> "Steven M Hodell" <st...@...> wrote: > I am about to hang a G7-220 on the side of my tower, > what spacing did you use? > How far from the tower is your G7-220?
I use a G7-220 on top of one tower as the receive antenna for a 224 Combiner System and it works great. The newer Generation G7-220 Antenna are constructed with stronger materials so birds are not bending or knocking off the ground radials in the first month of operation. Side tower spacing is normally considered in 1/4 wave increments and some of the more common spacing values are 1/4 and 1/2 wave spacing. However, the size of the tower, the antenna and the spacing all interplay to achieve directive and quasi omni patterns, so there are variants to every expected rule. Sinclair put out a blurb sheet showing basic expected patterns with the more standard above mentioned spacings. I have a copy of that single sheet in PDF format and of course I can send out free copies by Email. In addition to omni antennas the sheet also covers some directional (Yagi) spacings. If you look at Decibel Products antenna mounting instructions for their more popular folded dipole antenna models... you'll see how the antenna spacing and the dipole orientation effect the pattern. In most cases there is rarely a perfect omni pattern but what Decibel calls a "quasi omni" pattern is possible using the provided information and a bit of as-built testing & adjustment. cheers, s. > ----- Original Message ----- > From: skipp025 > To: Repeater-Builder@yahoogroups.com > Sent: Friday, January 08, 2010 11:56 AM > Subject: [Repeater-Builder] Re: DB224-JJ Dimensions Wanted > > > > > > I'm looking for a DB224-JJ. They are becoming hard to > > find, even from manufacturers. I would also consider > > a Hustler HD6-22225 or something similar to that. > > If someone has the dimensions for the 224-JJ Loops and maybe > the spacing distance... I think I can get them made. A local > (to me) Ham has made a metal forming jig for loop antenna > materials and is currently cranking out 440 loop antennas like > crazy. I could get him to re-size the jig and crank out some > 224 MHz loops with their mounts. Anyone have the "JJ" info > available? > > > I'm currently using a Hustler G7-220 side mounted, which > > works OK, but looking for something that could be top > > mounted. > > I've got a G7-220 Tower Top Mounted and it works killer (good). > > > Having problems getting coverage in the areas I need > > due to shadowing from the tower. Any help or suggestions > > would be greatly appreciated! > > Changing the spacing of the antenna to the tower would modify > the pattern. > > s. >
