I'm preparing myself for getting flamed for this...
The DB antennas are significantly different than many other folded
dipole designs. The dipoles on the DB are considerably closer to the
mast than Sinclair or Telewave (for example). This is enough
difference to considerably change the radiation pattern of the
antenna. Note many (like Sinclair and Telewave) change the pattern by
changing the distance of the dipoles to the mast, and DB changes the
pattern by arranging the dipoles around the mast differently.
On Jul 23, 2009, at 9:15 AM, Laryn Lohman wrote:
> With all dipoles lined up, and the gain is 9dbd to the east, let's
> say, does anyone know what the actual gain figure is to the north
> and south? Yes, I've seen the little plots in the DB catalogs, and
> they would indicate that there is close to 6dbd gain north and
> south. But Sinclair's plots indicate considerably less than that.
> Surely the antennas are close enough in basic design, so I would
> expect the gain in the north south directions to be nearly the same
> for both brands. Which one is closest to correct?
>
> I have an application near Lake Michigan that would require at least
> 6dbd gain between 350 and 190 degrees. In other words, starting just
> west of north, moving through east, finishing just west of south.
> Little gain is needed between 190 and 350 degrees. The antenna is
> top-mounted.
>
> Thanks all.
>
> Laryn K8TVZ
>
>
>
--
Cort Buffington
H: +1-785-838-3034
M: +1-785-865-7206
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