Description of the Sterba Curtain Beam Pattern and Gain. Other Notes. ---------------------------------------------------------- Well, the books don't go into great detail on the pattern. But there are many references to a mean height of 3/4 wavelength, (Which this one is), and a very Narrow broadside beam. Take off angle of about 17 degrees is shown. The horizontal Beamwidth is described as Similar to a dipole in chapter 4 which covers general information on broadside arrays. When I mentioned 'Narrow Broadside beam' and the contradictory "Similar to a dipole", I mean: The beam stretches out so far as to appear narrow! Also, since it is a closed loop, the antenna can be fed with a DC or AC current to melt off any Ice during the winter! Gain is additive, with each half wave section accounting for approximately 2.2 dB gain. So, adding the 2, 1/4 wave sections to the 3, 1/2 wave sections you get 4, 1/2 wave sections. Total Gain:4*2.2=8.4 dB. I think this is conservative. formulas: 1/2 wave phasing line: (Free Space formula) 492/F(MHz) 1/2 wave elements : (End effect formula) 468/F(MHz) 1/4 wave elements : (End effect formula) 234/F(MHz) Height above ground: Free space 1/2 wavelength, bottom element. It is imperative that the phasing lines be an electrical 1/2 wavelength and OPEN WIRE LINE!!!! Otherwise you'll have to use 1 wavelength Coax or something to keep the spacing 1/2 wavelength and the phasing at 0/360 degrees. Best 73! -Ed Loranger, we6w