Rick Thanks for the reply.
I'm glad to hear that it's that simple. I used the same principle when the verticals were dedicated to 40M and were 1/4wl tall where I fed them with 3/4wl and 5/4wl coaxial runs. The gain and side nulls were impressive. I will invest in some coax and let you know how things develop. Thanks again Carl AG6X -----Original Message----- From: Richard (Rick) Karlquist [mailto:[email protected]] Sent: Sunday, November 29, 2015 11:02 AM To: Carl Braun; [email protected] Subject: Re: Topband: 1/2 wl verticals and spaving On 11/28/2015 6:23 AM, Carl Braun wrote: > Any suggestions or websites available on ½ wl spacing and ½ wl radiators? > > Carl AG6X > I did some modeling of this a long time ago. Basically, the issue is that if you feed the 1/2 wave verticals at the base, you need to have a *voltage* forcing feed, rather than the usual current forcing feed used for 1/4 wave verticals. This is tough to do if you need a 90 degree phase shift as in a 4 square. However, you are in luck because you only need a 0 degree or 180 degree phase shift. As long as your array is physically symmetrical, any symmetrical feed network will give the right phasing. I suggest a simple T junction (in coax) with 1/2 wave lines to the verticals. Make one of them 3/2 wave for 180 degree phasing. The impedance at this point may be too high for an off the shelf transmatch, so you might have to roll your own. Rick N6RK _________________ Topband Reflector Archives - http://www.contesting.com/_topband
