Message-ID: <3C873738.54E2C4BC@netscapeonline.co.uk>
Date: Thu, 07 Mar 2002 09:47:36 +0000
From: "gii3kev" <gii3kev@netscapeonline.co.uk>
Organization: Netscape Online member
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To: rsgb_lf_group@blacksheep.org
Subject: Re: LF: Re: loops
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Dave Pick wrote:

> TX loop enthusiasts.
>
> The main problem with transmitting loops is the enourmous current and
> Voltage which is generated when exciting them with decent power. It's all
> very well to put 1W into a loop but try 1kW and see what happens..... High Q
> (which you MUST have for good efficiency) necessarily means high Voltage and
> current.
> Stand well back!

This is going to be the problem in the UK and possibly other Countries where up
to 5W erp is permitted, something like 2 kw or more RF exciting the loop. Trees
adjacent to the loop that were safe with 1W are likely to ignite at the KW
level, it could be back to the vertical although they have been known also to
ignite.
High power in the KW region is a totally different game for any antenna and
especially small loops compared to QRP. It is not only the loop wire but the
components like toroids, wire guage, insulators and capacitors needed to
resonate and match the feed, these have to be hefty and able to handle the
k/volts and amperage present.
In spite of all these obstacles and hazards the problems will be overcome, in
the meantime look out for smoke as some of those big Oregon pines, red cedars
and Norwegian spruces burst into flames!!
de G3KEV


>
>
> 73.
> Dave
> G3YXM
>
> > Some distances
> > covered with 1w to the antenna are remarkable and think of the potential
> > with kilowatts that some are using in the UK from the Decca Jeeps to one
> > of these loops.
> > 73 de Mal/G3KEV
> >
> >
> >
> >