Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by mtain-ma01.r1000.mx.aol.com (Internet Inbound) with ESMTP id E7EAE3800008C; Fri, 19 Aug 2011 19:28:47 -0400 (EDT) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1QuYTR-0003zf-CF for rs_out_1@blacksheep.org; Sat, 20 Aug 2011 00:27:37 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1QuYTQ-0003zV-CR for rsgb_lf_group@blacksheep.org; Sat, 20 Aug 2011 00:27:36 +0100 Received: from nm28-vm0.bullet.mail.sp2.yahoo.com ([98.139.91.234]) by relay1.thorcom.net with smtp (Exim 4.63) (envelope-from ) id 1QuYTO-0004o7-UR for rsgb_lf_group@blacksheep.org; Sat, 20 Aug 2011 00:27:36 +0100 Received: from [98.139.91.67] by nm28.bullet.mail.sp2.yahoo.com with NNFMP; 19 Aug 2011 23:27:26 -0000 Received: from [98.139.91.53] by tm7.bullet.mail.sp2.yahoo.com with NNFMP; 19 Aug 2011 23:27:26 -0000 Received: from [127.0.0.1] by omp1053.mail.sp2.yahoo.com with NNFMP; 19 Aug 2011 23:27:26 -0000 X-Yahoo-Newman-Property: ymail-3 X-Yahoo-Newman-Id: 964922.89209.bm@omp1053.mail.sp2.yahoo.com Received: (qmail 571 invoked by uid 60001); 19 Aug 2011 23:27:26 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=yahoo.com; s=s1024; t=1313796446; bh=jZJdPB7YuAxyJYU9kofMvkrDSHL0E4M2l1nfY+SQhBQ=; h=X-YMail-OSG:Received:X-Mailer:References:Message-ID:Date:From:Reply-To:Subject:To:In-Reply-To:MIME-Version:Content-Type; b=mXFJ/3GOR/7VvTig/YtkafTX94nvjCMBCKDXP/3EowAC+XNZui0RY94GRpPiAz92wY7G7vQwtYU7YqLblvTj+3qL5+ErwiS3z7p/lbQDnRRTFvxk8nJV4D2bSVJCMLt76UXwhkShGpXZgN0pjPfT+GmpqXY0igtBFYUTnpTVZbk= 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=onY7gL/Dd9s7482TU1qSV83fTnKb5uV2EAXtzDYVtKAbtrQ66DoLeBNX9QTiiCK/ZTvBXBoXBe2SC64BZ1EV4XJfKxuwO6ikZ5APTdseA9v8TJUL9UMfUPN1EtLOFSafq5Ps0oLVxLBfiKFSxQLWviu2NmtjqolGqD3JNf4bj18=; X-YMail-OSG: DEkJwlwVM1nqk_LiSi1Uxv3hrW5W8ophNmEilr.lqTqOc7s vq.UBR4ZnYv7sqhj2Y0oMyxM1GDmOo8DjNWDK3cxsmZUCC_elRhwC8RmHPEU Um5VBESV7gGglsEkD6VjWj5TOUGbxHNS6K9Dal7RPg8KaRdD.fGprwGvxdzr P0VY9KzB3mZUDzzWKZ3WJO7ikyEn5vP_jMj7j35bamXUYb11BbYerh87stRe lrkRoRNNXfUhbooCHAX3gtY3CmN7f8Bo78UJ0Dk1hfUPCCjLi691hKY4FDTK NBmk0b_dMhttJNEQ.fHB4DI5Axs_nsF6C_Te7mboJmi4RT3zEdyE7dfEmBwX j18as4rvofGBoZPR_.sgkq4PCzyz7zejIlnw6Rgj5fDJ_Og-- Received: from [87.3.20.14] by web111904.mail.gq1.yahoo.com via HTTP; Fri, 19 Aug 2011 16:27:26 PDT X-Mailer: YahooMailWebService/0.8.113.313619 References: <1QuXrB-0vDGu80@fwd17.t-online.de> Message-ID: <1313796446.88869.YahooMailNeo@web111904.mail.gq1.yahoo.com> Date: Fri, 19 Aug 2011 16:27:26 -0700 (PDT) From: Daniele Tincani To: "rsgb_lf_group@blacksheep.org" In-Reply-To: <1QuXrB-0vDGu80@fwd17.t-online.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 wideband antennas? Content-Type: multipart/alternative; boundary="0-2037099156-1313796446=:88869" 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: 0:2:489706336:93952408 X-AOL-SCOLL-URL_COUNT: 0 X-AOL-SCOLL-AUTHENTICATION: mail_rly_antispam_dkim-d221.1 ; domain : yahoo.com DKIM : fail x-aol-sid: 3039ac1d60094e4ef1af08db X-AOL-IP: 195.171.43.25 X-AOL-SPF: domain : blacksheep.org SPF : none --0-2037099156-1313796446=:88869 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable Hello Ha-Jo,=0A=A0=0Ayes now I see your point, thanks.=0A=A0=0ABest regards= =0ADaniele=0A=0AFrom: "hajo.brandt.dj1zb@t-online.de" =0ATo: rsgb_lf_group@blacksheep.org=0ASent: Saturday, August 20, = 2011 12:47 AM=0ASubject: Re: LF: Ferrite wideband antennas?=0A=0A=0A T-Onli= ne eMail Dear Daniele,=0A=0AI guess the=0Ainformation =0AYou want is also c= ontained in my email, at least indirectly.=0A=0AA=0Agerman =0Areceive-only = radio amateur has built such a ferrite antenna by cut and=0Atry only =0Aand= finally succeeded to receive VLF with a ferrite rod combined from=0Aserver= al =0Aferrite parts and has written an article about this in the german rad= io=0Aamateur =0Amagazine cq-DL. He described his rod according to its dimen= sions and=0Anumber of =0Aturns but did not give its inductivity; at that ti= me he could not=0Ameasure it. We =0Ahave been in email concact for some tim= e on the subject of inductive=0Abroadband =0Aantennas, and I have encourage= d him to buy a Rohde & Schwarz LARU=0Awhich had =0Abeen offered to him. Now= he knows the=A0inductivity of 3 mH which he=0Ahad =0Aachieved!=A0=0A=0AFin= ally he has kept this ferrite antenna=0Aand=A0some =0Aothers=A0for higher f= requencies for portable use. But for his=0Ahome =0Ainstallation he has adop= ted the principle of using a wire loop (even=0Alarger than =0Amine) and a t= ransformer to the 50 ohms cable. I have found my dimension=0Arules =0Afor l= oops by using the ARRL Radio =0ADesigner.=A0=0A=0AOK?=0A=0A73 Ha-Jo, DJ1ZB= =0A=0A=0A"Daniele=0A=0ATincani" schrieb: =0AHell= o Ha-Jo, =0A>=A0 =0A>thank you for your reply, which contains many interest= ing information. =0A>=A0 =0A>However, please note that my question was spe= cifically=0Aabout the possibility to realize wideband rx antennas on ferri= te=0Acores. =0A>=A0 =0A>Best regards =0A>Danile =0A>=0A> =0A>From: "hajo.br= andt.dj1zb@t-online.de" =0A>To: rsgb_lf_gro= up@blacksheep.org=0A>Sent: Friday, August 19, 2011=0A11:58 PM=0A>Subject: = Re: LF:=0AFerrite wideband antennas?=0A>=0A>=0A>Dear Daniele,=0A>=0A>At my= locaton in eastern Bavaria I=0Aam using =0A such a vertical broadband loo= p pointing north from 10 kHz to 500 kHz =0A since=A0several years and have= also made experiments with a=0Ahorizontal loop =0A covering 1,8 to 30 MHz= .=0A>=0A>Their principle is as =0A follows:=0A>=0A>A=A0broadband transform= er is needed between the=0Aloop =0A and=A0the cable going into the shack.= =0A>Without such a transformer=0Athe =0A loop inductivity has to be so hig= h=A0when feeding usual cable=0Aimpedances =0A that a ferrite core will be = needed to realize the inductivity needed=0Afor =0A broadband performance. = I have used wire loops only so far.=0A>=0A>The=0A=0A inductive reactance o= f the secondary of this transformer should be 4=0Atimes the =0A cable impe= dance (3.2 mH for 10 kHz). The loop=0Acircumference=A0should be low =0A in= length compared to=A0a quarter of the highest frequency (for VLF=0Ato MF = =0A usually no problem, for HF the=A0circumference had been 2 =0A meters)= .=0A>=0A>The=A0inductivity of the primary of the broadband =0A transformer= should be equal to the inductivity of the loop (in my =0A case=A030uH and= 17 meters circumference for 10 to 500=0AkHz).=0A>=0A>When =0A meeting the= se conditions, the inductive reactance of the loop itself =0A will=A0alway= s be=A0higher by a factor of 4 at least compared=0Ato=A0the =0A cable impe= dance transformed down by the turns ratio. This=A0is the=0A=0A condition f= or the loop to operate broadband.=0A>=0A>But the problem=0Afor the =0A rec= eiver may come in the shack: It must be capable of taking all =0A the=A0po= wer delivered by the broadband loop, including the power=0Areceived =0A by= broadcast transmitters! Otherwise the receiver may be overloaded=0Aand may= =0A need a more linear frontend=A0or has to be equipped with a good=0Afro= nt end =0A selectivity.=A0=A0=A0 =0A>=0A>AT VLF to MF a long=0Acable into = =0A the shack usually will be no problem because of its low attenuation at= =0Alow =0A frequencies, therefore all additional selectivity I can provide= in the=0Ashack. =0A For HF and higher the situation is different of cours= e and may need at=0Aleast =0A part of selectivity and preamplification alr= eady at the loop =0A output.=0A>=0A>For the time being however, I have pro= blems using my=0Aloop for =0A the reception of SAQ, since a solar panel ha= d been installed on a roof=0Atwo =0A houses from here,=A0in autumn 2010. O= bviously the chopper of this =0A installation is generating a strong=A0300= Hz spectrum up to 20 kHz=0Ain my =0A loop. As I could clear=A0interferenc= e into my active antenna =0A completely=A0the interfering field should=A0b= e=0Ainductive.=A0It seems =0A to come from several directions (including t= he wiring of three houses=0Abecause =0A the=A0installation is=A0feeding=A0= three phase=0Acurrent=A0into the =0A mains)!=A0=A0=0A>=0A>OK?=0A>=0A>73 Ha= -Jo, =0A DJ1ZB=A0=A0=0A>=0A>=0A>"Daniele Tincani" =0A schrieb: =0A>Hello LF, =0A>>=0A>>a very interesting discussion is i= n progress on the reflector=0Aon ferrite rx antennas. My understanding how= ever is that until now we=0Ahave been talking about narrow-band antennas. = May I ask the experts if a=0Awide-band ferrite antenna could be feasible, = able=A0to=A0(partially)=0Amatch the "panoramic" approach of SDR receivers,= at least in the LF/NDB and/or=0AMW bands? Such an "ideal" antenna would c= ombine some advantages of=0Aair-cored loops with a=A0reduced size (uhm... = too "ideal" to be real=0A:-)) =0A>>=0A>>Regards =0A>>Daniele =0A>>=A0 =0A>= =0A>=A0 --0-2037099156-1313796446=:88869 Content-Type: text/html; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable
Hello Ha-Jo,
 
yes now I see your point, than= ks.
 
Best regards
Daniele

From: "hajo.brandt.dj1zb@t-online.de"= <hajo.brandt.dj1zb@t-online.de>
To: rsgb_lf_group@blacksheep.org
Sent: Saturday, August 20, 2011 12:47 AM
Subject: Re: LF: Ferrite wideband ante= nnas?

=0AT-Online eMail=0A=0A =0A = =0A=0A=0ADear Daniele,

I guess the=0Ainformation =0AYou want is also con= tained in my email, at least indirectly.

A=0Agerman =0Areceive-only = radio amateur has built such a ferrite antenna by cut and=0Atry only =0Aand= finally succeeded to receive VLF with a ferrite rod combined from=0Aserver= al =0Aferrite parts and has written an article about this in the german rad= io=0Aamateur =0Amagazine cq-DL. He described his rod according to its dimen= sions and=0Anumber of =0Aturns but did not give its inductivity; at that ti= me he could not=0Ameasure it. We =0Ahave been in email concact for some tim= e on the subject of inductive=0Abroadband =0Aantennas, and I have encourage= d him to buy a Rohde & Schwarz LARU=0Awhich had =0Abeen offered to him.= Now he knows the inductivity of 3 mH which he=0Ahad =0Aachieved! = ;

Finally he has kept this ferrite antenna=0Aand some =0Aothers=  for higher frequencies for portable use. But for his=0Ahome = =0Ainstallation he has adopted the principle of using a wire loop (even=0Al= arger than =0Amine) and a transformer to the 50 ohms cable. I have found my= dimension=0Arules =0Afor loops by using the ARRL Radio =0ADesigner. <= br>
OK?

7= 3 Ha-Jo, DJ1ZB


"Daniele=0A=0ATincani" <danieletincani@= yahoo.com> schrieb: =0A
=0A
=0A
Hello Ha-Jo,<= /span>
=0A
 
=0A
thank you fo= r your reply, which contains many interesting =0A information.=0A
 
=0A
However, please note th= at my question was specifically=0Aabout the =0A possibility to realize wid= eband rx antennas on ferrite=0Acores.
=0A
&n= bsp;
=0A
Best regards
=0A
Danile
=0A

=0A
=0A
=0A
From:=0A"hajo.brandt.dj1zb@t-online.de" =0A <hajo.brandt.dj1zb@t-onlin= e.de>
To: =0A rsgb_= lf_group@blacksheep.org
Sent: Friday, August 19, 2011=0A11:58 =0A PM
Subject: Re: LF:=0AFerrite =0A wideband antennas?<= br>
=0A =0A
Dear Daniele,

At my locat= on in eastern Bavaria I=0Aam using =0A such a vertical broadband loop poin= ting north from 10 kHz to 500 kHz =0A since several years and have al= so made experiments with a=0Ahorizontal loop =0A covering 1,8 to 30 MHz.
Their principle is as =0A follows:

A broadband transform= er is needed between the=0Aloop =0A and the cable going into the shac= k.
Without such a transformer=0Athe =0A loop inductivity has to be so h= igh when feeding usual cable=0Aimpedances =0A that a ferrite core wil= l be needed to realize the inductivity needed=0Afor =0A broadband performa= nce. I have used wire loops only so far.

The=0A=0A inductive reacta= nce of the secondary of this transformer should be 4=0Atimes the =0A cable= impedance (3.2 mH for 10 kHz). The loop=0Acircumference should be low= =0A in length compared to a quarter of the highest frequency (for VL= F=0Ato MF =0A usually no problem, for HF the circumference had been 2= =0A meters).

The inductivity of the primary of the broadband = =0A transformer should be equal to the inductivity of the loop (in my =0A = case 30uH and 17 meters circumference for 10 to 500=0AkHz).

Wh= en =0A meeting these conditions, the inductive reactance of the loop itsel= f =0A will always be higher by a factor of 4 at least compared= =0Ato the =0A cable impedance transformed down by the turns ratio. Th= is is the=0A=0A condition for the loop to operate broadband.

B= ut the problem=0Afor the =0A receiver may come in the shack: It must be ca= pable of taking all =0A the power delivered by the broadband loop, in= cluding the power=0Areceived =0A by broadcast transmitters! Otherwise the = receiver may be overloaded=0Aand may =0A need a more linear frontend = or has to be equipped with a good=0Afront end =0A selectivity.  =  

AT VLF to MF a long=0Acable into =0A the shack usual= ly will be no problem because of its low attenuation at=0Alow =0A frequenc= ies, therefore all additional selectivity I can provide in the=0Ashack. =0A= For HF and higher the situation is different of course and may need at=0A= least =0A part of selectivity and preamplification already at the loop =0A= output.

For the time being however, I have problems using my=0Aloo= p for =0A the reception of SAQ, since a solar panel had been installed on = a roof=0Atwo =0A houses from here, in autumn 2010. Obviously the chop= per of this =0A installation is generating a strong 300 Hz spectrum u= p to 20 kHz=0Ain my =0A loop. As I could clear interference into my a= ctive antenna =0A completely the interfering field should be=0Ai= nductive. It seems =0A to come from several directions (including the= wiring of three houses=0Abecause =0A the installation is feedin= g three phase=0Acurrent into the =0A mains)!  

= OK?

73 Ha-Jo, =0A DJ1ZB  


"Danie= le Tincani" =0A <danieletincani@yahoo.com> schrieb: =0A =0A
=0A
Hello LF,
=0A
 
=0A
a= very interesting discussion is in progress on the reflector=0Aon =0A fe= rrite rx antennas. My understanding however is that until now we=0Ahave bee= n =0A talking about narrow-band antennas. May I ask the experts if a=0Aw= ide-band =0A ferrite antenna could be feasible, able to (parti= ally)=0Amatch the =0A "panoramic" approach of SDR receivers, at least in= the LF/NDB and/or=0AMW =0A bands? Such an "ideal" antenna would combine= some advantages of=0Aair-cored =0A loops with a reduced size (uhm.= .. too "ideal" to be real=0A:-))
=0A
 
=0A
R= egards
=0A
Daniele
=0A
 
  =0A <= div>
=0A=0A

  =0A
=0A

=
--0-2037099156-1313796446=:88869--