Duo-band two element yagi beam for 30 and 40 meter

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Jose Antonio Gonzalez:
Hello!

I have been looking for a 30 and 40 meters beam.

So far, all the antennas I have found have 4 elements (2 elements for each band in the same boom) (Force 12 EF240/230, Force 12 Delta 240/230, Titanex TY4030, Optibeam OB4030, etc). However I have found a Japanese antenna, the Nagara TA-3040D which has only 2 elements in the boom and the manufacturer claims to be a “high performance duo-band two element yagi beam for 30 and 40 meter band). See here (Bottom of the page) : http://www.eonet.ne.jp/~antenna/nagarant-e/p10e.pdf

This is the web page of the Japanese manufacturer, Nagara: http://www.eonet.ne.jp/~antenna/nagarant-e/index_e.html

My question is: can I expect the same performance of this two kind of beams (the 4 elements in boom, 2 elements per band and the 2 elements in boom, two elements per band)?.

The Japanese manufacturer does not specify antenna gain or F/B ratios, just boom length (4.32 meters), and max. ele. Length (13.60 meters)

Thanks for you support.

Chris Harris:

 My question is: can I expect the same performance of this two kind of beams (the 4 elements in boom, 2 elements per band and the 2 elements in boom, two elements per band)?.

The Japanese manufacturer does not specify antenna gain or F/B ratios, just boom length (4.32 meters), and max. ele. Length (13.60 meters)


 >>>  The specifications for the Nagara are incomplete and should be questioned.

 The SWR data for 40 meters seems a little too good to be true for a 40/30 meter yagi on such as small boom. Although a 2 element yagi has optimum gain typically around 0.1 wavelength spacing, there's a trade-off:  as boom size decreases, so doesn't the bandwidth.

 Compare the SWR data from Force for the EF-240/230 which uses a 7.3 meter boom, which is almost double the size of the Nagara.:

 The SWR curve for the Force antenna is 200-250Khz for a 2:1 SWR bandwidth, while the Nagara claims to be below 1.3-1.5:1 across 100 Khz of the 40 meter band - with no other data.


 The Optimbeam looks good and gets good reviews on eHam but it's DOUBLE the price of the Force EF240/230.


  WA1RNE....

tom lish II:
check out the 3 ele steppir with the 40/30 add on kit.. sweet

Chris Harris:

     The 40/30 add-on is a convenient option but it's just a dipole.  It doesn't provide any gain or F/B advantage like a dedicated yagi.


 WA1RNE

Michael S. Higgins:
Check with SteppIR at Dayton this year. I understand they are working on a two element design for 40/30/20 meters.

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