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[195.171.43.25]) by mx.google.com with ESMTP id t1si3397142lag.67.2013.07.05.10.29.05 for ; Fri, 05 Jul 2013 10:29:06 -0700 (PDT) Received-SPF: neutral (google.com: 195.171.43.25 is neither permitted nor denied by best guess record for domain of owner-rsgb_lf_group@blacksheep.org) client-ip=195.171.43.25; Authentication-Results: mx.google.com; spf=neutral (google.com: 195.171.43.25 is neither permitted nor denied by best guess record for domain of owner-rsgb_lf_group@blacksheep.org) smtp.mail=owner-rsgb_lf_group@blacksheep.org; dkim=pass header.i=@mx.aol.com Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1Uv9nI-0000vJ-Po for rs_out_1@blacksheep.org; Fri, 05 Jul 2013 18:27:40 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1Uv9nI-0000vA-5L for rsgb_lf_group@blacksheep.org; Fri, 05 Jul 2013 18:27:40 +0100 Received: from omr-m04.mx.aol.com ([64.12.143.78]) by relay1.thorcom.net with esmtps (TLSv1:AES256-SHA:256) (Exim 4.77) (envelope-from ) id 1Uv9nF-0003o9-4Z for rsgb_lf_group@blacksheep.org; Fri, 05 Jul 2013 18:27:39 +0100 Received: from mtaout-ma06.r1000.mx.aol.com (mtaout-ma06.r1000.mx.aol.com [172.29.41.6]) by omr-m04.mx.aol.com (Outbound Mail Relay) with ESMTP id CCDE2700680FB; Fri, 5 Jul 2013 13:24:32 -0400 (EDT) Received: from [192.168.1.68] (host-92-8-80-39.as43234.net [92.8.80.39]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by mtaout-ma06.r1000.mx.aol.com (MUA/Third Party Client Interface) with ESMTPSA id B649BE00008B; Fri, 5 Jul 2013 13:24:31 -0400 (EDT) Message-ID: <51D7014D.9020509@aol.com> Date: Fri, 05 Jul 2013 18:24:29 +0100 From: pat Organization: G4GVW User-Agent: Mozilla/5.0 (X11; Linux i686; rv:17.0) Gecko/20130623 Thunderbird/17.0.7 MIME-Version: 1.0 To: rsgb_lf_group@blacksheep.org CC: M0FMT References: <977A4C4B-4EE3-4BBD-9B0E-15DC077C197C@gmail.com> <1373034403.49430.YahooMailNeo@web133206.mail.ir2.yahoo.com> In-Reply-To: <1373034403.49430.YahooMailNeo@web133206.mail.ir2.yahoo.com> x-aol-global-disposition: G DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=mx.aol.com; s=20121107; t=1373045072; bh=lmmaoxg2UY1gcKd8P+Co0YDbCCN/dUr8aVh2QAo8mQ0=; h=From:To:Subject:Message-ID:Date:MIME-Version:Content-Type; b=yOXFhf5noOdj79yYE0BayjY+S731vjisqnCyx80Mu+fL3SjKekhR5h/pWAoDGuWYV GZd7JDedhtlq2SMs92i4I7c+Rb/1wDbZ6vsHzoY1CoAXNkNJiXLc27NmrtmYN/bSSC QYz6s22gdLGRgPiym1eBi5mK8Oxzc3OX3ZVuHU+o= X-AOL-SCOLL-SCORE: 0:2:448251872:93952408 X-AOL-SCOLL-URL_COUNT: 0 x-aol-sid: 3039ac1d290651d7014f2d67 X-AOL-IP: 92.8.80.39 X-Spam-Score: 0.8 (/) X-Spam-Report: Spam detection software, running on the system "relay1.thorcom.net", has identified this incoming email as possible spam. The original message has been attached to this so you can view it (if it isn't spam) or label similar future email. If you have any questions, see the administrator of that system for details. Content preview: Pete, I have that book and have found it useful. However, apart from the academic arguments (we are trying to arrive at a definition for the word antenna, I think), I still prefer simply getting on with the thought I mentioned earlier ie. I think of a "small" antenna as being one plate of a capacitor whose other plate is the rest of the universe! The environment contains so very many other physical influences and variables that it is even difficult to concieve of an isotropic element in practical terms. [...] Content analysis details: (0.8 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- -0.0 RCVD_IN_DNSWL_NONE RBL: Sender listed at http://www.dnswl.org/, no trust [64.12.143.78 listed in list.dnswl.org] 0.0 FREEMAIL_FROM Sender email is commonly abused enduser mail provider (g4gvw[at]aol.com) -0.0 SPF_PASS SPF: sender matches SPF record -0.2 RP_MATCHES_RCVD Envelope sender domain matches handover relay domain 0.0 HTML_MESSAGE BODY: HTML included in message 0.0 T_DKIM_INVALID DKIM-Signature header exists but is not valid 1.0 FREEMAIL_REPLY From and body contain different freemails X-Scan-Signature: d4b11820086e28e9e085cef3e7768d06 Subject: Re: LF: Wellbrook RX loops Content-Type: multipart/alternative; boundary="------------060109090508060308060005" X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.9 required=5.0 tests=HTML_30_40,HTML_FONT_BIG, HTML_MESSAGE 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 Status: O X-Status: X-Keywords: X-UID: 3344 This is a multi-part message in MIME format. --------------060109090508060308060005 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Pete, I have that book and have found it useful. However, apart from the academic arguments (we are trying to arrive at a definition for the word antenna, I think), I still prefer simply getting on with the thought I mentioned earlier ie. I think of a "small" antenna as being one plate of a capacitor whose other plate is the rest of the universe! The environment contains so very many other physical influences and variables that it is even difficult to concieve of an isotropic element in practical terms. My three'aporth 73 On 05/07/13 15:26, M0FMT wrote: > Hi Roger > In My Humble Opinion after spending a small fortune on one of these > "Frame Aerials" (I have not) nobody will give you a bad report. That > outfit relies on "Black Magic" since they will not publish their > Schematic. > I am glad Dave has given an honest appraisal of its performance. It is > about the same as any frame antenna. I have made frame antennas from > about 3m to 1m currently in use down to 250mm. They are great for > direction finding. They could be said to allow one to steer away from > noise but if the noise is between you and the desired station they are > of no advantage. > Make up a simple frame inductor and tune it with a capacitor and > amplify it there are plenty of schematics on the net. > Also there is a technical treatise in the 1938 BR 230 Admiralty > Handbook of Wireless Telegraphy Vol II Wireless Telegraphy Theory > section T page 1. available from any good book shop!! But pirate > copies from FMT press. > > 73 es GL Pete M0FMT IO91UX > > *From:* Roger Lapthorn > *To:* "rsgb_lf_group@blacksheep.org" > *Sent:* Friday, 5 July 2013, 10:28 > *Subject:* Re: LF: Wellbrook RX loops > > Dave, > > Thanks for that. Yes I can see the potential issue: you transfer > the overload issue from the active antenna to the RX. A bandpass > filter for each band is not hard though. Guess it is a question of > whether the wideband/no tune approach is better/more flexible, > than a tuned loop. > > My current RX situation is not good on 136/472kHz and I am looking > for a good solution on RX at the new QTH - moving in August all of > 300m further east! > > 73s > Roger G3XBM > > > On 5 July 2013 08:27, DAVE PICK > wrote: > > Roger > > I have used a Wellbrook for many years on 136 and (now) on > 472kHz. It performs well but it will put massive signals from > broadcast stations into your RX! You may need a band-pass > filter between the loop and the receiver. Obviously it is > directional. > It will be around 10dB down on a proper aerial, but that's not > a problem on LF. > > Dave G3YXM > > > On 5 July 2013 08:00, Roger Lapthorn > wrote: > > Can anyone advise, from actual use, how well a Wellbrook > loop works on 136 and 472kHz RX ? The excellent OIP2 and > OIP3 figures and directivity suggest one could be very useful. > > 73s > Roger G3XBM > > > > > > -- > http://g3xbm-qrp.blogspot.com/ > http://www.g3xbm.co.uk/ > https://sites.google.com/site/sub9khz/ > http://qss2.blogspot.com/ > http://www.youtube.com/user/g3xbm > > > -- 73 de pat g4gvw es gd dx qth nr Felixstowe East Coast UK --------------060109090508060308060005 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit
Pete,
I have that book and have found it useful. However, apart from the academic arguments (we are trying to arrive at a definition for the word antenna, I think), I still prefer simply getting on with the thought I mentioned earlier ie. I think of a "small" antenna as being one plate of a capacitor whose other plate is the rest of the universe! The environment contains so very many other physical influences and variables that it is even difficult to concieve of an isotropic element in practical terms.

My three'aporth

73


On 05/07/13 15:26, M0FMT wrote:
Hi Roger
 
In My Humble Opinion after spending a small fortune on one of these "Frame Aerials" (I have not) nobody will give you a bad report. That outfit relies on "Black Magic" since they will not publish their Schematic.
I am glad Dave has given an honest appraisal of its performance. It is about the same as any frame antenna. I have made frame antennas from about 3m to 1m currently in use down to 250mm. They are great for direction finding. They could be said to allow one to steer away from noise but if the noise is between you and the desired station they are of no advantage. 
 
Make up a simple frame inductor and tune it with a capacitor and amplify it there are plenty of schematics  on the net.
Also there is a technical treatise in the 1938 BR 230 Admiralty Handbook of Wireless Telegraphy Vol II Wireless Telegraphy Theory section T page 1. available from any good book shop!! But pirate copies from FMT press.

73 es GL Pete M0FMT IO91UX
From: Roger Lapthorn <rogerlapthorn@gmail.com>
To: "rsgb_lf_group@blacksheep.org" <rsgb_lf_group@blacksheep.org>
Sent: Friday, 5 July 2013, 10:28
Subject: Re: LF: Wellbrook RX loops

Dave,

Thanks for that. Yes I can see the potential issue: you transfer the overload issue from the active antenna to the RX. A bandpass filter for each band is not hard though. Guess it is a question of whether the wideband/no tune approach is better/more flexible, than a tuned loop.

My current RX situation is not good on 136/472kHz and I am looking for a good solution on RX at the new QTH - moving in August all of 300m further east!

73s
Roger G3XBM


On 5 July 2013 08:27, DAVE PICK <daveyxm@virginmedia.com> wrote:
Roger

I have used a Wellbrook for many years on 136 and (now) on 472kHz. It performs well but it will put massive signals from broadcast stations into your RX! You may need a band-pass filter between the loop and the receiver. Obviously it is directional.
It will be around 10dB down on a proper aerial, but that's not a problem on LF.

Dave G3YXM


On 5 July 2013 08:00, Roger Lapthorn <rogerlapthorn@gmail.com> wrote:
Can anyone advise, from actual use,  how well a Wellbrook loop works on 136 and 472kHz RX ? The excellent OIP2 and OIP3 figures and directivity suggest one could be very useful.

73s
Roger G3XBM




-- 




-- 
73 de pat g4gvw
es gd dx
qth nr Felixstowe
East Coast UK
--------------060109090508060308060005--