Return-Path: Received: from mtain-mk01.r1000.mx.aol.com (mtain-mk01.r1000.mx.aol.com [172.29.97.133]) by air-me01.mail.aol.com (v129.10) with ESMTP id MAILINME012-8ba14df0a03e17b; Thu, 09 Jun 2011 06:28:14 -0400 Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by mtain-mk01.r1000.mx.aol.com (Internet Inbound) with ESMTP id 47226380000AF; Thu, 9 Jun 2011 06:28:12 -0400 (EDT) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1QUcSb-00014a-CM for rs_out_1@blacksheep.org; Thu, 09 Jun 2011 11:27:33 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1QUcSa-00014R-SV for rsgb_lf_group@blacksheep.org; Thu, 09 Jun 2011 11:27:32 +0100 Received: from outbound-queue-1.mail.thdo.gradwell.net ([212.11.70.34]) by relay1.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1QUcSZ-00083R-EA for rsgb_lf_group@blacksheep.org; Thu, 09 Jun 2011 11:27:32 +0100 Received: from outbound-edge-2.mail.thdo.gradwell.net (bonnie.gradwell.net [212.11.70.2]) by outbound-queue-1.mail.thdo.gradwell.net (Postfix) with ESMTP id BE7EF221C7 for ; Thu, 9 Jun 2011 11:27:27 +0100 (BST) Received: from ctuash.plus.com (HELO Hugh) (212.159.90.113) (smtp-auth username ashford, mechanism login) by outbound-edge-2.mail.thdo.gradwell.net (qpsmtpd/0.83) with ESMTPA; Thu, 09 Jun 2011 11:27:27 +0100 Message-ID: <30FE713D08D0403A8BD97BF84BD0A6CC@Hugh> From: "Hugh_m0wye" To: References: <9E1D0F6DD9224C7A86D4227122F486E5@MLB> Date: Thu, 9 Jun 2011 11:27:21 +0100 MIME-Version: 1.0 X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.5931 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.5994 X-Gradwell-MongoId: 4df0a00f.e818-36f-2 X-Gradwell-Auth-Method: smtpauth X-Gradwell-Auth-Credentials: ashford X-Spam-Score: 3.4 (+++) X-Spam-Report: autolearn=disabled,FORGED_MUA_OUTLOOK=3.36,HTML_MESSAGE=0.001 Subject: LF: Re: antenna for 137kHz. Content-Type: multipart/alternative; boundary="----=_NextPart_000_004F_01CC2698.32A23F00" X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: ** X-Spam-Status: No, hits=2.1 required=5.0 tests=FORGED_MUA_OUTLOOK,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 x-aol-global-disposition: G x-aol-sid: 3039ac1d61854df0a03c3a69 X-AOL-IP: 195.171.43.25 X-AOL-SPF: domain : blacksheep.org SPF : none ------=_NextPart_000_004F_01CC2698.32A23F00 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable I also use an upstairs room for radio, and I have found it best to run a nu= mber of coaxial cables down to a waterproof box at ground level in the gard= en. Here I can connect my aerials to them, and this is also the centre of t= he network of ground cables and earth-stakes, so it is all securely grounde= d at this point.=20 The matching components (where possible) are also located in this box. This= reduces the pick-up of interferance sources in the house. You can think of it as moving the antenna socket of the radio out into the = middle of the garden. 73 Hugh M0WYE ----- Original Message -----=20 From: Martin Evans.=20 To: rsgb_lf_group@blacksheep.org=20 Sent: Thursday, June 09, 2011 11:07 AM Subject: LF: antenna for 137kHz. Gentlemen - some advice, please. My radio room is in a bedroom at the back of my house. Currently, I use a wire running from the bedroom up to a pole on the chim= ney about 35ft (10m) above ground,=20 then to a pole at the bottom of the garden about 100ft (35m) away, then d= own to the bottom of the pole, where=20 it is tied off. I tried running the wire back to the house (end not connected to anything= ) at about 8ft above ground (2.5m)=20 but this runs alongside a long building with my office, with electicity c= ables, computers, etc, so it picked=20 up a lot of noise. The signals seem "cleaner" when this return run is cut off. How can I improve this setup? I am thinking of pulling the far end of the wire over to the other side o= f the garden and running it back to=20 the house there, probably about 10ft (3m) above ground, then back inside = to make a loop. I would then have a loop aerial in a 45 degree plane, roughly. Does this sound as if it could be an improvement over my current setup? W= ould lifting the bottom of the loop=20 up to be more horizintal be better or worse? Any other suggestions? My garden runs roughly East-West. Does my current "Inverted U" aerial hav= e any directivity at this frequency=20 (137kHz)? What would be the directivity of my proposed 45 degree loop? Thanks for any help & suggestions, Martin GW3UCJ deep in the Swansea Valley!=20 ------=_NextPart_000_004F_01CC2698.32A23F00 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
I also use an upstairs room for radio, and I have= found=20 it best to run a number of coaxial cables down to a waterproof box at groun= d=20 level in the garden. Here I can connect my aerials to them, and t= his=20 is also the centre of the network of ground cables and earth-stakes, s= o it=20 is all securely grounded at this point.
 
The matching components (where possible) are also=20 located in this box. This reduces the pick-up of interferance sources = in=20 the house.
You can think of it as moving the antenna socket = of the=20 radio out into the middle of the garden.
73
Hugh M0WYE
 
----- Original Message -----
From:=20 Martin Evans.
Sent: Thursday, June 09, 2011 11:0= 7=20 AM
Subject: LF: antenna for 137kHz.

Gentlemen - some advice, please.

My radio room is i= n a=20 bedroom at the back of my house.

Currently, I use a wire running f= rom=20 the bedroom up to a pole on the chimney about 35ft (10m) above ground,=20
then to a pole at the bottom of the garden about 100ft (35m) away, th= en=20 down to the bottom of the pole, where
it is tied off.

I tried=20 running the wire back to the house (end not connected to anything)  = at=20 about 8ft above ground (2.5m)
but this runs alongside a long building= with=20 my office, with electicity cables, computers, etc, so it picked
up a = lot=20 of noise.

The signals seem "cleaner" when this return run is cut=20 off.

How can I improve this setup?

I am thinking of pulling= the=20 far end of the wire over to the other side of the garden and running it b= ack=20 to
the house there, probably about 10ft (3m) above ground, then back=20 inside to make a loop.

I would then have a loop aerial in a 45 deg= ree=20 plane, roughly.

Does this sound as if it could be an improvement o= ver=20 my current setup? Would lifting the bottom of the loop
up to be more=20 horizintal be better or worse?

Any other suggestions?

My ga= rden=20 runs roughly East-West. Does my current "Inverted U" aerial have any=20 directivity at this frequency
(137kHz)? What would be the directivity= of=20 my proposed 45 degree loop?

Thanks for any help &=20 suggestions,

Martin  GW3UCJ deep in the Swansea Valley!=20



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