A 5 element OWA Yagi for 28MHz with a 5.97mtr boom - 5OWA28SEK
Revised August 2010 v1.0
Premium commercial versions of this antenna at Innovantennas
I WILL MODEL THIS ANTENNA IN ANY TUBE SIZE OR TAPER SCHEDULE FOR YOU, CONTACT ME VIA EMAIL
This antenna was designed for GM3SEK
This is a high-gain, wideband OWA (Optimised Wideband Array) Yagi which covers the whole of the 10m band with an SWR of less than1.1:1 from 28-29MHz. It is a very noncritical antenna so both metric and imperial sized tubing can be used with the same dimensions. I have included both SWR plots below and as you will see they are both very similar. This antenna has a two stage taper.
This Antenna has been modelled using NEC4 and confirmed by FEKO. This is thousands of dollars of the very latest antenna design software available and the results are highly accurate. When loading into your software, you will see similar SWR but not the same. Please do not alter the model, build to these dimensions for the best results.
Contact me if you are unsure what correction (if any) you require for the element holders/stand-offs you will use or any other questions you may have.
Also read 'An Intro to OWA Yagis' and also 'Creating a Balun'
Built by VK4NDX
Built by V85TX
The 5el 28MHz OWA at IT9BLB
The 5OWA28SEK and a 6el 7.3m LFA for 50MHz at VK4DDC
The 5OWA28SEK at ZL1RS
'..only at 6 meters high but SWR still flat from 27.9 to 29.1'
Bob, ZL1RS
The 5OWA28SEK installed at ON6AB with his comments below
'Hi Justin,
I finished the antenna this weekend and it is really working extremely well (and with a flat SWR).
I put it up on my tilting mast at 15m up.
Attached you'll find some pictures.
I used anti-skid tape between the boom and the elements to be able to align them perfectly and prevent them from twisting.
Thanks again for designing!
73,
Bruno
ON6AB'
The 5OWA28SEK at LY2W above a full-sized 3el 40M Yagi
'Hi Justin,
I send photos with done 5owa28sek antenna in ly2w position.
The SWR are 1.0 at 28000kc to 1.2 at 29000kc !!! :-)
The balun made simple 7 cable turns.
img-2833 your antenna under fool size 40m 3 el.beam elevated.
img-0203 antenna under ground , img-0200 some turbo elements :-) for fan
73! sincerely
Richard LY2FN'
2 x 5el G0KSC OWAs at EA2EA / EE2W Contest Station
'Hi Justin,
there is a little present for you: Some photos of the antennas we used
at EA2EA / EE2W (M/M) in the CQ WW contest.
The antennas used for 28 Mhz were 2 x 5 el. OWA vertical stacked.
They showed an outstanding performance that permitted us to make
almost 700 QSO's in that "dead" band in the CW contest.'
73 de Iñaki, EB1RL.
Antenna Layout and Construction:
Performance
9.74dBi @ 28.500MHz
20.76dB @ 28.500MHz
SWR: Below 1.1.1 from 28MHz to 29MHz
Construction details
Refer to the above drawing.
Antenna Dimensions For either UK/USA sized tubing or European/metric sized tubing
Taper: Mid Section, 5/8 inch or 16mm tube (total length 1.473m). End sections as per below schedule in either 1/2 inch or 13mm tube.
Spacing End Section Length (All below sizes in Metres)
Reflector 0 1.9325
DE1 1.173 1.8705
D1 1.687 1.7355
D2 3.531 1.7025
D3 5.967 1.5745
Second version using 20mm/15mm tubing designed for LY2FN
Antenna Dimensions For either UK/USA sized tubing or European/metric sized tubing
Taper: Mid Section, 3/4 inch or 20mm tube (total length 1.473m). End sections as per below schedule in either 5/8 inch or 15mm tube.
Spacing End Section Length (All below sizes in Metres)
Reflector 0 1.9255
DE1 1.053 1.8885
D1 1.533 1.7475
D2 3.511 1.7015
D3 5.967 1.5965
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