Return-Path: X-Spam-DCC: paranoid 1170; Body=2 Fuz1=2 Fuz2=2 X-Spam-Checker-Version: SpamAssassin 3.1.3 (2006-06-01) on lipkowski.org X-Spam-Level: X-Spam-Status: No, score=-2.4 required=5.0 tests=BAYES_00,DNS_FROM_AHBL_RHSBL, HTML_MESSAGE autolearn=no version=3.1.3 Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by paranoid.lipkowski.org (8.13.7/8.13.7) with ESMTP id tA2DPte2020429 for ; Mon, 2 Nov 2015 14:25:55 +0100 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1ZtF48-0006Uu-Qq for rs_out_1@blacksheep.org; Mon, 02 Nov 2015 13:22:28 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1ZtF48-0006Ui-EX for rsgb_lf_group@blacksheep.org; Mon, 02 Nov 2015 13:22:28 +0000 Received: from mail-wi0-f176.google.com ([209.85.212.176]) by relay1.thorcom.net with esmtps (TLSv1.2:ECDHE-RSA-AES128-GCM-SHA256:128) (Exim 4.86) (envelope-from ) id 1ZtF3H-00011H-BB for rsgb_lf_group@blacksheep.org; Mon, 02 Nov 2015 13:22:27 +0000 Received: by wicfx6 with SMTP id fx6so49645521wic.1 for ; Mon, 02 Nov 2015 05:21:18 -0800 (PST) X-DKIM-Result: Domain=gmail.com Result=Good and Known Domain DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :content-type; bh=wgYA/RIIyIOvJqphTE85vpHbe+etrMleFXZmR8Puv4A=; b=cj5zWOc/MshbFfeIBPSJWDd7imOD69Y77DDDQ80DV2OGEMLkKTE/ElF2qvCdfPTmXo ERfALiniaCSAXH6e5tsNQB5tPaL39IaW33otw8LxlRXFvlBdsMtQ4oTKgjZdfolumICe ULFrKLK12z4g44r1Zi0mGh8nMDbnJ5Zp9XTli0EC6ksPcvHj17KzPMtzj7VCSHLbFA9A PUJpstrT18ZnmyFfme2vRIxlCCC5U8rIDmznd9ZojT6jEjJirsgWC1rK5llR3U4UNk0t 1iMPommbg2i+GxckgrSm6kZwQIuYD5zElLOnY60yg+K2K2yQUm9wEgm8lOS91EhkiA+U ik+g== MIME-Version: 1.0 X-Received: by 10.194.62.15 with SMTP id u15mr25860483wjr.18.1446470478650; Mon, 02 Nov 2015 05:21:18 -0800 (PST) Received: by 10.28.183.139 with HTTP; Mon, 2 Nov 2015 05:21:18 -0800 (PST) In-Reply-To: <56375E6E.24975.AD8B5E@mike.dennison.ntlworld.com> References: <1887849276.20151030143118@chriswilson.tv> <5633D56C.20659.23BE4D8@mike.dennison.ntlworld.com> <316685691.20151031121552@chriswilson.tv> <56375E6E.24975.AD8B5E@mike.dennison.ntlworld.com> Date: Mon, 2 Nov 2015 13:21:18 +0000 Message-ID: From: Andy Talbot To: rsgb_lf_group@blacksheep.org X-Scan-Signature: 07fee8d4a4e8ea80934a0e0aaa44e788 Subject: Re: Re[2]: LF: Zmag of 45.6 Ohms OK, or should I try for better? Content-Type: multipart/alternative; boundary=047d7ba9750a0ee22405238ea797 X-SA-Exim-Scanned: Yes Sender: owner-rsgb_lf_group@blacksheep.org Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group X-SA-Exim-Rcpt-To: rs_out_1@blacksheep.org X-SA-Exim-Scanned: No; SAEximRunCond expanded to false X-Scanned-By: MIMEDefang 2.56 on 10.1.3.10 Status: O X-Status: X-Keywords: X-UID: 4784 --047d7ba9750a0ee22405238ea797 Content-Type: text/plain; charset=UTF-8 3C90 is a type of ferrite material, and doesn't specify a transformer type. What is the Ae (cross sectional area) of that core? Or just the diameter to work it out from? Andy On 2 November 2015 at 13:00, Mike Dennison wrote: > Chris, my 3C90 transformer has about 16 turns on each winding. (I say > approximately as I need to adjust by a turn or two between summer and > winter due to absorption/detuning by trees. I would suggest using the > thickest wire you have in case you want to run higher power in the > furture. > > As for the variometer, mine covers about 200-500mH and this will tune > about twice the width of the 136kHz band (in conjunction with my big > coil). Coincidentally it also tunes the 472kHz band when the big coil > is removed. > > Mike, G3XDV > ========== > > > yes, I still have trouble with the workshop alarm going off when I TX, > > but seemingly only at night, for whatever reason! Isolation is > > something I need to add. I have a 3C90 core spare and will wind a 1 : > > 1 transformer for now, just for isolation. How many turns should I use > > for best efficiency? I will probably use either 1.5 mm enamelled wire, > > or maybe some Teflon covered stuff. > > > > I also need to tame the variometer, it's obviously got far too many > > turns on it as just a couple of degrees moves resonance a long way. I > > picked up a 2 axis variometer, possibly a goniometer, that I may ise, > > with a motor drive. Photos at http://www.chriswilson.tv/goniometer.zip > > > > I only gave a fiver for it, so no big deal if it doesn't work out, but > > I am about to check what inductances it covers. I think it should > > withstand the voltages OK. What do you reckon? It would be easier to > > motor drive then the variometer in my loading coil. > > > > Thanks for the kind words about my progress. Most thanks should go to > > G3YXM for helping me get my amp done and reliable, he's been a > > Godsend, as have you gentlemen on here. > > > > > > > I agree with Stefan. A transformer (using a suitable core material > > > such as 3C90) gives you more flexibility in the future It also > > > provides the opportunity to isolate the RF ground from the mains > > > supply ground which can improve EMC both on transmit and receive. > > > > > Well done so far. Your signal is very impressive with such low RF > > > power. > > > > > Mike, G3XDV > > > ========== > > > > > > > > > > > > > > > > -- > > Best regards, > > Chris mailto:chris@chriswilson.tv > > > > > > > > > > ----- > > No virus found in this message. > > Checked by AVG - www.avg.com > > Version: 2016.0.7163 / Virus Database: 4457/10921 - Release Date: > > 10/31/15 > > > > > > --047d7ba9750a0ee22405238ea797 Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable
3C90 is a type of ferrite material, and doesn't specif= y a transformer type.

What is the Ae (cross sectional area) of= that core?
Or just the diameter to work it out from?
<= br>
Andy


On 2 November 2015 at 13:00, Mike Denniso= n <mike.dennison@ntlworld.com> wrote:
Chris, my 3C90 transformer has about 16 turns on each = winding. (I say
approximately as I need to adjust by a turn or two between summer and
winter due to absorption/detuning by trees. I would suggest using the
thickest wire you have in case you want to run higher power in the
furture.

As for the variometer, mine covers about 200-500mH and this will tune
about twice the width of the 136kHz band (in conjunction with my big
coil). Coincidentally it also tunes the 472kHz band when the big coil
is removed.

Mike, G3XDV
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D

> yes, I still have trouble with the workshop alarm going off when I TX,=
> but seemingly only at night, for whatever reason! Isolation is
> something I need to add. I have a 3C90 core spare and will wind a 1 :<= br> > 1 transformer for now, just for isolation. How many turns should I use=
> for best efficiency? I will probably use either 1.5 mm enamelled wire,=
> or maybe some Teflon covered stuff.
>
> I also need to tame the variometer, it's obviously got far too man= y
> turns on it as just a couple of degrees moves resonance a long way. I<= br> > picked up a 2 axis variometer, possibly a goniometer, that I may ise,<= br> > with a motor drive. Photos at http://www.chriswilson.tv= /goniometer.zip
>
> I only gave a fiver for it, so no big deal if it doesn't work out,= but
> I am about to check what inductances it covers. I think it should
> withstand the voltages OK. What do you reckon? It would be easier to > motor drive then the variometer in my loading coil.
>
> Thanks for the kind words about my progress. Most thanks should go to<= br> > G3YXM for helping me get my amp done and reliable, he's been a
> Godsend, as have you gentlemen on here.
>
>
> > I agree with Stefan. A transformer (using a suitable core materia= l
> > such as 3C90) gives you more flexibility in the future It also > > provides the opportunity to isolate the RF ground from the mains<= br> > > supply ground which can improve EMC both on transmit and receive.=
>
> > Well done so far. Your signal is very impressive with such low RF=
> > power.
>
> > Mike, G3XDV
> > =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
>
>
>
>
>
>
>
> --
> Best regards,
>=C2=A0 Chris=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2= =A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 mailto:chris@chriswilson.tv
>
>
>
>
> -----
> No virus found in this message.
> Checked by AVG - www.avg.com
> Version: 2016.0.7163 / Virus Database: 4457/10921 - Release Date:
> 10/31/15
>




--047d7ba9750a0ee22405238ea797--