Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by mtain-df01.r1000.mx.aol.com (Internet Inbound) with ESMTP id 60E3738000092; Sun, 14 Aug 2011 18:11:10 -0400 (EDT) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1Qsisz-0002Mc-0L for rs_out_1@blacksheep.org; Sun, 14 Aug 2011 23:10:25 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1Qsisy-0002MT-Ds for rsgb_lf_group@blacksheep.org; Sun, 14 Aug 2011 23:10:24 +0100 Received: from relay.uni-heidelberg.de ([129.206.100.212]) by relay1.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1Qsisx-0004sD-1N for rsgb_lf_group@blacksheep.org; Sun, 14 Aug 2011 23:10:24 +0100 Received: from freitag.iup.uni-heidelberg.de (freitag.iup.uni-heidelberg.de [129.206.29.204]) by relay.uni-heidelberg.de (8.14.1/8.14.1) with ESMTP id p7EMAMgp025759 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO) for ; Mon, 15 Aug 2011 00:10:22 +0200 Received: from [129.206.22.206] (pc206.iup.uni-heidelberg.de [129.206.22.206]) by freitag.iup.uni-heidelberg.de (8.12.11.20060308/8.11.2) with ESMTP id p7EMALpQ010095 for ; Mon, 15 Aug 2011 00:10:21 +0200 Message-ID: <4E48470B.1020906@iup.uni-heidelberg.de> Date: Mon, 15 Aug 2011 00:07:07 +0200 From: =?UTF-8?B?U3RlZmFuIFNjaMOkZmVy?= User-Agent: Mozilla/5.0 (Windows; U; Windows NT 6.1; de; rv:1.9.1.8) Gecko/20100227 Thunderbird/3.0.3 MIME-Version: 1.0 To: rsgb_lf_group@blacksheep.org References: <68BE37BD69E54DEE89CEBA8E30E9B94E@PcMinto> <4E47FFE9.10100@iup.uni-heidelberg.de> <3ED8E5422F1F45DBB8186E9D9870AD63@PcMinto> <4E480E02.9020706@iup.uni-heidelberg.de> <938BF599006244949F6CDDB5BA91F347@PcMinto> <4E482FBD.7030402@freenet.de> <7F63C990AB12460D9E0A1FC11C87385D@PcMinto> In-Reply-To: <7F63C990AB12460D9E0A1FC11C87385D@PcMinto> X-Spam-Score: 1.4 (+) X-Spam-Report: autolearn=disabled,HTML_MESSAGE=0.001,RATWARE_GECKO_BUILD=1.426 Subject: Re: LF: Ferrite RX antennas Content-Type: multipart/alternative; boundary="------------020603000408020902000006" X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.8 required=5.0 tests=HTML_30_40,HTML_MESSAGE 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 x-aol-global-disposition: G X-AOL-SCOLL-SCORE: 0:2:486903712:93952408 X-AOL-SCOLL-URL_COUNT: 0 x-aol-sid: 3039ac1d40d54e4847fd24f6 X-AOL-IP: 195.171.43.25 X-AOL-SPF: domain : blacksheep.org SPF : none This is a multi-part message in MIME format. --------------020603000408020902000006 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: quoted-printable X-MIME-Autoconverted: from 8bit to quoted-printable by relay.uni-heidelberg.de id p7EMAMgp025759 Hi Minto, Wolf, LF, With a ferrite antenna you don't even need a fishing pole. 1m above=20 ground must be OK i think. You can go hiking or riding the bike or take=20 it to the holidays (even at Ryan air ;-) ) and need no extra power=20 supply! Hmmm.... Another link with an impressive rod: Search for R33-075-1200 at=20 http://www.amidon.de/contents/de/d649.html OK it's a little expensive ;-) But the 20cm pieces for just 6 EUR should be fine for a first try. I=20 already thought about ordering some :-) 73, Stefan/DK7FC Am 14.08.2011 23:33, schrieb Minto Witteveen: > > Hi Wolf, Stefan, LF > > Interesting=E2=80=A6 might be worth a try. It is easy to set up, I alre= ady=20 > have the SA612 employed in my 137 KHz receiver. > So=E2=80=A6 just a ferrite bar, varco, buffered and amplified using a J= 310,=20 > into my current lowpass filter?.. And then (if and when weather=20 > permits, it has been raining here for more than two months) out into=20 > the field with a fishing pole, miniwhip, ferrite bar, ft817,laptop,=20 > etc etc. I was planning to do that anyway to see what the S/N is=20 > there, as a comparison with my QTH. > > 73=E2=80=99s Minto pa3bca > > -----------------------------------------------------------------------= --- > Ceterum censeo Carthaginem delendam esse > *From:* wolf_dl4yhf > *Sent:* Sunday, August 14, 2011 22:27 > *To:* rsgb_lf_group@blacksheep.org > *Subject:* Re: LF: Re: 137 grabbers > Ferrite RX antennas.. been there when 136 kHz started. > Not as good as a larger air-core loop, possibly noise caused by the=20 > Barkhausen effect or similar effects, nonlinearities, etc. > Also beware the ferrite is a semiconductor so you will need some=20 > E-field screening, otherwise the ferrite material will couple noise=20 > into the windings. But it's not as bad as this may sound; actually I=20 > used a ferrite antenna for reception for some years until I discovered=20 > I had to disconnect the ...errr... RF counterpoise from the main=20 > antenna from the mains "ground", and only use an earthstake during=20 > receive, at DF0WD. > > On the other hand, it's compact, relatively light-weight, and (in a=20 > resonant configuration) gives a nice preselector. > I remember when I connected a ferrite antenna to a tiny receiver with=20 > SA612 "gilbert cell mixer", the first signal I heard was G3KEV calling=20 > cq in CW. Q5 in SSB bandwidth. > Such a receiver is extremely handy to go /p for reception, and compare=20 > different sites. > > 73, > Wolf DL4YHF. > > > Am 14.08.2011 21:43, schrieb Minto Witteveen: >> >> I haven=E2=80=99t thought about ferrite RX antenna for LF=E2=80=A6.My = guess is that=20 >> it is not going to work =E2=80=93 not without an external antenna coup= led to=20 >> the ferrite, and then what=E2=80=99s the point? >> DCF77 clocks often have trouble locking indoors or in the=20 >> neighborhood of =E2=80=98QRM=E2=80=99 generators like PC=E2=80=99s, an= d look what power DCF77=20 >> is using=E2=80=A6 >> I could be entirely wrong of course=E2=80=A6 >> >> 73=E2=80=99 Minto pa3bca >> >> *From:* Stefan Sch=C3=A4fer >> *Sent:* Sunday, August 14, 2011 20:03 >> *To:* rsgb_lf_group@blacksheep.org >> *Subject:* Re: LF: Re: 137 grabbers >> >> BTW what do you think about a ferrite RX antenna for LF? Now i'm=20 >> opening an older discussion i expect ;-) >> >> 73, Stefan/DK7FC >> >> > --------------020603000408020902000006 Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable X-MIME-Autoconverted: from 8bit to quoted-printable by relay.uni-heidelberg.de id p7EMAMgp025759 Hi Minto, Wolf, LF,

With a ferrite antenna you don't even need a fishing pole. 1m above ground must be OK i think. You can go hiking or riding the bike or take it to the holidays (even at Ryan air ;-) ) and need no extra power supply! Hmmm....

Another link with an impressive rod: Search for R33-075-1200 at http://www.amidon.de/contents/de/d649.html
OK it's a little expensive ;-)

But the 20cm pieces for just 6 EUR should be fine for a first try. I already thought about ordering some :-)

73, Stefan/DK7FC

Am 14.08.2011 23:33, schrieb Minto Witteveen:

Hi Wolf, Stefan, LF

Interesting=E2=80=A6 might be worth a try. It is easy t= o set up, I already have the SA612 employed in my 137 KHz receiver.
So=E2=80=A6 just a ferrite bar, varco, buffered and amplified using a J31= 0, into my current lowpass filter?.. =C2=A0And then = (if and when weather permits, it has been raining here for more than two months) out into the field with a fishing pole, miniwhip, ferrite bar, ft817,laptop, etc etc. I was planning to do that anyway to see what the S/N is there, as a comparison with my QTH.

73=E2=80=99s Minto pa3bca

=C2=A0
--= ------------------------------------------------------------------------<= br> Ceterum censeo Carthaginem delendam esse
=C2=A0
Sent: Sunday, August 14, 2011 22:27
Subject: Re: LF: Re: 137 grabbers
=C2=A0
Ferrite RX antennas.. been there when 136 kHz started.
Not as good as a larger air-core loop, possibly noise caused by the Barkhausen effect or similar effects, nonlinearities, etc.
Also beware the ferrite is a semiconductor so you will need some E-field screening, otherwise the ferrite material will couple noise into the windings. But it's not as bad as this may sound; actually I used a ferrite antenna for reception for some years until I discovered I had to disconnect the ...errr... RF counterpoise from the main antenna from the mains "ground", and only use an earthstake during receive, at DF0WD.

On the other hand, it's compact, relatively light-weight, and (in a resonant configuration) gives a nice preselector.
I remember when I connected a ferrite antenna to a tiny receiver with SA612 "gilbert cell mixer", the first signal I heard was G3KEV calling cq in CW.=C2=A0 Q5 in SSB bandwidth.
Such a receiver is extremely handy to go /p for reception, and compare different sites.

73,
=C2=A0=C2=A0 Wolf DL4YHF.


Am 14.08.2011 21:43, schrieb Minto Witteveen:

I haven=E2=80=99t thought about ferrite RX antenna for = LF=E2=80=A6.My guess is that it is not going to work =E2=80=93 not without an external a= ntenna coupled to the ferrite, and then what=E2=80=99s the point?
DCF77 clocks often have trouble locking indoors or in the neighborhood of =E2=80=98QRM=E2=80=99 generators like PC=E2=80=99s, and look what powe= r DCF77 is using=E2=80=A6
I could be entirely wrong of course=E2=80=A6

73=E2=80=99 Minto pa3bca

=C2=A0
Sent: Sunday, August 14, 2011 20:03
Subject: Re: LF: Re: 137 grabbers
=C2=A0
<snip>
BTW what do you think about a ferrite RX antenna for LF? Now i'm opening an older discussion i expect ;-)

73, Stefan/DK7FC



--------------020603000408020902000006--