Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by mtain-mk05.r1000.mx.aol.com (Internet Inbound) with ESMTP id 79D45380000CC; Mon, 15 Aug 2011 14:08:48 -0400 (EDT) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1Qt1a3-0006Nl-0F for rs_out_1@blacksheep.org; Mon, 15 Aug 2011 19:08:07 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1Qt1a2-0006Nc-78 for rsgb_lf_group@blacksheep.org; Mon, 15 Aug 2011 19:08:06 +0100 Received: from nm25-vm0.bullet.mail.sp2.yahoo.com ([98.139.91.228]) by relay1.thorcom.net with smtp (Exim 4.63) (envelope-from ) id 1Qt1Zz-0008Me-HN for rsgb_lf_group@blacksheep.org; Mon, 15 Aug 2011 19:08:06 +0100 Received: from [98.139.91.68] by nm25.bullet.mail.sp2.yahoo.com with NNFMP; 15 Aug 2011 18:07:55 -0000 Received: from [98.139.91.17] by tm8.bullet.mail.sp2.yahoo.com with NNFMP; 15 Aug 2011 18:07:55 -0000 Received: from [127.0.0.1] by omp1017.mail.sp2.yahoo.com with NNFMP; 15 Aug 2011 18:07:55 -0000 X-Yahoo-Newman-Property: ymail-3 X-Yahoo-Newman-Id: 544155.73380.bm@omp1017.mail.sp2.yahoo.com Received: (qmail 48864 invoked by uid 60001); 15 Aug 2011 18:07:55 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=yahoo.com; s=s1024; t=1313431675; bh=vmRPlgoBr1g7ysWEdO9Z6Zv+2GJ8pCTFHrOARrgQeYo=; h=X-YMail-OSG:Received:X-Mailer:References:Message-ID:Date:From:Reply-To:Subject:To:In-Reply-To:MIME-Version:Content-Type; b=nG9cQGwhACtYoVlau5/QiD7bW6D7HmT+H0WZsmbIrT6i66OqJQJikeIiCRXLbripZZNbq1aqAtBQhqBsk+S8PbD/LTi0y8hFe52vgq2EajMlYx0Y9oEHdp0foJiZxFJBSPiXLp6moU+rHsLJfW6XwzdDntva67Z4X5i6ZplMtyE= DomainKey-Signature:a=rsa-sha1; q=dns; c=nofws; s=s1024; d=yahoo.com; h=X-YMail-OSG:Received:X-Mailer:References:Message-ID:Date:From:Reply-To:Subject:To:In-Reply-To:MIME-Version:Content-Type; b=2nRu0CEtyJXXsNBxg54WxdKSsL+wYN0Bn5Ln8y+LObx9IBZfxIeg9e/KUUebNDNdwXyrQkq0uX6sSupjuIYIJWL++0tejzqYaGy5TF5Qa60MvWLeh1f5lfTNUOp7xvoCAPYW2dL0KBftb8WrkznIxZidtvebhSXiTsaCyhKVXgI=; X-YMail-OSG: yG9D0z8VM1lBz2GRL2buXh6FzMvQi2Zqaj8BuFfrYhaxz.Z gvR8jyp9GZCMK5IamTRl9eTDa6L8dra39zYCJeSE26eRtmbBykrxCJaI4Jyj s8MtnmVMZMBsi.EZ59OcdMkc0HGcndSoETyj29x9ELTAiIUX_BtCAaqGLpYG .2hRomPP14TPYsPhrQH0.i0evAGUvNk1QdEkJ3RIMBP30K1t530ZkwMBzjQ4 vntSDaI1G4.hBk9JOsZLlkwNu7fy4UJxwTJjoJ03sp8w3bFC4HNL45wkLzzc G7KHh0NGMHXzHnoBL8VMgQJBTCIIJiu8oEJ56vsU0x4cwZeWlb9vwLPozU2v P3UpWYfb1Ga3946pVehKHdePYT_HeGvK6Qf5bOqPGCiukBetCXycOc3iAld8 jCX5H4.aVgVVIz91N6ATt.TCt_lMfkDY5lCKv3dnr5bHhQLt1BGkUVHaI6ws 4up02.lch1F5oP3RyWwpXYpGgwfWBoT38woJ1orstcBof1XhssaUSfYTI7OO X5zWThr8QpkHZXANpwKlrgWNanYGWMbige0avmadH3478.hhY2i6M.znNqjT U4wMulKFdikdjutQbQ9ix6OmoFDvPpjLl.aAOSzkmZ6632nMXQcUkxBpK3df ziexlIJf.NaxgfVmRaRI3EetCbNdHTXbGXhvMQ2sS_cP.jiHfa1R9YxiG1GN Sl7FseSEvvnkWlumawpLHxxgFKv4jfP3P3.3MogPFjLLNwtziM_IRqdRR Received: from [87.1.203.2] by web111912.mail.gq1.yahoo.com via HTTP; Mon, 15 Aug 2011 11:07:54 PDT X-Mailer: YahooMailWebService/0.8.113.313619 References: <68BE37BD69E54DEE89CEBA8E30E9B94E@PcMinto> <4E47FFE9.10100@iup.uni-heidelberg.de> <3ED8E5422F1F45DBB8186E9D9870AD63@PcMinto> <4E480E02.9020706@iup.uni-heidelberg.de> <938BF599006244949F6CDDB5BA91F347@PcMinto> <4E482FBD.7030402@freenet.de> <4E484183.9090805@iup.uni-heidelberg.de> <4E494A57.90105@freenet.de> <4E4956DA.1060201@iup.uni-heidelberg.de> Message-ID: <1313431674.11413.YahooMailNeo@web111912.mail.gq1.yahoo.com> Date: Mon, 15 Aug 2011 11:07:54 -0700 (PDT) From: Daniele Tincani To: "rsgb_lf_group@blacksheep.org" In-Reply-To: <4E4956DA.1060201@iup.uni-heidelberg.de> MIME-Version: 1.0 DomainKey-Status: good (testing) X-Spam-Score: 1.4 (+) X-Spam-Report: autolearn=disabled,HTML_MESSAGE=0.001,HTML_TINY_FONT=1.425 Subject: Re: LF: Ferrite RX antennas Content-Type: multipart/alternative; boundary="0-1087762727-1313431674=:11413" X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=1.0 required=5.0 tests=FORGED_YAHOO_RCVD,HTML_20_30, HTML_MESSAGE,TO_ADDRESS_EQ_REAL 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: 0:2:498333216:93952408 X-AOL-SCOLL-URL_COUNT: 0 X-AOL-SCOLL-AUTHENTICATION: mail_rly_antispam_dkim-m245.2 ; domain : yahoo.com DKIM : fail x-aol-sid: 3039ac1d61894e4960af37c4 X-AOL-IP: 195.171.43.25 X-AOL-SPF: domain : blacksheep.org SPF : none --0-1087762727-1313431674=:11413 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Just to complete the picture about LF-enabled antennas, recently Claudio Re= =C2=A0I1RFQ has introduced his so-called MaxiWhip design (as "opposite" to = the MiniWhip :-)). If my understanding is correct, it basically consists of= a vertical element (9 m tall, supported by a fishing rod for example) and = a special 32:1 balun (probably un-un). The report at following link (by Ang= elo Brunero IK1QLD) is in Italian, but shows interesting results in a direc= t comparison with the MiniWhip:=C2=A0http://www.brunero.it/ik1qld/antenna/.= =0A=C2=A0=0APersonally, I prefer to work with small wideband or tuned=C2=A0= loops. In my particular, unfortunate condition (very noisy urban area aroun= d my QTH), it seems to me that loops offer more predictable results. In my = modest opinion, E-probes tend to be more subject=C2=A0to external, environm= ental factors than loops, so are more suitable for open areas with a good d= istance from noise sources, metal structures, etc.. Difficult to obtain wit= h a decent predictability in my personal case.=0A=C2=A0=0ABest regards=0ADa= niele=0A=0AFrom: Stefan Sch=C3=A4fer =0ATo: rsgb_lf_group@blacksheep.org=0ASent: Monday, August 15, 2011 7:26 P= M=0ASubject: Re: LF: Ferrite RX antennas=0A=0A=0A Hello Wolf, =0A=0AThanks = to the link to your nice to read article. I just found it a hour=0Abefore y= our mail and already read it ;-)=0A=0AWell, i also prefer the usual configu= ration instead of that sleeve=0Aantenna. Also i have to keep the focus on m= y actual goal: Making a=0Ahandy antenna for amateur LF / p operation withou= t a car! And the 16=0Arods i will get (14 cm long, 8mm diameter) will be be= st in a 2x7=0Aconfig. i think. Or do you rather suggest 3x5 or even 4x4?=0A= 2x7 is then about 30 cm long which is very fine for a backpack and=0Ashould= be robust enough.=0AI would use the same double side bonding tape, this is= very useful to=0Aget a first fixed arrangement. Then putting all that in a= PVC tube, 2mm=0Athickness and add the turns above the tube. =0AWould you r= ecommend litz wire or standard 0.5 mm enamelled wire?=0AAs an E field shiel= d i would use aluminium bonding tape, without making=0Aa shutcut turn of co= urse.=0A=0ASo the newcomers should not think that this antenna is the best = what=0Aone can use for LF. Just in that special case of /p i see advantages= .=0AOtherwise a well designed loop (+ preamp or a very sensitive RX, if a= =0Asamll loop is used) or E field antenna such as the PA0RDT should be=0Apr= eferred, as Alan already pointed out.=0A=0ALooking forward to a direct comp= arison of the DCF39 SNR that can be=0Aachieved and to the first amateur sig= nal received with that antenna in=0A/p...=0A=0A73, Stefan/DK7FC=0A=0A=0A=0A= =0AAm 15.08.2011 18:33, schrieb wolf_dl4yhf: =0AHi Stefan,=0A>The rods were= found in Friedrichshafen for a bargain price. I later=0Adiscovered (most l= ikely after the topic had been discussed here, or in=0Athe VLF group) that = these rods are used for inductive welding=0A(google("Ferrite Impeder Rod").= Here's a bundle of them:=0A>=0A>http://www.qsl.net/dl4yhf/vlf_rdf/vlf_rdf_= loop.html=0A>=0A>They are 20 cm long. =0A>=0A>The most effective use (to "c= atch the magnetic field from a distant=0Atransmitter") is NOT to connect th= em 'parallel' in a bundle, but to=0Aconnect them in series (up to a certain= point). This is much in=0Acontrast to the esoteric sleeve thingy seen some= where on the web.=0A>=0A>73,=0A>=C2=A0=C2=A0 Wolf . =0A>=0A>=0A>=0A>Am 14.0= 8.2011 23:43, schrieb Stefan Sch=C3=A4fer: =0A>Wolf, =0A>>=0A>>Which dimens= ions has your ferrite rod had? =0A>>=0A>>Never thought i will find a source= for rods that are longer than 10 cm=0Abut see: http://www.box73.de/catalog= /product_info.php?products_id=3D1422&osCsid=3Drqlpfme957i65d7etjil1ntru5=0A= >>=0A>>even an official distributor..=0A>>=0A>>Any better links? =0A>>=0A>>= 73, Stefan/DK7FC=0A>>=0A>>Am 14.08.2011 22:27, schrieb wolf_dl4yhf: =0A>>Fe= rrite RX antennas.. been there when 136 kHz started. =0A>>>Not as good as a= larger air-core loop, possibly noise caused by the=0ABarkhausen effect or = similar effects, nonlinearities, etc.=0A>>>Also beware the ferrite is a sem= iconductor so you will need some=0AE-field screening, otherwise the ferrite= material will couple noise=0Ainto the windings. But it's not as bad as thi= s may sound; actually I=0Aused a ferrite antenna for reception for some yea= rs until I discovered=0AI had to disconnect the ...errr... RF counterpoise = from the main=0Aantenna from the mains "ground", and only use an earthstake= during=0Areceive, at DF0WD.=0A>>>=0A>>>On the other hand, it's compact, re= latively light-weight, and (in a=0Aresonant configuration) gives a nice pre= selector.=0A>>>I remember when I connected a ferrite antenna to a tiny rece= iver with=0ASA612 "gilbert cell mixer", the first signal I heard was G3KEV = calling=0Acq in CW.=C2=A0 Q5 in SSB bandwidth. =0A>>>Such a receiver is ext= remely handy to go /p for reception, and compare=0Adifferent sites.=0A>>>= =0A>>>73,=0A>>>=C2=A0=C2=A0 Wolf DL4YHF.=0A>>>=0A>>>=0A>>>Am 14.08.2011 21:= 43, schrieb Minto Witteveen: =0A>>>I haven=E2=80=99t thought about ferrite = RX=0Aantenna for LF=E2=80=A6.My guess is that it is not going to work =E2= =80=93 not without=0Aan external antenna coupled to the ferrite, and then w= hat=E2=80=99s the point?=0A>>>>DCF77 clocks often have trouble locking indo= ors or in the neighborhood=0Aof =E2=80=98QRM=E2=80=99 generators like PC=E2= =80=99s, and look what power DCF77 is using=E2=80=A6=0A>>>>I could be entir= ely wrong of course=E2=80=A6 =0A>>>>73=E2=80=99 Minto pa3bca =0A>>>>=0A>>>= >From: Stefan Sch=C3=A4fer =0A>>>>Sent: Sunday, August 14, 2011 20:03 =0A>= >>>To: rsgb_lf_group@blacksheep.org =0A>>>>Subject: Re: LF: Re: 137 grabbe= rs =0A>>>> =0A>>>>BTW what do you think about a ferrite RX antenna = for LF? Now i'm=0Aopening an older discussion i expect ;-)=0A>>>>=0A>>>>73,= Stefan/DK7FC=0A>>>>=0A>>>>=0A>>>> =0A>>> =0A> --0-1087762727-1313431674=:11413 Content-Type: text/html; charset=utf-8 Content-Transfer-Encoding: quoted-printable
Just to complete the = picture about LF-enabled antennas, recently Claudio Re I1RFQ has intro= duced his so-called MaxiWhip design (as "opposite" to the MiniWhip :-)). If= my understanding is correct, it basically consists of a vertical element (= 9 m tall, supported by a fishing rod for example) and a special 32:1 balun = (probably un-un). The report at following link (by Angelo Brunero IK1QLD) i= s in Italian, but shows interesting results in a direct comparison with the= MiniWhip: http://ww= w.brunero.it/ik1qld/antenna/.
 
Personally, I prefer to work with small wideband or tuned = loops. In my particular, unfortunate condition (very noisy urban area aroun= d my QTH), it seems to me that loops offer more predictable results. In my modest opinion, E-probes tend to be more subject to external, envi= ronmental factors than loops, so are more suitable for open areas with a go= od distance from noise sources, metal structures, etc.. Difficult to obtain= with a decent predictability in my personal case.
<= /span> 
Best regards
Daniele

Fr= om: Stefan Sch=C3=A4fer <Stefan.Schaefer@iup.uni-heidelberg.d= e>
To: rsgb_lf_group@blacksheep.org
Sent= : Monday, August 15, 2011 7:26 PM
Subject: Re: LF: Ferrite RX antennas

=0A=0A=0A =0A=0A =0AHello Wolf,
=0A
=0AThanks to the link = to your nice to read article. I just found it a hour=0Abefore your mail and= already read it ;-)
=0A
=0AWell, i also prefer the usual configurati= on instead of that sleeve=0Aantenna. Also i have to keep the focus on my ac= tual goal: Making a=0Ahandy antenna for amateur LF / p operation without a = car! And the 16=0Arods i will get (14 cm long, 8mm diameter) will be best i= n a 2x7=0Aconfig. i think. Or do you rather suggest 3x5 or even 4x4?
=0A= 2x7 is then about 30 cm long which is very fine for a backpack and=0Ashould= be robust enough.
=0AI would use the same double side bonding tape, thi= s is very useful to=0Aget a first fixed arrangement. Then putting all that = in a PVC tube, 2mm=0Athickness and add the turns above the tube.
=0AWou= ld you recommend litz wire or standard 0.5 mm enamelled wire?
=0AAs an E= field shield i would use aluminium bonding tape, without making=0Aa shutcu= t turn of course.
=0A
=0ASo the newcomers should not think that this = antenna is the best what=0Aone can use for LF. Just in that special case of= /p i see advantages.=0AOtherwise a well designed loop (+ preamp or a very = sensitive RX, if a=0Asamll loop is used) or E field antenna such as the PA0= RDT should be=0Apreferred, as Alan already pointed out.
=0A
=0ALookin= g forward to a direct comparison of the DCF39 SNR that can be=0Aachieved an= d to the first amateur signal received with that antenna in=0A/p...
=0A<= br>=0A73, Stefan/DK7FC
=0A
=0A
=0A
=0A
=0AAm 15.08.2011 18:3= 3, schrieb wolf_dl4yhf:=0A
=0A =0AHi Stefan,
= =0AThe rods were found in Friedrichshafen for a bargain price. I later=0Adi= scovered (most likely after the topic had been discussed here, or in=0Athe = VLF group) that these rods are used for inductive welding=0A(google("Ferrit= e Impeder Rod"). Here's a bundle of them:
=0A
=0A http://www.qsl.net/dl4= yhf/vlf_rdf/vlf_rdf_loop.html
=0A
=0AThey are 20 cm long.
= =0A
=0AThe most effective use (to "catch the magnetic field from a dis= tant=0Atransmitter") is NOT to connect them 'parallel' in a bundle, but to= =0Aconnect them in series (up to a certain point). This is much in=0Acontra= st to the esoteric sleeve thingy seen somewhere on the web.
=0A
=0A= 73,
=0A   Wolf .
=0A
=0A
=0A
=0AAm 14.08.20= 11 23:43, schrieb Stefan Sch=C3=A4fer:=0A
=0A = =0AWolf,
=0A
=0AWhich dimensions has your ferrite rod had?
= =0A
=0ANever thought i will find a source for rods that are longer t= han 10 cm=0Abut see: http:/= /www.box73.de/catalog/product_info.php?products_id=3D1422&osCsid=3Drqlp= fme957i65d7etjil1ntru5
=0A
=0Aeven an official distributor..<= br>=0A
=0AAny better links?
=0A
=0A73, Stefan/DK7FC
= =0A
=0AAm 14.08.2011 22:27, schrieb wolf_dl4yhf:=0A
=0A =0AFerrite RX antennas.. been there when 136 kHz star= ted.
=0ANot as good as a larger air-core loop, possibly noise caused by= the=0ABarkhausen effect or similar effects, nonlinearities, etc.
=0AAls= o beware the ferrite is a semiconductor so you will need some=0AE-field scr= eening, otherwise the ferrite material will couple noise=0Ainto the winding= s. But it's not as bad as this may sound; actually I=0Aused a ferrite anten= na for reception for some years until I discovered=0AI had to disconnect th= e ...errr... RF counterpoise from the main=0Aantenna from the mains "ground= ", and only use an earthstake during=0Areceive, at DF0WD.
=0A
= =0AOn the other hand, it's compact, relatively light-weight, and (in a=0Are= sonant configuration) gives a nice preselector.
=0AI remember when I con= nected a ferrite antenna to a tiny receiver with=0ASA612 "gilbert cell mixe= r", the first signal I heard was G3KEV calling=0Acq in CW.  Q5 in SSB = bandwidth.
=0ASuch a receiver is extremely handy to go /p for reception= , and compare=0Adifferent sites.
=0A
=0A73,
=0A   = Wolf DL4YHF.
=0A
=0A
=0AAm 14.08.2011 21:43, schrieb M= into Witteveen:=0A
=0A=0A =0A =
=0A
=0A
=0A
I haven=E2=80=99t thought about ferrite RX=0Aantenna for LF= =E2=80=A6.My guess is that it is not going to work =E2=80=93 not without=0A= an external antenna coupled to the ferrite, and then what=E2=80=99s the poi= nt?
=0ADCF77 clocks often have trouble locking indoors or in the neighbo= rhood=0Aof =E2=80=98QRM=E2=80=99 generators like PC=E2=80=99s, and look wha= t power DCF77 is using=E2=80=A6
=0AI could be entirely wrong of course= =E2=80=A6
=0A
73=E2=80=99 Minto pa3bca
=0A
=0A <= div style=3D'color: rgb(0, 0, 0); font-family: "Calibri"; font-size: small;= font-style: normal; font-weight: normal; text-decoration: none; display: i= nline;'>=0A =0A
<snip>
=0ABTW what do yo= u think about a ferrite RX antenna for LF? Now i'm=0Aopening an older discu= ssion i expect ;-)
=0A
=0A73, Stefan/DK7FC
=0A
=0A
=0A =
=0A
=0A
=0A
=0A =
=0A
=0A
=0A
=0A
=0A =0A= =0A

--0-1087762727-1313431674=:11413--