In article <34iqb6$epf@netnews.upenn.edu>, depolo@blue.seas.upenn.edu (Jeff DePolo) writes:
> In article <kgk-0609941536070001@kgkmac.repoc.nwu.edu>,
> Kenneth Kalan <kgk@nwu.edu> wrote:
> >
> >Some companies list the gain in dB, while others use dBd or dBi. From my limited research, it appears that an antenna rated at 8 dBi is around 6 dB.
>
> dBi is decibels with an isotropic radiator as the 0dB reference
> dbd is decibles with a half-wave dipole as the 0dB reference
>
<Stuff deleted>
>
> It has been my experience that Cushcraft, Diamond, Comet, and several of the
> other manufacturers inflate their gain figures. Assume that the numbers
> they give are dBi unless otherwise stated. Remember: marketing guys write
> the catalogs, not the engineers. To the marketing guys, 9.0 dB looks better
> than 6.9 dB, so they use the 9.0 value and leave off the "i" in dBi.
>
> --- Jeff
Even when they say dbi or dbd, I'm skeptical. You can find essentially identical
antennas in the Diamond and Comet catalogs, with exactly the same gain numbers,
only one says dbi and the other says dbd. Personally, I define the abbreviations
as 'db imaginary', 'db doubtful' and plain db as 'don't believe'.
This is not to say the companies don't make good antennas. You just have to take
most claimed gain figures with a few grains of salt.
Roger Grady K9OPO c21rag@kocrsv01.delcoelect.com
Delco Electronics Corp. Kokomo, IN
"All information and opinions are personal unless otherwise stated."
