I was thinking about the possibility of him converting the DB-411 into a corner reflector. Might work. Get the info from the Decibel corner reflector and apply it to the DB-411.
Chuck WB2EDV ----- Original Message ----- From: "Jeff DePolo" <j...@broadsci.com> To: <Repeater-Builder@yahoogroups.com> Sent: Thursday, November 19, 2009 11:49 AM Subject: RE: [Repeater-Builder] Antenna Pattern Question > > 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 >> >> >> > > > > ------------------------------------ > > > > Yahoo! Groups Links > > > -------------------------------------------------------------------------------- No virus found in this incoming message. Checked by AVG - www.avg.com Version: 9.0.707 / Virus Database: 270.14.73/2513 - Release Date: 11/19/09 02:51:00
