Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by mtain-dc06.r1000.mx.aol.com (Internet Inbound) with ESMTP id 8CA1D38000060; Sun, 14 Aug 2011 16:04:00 -0400 (EDT) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1Qsgtv-0001Lz-Rg for rs_out_1@blacksheep.org; Sun, 14 Aug 2011 21:03:15 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1Qsgtv-0001Lq-1l for rsgb_lf_group@blacksheep.org; Sun, 14 Aug 2011 21:03:15 +0100 Received: from mail-wy0-f171.google.com ([74.125.82.171]) by relay1.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1Qsgts-0002dn-Mw for rsgb_lf_group@blacksheep.org; Sun, 14 Aug 2011 21:03:15 +0100 Received: by wyh13 with SMTP id 13so4886868wyh.16 for ; Sun, 14 Aug 2011 13:03:07 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=message-id:from:to:references:in-reply-to:subject:date:mime-version :content-type:x-priority:x-msmail-priority:importance:x-mailer :x-mimeole; bh=pPemgVIRjqTGU/GWL8NOv9aeQjB8SgO7wnHCCbhJSS0=; b=ZYjr6v2dT9bpK1GXV1nytSD4qczE4sxYrApICgl5a06GWyJEJoh+Of9w2gH6TwiOJd HJzseAWPlwPQs6eUa3Ruo9ivoPep8SNEt7fmGM69GUpJVsaHkDem3H/XbsMoSnuSotAD VZsivA5rhOiuUOjCiS8XUsZd3nAQ9M0SiDABc= Received: by 10.227.121.74 with SMTP id g10mr953505wbr.112.1313352187113; Sun, 14 Aug 2011 13:03:07 -0700 (PDT) Received: from PcMinto (h50208.upc-h.chello.nl [62.194.50.208]) by mx.google.com with ESMTPS id ej15sm4007185wbb.48.2011.08.14.13.03.05 (version=SSLv3 cipher=OTHER); Sun, 14 Aug 2011 13:03:06 -0700 (PDT) Message-ID: From: Minto Witteveen To: References: <68BE37BD69E54DEE89CEBA8E30E9B94E@PcMinto> <4E47FFE9.10100@iup.uni-heidelberg.de> <3ED8E5422F1F45DBB8186E9D9870AD63@PcMinto> <1313344278.62085.YahooMailNeo@web111919.mail.gq1.yahoo.com> <17D19FD7142949738965F1243D471F55@PcMinto> <1313351640.32350.YahooMailNeo@web111914.mail.gq1.yahoo.com> In-Reply-To: <1313351640.32350.YahooMailNeo@web111914.mail.gq1.yahoo.com> Date: Sun, 14 Aug 2011 22:02:58 +0200 MIME-Version: 1.0 X-Priority: 3 X-MSMail-Priority: Normal Importance: Normal X-Mailer: Microsoft Windows Live Mail 15.4.3538.513 X-MimeOLE: Produced By Microsoft MimeOLE V15.4.3538.513 X-Spam-Score: 0.0 (/) X-Spam-Report: autolearn=disabled,HTML_MESSAGE=0.001 Subject: LF: Re: 137 grabbers Content-Type: multipart/alternative; boundary="----=_NextPart_000_0397_01CC5ACD.EDA43920" X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: ** X-Spam-Status: No, hits=2.5 required=5.0 tests=HTML_40_50,HTML_MESSAGE, MISSING_OUTLOOK_NAME,WEIRD_PORT 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: 0:2:472017568:93952408 X-AOL-SCOLL-URL_COUNT: 0 X-AOL-SCOLL-AUTHENTICATION: mail_rly_antispam_dkim-d021.1 ; domain : gmail.com DKIM : fail x-aol-sid: 3039ac1d40864e482a306ae2 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_0397_01CC5ACD.EDA43920 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Hi Daniele, I felt real guilty.. and added a reference to the author=E2=80=99s site = on my webpage. 73=E2=80=99s Minto pa3bca -------------------------------------------------------------------------= - Ceterum censeo Carthaginem delendam esse From: Daniele Tincani=20 Sent: Sunday, August 14, 2011 21:54 To: rsgb_lf_group@blacksheep.org=20 Subject: Re: LF: Re: 137 grabbers Don't worry Minto, this circuits was re-published a number of times on = the web :-) Anyway, I agree that a reference to the original article may give a more = complete background and might be helpful to the reader. Best 73 Daniele From: Minto Witteveen To: rsgb_lf_group@blacksheep.org Sent: Sunday, August 14, 2011 9:18 PM Subject: LF: Re: 137 grabbers Hi Daniele, Yup that=E2=80=99s the one. My shameless theft is exposed J I see that the only thing _I_ did was re-draw the schematics (I use = Kicad). Of course I should have acknowledged the original author on my webpage = =E2=80=93 will do that next time I update my website. Regards, Minto pa3bca. From: Daniele Tincani=20 Sent: Sunday, August 14, 2011 19:51 To: rsgb_lf_group@blacksheep.org=20 Subject: Re: LF: Re: 137 grabbers Minto, this is the M0AYF page I referred to: http://www.qsl.net/m0ayf/active-loop-receiving-antenna.html May be you "stole" the original schematics from there? :-) Best regards Daniele From: Minto Witteveen To: rsgb_lf_group@blacksheep.org Sent: Sunday, August 14, 2011 7:33 PM Subject: LF: Re: 137 grabbers Stefan, LF Not my own design, I don=E2=80=99t remember exactly where I got it but I = am pretty sure I stole the idea =E2=80=98from the Internet=E2=80=99 and = possible made some changes. The bc337 was used as I have a lot of them = lying around, and they are much better than for instance the bc547 (my = other jellybean transistor). The reason I used a -43 type toroid is because I built it for use on 500 = KHz and up. Especially for 80 and 40 meters. Type-43 is better here = than Type-77. On HF this loop is _much, much_ better than my end-fed TX = wire in terms of S/N. The wire picks up a lot of noise from the house = (and from my neighbors houses). The loop is placed to null- out this QRM = as much as possible. Above 10 MHz the gain drops off rapidly, it is nearly useless at 14 MHz. = a -77 type would be much worse there I think. As for the Q: I did a comparison between an FT50-43 and a 14 mm 4C6 (for = my 137 KHz low-pass filter, see my website). The Q of the FT50-43 coil = was abt 50, the 4C6 =E2=80=93 with a lower Al - was 140 !! Needed more = turns ofcourse. On the other hand the Q of this toroid is not very = important here as it is used as a broad-band transformer. This is only my hobby=E2=80=A6 Originally I am a Civil Engineer (but my = job now is in IT). 73=E2=80=99s Minto pa3bca -------------------------------------------------------------------------= - Ceterum censeo Carthaginem delendam esse From: Stefan Sch=C3=A4fer=20 Sent: Sunday, August 14, 2011 19:03 To: rsgb_lf_group@blacksheep.org=20 Subject: Re: LF: Re: 137 grabbers This looks like a very good design. Fascinating easy!! Is it completely = grown in your head or have you seen it somewhere in the web? What is the gain, about? I know the BC337 as a low noise NPN transistor. Your loop is 2m diameter? How many dBs is the background noise abovethe = soundcard noise? Another question: Why are the T37-43 (the 43 types in general) preferred = to the 77 types? The 77 types have a higher AL value and should come out = with less turns. I tried to wind a band pass coil with but of the types = (T50-43 and T50-77) and achieved about the same Q. Is it just a question = of an available distributor? And what is your job? Do you have to design electrical circuits? ;-) 73, Stefan/DK7FC Am 14.08.2011 18:07, schrieb Minto Witteveen:=20 Loop antenna: = http://www.pa3bca.nl/index.php?option=3Dcom_content&view=3Darticle&id=3D1= 0&Itemid=3D14 From: Minto Witteveen=20 Sent: Sunday, August 14, 2011 18:03 To: rsgb_lf_group@blacksheep.org=20 Subject: Re: LF: 137 grabbers Mal, LF, I am now using a single-turn loop in the backyard (hight abt 2 meters) = instead of the miniwhip.=20 One of these days I will test again with the miniwhip. First = impression (testing the noise against DCF39) was that they dont differ = very much. 73=E2=80=99s Minto pa3bca (grabber at http://pa3bca.pa3bca.nl:8181)=20 = -------------------------------------------------------------------------= - Ceterum censeo Carthaginem delendam esse From: mal hamilton=20 Sent: Sunday, August 14, 2011 17:51 To: rsgb=20 Subject: LF: 137 grabbers LF My signal seems consistant on the PA3PCA grabber but varies a lot on = the DK7FC grabber, sometimes stronger on this grabber and others like = now barely visible. Could it be the type of antenna in use ie one is = more prone to noise es qsb than the other? de mal/g3kev ------=_NextPart_000_0397_01CC5ACD.EDA43920 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
Hi Daniele,
I felt real guilty.. and added a reference to the author=E2=80=99s = site on my=20 webpage.
 
73=E2=80=99s Minto pa3bca
 
-------------------------------------------------------------------= -------
Ceterum=20 censeo Carthaginem delendam esse
 
Sent: Sunday, August 14, 2011 21:54
Subject: Re: LF: Re: 137 grabbers
 
Don't worry Minto, this = circuits=20 was re-published a number of times on the web :-)
Anyway, I agree that a = reference=20 to the original article may give a more complete background and might be = helpful=20 to the reader.
Best 73
Daniele
 
From: Minto Witteveen=20 <minto.witteveen@gmail.com>
To:=20 rsgb_lf_group@blacksheep.org
Sent: Sunday, August 14, 2011 = 9:18=20 PM
Subject: LF: Re: = 137=20 grabbers

Hi Daniele,
Yup that=E2=80=99s the one. My shameless = theft is exposed=20 J
I see=20 that the only thing _I_ did was re-draw the schematics (I use = Kicad).
Of=20 course I should have acknowledged the original author on my webpage = =E2=80=93 will do=20 that next time I update my website.
Regards,
Minto = pa3bca.
 
Sent: Sunday, August 14, 2011 19:51
Subject: Re: LF: Re: 137 grabbers
 
Minto,
this is the M0AYF page I referred to:
May be you "stole" the  original schematics from there?=20 :-)
Best regards
Daniele
 
From:=20 Minto Witteveen <minto.witteveen@gmail.com>
To:=20 rsgb_lf_group@blacksheep.org
Sent: Sunday, August 14, 2011 = 7:33=20 PM
Subject: LF: Re: = 137=20 grabbers

Stefan, LF
Not my own design, I don=E2=80=99t = remember exactly where I=20 got it but I am pretty sure I stole the idea =E2=80=98from the = Internet=E2=80=99 and possible=20 made some changes. The bc337 was used as I have a lot of them lying = around, and=20 they are much better than for instance the bc547 (my other jellybean=20 transistor).
The reason I used a -43 type toroid is because I built = it for=20 use on 500 KHz and up.  Especially for 80 and 40 = meters.=20 Type-43 is better here than Type-77. On HF this loop is _much, much_ = better than=20 my end-fed TX wire in terms of S/N. The wire picks up a lot of noise = from the=20 house (and from my neighbors houses). The loop is placed to null- out = this QRM=20 as much as possible.
Above 10 MHz the gain drops off rapidly, it is = nearly=20 useless at 14 MHz. a -77 type would be much worse there I think.
As = for the=20 Q: I did a comparison between an FT50-43 and a 14 mm 4C6 (for my 137 KHz = low-pass filter, see my website). The Q of the FT50-43 coil was abt 50, = the 4C6=20 =E2=80=93 with a lower Al - was 140 !! Needed more turns ofcourse. On = the other hand the=20 Q of this toroid is not very important here as it is used as a = broad-band=20 transformer.
This is only my hobby=E2=80=A6 Originally = I am a Civil=20 Engineer (but my job now is in IT).
73=E2=80=99s Minto = pa3bca
 
-----------------------------------------= ---------------------------------
Ceterum=20 censeo Carthaginem delendam esse
 
Sent: Sunday, August 14, 2011 19:03
Subject: Re: LF: Re: 137 grabbers
 
This looks like a very good design. = Fascinating=20 easy!! Is it completely grown in your head or have you seen it somewhere = in the=20 web?
What is the gain, about? I know the BC337 as a low noise NPN=20 transistor.
Your loop is 2m diameter? How many dBs is the background = noise=20 abovethe soundcard noise?

Another question: Why are the T37-43 = (the 43=20 types in general) preferred to the 77 types? The 77 types have a higher = AL value=20 and should come out with less turns. I tried to wind a band pass coil = with but=20 of the types (T50-43 and T50-77) and achieved about the same Q. Is it = just a=20 question of an available distributor?

And what is your job? Do = you have=20 to design electrical circuits? ;-)

73, = Stefan/DK7FC




Am=20 14.08.2011 18:07, schrieb Minto Witteveen:=20
Loop antenna: http://www.pa3bca.nl/index.php?option=3Dcom_content&vi= ew=3Darticle&id=3D10&Itemid=3D14
Sent: Sunday, August 14, 2011 18:03
Subject: Re: LF: 137 grabbers
 
Mal, LF,
 
I am now using a single-turn loop in the backyard (hight abt 2 = meters)=20 instead of the miniwhip.
One of these days I will test again with = the=20 miniwhip. First impression (testing the noise against DCF39) was that = they=20 dont differ very much.
 
73=E2=80=99s Minto pa3bca (grabber at http://pa3bca.pa3bca.nl:8181) =
 
-----------------------------------------= ---------------------------------
Ceterum=20 censeo Carthaginem delendam esse
 
Sent: Sunday, August 14, 2011 17:51
To: rsgb
Subject: LF: 137 grabbers
 
LF
My signal seems consistant on the PA3PCA = grabber but=20 varies a lot on the DK7FC grabber, sometimes stronger on this grabber = and=20 others like now barely visible. Could it be the type of antenna in use = ie one=20 is more prone to noise es qsb than the other?
de
mal/g3kev


=

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