Return-Path: Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by mtain-dg03.r1000.mx.aol.com (Internet Inbound) with ESMTP id 206E4380000AA; Fri, 22 Jun 2012 11:02:31 -0400 (EDT) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1Si5Mb-000686-6c for rs_out_1@blacksheep.org; Fri, 22 Jun 2012 16:01:33 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1Si5Ma-00067x-Ju for rsgb_lf_group@blacksheep.org; Fri, 22 Jun 2012 16:01:32 +0100 Received: from smtp08.online.nl ([194.134.42.53]) by relay1.thorcom.net with esmtp (Exim 4.77) (envelope-from ) id 1Si5MY-0006Yk-EL for rsgb_lf_group@blacksheep.org; Fri, 22 Jun 2012 16:01:31 +0100 Received: from smtp08.online.nl (localhost [127.0.0.1]) by smtp08.online.nl (Postfix) with ESMTP id 48200668FC for ; Fri, 22 Jun 2012 17:01:27 +0200 (CEST) Received: from pa3fnytrqxpddu (s529d275f.adsl.wanadoo.nl [82.157.39.95]) by smtp08.online.nl (Postfix) with SMTP for ; Fri, 22 Jun 2012 17:01:27 +0200 (CEST) From: To: Date: Fri, 22 Jun 2012 17:01:27 +0200 Message-ID: MIME-Version: 1.0 X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook IMO, Build 9.0.2416 (9.0.2911.0) X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.5994 In-Reply-To: <1340375757.35583.YahooMailNeo@web29503.mail.ird.yahoo.com> Importance: Normal X-Antivirus: avast! 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Content preview: Hello Daniele,once I used the 12au7 as mixerstage in an old tube broadcastreceiver with very good results,much more sensitive and less IM than the usual ECH81.I never tried it but my guess it 's very good for a hi-Z pre-amp [...] Content analysis details: (-0.7 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- -0.7 RCVD_IN_DNSWL_LOW RBL: Sender listed at http://www.dnswl.org/, low trust [194.134.42.53 listed in list.dnswl.org] -0.0 T_RP_MATCHES_RCVD Envelope sender domain matches handover relay domain 0.0 HTML_MESSAGE BODY: HTML included in message X-Scan-Signature: bb953ecadee360a40f72202c1637b86b Subject: RE: LF: RE: Ferrite broadband (LF-MF) antenna? Content-Type: multipart/alternative; boundary="----=_NextPart_000_004E_01CD5098.A96C23A0" X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: *** X-Spam-Status: No, hits=3.1 required=5.0 tests=FROM_ENDS_IN_NUMS,HTML_30_40, HTML_FONTCOLOR_BLUE,HTML_MESSAGE,MAILTO_TO_SPAM_ADDR,NO_REAL_NAME 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: 0:2:360178080:93952408 X-AOL-SCOLL-URL_COUNT: 0 x-aol-sid: 3039ac1d410b4fe489072197 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_004E_01CD5098.A96C23A0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Hello Daniele,once I used the 12au7 as mixerstage in an old tube broadcastreceiver with very good results,much more sensitive and less IM than the usual ECH81.I never tried it but my guess it 's very good for a hi-Z pre-amp 73 Victor PS.no semiconductor is a match for a warm glowing glass tube. -----Oorspronkelijk bericht----- Van: owner-rsgb_lf_group@blacksheep.org [mailto:owner-rsgb_lf_group@blacksheep.org]Namens Daniele Tincani Verzonden: vrijdag 22 juni 2012 16:36 Aan: rsgb_lf_group@blacksheep.org Onderwerp: Re: LF: RE: Ferrite broadband (LF-MF) antenna? Hello Victor, thanks for your reply. In fact, now I think I will use th= e 12AU7 for a hi-Z pre-amp for a whip or a tuned loop (this again is just f= or playing with that old glassy lady :-)). As for the BD139, I didn't even suspect it could be used in a RF preamp, I tought of it as good for power stages... 73 Daniele IZ5WWB Da: "victor13@online.nl" A: rsgb_lf_group@blacksheep.org Inviato: Venerd=EC 22 Giugno 2012 16:19 Oggetto: LF: RE: Ferrite broadband (LF-MF) antenna? Hello Daniele, some months ago I made a broadbanded ferriterod to cope with heavy qrm = on the 80 and 160m band.The ferite comes from a submarine and is specified 10KHz to 4 MHZ with a symmetrical feedingcable to a ELK675 or other recei= ver without a preamp.Since I don't have such a receiver I made a balanced two stage amp with 4x BD139 grounded base.The antenna copes good with the QRM= on 80 and 160,it also performs very well on the MW broadcastband.In the rang= e 200-500KHz it is sometimes better than the E-probe,below 200KHz the E-pro= be wins.IM is no problem but maby the noise of the amp is to high below 200K= Hz. The ferriterod is about750X100mm! I don't think the 12AU7 is a good choice for a low inputimpedance amp...Zinput 2X BD139 is about 3 Ohm. 73 GL Victor PA3FNY -----Oorspronkelijk bericht----- Van: owner-rsgb_lf_group@blacksheep.org [mailto:owner-rsgb_lf_group@blacksheep.org]Namens Daniele Tincani Verzonden: vrijdag 22 juni 2012 9:42 Aan: rsgb_lf_group@blacksheep.org Onderwerp: LF: Ferrite broadband (LF-MF) antenna? Hello LF, I apologize to you all for resuming a topic that was already largely debated here. I have seven of those quite known russian surplus ferrite r= ods (20cm x 1cm) and - just for my fun - I'm planning to spend some time in building an LF-MF antenna with them. I would like to obtain a broadband (untuned) antenna, ideally VLF-LF and/or LF-MF, suitable for outdoor installation, so what I would appreciate some suggestions about is the required low-impedance amplifier, similar to those used in air-core broadband loops, if it does make sense of course. Any ideas? I found an unused 12AU7 in my drawer, could it be effectively chosen as the active device (low voltage) for such amplifier? Thank you for any feedback 73 Daniele IZ5WWB ------=_NextPart_000_004E_01CD5098.A96C23A0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Hello=20 Daniele,once I used the 12au7 as mixerstage in an old tube=20 broadcastreceiver with very good results,much more sensitive and less IM = than=20 the usual ECH81.I never tried it but  my guess it 's very good for = a hi-Z=20 pre-amp
 
73
 
Victor
PS.no=20 semiconductor is a match for a warm glowing glass = tube.
-----Oorspronkelijk bericht-----
Van:=20 owner-rsgb_lf_group@blacksheep.org=20 [mailto:owner-rsgb_lf_group@blacksheep.org]Namens Daniele=20 Tincani
Verzonden: vrijdag 22 juni 2012 16:36
Aan: = rsgb_lf_group@blacksheep.org
Onderwerp: Re: LF: RE: Ferrite=20 broadband (LF-MF) antenna?

Hello Victor, thanks for your reply. In fact, now I think I = will=20 use the 12AU7 for a hi-Z pre-amp for a whip or a tuned loop (this = again is=20 just for playing with that old glassy lady :-)). As for the BD139, I = didn't=20 even suspect it could be used in a RF preamp, I tought of it as good = for power=20 stages...
73
Daniele IZ5WWB
 

Da:=20 "victor13@online.nl" <victor13@online.nl>
A: rsgb_lf_group@blacksheep.org =
Inviato: Venerd=EC = 22 Giugno=20 2012 16:19
Oggetto: = LF: RE:=20 Ferrite broadband (LF-MF) antenna?

Hello Daniele,
 
some months ago I made a broadbanded = ferriterod to cope=20 with heavy qrm on the 80 and 160m band.The ferite comes from a = submarine and=20 is specified 10KHz to 4 MHZ with a symmetrical feedingcable to a = ELK675 or=20 other receiver without a preamp.Since I don't have such a receiver I = made a=20 balanced two stage amp with 4x BD139 grounded base.The antenna copes = good with=20 the QRM on 80 and 160,it also performs very well on the MW = broadcastband.In=20 the range 200-500KHz it is sometimes better than the E-probe,below = 200KHz the=20 E-probe wins.IM is no problem but maby the noise of the amp is to high = below=20 200KHz.
The ferriterod is = about750X100mm!
I don't think the 12AU7 is a good choice for = a low=20 inputimpedance amp...Zinput 2X BD139 is about 3 = Ohm.
 
73
GL
Victor
PA3FNY
 
-----Oorspronkelijk = bericht-----
Van:=20 owner-rsgb_lf_group@blacksheep.org=20 [mailto:owner-rsgb_lf_group@blacksheep.org]Namens Daniele=20 Tincani
Verzonden: vrijdag 22 juni 2012 = 9:42
Aan:=20 rsgb_lf_group@blacksheep.org
Onderwerp: LF: Ferrite = broadband=20 (LF-MF) antenna?

Hello LF,
 
I apologize to you all for resuming a topic that was already = largely=20 debated here. I have seven of those quite known russian surplus = ferrite=20 rods (20cm x 1cm) and - just for my fun - I'm planning to spend = some=20 time in building an LF-MF antenna with them. I would like to obtain=20 a broadband (untuned) antenna, ideally VLF-LF and/or = LF-MF,=20 suitable for outdoor installation, so what I would appreciate some=20 suggestions about is the required low-impedance amplifier, similar = to those=20 used in air-core broadband loops, if it does make sense of course. = Any=20 ideas? I found an unused 12AU7 in my drawer, could it be=20 effectively chosen as the active device (low=20 voltage) for such amplifier?
Thank you for any feedback
73
Daniele IZ5WWB
 


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