I guess 90 degree phase shift might result in a cardioid pattern? Charlie, K4OTV
-----Original Message----- From: Topband [mailto:[email protected]] On Behalf Of Tom W8JI Sent: Wednesday, June 12, 2013 2:58 PM To: topband Subject: Re: Topband: My Turn For a Brain Pick - Sanity Check > Christman phasing is at 71 degrees? I was thinking 90 degree phasing. > Whats the reasoning for this? Optimum phasing of two verticals 1/4 wave apart is never 90 degrees, unless the user for some reason wants a single-point zero-angle null and less than maximum gain. Optimum element current delay for Ham use is always more than 90 degrees, and generally around 110-120 degrees, with 1/4 wave spacing. Making things more complex, phase shift in a delay line is never the line length unless the line is either 1/4 wave long or a multiple of 1/4 wave, or the line has a reasonably well-matched termination. With that in mind, a 71 degree long line might produce considerably different phase shift than the electrical line length, and the user probably wants phase to be some other value than 90 degrees (if the user understands arrays and patterns). 73 Tom All good topband ops know how to put up a beverage at night. _________________ Topband Reflector All good topband ops know how to put up a beverage at night. _________________ Topband Reflector
