Charles, I agree. I was thinking more of base to mobile operation.
Just for fun, I ran some numbers in Radio Mobile with parameters from
a real system that I am familiar with on 2M. I varied antenna HAAT
and transmitter power to determine changes in coverage area and
radius. The numbers with * are the real system. I hope this table
survives the posting process and is still readable... If not I'll
post in another format. Numbers have been rounded...
Ant. HAAT M Coverage sq mi Coverage radius mi
110 7431 27
55* 5235 23
27 3388 18
13 2350 15
Tx output W Coverage sq mi Coverage radius mi
400 7290 27
100* 5235 23
25 3411 18
6.25 2115 14
Laryn K8TVZ
--- In Repeater-Builder@yahoogroups.com, "Charles Miller" <ham-
[EMAIL PROTECTED]> wrote:
> Larry,
>
> Doubling the antenna height does not always increase the gain. It
does help
> in most cases but if the antenna's are line of sight it makes
little or no
> difference.
>
> Charles Miller
> WD5EEH
>
> ----- Original Message -----
> From: "Laryn Lohman" <[EMAIL PROTECTED]>
> To: <Repeater-Builder@yahoogroups.com>
> Sent: Saturday, August 28, 2004 2:34 PM
> Subject: [Repeater-Builder] Re: db comparisons
>
>
> >
> >
> > --- In Repeater-Builder@yahoogroups.com, mch <[EMAIL PROTECTED]> wrote:
> >
> > You can gain 3dB by either doubling your power (or ERP), or by
> > > doubling the antenna height.
> >
> > Actually, doubling antenna height is usually close to 6db gain.
> >
> > Laryn K8TVZ
> >
> >
> >
> >
> >
> >
> > Yahoo! Groups Links
> >
> >
> >
> >
> >
> >
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