In a message dated 97-07-05 15:19:20 EDT, dick.green@valley.net ("Dick
Green".) writes:
> In the most recent catalogs, the gain claimed by Hy-Gain for the TH7DX is
> "6.57 dBd average" (it used to be "9.6 db" in a catalog I have from ten
> years ago), and the gain claimed by KLM for the KT-34XA ranges from 8.5 to
> 11.3 "dBd" (depending on the band.) Since a dipole over perfect ground has
> 6 dBd of gain, is Hygain saying the TH7DX only has .57 dB more gain? Is
KLM
> saying the KT-34XA has from 2 to 5 db gain over a TH7DX?
>
Not only that, but Force 12 has TWO gain figures - 'gain' and 'net
gain'.
Now you know why the ARRL hasn't allowed antenna gain figures to be used
in their advertising for years. I have heard, though, that the League is
looking at this topic and, because of computer modelling verification
availability, may soon allow gain figures to be listed again.
Some manufacturer's gain figures come from engineering or R&D while
others seem to come from the marketing department.
I have it on good authority that in the next 6-12 months that there will
be some very interesting test results that may shed some light on this
interesting but contentious topic.
73, Steve K7LXC
TOWER TECH -- professional tower supplies for amateurs
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