FYI - Sinclair got the extra bandwidth by stager tuning the antenna element from the 1/4-wave matching transformer that is inside the element. The trade-off was a decrease in return loss (higher VSWR).
Chuck WB2EDV ----- Original Message ----- From: "skipp025" <skipp...@yahoo.com> To: <Repeater-Builder@yahoogroups.com> Sent: Sunday, November 15, 2009 10:15 AM Subject: [Repeater-Builder] Re: Building Low Band Loop Antennas (DB-212) > If you're building a Low-Band Loop Antenna from scratch... > forget the DB-212 and copy the Sinclair Version. The > Sinclair Low-Band loop has a lot wider band-width and it's > pretty much the same design... if properly done easier to > construct hardware wise. > > s. > > >> "cruizzer77" <atlant...@...> wrote: >> >> >> >> Thanks for the info. Somewhere else I read that from the mount to the >> outer edge the length should be 51 inches, this will be about the same as >> 52.5 inches from center to outer edge. >> >> But to build one from scratch I need more info, radius of the loop, >> diameter of the tube, coupling etc. Of course these can be calculated >> from formulas, but as the DB212 seems to be a particular good design it >> would be interesting to know. >> >> >> >> >> >> --- In Repeater-Builder@yahoogroups.com, "JOHN MACKEY" <jmackey@> wrote: >> > >> > I converted one about 15 years ago for use on 6 meters. It measured >> > 52.5 >> > inches from center to outer edge. >> > >> > ------ Original Message ------ >> > Received: Sat, 14 Nov 2009 10:41:05 AM PST >> > From: "cruizzer77" <atlantis7@> >> > To: Repeater-Builder@yahoogroups.com >> > Subject: [Repeater-Builder] DB-212 detailed info wanted >> > >> > > Does anyone have detailed info about the DB-212 antenna (converted to >> > > 6m) >> > that make it possible to build one from scratch? >> > > >> > > All the measures and info about the mount and feed point are >> > > interesting in >> > the first place. >> > > >> > > 73 de Martin HB9TZW >> > > >> > > >> > > >> > > >> > >> > > > > > ------------------------------------ > > > > Yahoo! Groups Links > > > -------------------------------------------------------------------------------- No virus found in this incoming message. Checked by AVG - www.avg.com Version: 9.0.707 / Virus Database: 270.14.66/2504 - Release Date: 11/15/09 02:50:00
