Return-Path: Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by klubnl.pl (8.14.4/8.14.4/Debian-8+deb8u2) with ESMTP id w9SHdOPm013753 for ; Sun, 28 Oct 2018 18:39:32 +0100 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1gGoxW-0000IQ-Rb for rs_out_1@blacksheep.org; Sun, 28 Oct 2018 17:34:42 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1gGoxW-0000IH-1G for rsgb_lf_group@blacksheep.org; Sun, 28 Oct 2018 17:34:42 +0000 Received: from mail-wm1-x32d.google.com ([2a00:1450:4864:20::32d]) by relay1.thorcom.net with esmtps (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.91_59-0488984) (envelope-from ) id 1gGoxU-0006uZ-EI for rsgb_lf_group@blacksheep.org; Sun, 28 Oct 2018 17:34:40 +0000 Received: by mail-wm1-x32d.google.com with SMTP id b203-v6so5792258wme.5 for ; Sun, 28 Oct 2018 10:34:40 -0700 (PDT) X-DKIM-Result: Domain=gmail.com Result=Good and Known Domain DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:mime-version:subject:date:references:to:in-reply-to:message-id; bh=V1u3JCtPemI15jblkIev4zKnBJPCTKnQ+l885haOcpQ=; b=bVEVjtuirpV5qjuIekm1aObg0zOvaHmeqSMKcZrrG3HuDNzgWnFXfBlSC1cqzdKtVX QdQZp+zBVKuPUqR5L0WnPTOj3dHPUCaO5QeSRF4P2zRxvJZXIv8+Fb+/0V7xM4uznydq z4WaXQTRaCeiKGAz71qdJJnvW5xd3gC0jbM5c1rhOFAb2O5+xl9IpwGIqzdBPYRLgqCO NyiR0uX1QJlbt//uaEnpn1AA2un0Y/WxduyUaR0rU9jpfOxXERPf0zWZP7pdl7zlUIKw LXdu4FCtNMn51/pGfpZUvkKid6/Lp6/pY3+DQ2L5UDCoUM12WsqRkKsMVxlFrBQqN2jJ x6Qw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:mime-version:subject:date:references:to :in-reply-to:message-id; bh=V1u3JCtPemI15jblkIev4zKnBJPCTKnQ+l885haOcpQ=; b=GapJNiz+EfetcV6B2+Gnz5k5fgrSxRbpd66+izf1LxU8skw3OdC/Orrl7gN2WhkncB a74ceuS0INFZVZzvdyNZbl2GdBwiMhRjdLZfHUCj9r0A55rnFrrjhEi29oIChITDtua2 BG26ATHm2fo1EIBqnmwuVfQ2I8K7DqGF3tcdcshOIdtlJqdJUI1dkULDMrOk1ragJNxg AubIbVT0miJ4CkEYatJafbcYOKRjx16LmUV6+2q317nqCM5AkIiek4tvgUc4ws3ta/w3 t8I+Z/zhXMYbR3+znZCzilSUiP/ZT8DMTEHw7edqVsH2wr9hubBnur+BCE/HAciumUDW w80g== X-Gm-Message-State: AGRZ1gKlEs8p63yTaNAfWWxyLgaOJO0aVPfKVsZRE6MG6BTkluP6S1I1 xneHPglk8dDVvp0qGbPweHkfrP9R X-Google-Smtp-Source: AJdET5fRIvpRaLpidp0iwX7/V8LCaXESEpfofrfToNAyDY7TzpAZsMY9ncrj9yeLBNsuH+qII+foJw== X-Received: by 2002:a1c:cc0f:: with SMTP id h15-v6mr11600891wmb.1.1540748078573; Sun, 28 Oct 2018 10:34:38 -0700 (PDT) Received: from [192.168.1.106] ([82.98.23.94]) by smtp.gmail.com with ESMTPSA id o81-v6sm6958426wmo.38.2018.10.28.10.34.37 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Sun, 28 Oct 2018 10:34:37 -0700 (PDT) From: John Rabson Mime-Version: 1.0 (Mac OS X Mail 12.0 \(3445.100.39\)) Date: Sun, 28 Oct 2018 18:34:35 +0100 References: To: rsgb_lf_group@blacksheep.org In-Reply-To: Message-Id: X-Mailer: Apple Mail (2.3445.100.39) X-Spam-Score: 0.3 (/) X-Spam-Report: Spam detection software, running on the system "relay1.thorcom.net", has NOT identified this incoming email as spam. The original message has been attached to this so you can view it or label similar future email. If you have any questions, see @@CONTACT_ADDRESS@@ for details. Content preview: Dave, I wish I could give you a talk, but journeys of the order of 1000 km are now beyond me. Here are my comments on the technical aspects of 2200 m. No doubt some more active practitioners will be able to correct my misunderstandings. [...] Content analysis details: (0.3 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- -0.0 RCVD_IN_DNSWL_NONE RBL: Sender listed at http://www.dnswl.org/, no trust [2a00:1450:4864:20:0:0:0:32d listed in] [list.dnswl.org] 0.2 FREEMAIL_ENVFROM_END_DIGIT Envelope-from freemail username ends in digit (john.rabson07[at]gmail.com) -0.0 SPF_PASS SPF: sender matches SPF record 0.0 FREEMAIL_FROM Sender email is commonly abused enduser mail provider (john.rabson07[at]gmail.com) 0.0 HTML_MESSAGE BODY: HTML included in message 0.0 T_DKIM_INVALID DKIM-Signature header exists but is not valid X-Scan-Signature: b14bcaca65d4b584f77d02a84d381cb4 Content-Type: multipart/alternative; boundary="Apple-Mail=_4508313F-F8CB-451E-924E-23BF53DC5832" Subject: Re: LF: Could anyone in/around Essex give a talk to our radio club about low frequency operation? X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: * X-Spam-Status: No, hits=1.3 required=5.0 tests=FROM_ENDS_IN_NUMS,HTML_20_30, 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 --Apple-Mail=_4508313F-F8CB-451E-924E-23BF53DC5832 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=utf-8 Dave, I wish I could give you a talk, but journeys of the order of 1000 km are = now beyond me. Here are my comments on the technical aspects of 2200 m. No doubt some = more active practitioners will be able to correct my misunderstandings.=20= Looking at the DHARS website I get the impression that the top band = antenna is a vertical (40 m?). This might be worth investigating for = 136, as would a flat-top of two or three well-spaced wires about 40 m = long at a height of perhaps 10 m, such as I used a few years ago and = with an ERP of 2 mW was received in Hertfordshire. On the receive side, a very large antenna is not always necessary. = Indeed it can sometimes be a disadvantage if you have high power = neighbours or interference sources. For many of my experiments I used a = 2 x 2 m rectangular loop oriented for minimum signal from the nearest LW = broadcast station (France Inter which closed down a few years ago). I am = about to rebuild the loop as it was demolished by a wild animal from the = local forest.=20 Although some people concentrate on =E2=80=9Cbest DX=E2=80=9D, and have = obtained good results, many experimenters on that band concentrate on = modulation methods and similar aspects of amateur radio.=20 73 John F5VLF=20 > On 27 Oct 2018, at 22:24, Dr. David Kirkby = wrote: >=20 > Our radio club=20 >=20 > https://www.dhars.org.uk/ >=20 > is on a farm with a 20 acre field. In principle we could do some LF = stuff, but know little about it. I wonder if anyone in/around Essex = would be willing to give us a talk one Monday evening? (Postcode CM3 = 6DU). We can pay traveling expenses. We have a quarter wave on top band, = some beverage antennas, beams for 2 m, 6m and a tri-bander. But we have = the space to run some long wires.=20 >=20 > Dave, G8WRB.=20 >=20 > --=20 > Dr David Kirkby Ph.D C.Eng MIET > Kirkby Microwave Ltd > Registered office: Stokes Hall Lodge, Burnham Rd, Althorne, = CHELMSFORD, Essex, CM3 6DT, United Kingdom. > Registered in England and Wales as company number 08914892 > https://www.kirkbymicrowave.co.uk/ = > Tel 01621-680100 / +44 1621-680100 >=20 --Apple-Mail=_4508313F-F8CB-451E-924E-23BF53DC5832 Content-Transfer-Encoding: quoted-printable Content-Type: text/html; charset=utf-8 Dave,

I = wish I could give you a talk, but journeys of the order of 1000 km are = now beyond me.

Here are my comments on the technical aspects of 2200 m. No = doubt some more active practitioners will be able to correct my = misunderstandings. 

Looking at the DHARS website I get the impression that the = top band antenna is a vertical (40 m?). This might be worth = investigating for 136, as would a flat-top of two or three well-spaced = wires about 40 m long at a height of perhaps 10 m, such as I used a few = years ago and with an ERP of 2 mW was received in = Hertfordshire.

On the receive side, a very large antenna is not always = necessary. Indeed it can sometimes be a disadvantage if you have high = power neighbours or interference sources. For many of my experiments I = used a 2 x 2 m rectangular loop oriented for minimum signal from the = nearest LW broadcast station (France Inter which closed down a few years = ago). I am about to rebuild the loop as it was demolished by a wild = animal from the local forest. 

Although some people concentrate on = =E2=80=9Cbest DX=E2=80=9D, and have obtained good results, many = experimenters on that band concentrate on modulation methods and similar = aspects of amateur radio. 

73 John F5VLF 

On 27 Oct 2018, at 22:24, Dr. David Kirkby <drkirkby@kirkbymicrowave.co.uk> wrote:

Our radio club

https://www.dhars.org.uk/

is on a farm with a 20 acre field. In = principle we could do some LF stuff, but know little about it. I wonder = if anyone in/around Essex would be willing to give us a talk one Monday = evening? (Postcode CM3 6DU). We can pay traveling expenses. We have a = quarter wave on top band, some beverage antennas, beams for 2 m, 6m and = a tri-bander. But we have the space to run some long wires.

Dave, G8WRB.

--
Dr = David Kirkby Ph.D C.Eng MIET
Kirkby Microwave Ltd
Registered office: Stokes Hall Lodge, Burnham Rd, Althorne, = CHELMSFORD, Essex, CM3 6DT, United Kingdom.
Registered in = England and Wales as company number 08914892
https://www.kirkbymicrowave.co.uk/
Tel = 01621-680100 / +44 1621-680100


= --Apple-Mail=_4508313F-F8CB-451E-924E-23BF53DC5832--