tuning by shifting the 12mm-parts.
Match with 2xLambda/4 50-Ohm-coax in parallel to a grounded socket, feedpoint impedance 50Ohm.
An other construction for the radiator is a folded dipole with an impedance of 50Ohm (4x12.5Ohm). At the feedpoint use a toroid balun 1:1 (T 200-6) or a coax-cable choke to match the symmetrical load to the coax-cable.
The lobe with 26° elevation is for ES in the range of 1000-2000 km, the lobe with 8° for long haul DX!