Message-ID: <38E3350D.4717@xtra.co.nz>
Date: Thu, 30 Mar 2000 23:05:49 +1200
From: "vernall" <vernall@xtra.co.nz>
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To: rsgb_lf_group@blacksheep.org
Subject: Re: LF: Amp metres
References: <E12aXkP-0005RG-00@rabacal.direct.ca>
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Bob Eldridge wrote:
> 
> >An amateur regulatory constraint of 1 watt eirp limit starts to bite in
> >to the transmitter power budget for taller (more efficient) antenna
> >systems.
> >
> Bites in even more with a smaller antenna surely!

What I meant to suggest was that a small antenna needs a great deal of
applied power to achieve a radiated power of 1 watt.  For most hams, it
is impractical to get near 1 watt eirp with realistic transmitter
power.  On the other hand, the big antenna only nneds a QRP transmitter
connected to get 1 watt eirp.
 
> Didn't Dud Charman's indoor antenna circus demonstrate the truth of the
> axiom that a small antenna has the same radiation pattern as a very small
> antenna?

I also believe that all short verticals have the same basic radiation
pattern (the upper hemishere of a doughnut, with low angle suckin if
ground loss is significant). 

> Maybe a decommissioned Decca site could be better used to demonstrate the
> efficacy of passive reradiation from an adjacent tower.

Any tests would be interesting.  Big sticks are hard to come by.

Bob ZL2CA