Message-ID: <01C24BC1.50F99360.g4jnt@thersgb.net>
From: "A C Talbot" <g4jnt@thersgb.net>
To: rsgb_lf_group@blacksheep.org
Subject: RE: LF: toroid cores
Date: Sat, 24 Aug 2002 22:55:06 +0100
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For my 700 Watt transmitter I use an ETD49 core (approx 200mm^2 core area) 
of 3C85 material as the output transformer.  This matches the 28 ohms 
output impedance from 12 turns on the primary, to a range of impedances via 
a tapped secondary.  Primary uses 2.5mm diameter Litz wire (ex Decca Tx) 
and the secondary is wound with plain 1mm enammelled.  The transformer runs 
around 30 degrees above ambient after the Tx has been operating for about 
half an hour with 100% duty cycle.

Full details of this Tx will be appearing inthe November/December edition 
of QEX.

Andy  G4JNT

> Hello LF group,
>
> I am trying to make a list of toroid core material that is suitable for
> 136kHz power applications, for impedance transformers and low-pass 
filters.
> I would appreciate any information about the material (brand-type), the
> application (transformer or filter) and the power level it was 
used/tested.
>
> many thanks in advance,
>
> 73, Rik   ON7YD
>
>
Hi Rik,