Message-ID: <5C95AD9F393E467884DFB2F614EAB2BB@DELL4>
From: <jrusgrove@comcast.net>
To: <rsgb_lf_group@blacksheep.org>
References: <3610102492.20180308120003@gmail.com>
Date: Thu, 8 Mar 2018 08:15:13 -0500
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Subject: LF: Re: Can an air cored LPF inductor have as high a "Q" as a toroidal wound one?
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Tested -3 material ... it has higher losses at LF.

Jay W1VD


----- Original Message ----- 
From: "Chris Wilson" <dead.fets@gmail.com>
To: <rsgb_lf_group@blacksheep.org>
Cc: <dead.fets@gmail.com>
Sent: Thursday, March 08, 2018 7:00 AM
Subject: LF: Can an air cored LPF inductor have as high a "Q" as a toroidal wound one?


> 
> 
> Hello  expert LF'ers!
> 
> The  centre  toroid  of  my  three  toroid  LPF heats up on the longer
> transmissions  like  WSPR15.  I  have  added  a  small fan as a crutch
> (thanks  N1BUG!) but I guess that's a crutch for inadequate hardware. I
> was  wondering  whether  instead of buying a larger toroid, which seem
> only  to  be  available  from the US at high cost, I could wind an air
> cored  coil  of  similar  inductance. But I am unsure whether it would
> have the required "Q" factor. Your opinions please? Thanks,
> 
> Also  I  am  wondering,  looking  at the Micrometals site, whether the
> current -2 material can be bettered by using -3 material?
> 
> http://www.w1vd.com/LPF.pdf
> 
> and info on frequency range of these cores is at: http://toroids.info/
> 
>  
> 
> -- 
> Best regards,
> Chris                          mailto:dead.fets@gmail.com
> 
>