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Message-ID: <65AECDF1F89AD411900400508BFC869F0D7581@pdw-mail-1.dera.gov.uk>
From: "Talbot Andrew" <ACTALBOT@dera.gov.uk>
To: rsgb_lf_group@blacksheep.org
Subject: LF: RE: 3C85 Material: Obsolete?
Date: Wed, 31 Jan 2001 14:55:04 -0000
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N87 or N67 is a better material than 3C85 now.  Also 3E5 and 3F3 and
3C90.  In fact any ferrite meaterial specified as being suitable for
power transformers.  I don't know if torroid cores are available
(Farnell do not have any), but a wide range of SMPSU transformer cores
are made in it.

One promising looking core for the kiloWatt region is the ETD54 and
ETD59 sizes in 3C90 available from Farnell.   and are specified for use
up to 200kHz.

For my 600W Tx I use an ETD49 core in 3C85 which looks to be the
smallest useable at this level, and  runs at about 50 deg after several
hours transmitting at 100% duty cycle.   
As part of a project for the other end of the spectrum, I'm in the
process of designing a 300 - 400W SMPSU for converting a 12V car battery
supply to 28V so will be looking into similar sized cores as needed for
137kHz kW systems.

Andy  G4JNT


> -----Original Message-----
> From: Steve Rawlings [mailto:steve@alg.demon.co.uk]
> Sent: 2001-01-30 22:59
> To: LF Group
> Subject: LF: 3C85 Material: Obsolete?
> 
> 
> Dear All,
> 
> I have received an Email from Wilfried DL5SWB reporting that the
> link no longer works from my web site to the Philips 3C85 data
> sheet previously at:
> http://www.acm.components.philips.com/pdf/3c85.pdf
> 
> Following their use by David Bowman in the G0MRF 136 kHz Power
> Amplifier, toroidal cores of Philips 3C85 material have become
> the preferred core material for many LF experimenters.
> 
> Wilfried writes:
> > I found on Your Website a link to download the 3c85.pdf. But it
> > isn't still available. I guess this type of material will not
> > produced any longer by Philips or now by Ferroxcube. I got the
> > new catalogue from http://www.ferroxcube.com without any 3C85
> > mentioned. There are more new ones. Perhaps You know, what new
> > material is good for 136 kHz.
>  
> > It would be nice, if You could send me the 3c85.pdf by eMail.
> 
> I wonder if anyone has stored a copy of 3c85.pdf that they can
> send me?  If so, I will forward it to Wilfried.
> 
> Also, does anyone know a suitable alternative to those magical
> 3C85 cores having a diameter of 25; 42; and 58 mm?
> 
> Regards to all,
> Steve GW4ALG
> 


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