Message-ID: <2000120616113268199@zetnet.co.uk>
Date: Wed, 6 Dec 2000 16:11:32 GMT
To: rsgb_lf_group@blacksheep.org
From: "Peter Dodd" <g3ldo@zetnet.co.uk>
Subject: LF: Re: Coils and amplifiers
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Andy said:

> Some of us don't have such large antennas as you, Peter.  For 1 Watt ERP
> I would need approx 4kW RF.  

Yes, I am well aware of that - and that is why I mentioned I5TGC's LF 
antenna, which must be the smallest of the LF antennas in the LF group.
However, the subject was loading coil cooling - and was it necessary. 
I only quoted my transmitter power and antenna current because that 
was the only experience I had of using higher power at LF

While on the subject of power amplifiers the only successful design 
that I have seen is the one by G3LNP, see 'The LF Experimenter's 
Source Book', second edition. 
I have seen solid state amplifiers that use many separate amplifiers 
with the outputs combined using a ferrite transformer. This might be 
the way to go in the construction of a less lethal design.
The Decca transmitters were designed with safety (and reliability) in mind.  


-- 
Regards, Peter, G3LDO

<g3ldo@zetnet.co.uk>