I'm basically looking to null an area of about 45 degrees behind the antenna. Kinda like I want omni coverage except for this 45 degree area. I don't think beans will cut it. I'll check Comprod's web site.
Thanks and 73, Dan N8DJP --- In Repeater-Builder@yahoogroups.com, "Jeff DePolo" <j...@...> wrote: > > > Comprod makes dipole arrays with a screen reflector, at least for VHF, not > sure about UHF. I'm looking in the catalog and it shows a backside null > close to 20 dB down from the main lobe. > > The screen reflector should be nominally about 1/4 wave behind the radiator > for maximum forward gain. It could be modeled fairly easily. > > How wide of a forward beamwidth do you want? Would a couple of corner > reflectors be a better way to go? > > --- Jeff > > > -----Original Message----- > > From: Repeater-Builder@yahoogroups.com > > [mailto:repeater-buil...@yahoogroups.com] On Behalf Of Dan Hancock > > Sent: Thursday, November 19, 2009 11:43 AM > > To: repeater builders > > Subject: [Repeater-Builder] Antenna Pattern Question > > > > > > > > I have a repeater that I need to have as tight a cardiod > > pattern as possible. I have looked at the dipole antennas > > such as the DB-411 and they don't really shut down the back > > door quite enough. > > Does anyone have any antenna modeling software that would > > show the result of adding an 18" wide screen to the back side > > of the mast on the DB-411? Does anyone have any experience in > > home-brewing a modification like this? > > > > Dan Hancock N8DJP > > > > > > > > > > > > No virus found in this incoming message. > > Checked by AVG - www.avg.com > > Version: 8.5.425 / Virus Database: 270.14.61/2498 - Release > > Date: 11/19/09 07:51:00 > > > > > > >
