Return-Path: Received: from rly-mf02.mx.aol.com (rly-mf02.mail.aol.com [172.20.29.172]) by air-mf05.mail.aol.com (v121.4) with ESMTP id MAILINMF052-947476f84ab1bd; Mon, 24 Dec 2007 05:06:49 -0500 Received: from post.thorcom.com (post.thorcom.com [193.82.116.20]) by rly-mf02.mx.aol.com (v121.4) with ESMTP id MAILRELAYINMF025-947476f84ab1bd; Mon, 24 Dec 2007 05:06:37 -0500 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1J6kC7-0003So-GJ for rs_out_1@blacksheep.org; Mon, 24 Dec 2007 10:05:59 +0000 Received: from [193.82.116.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1J6kC6-0003Sf-Qm for rsgb_lf_group@blacksheep.org; Mon, 24 Dec 2007 10:05:58 +0000 Received: from cas-mta2-fe.casema.nl ([83.80.1.24] helo=mta-fe.casema.nl) by relay1.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1J6kC3-0003H0-2Y for rsgb_lf_group@blacksheep.org; Mon, 24 Dec 2007 10:05:58 +0000 Received: from localhost (cas-filter6.mgmt.casema.nl [10.42.32.119]) by mta-fe.casema.nl (Postfix) with ESMTP id B9AFA409D for ; Mon, 24 Dec 2007 11:05:45 +0100 (CET) X-Virus-Scanned: amavisd-new at casema.nl Received: from mta-fe.casema.nl ([10.42.32.24]) by localhost (cas-filter6.mgmt.casema.nl [10.42.32.211]) (amavisd-new, port 20024) with ESMTP id QOiWz3MmwIfv for ; Mon, 24 Dec 2007 11:05:45 +0100 (CET) Received: from crazypeecee.casema.nl (5354976F.cable.casema.nl [83.84.151.111]) by mta-fe.casema.nl (Postfix) with ESMTP id 68C794107 for ; Mon, 24 Dec 2007 11:05:45 +0100 (CET) X-Mailer: QUALCOMM Windows Eudora Version 7.1.0.9 Date: Mon, 24 Dec 2007 11:05:39 +0100 To: LF-Group From: Dick Rollema Mime-Version: 1.0 Message-Id: <20071224100545.68C794107@mta-fe.casema.nl> X-Karma: 0: X-Spam-Score: 0.0 (/) X-Spam-Report: autolearn=disabled,HTML_MESSAGE=0.001 Subject: LF: SAQ on 24 Dec. 2007 Content-Type: multipart/alternative; boundary="=====================_96178265==.ALT" X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.8 required=5.0 tests=HTML_30_40,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-IP: 193.82.116.20 X-AOL-SCOLL-AUTHENTICATION: listenair ; SPF_helo : n X-AOL-SCOLL-AUTHENTICATION: listenair ; SPF_822_from : n --=====================_96178265==.ALT Content-Type: text/plain; charset="iso-8859-1"; format=flowed Content-Transfer-Encoding: quoted-printable To All from PA0SE Today I had again good reception of SAQ on=20 17.2kHz. I used a Wandel & Goltermann SLM type=20 SPM-12 connected to the aerial system for 136kHz=20 with 26nF extra in parallel with the loading coil. Replacing the aerial by a one-turn untuned square=20 loop of 1 x 1 m the signal was sufficiently over=20 the noise to be measured at 0.155 microvolt (25Hz I.F. bandwidth). From this follows a field strength of about 429 microvolt/metre (52.6 dB= =B5V). On June 30, 2002 I measured 482 microvolt/metre=20 (53.6 microvolt/metre. So the measurements are rather consistent. This makes it possible to do some speculation as=20 to the power radiated by SAQ (Effective Monopole Radiated Power, EMRP). The coordinates of SAQ are given as 57.07N,=20 12.24E. Using a computer program written by=20 Harry, PA0LQ, I find as QTH locator JO67CB. My=20 own locator is JO22GD. Again using Harry's program yields a distance of 735k= m. We can now enter these data into the graphs of=20 CCIR Recommendation 368-7 for ground-wave propagation. This results in: Type of ground dielectric constant conductivity (mS/m) EMRP Perfect=20 ground -=20 - 1.4kW Land 40=20 30 3.0kW Land 22=20 3 3.7kW Medium=20 dry 15=20 1 4.7kW ground Dry=20 ground 7=20 0.3 5.9kW ground If we estimate from these data an EMRP of 4kW=20 then with an alternator output of 200kW the=20 efficiency of the aerial system is (4/200) * 100% =3D 2%. This may not seem impressive but for an aerial at=20 such a low frequency it is not too bad I think. The aerial system consists of six vertical=20 radiators of 127 m high. They are fed in phase=20 at the top and each radiator has its own loading=20 coil and earth electrode (system also designed by=20 Alexanderson) . The total horizontal length is=20 2200 m, which is only 0.13 wavelength. So the=20 system may have been designed to give some gain=20 in the wanted direction I cannot see how this could have been achieved. It would be nice if someone nearer to Grimeton=20 would measure the field strength outside the near=20 field area, for instance at 5 wavelength distance, or 87km. At that distance at 17.2km perfect ground can be=20 assumed for calculating the EMRP (1kw produces=20 300mV/m at 1km distance, decreasing in a linear way with distance). 73, Dick, PA0SE =20 --=====================_96178265==.ALT Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable To All from PA0SE

Today I had again good reception of SAQ on 17.2kHz. I used a Wandel & Goltermann SLM type SPM-12 connected to the aerial system for 136kHz with 26nF extra in parallel with the loading coil.

Replacing the aerial by a one-turn untuned square loop of 1 x 1 m the signal was sufficiently over the noise to be measured at 0.155 microvolt (25Hz I.F. bandwidth).

From this follows a field strength of about 429 microvolt/metre (52.6 dB=B5V).
On June 30, 2002  I measured 482 microvolt/metre (53.6 microvolt/metre. So the measurements are rather consistent.

This makes it possible to do some speculation as to the power radiated by SAQ (Effective Monopole Radiated Power, EMRP).

The coordinates of SAQ are given as 57.07N, 12.24E. Using a computer program written by Harry, PA0LQ, I find as QTH locator JO67CB. My own locator is JO22GD. Again using Harry's program yields a distance of 735km.

We can now enter these data into the graphs of CCIR Recommendation 368-7 for ground-wave propagation. This results in:

Type of ground  dielectric constant    conductivity (mS/m)  EMRP

Perfect ground          -            &nb= sp;            &= nbsp;            = ;  -            &nb= sp;            &= nbsp;  1.4kW

Land            =             &nbs= p;  40            &n= bsp;            =             30            &n= bsp;             3.0kW

Land            =             &nbs= p;  22            &n= bsp;            =             &nbs= p; 3            &nb= sp;             3.7kW

Medium dry            &= nbsp;  15            &n= bsp;            =             &nbs= p; 1            &nb= sp;            4.7kW
ground

Dry ground           &nbs= p;      7            &nb= sp;            &= nbsp;            = ; 0.3            &= nbsp;         5.9kW
ground

If we estimate from these data an EMRP of 4kW then with an alternator output of 200kW the efficiency of the aerial system is (4/200) * 100% =3D 2%.

This may not seem impressive but for an aerial at such a low frequency it is  not too bad I think.

The aerial system consists of six vertical radiators of 127 m high.  They are fed in phase at the top and each radiator has its own loading coil and earth electrode (system also designed by Alexanderson) .  The total horizontal length is 2200 m, which is only 0.13 wavelength.  So the system may have been designed to give some gain in the wanted direction I cannot see how this could have been achieved.

It would be nice if someone nearer to Grimeton would measure the field strength outside the near field area, for instance  at 5 wavelength distance, or 87km.
At that distance at 17.2km perfect ground can be assumed for calculating the EMRP (1kw produces 300mV/m at 1km distance, decreasing in a linear way with distance). 

73, Dick, PA0SE --=====================_96178265==.ALT--