Return-Path: Received: from mtain-ma06.r1000.mx.aol.com (mtain-ma06.r1000.mx.aol.com [172.29.96.14]) by air-db10.mail.aol.com (v129.4) with ESMTP id MAILINDB103-864c4bec627121a; Thu, 13 May 2010 16:34:58 -0400 Received: from post.thorcom.com (post.thorcom.com [193.82.116.20]) by mtain-ma06.r1000.mx.aol.com (Internet Inbound) with ESMTP id 0FB9738000110; Thu, 13 May 2010 16:34:55 -0400 (EDT) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1OCf5v-0005GB-1U for rs_out_1@blacksheep.org; Thu, 13 May 2010 21:33:23 +0100 Received: from [193.82.116.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1OCf5u-0005G2-IU for rsgb_lf_group@blacksheep.org; Thu, 13 May 2010 21:33:22 +0100 Received: from blu0-omc1-s15.blu0.hotmail.com ([65.55.116.26]) by relay1.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1OCf5t-0005Zh-8V for rsgb_lf_group@blacksheep.org; Thu, 13 May 2010 21:33:22 +0100 Received: from BLU146-W21 ([65.55.116.9]) by blu0-omc1-s15.blu0.hotmail.com with Microsoft SMTPSVC(6.0.3790.4675); Thu, 13 May 2010 13:33:12 -0700 Message-ID: X-Originating-IP: [138.32.32.166] From: Laurence KL1X To: Date: Thu, 13 May 2010 12:33:12 -0800 Importance: Normal In-Reply-To: References: <003501caf1fd$9d39a0e0$0401a8c0@xphd97xgq27nyf>,,<4BEBEE46.9040702@iup.uni-heidelberg.de>,<4BEC496D.3000300@iup.uni-heidelberg.de>, MIME-Version: 1.0 X-OriginalArrivalTime: 13 May 2010 20:33:12.0374 (UTC) FILETIME=[81D94560:01CAF2DB] X-Spam-Score: 0.0 (/) X-Spam-Report: autolearn=disabled,HTML_MESSAGE=0.001 Content-Type: multipart/alternative; boundary="_52a996f3-eb56-464c-8647-66957f2241e1_" Subject: RE: VLF: Outdoor test for different places for active E-field antennas for VLF X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.0 required=5.0 tests=FORGED_HOTMAIL_RCVD, 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: 3039ac1d600e4bec626f2c9b X-AOL-IP: 193.82.116.20 X-Mailer: Unknown (No Version) --_52a996f3-eb56-464c-8647-66957f2241e1_ Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable I found, on average, that moving the antennae out off the edge and above= of the building (just a couple of metres) at the corners improved the sig= nals at VLF/137 the most -=20 =20 As ever I used a coaxial cable (havenet figured out the fiber optic soluti= on yet) back which was bonded to the building rebar/earthing before it en= tered inside -=20 =20 Unfortunatley for me in this Oklahoma and my home in Alaska constructed "s= tick built" wooden property I dont have concrete and rebar reinforcement,= except on the footings, so nothing except true earth to bond to. My buil= ding is virtually transparent to a load of frequencies and we dont keep th= e noise within the interior of the building :-(( - My previous QTH in Chi= na and Singapore did have the rebar/concrete construction and it knocked= off 40dB or so of common mode noise... =20 Laurence KL 1 X/ BY3A etc =20 =20 > To: rsgb_lf_group@blacksheep.org > Date: Thu, 13 May 2010 19:27:07 +0000 > From: roelof@ndb.demon.nl > Subject: Re: VLF: Outdoor test for different places for active E-field= antennas for VLF >=20 > Hello Stefan, >=20 > Many thanks for sharing your findings. > I have done similar tests at 137 kHz and 400 kHz. > In a nutshell, it did not pay off to raise the antenna 6 meter ( total= =20 > height 12 meter) above the semi flat roof of my house, compared to 5 met= re=20 > high in the garden as the signal to noise ratio did not improve. >=20 > Unfortunately, I did not monitor the Russian Alpha signals at the time. > I did find a 15 dB lower signal level at 11.906 kHz at my city location= =20 > compared to a a free field location, though. > Both antennas were at the same height. >=20 > I have a few chestnut trees 20 metre away which are full with new leaves= =20 > and blossom. > At 400 kHz they have a screening effect of 1.5 to 2 dB! >=20 > Maybe you can check the signal to noise issue again when you have a real= =20 > signal for comparison, to make sure that your assumptions are valid. >=20 > Enjoy your weekend! >=20 > 73, > Roelof, pa0rdt >=20 =20 _________________________________________________________________ The New Busy think 9 to 5 is a cute idea. Combine multiple calendars with= Hotmail.=20 http://www.windowslive.com/campaign/thenewbusy?tile=3Dmulticalendar&ocid= =3DPID28326::T:WLMTAGL:ON:WL:en-US:WM_HMP:042010_5=3D --_52a996f3-eb56-464c-8647-66957f2241e1_ Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable I found, on average, that moving the antennae out off the edge and above= of the building (just a couple of metres) at the corners improved th= e signals at VLF/137 the most -
 
As ever I used a coaxial cable (havenet figured out the fiber optic= solution yet)  back which was bonded to the building rebar/earthing= before it entered inside -
 
Unfortunatley for me in this Oklahoma and my home in Alaska constructed&nb= sp;"stick built" wooden property I dont have concrete and rebar reinforcem= ent, except on the footings,  so nothing except true earth to bo= nd to. My building is virtually transparent to a load of frequencies= and we dont keep the noise within the interior of the building :-((&= nbsp; - My previous QTH in China and Singapore did have the rebar/con= crete construction and it knocked off 40dB or so of common mode noise...  
Laurence KL 1 X/ BY3A etc
 

 
> To: rsgb_lf_group@blacksheep.org
> Date: Thu, 13= May 2010 19:27:07 +0000
> From: roelof@ndb.demon.nl
> Subject= : Re: VLF: Outdoor test for different places for active E-field antennas= for VLF
>
> Hello Stefan,
>
> Many thanks for= sharing your findings.
> I have done similar tests at 137 kHz and= 400 kHz.
> In a nutshell, it did not pay off to raise the antenna= 6 meter ( total
> height 12 meter) above the semi flat roof of my= house, compared to 5 metre
> high in the garden as the signal to= noise ratio did not improve.
>
> Unfortunately, I did not mo= nitor the Russian Alpha signals at the time.
> I did find a 15 dB lo= wer signal level at 11.906 kHz at my city location
> compared to a= a free field location, though.
> Both antennas were at the same hei= ght.
>
> I have a few chestnut trees 20 metre away which are= full with new leaves
> and blossom.
> At 400 kHz they have= a screening effect of 1.5 to 2 dB!
>
> Maybe you can check= the signal to noise issue again when you have a real
> signal for= comparison, to make sure that your assumptions are valid.
>
>= ; Enjoy your weekend!
>
> 73,
> Roelof, pa0rdt
>=

The New Busy think 9 to 5 is a cute= idea. Combine multiple calendars with Hotmail. Get busy. =3D --_52a996f3-eb56-464c-8647-66957f2241e1_--