Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by mtain-db05.r1000.mx.aol.com (Internet Inbound) with ESMTP id 2724538000117; Tue, 16 Aug 2011 14:58:11 -0400 (EDT) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1QtOpK-0004ur-Bn for rs_out_1@blacksheep.org; Tue, 16 Aug 2011 19:57:26 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1QtOpJ-0004ui-QT for rsgb_lf_group@blacksheep.org; Tue, 16 Aug 2011 19:57:25 +0100 Received: from out1.ip08ir2.opaltelecom.net ([62.24.128.244]) by relay1.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1QtOpH-0003Pm-LB for rsgb_lf_group@blacksheep.org; Tue, 16 Aug 2011 19:57:25 +0100 X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: AtoAAOO8Sk5cF/tG/2dsb2JhbABBgk2Be5AihASPVHiBOwUBAQUIAQEDFjMCLAEBAwUCAQMRBAEBCiECAhQBBBoGFggGEwoBAgIBAYdhqAKRfoU4gRAEglGaN4cA X-IronPort-AV: E=Sophos;i="4.68,235,1312153200"; d="scan'208,217";a="499212652" Received: from host-92-23-251-70.as13285.net (HELO xphd97xgq27nyf) ([92.23.251.70]) by out1.ip08ir2.opaltelecom.net with SMTP; 16 Aug 2011 19:57:17 +0100 Message-ID: <009b01cc5c46$4880d2d0$0401a8c0@xphd97xgq27nyf> From: "mal hamilton" To: 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> Date: Tue, 16 Aug 2011 19:57:01 +0100 MIME-Version: 1.0 X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2600.0000 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2600.0000 X-Spam-Score: 0.0 (/) X-Spam-Report: autolearn=disabled,HTML_MESSAGE=0.001 Subject: LF: Re: Re: 137 grabbers Content-Type: multipart/alternative; boundary="----=_NextPart_000_0098_01CC5C4E.A9DEB0D0" 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: 0:2:489503904:93952408 X-AOL-SCOLL-URL_COUNT: 0 x-aol-sid: 3039ac1d40594e4abdc3097d X-AOL-IP: 195.171.43.25 X-AOL-SPF: domain : blacksheep.org SPF : none This is a multi-part message in MIME format. ------=_NextPart_000_0098_01CC5C4E.A9DEB0D0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Minto Good grabber but can u set it for QRS3=20 TNX=20 de mal/g3kev ----- Original Message -----=20 From: Minto Witteveen=20 To: rsgb_lf_group@blacksheep.org=20 Sent: Sunday, August 14, 2011 10:33 PM Subject: LF: Re: 137 grabbers Hi Wolf, Stefan, LF Interesting=E2=80=A6 might be worth a try. It is easy to set up, I = already have the SA612 employed in my 137 KHz receiver.=20 So=E2=80=A6 just a ferrite bar, varco, buffered and amplified using a = J310, into my current lowpass filter?.. And 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 = -------------------------------------------------------------------------= - Ceterum censeo Carthaginem delendam esse From: wolf_dl4yhf=20 Sent: Sunday, August 14, 2011 22:27 To: rsgb_lf_group@blacksheep.org=20 Subject: Re: LF: Re: 137 grabbers Ferrite RX antennas.. been there when 136 kHz started.=20 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. Q5 in SSB bandwidth.=20 Such a receiver is extremely handy to go /p for reception, and compare = different sites. 73, Wolf DL4YHF. Am 14.08.2011 21:43, schrieb Minto Witteveen:=20 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 antenna 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 power DCF77 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=20 Sent: Sunday, August 14, 2011 20:03 To: rsgb_lf_group@blacksheep.org=20 Subject: Re: LF: Re: 137 grabbers BTW what do you think about a ferrite RX antenna for LF? Now i'm = opening an older discussion i expect ;-) 73, Stefan/DK7FC ------=_NextPart_000_0098_01CC5C4E.A9DEB0D0 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable =EF=BB=BF
Minto
Good grabber but can u set it for QRS3 =
TNX
de mal/g3kev
 
----- Original Message -----
From:=20 Minto Witteveen
Sent: Sunday, August 14, 2011 = 10:33=20 PM
Subject: LF: Re: 137 = grabbers

Hi Wolf, Stefan, LF

Interesting=E2=80=A6 might be worth a try. It is easy = to set up, I=20 already have the SA612 employed in my 137 KHz receiver. =
So=E2=80=A6 just a ferrite=20 bar, varco, buffered and amplified using a J310, into my current = lowpass=20 filter?..  And then (if = and when=20 weather 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, = etc etc. I=20 was planning to do that anyway to see what the S/N is there, as a = comparison=20 with my QTH.

73=E2=80=99s Minto = pa3bca

 
----------------------------------------------------------------= ----------
Ceterum=20 censeo Carthaginem delendam esse
 
Sent: Sunday, August 14, 2011 22:27
Subject: Re: LF: Re: 137 grabbers
 
Ferrite=20 RX antennas.. been there when 136 kHz started.
Not as good as a = larger=20 air-core loop, possibly noise caused by the Barkhausen effect or = similar=20 effects, nonlinearities, etc.
Also beware the ferrite is a = semiconductor so=20 you will need some E-field screening, otherwise the ferrite material = will=20 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=20 antenna from the mains "ground", and only use an earthstake during = receive, at=20 DF0WD.

On the other hand, it's compact, relatively = light-weight, and=20 (in a resonant configuration) gives a nice preselector.
I remember = when I=20 connected a ferrite antenna to a tiny receiver with SA612 "gilbert = cell=20 mixer", the first signal I heard was G3KEV calling cq in CW.  Q5 = in SSB=20 bandwidth.
Such a receiver is extremely handy to go /p for = reception, and=20 compare different sites.

73,
   Wolf = DL4YHF.


Am=20 14.08.2011 21:43, schrieb Minto Witteveen:=20

I haven=E2=80=99t thought about ferrite RX antenna = for LF=E2=80=A6.My guess is=20 that it is not going to work =E2=80=93 not without an external = antenna coupled to=20 the ferrite, and then what=E2=80=99s the point?
DCF77 clocks = often have trouble=20 locking indoors or in the neighborhood of =E2=80=98QRM=E2=80=99 = generators like PC=E2=80=99s, and=20 look what power DCF77 is using=E2=80=A6
I could be entirely wrong = of=20 course=E2=80=A6

73=E2=80=99 Minto = pa3bca

 
From: Stefan Sch=C3=A4fer
Sent: Sunday, August 14, 2011 20:03
Subject: Re: LF: Re: 137 grabbers
 
<snip>
BTW what do you think about a = ferrite RX=20 antenna for LF? Now i'm opening an older discussion i expect = ;-)

73,=20 Stefan/DK7FC



<= /DIV>
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