X-GM-THRID: 1203350633376413987 X-Gmail-Labels: rsgb lf X-Gmail-Received: 705fe45e635efa1d50e22dc23caecf9584979428 Delivered-To: daveyxm@gmail.com Received: by 10.54.72.5 with SMTP id u5cs29791wra; Tue, 16 May 2006 03:44:55 -0700 (PDT) Received: by 10.49.5.11 with SMTP id h11mr4327474nfi; Tue, 16 May 2006 03:44:54 -0700 (PDT) Return-Path: Received: from post.thorcom.com (post.thorcom.com [193.82.116.20]) by mx.gmail.com with ESMTP id r33si759697nfc.2006.05.16.03.44.53; Tue, 16 May 2006 03:44:54 -0700 (PDT) Received-SPF: neutral (gmail.com: 193.82.116.20 is neither permitted nor denied by best guess record for domain of owner-rsgb_lf_group@blacksheep.org) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1Ffwzv-0000Bq-5W for rs_out_1@blacksheep.org; Tue, 16 May 2006 11:41:51 +0100 Received: from [193.82.59.130] (helo=relay2.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1Ffwzu-0000Bh-FV for rsgb_lf_group@blacksheep.org; Tue, 16 May 2006 11:41:50 +0100 Received: from cas-mta2-fe.casema.nl ([83.80.1.24] helo=mta-fe.casema.nl) by relay2.thorcom.net with esmtp (Exim 4.51) id 1FfyWN-0003ox-FT for rsgb_lf_group@blacksheep.org; Tue, 16 May 2006 13:19:31 +0100 Received: from s9z5i6.casema.nl (53556AF3.cable.casema.nl [83.85.106.243]) by mta-fe.casema.nl (Postfix) with ESMTP id B5E56E163 for ; Tue, 16 May 2006 12:41:15 +0200 (CEST) Message-Id: <6.1.0.6.2.20060516114055.030b0be0@127.0.0.1> X-Sender: dickrollema@casema.nl#mail.casema.nl@127.0.0.1 (Unverified) X-Mailer: QUALCOMM Windows Eudora Version 6.1.0.6 Date: Tue, 16 May 2006 12:44:56 +0200 To: rsgb_lf_group@blacksheep.org From: Dick Rollema In-Reply-To: <004701c67873$67748720$2201a8c0@PC2> References: <003c01c67744$f08f9160$2201a8c0@PC2> <6.1.0.6.2.20060515132009.037b1cf0@127.0.0.1> <004701c67873$67748720$2201a8c0@PC2> Mime-Version: 1.0 X-Antivirus: avast! (VPS 0620-0, 15-05-2006), Outbound message X-Antivirus-Status: Clean X-Spam-Score: 0.2 (/) X-Spam-Report: autolearn=disabled,AWL=-0.360,FORGED_RCVD_HELO=0.05,HTML_20_30=0.504,HTML_MESSAGE=0.001 Subject: Re: LF: DCF39 ERP and field strength Content-Type: multipart/alternative; boundary="=====================_6262361==.ALT" 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=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: 5421 --=====================_6262361==.ALT Content-Type: text/plain; charset="iso-8859-1"; format=flowed Content-Transfer-Encoding: quoted-printable Hello Jos=E9, I found the following results for DCF39, using the CCIR curves: Sea Water, average salinity, conductivity 5 S/m, dielectric constant 70,=20 EMRP =3D 40 kW. Wet Ground, conductivity 10 mS, dielectric constant 30, EMRP =3D 40 kW Land, conductivity 3 mS, dielectric constant 22, EMRP =3D 108 kW. Medium dry ground, conductivity 1 mS, dielectric constant 15, EMRP =3D 1364= kW. 1 kW EMRP produces 300 mV/m at 1 km distance. At 500 km over perfect (flat) ground 1 kW EMRP would produce 300/500 =3D 0.6= =20 mV/m. I measure 2078 =B5V/m. Over perfect ground this would correspond to (2078/600) squared x 1 kW =3D= 12=20 kW EMRP. So even over almost perfect conducting sea water there is 10log (40/12) =3D= =20 5.2 dB extra path loss. I think this must be refraction loss due to the=20 curvature of the earth. 73, Dick, PA0SE At 01:00 16-5-06, you wrote: >Hello Dick: > > I took a plot, last month, of the transmission of a Spanish colleague,=20 > who is in Madrid, at 500 km as well, and the signal level during the day= =20 > was not stable, varying around 3 or 4 dB; I guess that the D layer=20 > reflection for this range is not low. > >On the other hand, Dick , I think that the mean soil conductivity for your= =20 >path , in my modest opinion, should be lower than 0.01 S/m, taking into=20 >account the conductivity map that can be seen in the Geri=B4s page. > >I agree with you that, for this 500 km range, there is high uncertainty in= =20 >the determination of radiated power. > > >73 de Jos=E9, EA1PX > > > >----- Original Message ----- >From: Dick Rollema >To: rsgb_lf_group@blacksheep.org >Sent: Monday, May 15, 2006 2:11 PM >Subject: Re: LF: DCF39 ERP and field strength > >Dear Jose, > >You wrote: >> >>In the web of Geri, DK8KW, can be seen that DCF39 ERP is 40KW (22KW=20 >>EMRP), based on measurements made by Geri some years ago. For this=20 >>radiater power corresponds, at 1800 Km, in function of inverse of=20 >>distance, 58 dB(uV/m); last nigth I made measurement of 60 dB(uV/m), so I= =20 >>wonder if still DCF39=B4s power is the same as before, and if the previous= =20 >>theorical field strength, with no reflection loss, can be exceeded some=20 >>times due to the several propagation factors involved. > >I measure the field strength of DCF39 at 2078 microvolt/metre (66.35 dB=B5V= )=20 >, as it is always at daytime. > >The distance between my location and DCF39 is about 500 km. Using the=20 >graph for "LAND" (conductivity 0.03 S/m, dielectric constant 40) in CCIR= =20 >Recommandation 368-7: GROUND-WAVE PROPAGATION CURVES FOR FREQUENCIES=20 >BETWEEN 10 KHz AND MHz I find the power of DCF39 to be 39.8 kW. This=20 >should be rounded to 40 kW of course. That this agrees so well with the=20 >40 kW mentioned by Geri is pure coincidence, given the uncertainties= involved. > >73, Dick, PA0SE >JN22GD --=====================_6262361==.ALT Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Hello Jos=E9,

I found the following results for DCF39, using the CCIR=20 curves:

Sea Water, average salinity, conductivity 5 S/m, dielectric constant 70, EMRP =3D 40 kW.

Wet Ground, conductivity 10 mS, dielectric constant 30, EMRP =3D 40 kW

Land, conductivity 3 mS, dielectric constant 22,  EMRP =3D 108 kW.

Medium dry ground,  conductivity 1 mS, dielectric constant 15, EMRP =3D 1364 kW.

1 kW EMRP produces 300 mV/m at 1 km distance.
At 500 km over perfect (flat) ground 1 kW EMRP would produce 300/500 =3D 0.6 mV/m.
I measure 2078 =B5V/m.
Over perfect ground this would correspond to (2078/600) squared x 1 kW =3D 12 kW EMRP.

So even over almost perfect conducting sea water there is 10log (40/12) =3D 5.2 dB  extra path loss. I think this must be refraction loss due to  the curvature of the earth. 

73, Dick, PA0SE

At 01:00 16-5-06, you wrote:
Hello Dick:
 
 I took a plot, last month, of the transmission of a Spanish colleague, who is in Madrid, at 500 km as well, and the signal level during the day was not stable, varying around 3 or 4 dB; I guess that the D layer reflection for this range is not low.
 
On the other hand, Dick , I think that the mean soil conductivity for your path , in my modest opinion, should be lower than 0.01 S/m, taking into account the conductivity map that can be seen in the Geri=B4s page.
 
I agree with you that, for this 500 km range, there is high uncertainty in the determination of radiated power.
 
 
73 de Jos=E9, EA1PX
 
 
 
----- Original Message -----
From: Dick Rollema
To: rsgb_lf_group@blacksheep.org
Sent: Monday, May 15, 2006 2:11 PM
Subject: Re: LF: DCF39 ERP and field strength

Dear Jose,

You wrote:

In the web of Geri, DK8KW, can be seen= that DCF39 ERP is 40KW (22KW EMRP), based on measurements made by Geri some= years ago. For this radiater power corresponds, at 1800 Km, in function of= inverse of distance, 58 dB(uV/m); last nigth I made measurement of 60= dB(uV/m), so I wonder if still DCF39=B4s power is the same as before, and= if the previous theorical field strength, with no reflection loss, can be= exceeded some times due to the several propagation factors= involved.

I measure the field strength of DCF39 at 2078 microvolt/metre (66.35= dB=B5V) , as it is always  at daytime.

The distance between my  location and DCF39 is about 500 km. Using= the graph for "LAND" (conductivity 0.03 S/m, dielectric constant= 40)  in CCIR Recommandation 368-7: GROUND-WAVE PROPAGATION CURVES FOR= FREQUENCIES BETWEEN 10 KHz AND MHz I find the power of DCF39 to be 39.8= kW.  This should be rounded to 40 kW of course.  That this agrees= so well with the 40 kW mentioned by  Geri is pure coincidence, given= the uncertainties involved.

73, Dick, PA0SE
JN22GD
--=====================_6262361==.ALT--