Construction Details

2-El.-12,5-Ohm (0,40 m)   

2-El.-28-Ohm (0,60 m)

3-El.-12,5-Ohm (1,90m+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 + 4,00 m)

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

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.

IS0/DK7ZB 

in JM49EL

during the UKSMG-50-MHz-Contest 2011

1.st place single op/ portable

 

Rig: IC-7000

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

horizontal rule

3-Element-12,5-Ohm-DK7ZB-Yagi with 1,90m-Boom

Short data: 

Gain 6.4dBd

F/B 20dB

Bandwidth 500KHz (49.9-50.4 MHz) at SWR < 1.5

 

Link: Details of a built yagi with a lot of Photos on the Homepage of  DL1GNM

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)
Ref 0mm 2970mm 2974mm
Rad 600mm 2820mm (see text below) 2820mm (see text below)
Dir 1 1850mm 2654mm 2666mm

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!