Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by mtain-dg06.r1000.mx.aol.com (Internet Inbound) with ESMTP id 363C53800009B; Fri, 19 Aug 2011 18:11:11 -0400 (EDT) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1QuXGb-0003G9-PE for rs_out_1@blacksheep.org; Fri, 19 Aug 2011 23:10:17 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1QuXGb-0003G0-4j for rsgb_lf_group@blacksheep.org; Fri, 19 Aug 2011 23:10:17 +0100 Received: from nm26-vm0.bullet.mail.sp2.yahoo.com ([98.139.91.230]) by relay1.thorcom.net with smtp (Exim 4.63) (envelope-from ) id 1QuXGZ-0003Vf-Qd for rsgb_lf_group@blacksheep.org; Fri, 19 Aug 2011 23:10:17 +0100 Received: from [98.139.91.64] by nm26.bullet.mail.sp2.yahoo.com with NNFMP; 19 Aug 2011 22:10:08 -0000 Received: from [98.139.91.32] by tm4.bullet.mail.sp2.yahoo.com with NNFMP; 19 Aug 2011 22:10:08 -0000 Received: from [127.0.0.1] by omp1032.mail.sp2.yahoo.com with NNFMP; 19 Aug 2011 22:10:08 -0000 X-Yahoo-Newman-Property: ymail-3 X-Yahoo-Newman-Id: 169827.82740.bm@omp1032.mail.sp2.yahoo.com Received: (qmail 51131 invoked by uid 60001); 19 Aug 2011 22:10:07 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=yahoo.com; s=s1024; t=1313791807; bh=mcwiXvd1Fhrx2RsJ24Q7T8tQ0Yca+TQvVXa0QkOQyN8=; h=X-YMail-OSG:Received:X-Mailer:References:Message-ID:Date:From:Reply-To:Subject:To:In-Reply-To:MIME-Version:Content-Type; b=HgGz3NR5iBkRnd2KbB02QkLaiJqXyz08O4buxXXDW1JFQRS9djS+8b5yeGTH5+NrnLWkDECL4ShQy1iIWSA63VthOwyNI4ybbNvmvDLS2hv4tdg/Z1mztD3yJFKiiZxwIBiWd9IJzZxXKbxLbSqTYe5PDCVezNYK3LCW06kn7JE= 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=dC7LK6NbnMw0FEcb8IKvh15cVSZBUKOFZ2xGS5GgjszJ3A0kWOzxFKLsBku9EGb4ZD/wLM8H7frRmsuHu+KluhmI7mC+CcdY7TNLN7r7QHipPwsZYUO+KH3r4CSn3lk8QAycNp5ItNef0w7Jg4412opOftNK45mueOcpxzSrve0=; X-YMail-OSG: SQtkW5IVM1lUo4xAU58yiHrAWKoM8T4WRaCGEMata0tRkKr 8kCskp9AC5uErOnqwZfLc5.bwmaRAsjTfqj9t1qAkeONE9uT88OhR2AKXl0Q zf.cZk_848crEUTHeCiXLxbSZi87Hoie4.fcHyqneVeMWwxK8uBAQAGiKaS2 ipJW142vP4IT6jSPGmsz8o14G_r67NdK4ECDxOo4xoSvgpp6BHPVE68A6BmD V3d0Yfxo1.BbI9OjXkpVBnPa1u2fN8pLzIcQqJUvZAbOGfg_qiDJ4SJr3OL0 Bg_jSlZf0DRTiZcoqg9rgYrr8HFs9LNmC_8_i4705eCuT.IcA6nlo65pZ_Nj V9P4MuCnoeq19Xq55IE5_extbWsa0fnWSx7LwuVqnxrbYNHoU Received: from [87.11.202.14] by web111913.mail.gq1.yahoo.com via HTTP; Fri, 19 Aug 2011 15:10:07 PDT X-Mailer: YahooMailWebService/0.8.113.313619 References: <1QuX5G-04DESe0@fwd20.t-online.de> Message-ID: <1313791807.11329.YahooMailNeo@web111913.mail.gq1.yahoo.com> Date: Fri, 19 Aug 2011 15:10:07 -0700 (PDT) From: Daniele Tincani To: "rsgb_lf_group@blacksheep.org" In-Reply-To: <1QuX5G-04DESe0@fwd20.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="0-610014067-1313791807=:11329" 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: 0:2:468690752:93952408 X-AOL-SCOLL-URL_COUNT: 0 X-AOL-SCOLL-AUTHENTICATION: mail_rly_antispam_dkim-d014.1 ; domain : yahoo.com DKIM : fail x-aol-sid: 3039ac1d410e4e4edf7f5457 X-AOL-IP: 195.171.43.25 X-AOL-SPF: domain : blacksheep.org SPF : none --0-610014067-1313791807=:11329 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable Hello Ha-Jo,=0A=A0=0Athank you for your reply, which contains many interest= ing information.=0A=A0=0AHowever, please note that my question was specific= ally about the possibility to realize wideband rx antennas on ferrite cores= .=0A=A0=0ABest regards=0ADanile=0A=0AFrom: "hajo.brandt.dj1zb@t-online.de" = =0ATo: rsgb_lf_group@blacksheep.org=0ASent: = Friday, August 19, 2011 11:58 PM=0ASubject: Re: LF: Ferrite wideband antenn= as?=0A=0A=0A T-Online eMail Dear Daniele,=0A=0AAt my locaton in eastern Bav= aria I am=0Ausing =0Asuch a vertical broadband loop pointing north from 10 = kHz to 500 kHz =0Asince=A0several years and have also made experiments with= a=0Ahorizontal loop =0Acovering 1,8 to 30 MHz.=0A=0ATheir principle is as = =0Afollows:=0A=0AA=A0broadband transformer is needed between the loop=0A=0A= and=A0the cable going into the shack.=0AWithout such a transformer=0Athe lo= op =0Ainductivity has to be so high=A0when feeding usual cable impedances= =0Athat a =0Aferrite core will be needed to realize the inductivity needed = for=0Abroadband =0Aperformance. I have used wire loops only so far.=0A=0ATh= e inductive=0Areactance =0Aof the secondary of this transformer should be 4= times the cable=0Aimpedance (3.2 =0AmH for 10 kHz). The loop circumference= =A0should be low in length=0Acompared =0Ato=A0a quarter of the highest freq= uency (for VLF to MF usually no=0Aproblem, =0Afor HF the=A0circumference ha= d been 2=0Ameters).=0A=0AThe=A0inductivity of =0Athe primary of the broadba= nd transformer should be equal to the=0Ainductivity of =0Athe loop (in my c= ase=A030uH and 17 meters circumference for 10 to 500=0A=0AkHz).=0A=0AWhen m= eeting these conditions, the inductive reactance of=0Athe loop =0Aitself wi= ll=A0always be=A0higher by a factor of 4 at least=0Acompared =0Ato=A0the ca= ble impedance transformed down by the turns ratio.=0AThis=A0is =0Athe condi= tion for the loop to operate broadband.=0A=0ABut the problem=0Afor the =0Ar= eceiver may come in the shack: It must be capable of taking all=0Athe=A0pow= er =0Adelivered by the broadband loop, including the power received by=0Abr= oadcast =0Atransmitters! Otherwise the receiver may be overloaded and may n= eed a=0Amore =0Alinear frontend=A0or has to be equipped with a good front e= nd =0Aselectivity.=A0=A0=A0 =0A=0AAT VLF to MF a long cable=0Ainto the =0As= hack usually will be no problem because of its low attenuation at low =0Afr= equencies, therefore all additional selectivity I can provide in the=0Ashac= k. =0AFor HF and higher the situation is different of course and may need a= t=0Aleast =0Apart of selectivity and preamplification already at the loop= =0Aoutput.=0A=0AFor =0Athe time being however, I have problems using my loo= p for the reception=0Aof SAQ, =0Asince a solar panel had been installed on = a roof two houses from=0Ahere,=A0in =0Aautumn 2010. Obviously the chopper o= f this installation is generating a=0A=0Astrong=A0300 Hz spectrum up to 20 = kHz in my loop. As I could =0Aclear=A0interference into my active antenna c= ompletely=A0the=0Ainterfering =0Afield should=A0be inductive.=A0It seems to= come from several=0Adirections =0A(including the wiring of three houses be= cause the=A0installation =0Ais=A0feeding=A0three phase current=A0into the = =0Amains)!=A0=A0=0A=0AOK?=0A=0A73 Ha-Jo, =0ADJ1ZB=A0=A0=0A=0A=0A"Daniele Ti= ncani" =0A schrieb: =0AHello LF, =0A>=0A>a very i= nteresting discussion is in progress on the reflector on=0Aferrite rx ante= nnas. My understanding however is that until now we have been=0Atalking ab= out narrow-band antennas. May I ask the experts if a wide-band=0Aferrite a= ntenna could be feasible, able=A0to=A0(partially) match the=0A"panoramic" = approach of SDR receivers, at least in the LF/NDB and/or MW bands?=0ASuch a= n "ideal" antenna would combine some advantages of air-cored loops with a= =A0reduced size (uhm... too "ideal" to be real :-)) =0A>=0A>Regards =0A>Dan= iele =0A>=A0 --0-610014067-1313791807=:11329 Content-Type: text/html; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable
Hello Ha-Jo,
 
thank you for your reply, whic= h contains many interesting information.
&nbs= p;
However, please note that my question was specifically a= bout the possibility to realize wideband rx antennas on ferrite cores.
 
Best regards
<= div>Danile

From: "hajo.brandt.dj1zb@t-online.de" <hajo.brandt.dj= 1zb@t-online.de>
To:= rsgb_lf_group@blacksheep.org
Sent= : Friday, August 19, 2011 11:58 PM
Subject: Re: LF: Ferrite wideband antennas?

=0AT-Online eMail=0A=0A =0A =0A=0A=0ADear Daniel= e,

At my locaton in eastern Bavaria I am=0Ausing =0Asuch a vertical = broadband loop pointing north from 10 kHz to 500 kHz =0Asince several = years and have also made experiments with a=0Ahorizontal loop =0Acovering 1= ,8 to 30 MHz.

Their principle is as =0Afollows:

A broadb= and transformer is needed between the loop=0A=0Aand the cable going in= to the shack.
Without such a transformer=0Athe loop =0Ainductivity has t= o be so high when feeding usual cable impedances=0Athat a =0Aferrite c= ore will be needed to realize the inductivity needed for=0Abroadband =0Aper= formance. I have used wire loops only so far.

The inductive=0Areacta= nce =0Aof the secondary of this transformer should be 4 times the cable=0Ai= mpedance (3.2 =0AmH for 10 kHz). The loop circumference should be low = in length=0Acompared =0Ato a quarter of the highest frequency (for VLF= to MF usually no=0Aproblem, =0Afor HF the circumference had been 2=0A= meters).

The inductivity of =0Athe primary of the broadband tra= nsformer should be equal to the=0Ainductivity of =0Athe loop (in my case&nb= sp;30uH and 17 meters circumference for 10 to 500=0A=0AkHz).

When me= eting these conditions, the inductive reactance of=0Athe loop =0Aitself wil= l always be higher by a factor of 4 at least=0Acompared =0Ato&nbs= p;the cable impedance transformed down by the turns ratio.=0AThis is = =0Athe condition for the loop to operate broadband.

But the problem= =0Afor the =0Areceiver may come in the shack: It must be capable of taking = all=0Athe power =0Adelivered by the broadband loop, including the powe= r received by=0Abroadcast =0Atransmitters! Otherwise the receiver may be ov= erloaded and may need a=0Amore =0Alinear frontend or has to be equippe= d with a good front end =0Aselectivity.   

AT= VLF to MF a long cable=0Ainto the =0Ashack usually will be no problem beca= use of its low attenuation at low =0Afrequencies, therefore all additional = selectivity I can provide in the=0Ashack. =0AFor HF and higher the situatio= n is different of course and may need at=0Aleast =0Apart of selectivity and= preamplification already at the loop=0Aoutput.

For =0Athe time bein= g however, I have problems using my loop for the reception=0Aof SAQ, =0Asin= ce a solar panel had been installed on a roof two houses from=0Ahere, = in =0Aautumn 2010. Obviously the chopper of this installation is generating= a=0A=0Astrong 300 Hz spectrum up to 20 kHz in my loop. As I could =0A= clear interference into my active antenna completely the=0Ainterf= ering =0Afield should be inductive. It seems to come from several= =0Adirections =0A(including the wiring of three houses because the ins= tallation =0Ais feeding three phase current into the =0Amain= s)!  

OK?

73 Ha-Jo, =0ADJ1ZB  
=

"Daniele Tincani" =0A<danieletincani@yahoo.com> schrie= b: =0A
=0A
=0A
Hello LF,
=0A
 
= =0A
a very interesting discussion is in progress on the reflector on= =0Aferrite =0A rx antennas. My understanding however is that until now we = have been=0Atalking =0A about narrow-band antennas. May I ask the experts = if a wide-band=0Aferrite =0A antenna could be feasible, able to = (partially) match the=0A"panoramic" =0A approach of SDR receivers, at leas= t in the LF/NDB and/or MW bands?=0ASuch an =0A "ideal" antenna would combi= ne some advantages of air-cored loops with=0A=0A a reduced size (uhm.= .. too "ideal" to be real :-))
=0A
 
=0A
Regards=
=0A
Daniele
=0A
 
  =0A
= =0A

--0-610014067-1313791807=:11329--