Return-Path: Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by klubnl.pl (8.14.4/8.14.4/Debian-8+deb8u2) with ESMTP id w2L9uQmW029975 for ; Wed, 21 Mar 2018 10:56:27 +0100 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1eyaP6-0007fh-9M for rs_out_1@blacksheep.org; Wed, 21 Mar 2018 09:51:32 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1eyaP5-0007fY-SB for rsgb_lf_group@blacksheep.org; Wed, 21 Mar 2018 09:51:31 +0000 Received: from mail-wm0-x236.google.com ([2a00:1450:400c:c09::236]) by relay1.thorcom.net with esmtps (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.89) (envelope-from ) id 1eyaP0-0002uS-QC for rsgb_lf_group@blacksheep.org; Wed, 21 Mar 2018 09:51:30 +0000 Received: by mail-wm0-x236.google.com with SMTP id l9so8514002wmh.2 for ; Wed, 21 Mar 2018 02:51:26 -0700 (PDT) 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=20161025; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :cc; bh=rdcuQN0/2Ptw77dlo/N1e985uQEG6/jvzXcMtCCEZfs=; b=cdh6VIIWmO0KAZrnOC1IB3ux+nEvaBENjjUKepuRkD6MhANlnJXHgTsP5gwkk/jwbG jGkMFfY5ubCvcgKEIJNOTlYFldEfyMoVMHqd8qA8zVAgMk2VtTLr/TFwfRMBTKTPdHsg S7wWIfAC6lT/t+Ydhln+1L593Ggcbk5k3YCj/cbqfVANEUdnO7t4K9w+Hoq8NtiQ726k FVAp440qfwIU13KU6Zmn1mNlWEM8pmKMzyHZyntEwhtBALemB2IaXtm5JND9J/7ltaL7 dqo8K9ehRiRI2L260DHWssx23eytK/uSVHhMdw0JKI5jhFUq+2Hepq517J9/mq3S4Gbk Aemg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:in-reply-to:references:from:date :message-id:subject:to:cc; bh=rdcuQN0/2Ptw77dlo/N1e985uQEG6/jvzXcMtCCEZfs=; b=bhAFS+6+nIEADonhPibyStisyypzZKjrKtc/aACh7DN/fsgcQyNN9gs+EICTdGjgC8 AS3bhdIi/d2cMamxKdMHueoYlKOOmBaEF6iPJOR6tOMXEcd8k7IM0lIdyTXfBKZ5zYVZ /HnRTzyvVDZMcTNGkTljetpoE3Yj+ZahKS/gQpVbCJ9Cu3CfKyNN1jKC2AeW3+CPgBOt agRuofpUoZFoa10cAE3WgHDqqVHgRfq96J0rVmtoUG4AAZk3juxgfuqbwSs10AUtshYt yoIwx1uMKiIVxMfqUoZCQOrbbkhNqHj2G4qF7kIeGpKVH+urXOF3icUnWdgTo7CU8sbu 5tHQ== X-Gm-Message-State: AElRT7EE9CDznoTjoeGED/xANHKH0Odq/doe6I0kwuw8DedUixoQkUcT AL4Q+9OcCPXMKj2Fvl5HCgxtdfu6EBq0B85lAvQPnQ== X-Google-Smtp-Source: AG47ELsoyl4phgbozWmd5nrmipws4amPyxpvaObpNXku880GPhBlUQifNeJ+SNaJAZAOV5VGvTmWhDaQVT6+MYxgFAI= X-Received: by 10.80.144.120 with SMTP id z53mr17048220edz.163.1521625885830; Wed, 21 Mar 2018 02:51:25 -0700 (PDT) MIME-Version: 1.0 Received: by 10.80.154.195 with HTTP; Wed, 21 Mar 2018 02:51:25 -0700 (PDT) In-Reply-To: <1521624654720.99564@kuleuven.be> References: <1521624654720.99564@kuleuven.be> From: Andy Talbot Date: Wed, 21 Mar 2018 09:51:25 +0000 Message-ID: To: LineOne Cc: "rsgb_lf_group@yahoogroups.co.uk" X-Spam-Score: 0.0 (/) X-Spam-Report: Spam detection software, running on the system "relay1.thorcom.net", has NOT identified this incoming email as spam. The original message has been attached to this so you can view it or label similar future email. If you have any questions, see the administrator of that system for details. Content preview: SNAP ! In fact it was looking at a pot core of that very type, only smaller, 63mm diameter, that gave me the idea Andy [...] Content analysis details: (0.0 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- 0.0 FREEMAIL_FROM Sender email is commonly abused enduser mail provider (andy.g4jnt[at]gmail.com) 0.0 HTML_FONT_LOW_CONTRAST BODY: HTML font color similar or identical to background 0.0 HTML_MESSAGE BODY: HTML included in message 0.0 T_DKIM_INVALID DKIM-Signature header exists but is not valid X-Scan-Signature: e7c02b6e85723bae4746298f7f529717 Subject: Re: LF: Re: [rsgb_lf_group] Idea for tuned inductor Content-Type: multipart/alternative; boundary="94eb2c0ded1667f2d00567e922b2" X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: ** X-Spam-Status: No, hits=2.2 required=5.0 tests=HTML_50_60,HTML_MESSAGE, HTML_TAG_EXISTS_TBODY,HTML_WEB_BUGS,PORN_4 autolearn=no version=2.63 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 --94eb2c0ded1667f2d00567e922b2 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable SNAP ! In fact it was looking at a pot core of that very type, only smaller, 63mm diameter, that gave me the idea Andy On 21 March 2018 at 09:30, Rik Strobbe wrote: > Hello Andy, > > > do you mean something like this: http://www.wireless.org.uk/dk5pt-f.htm= =E2=80=8B ? > > > 73, Rik ON7YD - OR7T > > > ------------------------------ > *Van:* rsgb_lf_group@yahoogroups.co.uk > namens Andy Talbot andy.g4jnt@gmail.com [rsgb_lf_group] < > rsgb_lf_group@yahoogroups.co.uk> > *Verzonden:* woensdag 21 maart 2018 10:22 > *Aan:* rsgb_lf_group; LineOne > *Onderwerp:* [rsgb_lf_group] Idea for tuned inductor > > > > Looking at some large pot cores , I was struck by this novel idea. > > Back in the very early days of 10GHz with wideband equipment, we tuned > Gunn oscillator using a dielectric probe on a micrometer head - that > allowed precise adjustment with a repeatable reading. Looking at my > gapped pot cores, it occurred to me something similar could be done with > them. > > Fix, somehow, one half core to the micrometer so it can me pulled away > from the other allowing a precise air gap. Of course, doing it this way > means you have a gap in outer and inner pieces, so the effective gap is > double the measured value > > Inductance is then uo * A / g where uo is mag permaeability of free > space, 4E-7 * pi A is the core area and g the adjustable gap (SI units= ) > > You'd have to watch out for saturation (V=3D 4.44 . N.A.B) but as a small > adjuster to a larger fixed loading coil at low frequencies, may have som= e > merit for fine repeatable setting > > Just a thought > > Andy G4JNT > > __._,_.___ > ------------------------------ > Posted by: Andy Talbot > ------------------------------ > Reply via web post > > =E2=80=A2 Reply to sender > = =E2=80=A2 Reply > to group > > =E2=80=A2 Start a new topic > > =E2=80=A2 Messages in this topic > > (1) > Visit Your Group > > > > [image: Yahoo! Groups] > > =E2=80=A2 Privacy =E2=80=A2 > Unsubscribe > =E2= =80=A2 Terms > of Use > > . > > __,_._,___ > --94eb2c0ded1667f2d00567e922b2 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
SNAP !

In fact it was looking at a pot = core of that very type, only smaller, 63mm diameter, that gave me the idea<= /div>

Andy


On 21 March 2018 at 09:30, Rik Strob= be <rik.strobbe@kuleuven.be> wrote:

Hello Andy,


do you mean something like this:=C2=A0http://www.wireless.org.uk/dk5pt-f.= htm=E2=80=8B ?


73, Rik=C2=A0 ON7YD - OR7T


Van: <= a href=3D"mailto:rsgb_lf_group@yahoogroups.co.uk" target=3D"_blank">rsgb_lf= _group@yahoogroups.co.uk <rsgb_lf_group@yahoogroups.co.uk>= ; namens Andy Talbot andy.g4jnt@gmail.com [rsgb_lf_group] <rsgb_lf_group@yahoogroups.co.uk>
Verzonden: woensdag 21 maart 2018 10:22
Aan: rsgb_lf_group; LineOne
Onderwerp: [rsgb_lf_group] Idea for tuned inductor
=C2=A0
=C2=A0

Looking at some large pot cores , I was struck by this nov= el idea.

Back in the very early days of 10GHz with wideband equipment, we tuned= Gunn oscillator using a dielectric probe on a micrometer head - that allow= ed precise adjustment with a repeatable reading.=C2=A0 =C2=A0 Looking at my= gapped pot cores, it occurred to me something similar could be done with them.

Fix, somehow, one half core to the micrometer so it can me pulled away= from the other allowing a precise air gap.=C2=A0 Of course, doing it this = way means you have a gap in outer and inner pieces, so the effective gap is= double the measured value

Inductance is then uo * A / g=C2=A0 =C2=A0 where uo is mag permaeabili= ty of free space, 4E-7 * pi=C2=A0 =C2=A0A is the core area and g the adjust= able gap=C2=A0 (SI units)=C2=A0

You'd have to watch out for saturation (V=3D 4.44 . N.A.B) but as = a small adjuster to a larger fixed loading coil at low frequencies,=C2=A0 m= ay have some merit for fine repeatable setting

Just a thought

Andy=C2=A0 G4JNT

__._,_.___
Posted by: Andy Talbot <andy.g4jnt@gmail.com>
Reply via web post =E2=80=A2 Reply = to sender =E2=80=A2 Reply to group =E2=80=A2 Start a new topic =E2=80=A2 Messages in this topic (1)
3D"Yahoo!
=E2=80=A2 Privacy =E2=80=A2 Unsubscribe =E2=80=A2 Terms of Use

.

__,_._,___

--94eb2c0ded1667f2d00567e922b2--