Return-Path: X-Spam-DCC: paranoid 1233; Body=2 Fuz1=2 Fuz2=2 X-Spam-Checker-Version: SpamAssassin 3.1.3 (2006-06-01) on lipkowski.org X-Spam-Level: X-Spam-Status: No, score=-2.6 required=5.0 tests=BAYES_00,HTML_MESSAGE autolearn=unavailable version=3.1.3 Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by paranoid.lipkowski.org (8.13.7/8.13.7) with ESMTP id s8K7STtw010104 for ; Sat, 20 Sep 2014 09:28:29 +0200 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1XVF31-0004Yz-Tx for rs_out_1@blacksheep.org; Sat, 20 Sep 2014 08:25:35 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1XVF31-0004Yq-IY for rsgb_lf_group@blacksheep.org; Sat, 20 Sep 2014 08:25:35 +0100 Received: from omr-m10.mx.aol.com ([64.12.143.86]) by relay1.thorcom.net with esmtps (TLSv1:DHE-RSA-AES256-SHA:256) (Exim 4.82) (envelope-from ) id 1XVF2z-0005Vs-9X for rsgb_lf_group@blacksheep.org; Sat, 20 Sep 2014 08:25:34 +0100 Received: from mtaout-mca01.mx.aol.com (mtaout-mca01.mx.aol.com [172.26.221.77]) by omr-m10.mx.aol.com (Outbound Mail Relay) with ESMTP id BF7E4700000B3 for ; Sat, 20 Sep 2014 03:25:30 -0400 (EDT) Received: from White (unknown [95.91.239.181]) by mtaout-mca01.mx.aol.com (MUA/Third Party Client Interface) with ESMTPA id 459BC38000084 for ; Sat, 20 Sep 2014 03:25:30 -0400 (EDT) Message-ID: <6830353EE87C4976A52C3E8B21B3E35B@White> From: "Markus Vester" To: References: Date: Sat, 20 Sep 2014 09:25:35 +0200 MIME-Version: 1.0 X-Priority: 3 X-MSMail-Priority: Normal Importance: Normal X-Mailer: Microsoft Windows Live Mail 12.0.1606 X-MimeOLE: Produced By Microsoft MimeOLE V12.0.1606 x-aol-global-disposition: G DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=mx.aol.com; s=20140625; t=1411197930; bh=145Ez7T0qKGxVn00ormp/pxxJLKPzw8vNgqUunF6Vvc=; h=From:To:Subject:Message-ID:Date:MIME-Version:Content-Type; b=KArS1zdU5klEVuEMSj2QHaFmlylJaJuAVH3hAvos6OYVk2koFWL8Mn+7MfuQScE9p PLaYuoqT6CWGcKiikn6zQhuprSNlSRgndQag1H3eNrWmzS+wNzOKXLg+xZe9XJfu8j uLNTKxwu+DXNgfLGpyhVxrOOiWloclthDtaKWF/M= x-aol-sid: 3039ac1add4d541d2bea1012 X-AOL-IP: 95.91.239.181 X-Scan-Signature: e3d323418d60e0f7f0af176deb9f3e2b Subject: Re: LF: DX with 472 kHz, earth electrode antenna, 25 Watts output :-) Content-Type: multipart/alternative; boundary="----=_NextPart_000_0013_01CFD4B4.D5924B10" 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-Scanned-By: MIMEDefang 2.56 on 10.1.3.10 Status: O X-Status: X-Keywords: X-UID: 460 Dies ist eine mehrteilige Nachricht im MIME-Format. ------=_NextPart_000_0013_01CFD4B4.D5924B10 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Hi Piotr, congratulations on those results from your ground dipole! In my opinion, it is somewhat difficult to estimate ERP directly from = WSPR SNR figures, because the variations in skywave sttenuation and = receiver noise floor are difficult to predict. I would probably go about = it by using a receiver to measure the effective loop area Aeff of the = ground dipole. This can be done with some broadcast station in the lower = medium wave band, comparing receive level with that from a simple = nonresonant loop with eg. 1 square meter. Only the voltage ratio (dB = difference) is required so you don't need an absolutely calibrated = receiver. Thus Aeff =3D voltage on ground antenna / voltage on reference loop * 1 m^2 If the frequency of the used broadcast station was significantly higher = than your transmit frequency, you can make a correction for the = increased skin depth: Aeff' =3D Aeff * sqrt (f_broadcast / f_amateur) Then, during your transmissions you'll only need to measure the current = to your ground antenna, and calculate ERP as ERP =3D 1.83 * 62342 ohms * Aeff'^2 / lambda^4 * current^2 Best 73, Markus (DF6NM) From: Piotr Herko=20 Sent: Saturday, September 20, 2014 8:32 AM To: rsgb_lf_group@blacksheep.org=20 Subject: LF: DX with 472 kHz, earth electrode antenna, 25 Watts output = :-) Hi, I reached OH8HTG WSPR, 1414, km with my earth electrode antenna! TX is = M1GEO project, DDS RN3AUS, electrodes are 20 meters apart. Antenna is = directly connected to 50 ohm tx filter with serial 2,2 nF capacitor. SWR = is about 1,1 to 1.4 according to weather. Direction of the antenna is = NE, 50 deg. So far my WSPR was received in DL, OK, OE corner by DH5RAE, DJ0ABR and = DC1RJJ, about 650 km far. Also closer by SP2OVY and SQ5KLN. Who can help me estimate EIRP power? I declare now in WSPR beacon 5 mW. 2014-09-20 02:14 SP5XSB 0.475636 -30 0 KO02ld 0.005 = OH8HTG KP34 1414 12 =20 2014-09-20 02:12 DK7FC 0.475684 -9 0 JN49ik 1 = SP5XSB KO02ld 911 66 =20 2014-09-20 02:06 SP5XSB 0.475636 -33 0 KO02ld 0.005 = OH8HTG KP34 1414 12 =20 Piotrek, sp5xsb ------=_NextPart_000_0013_01CFD4B4.D5924B10 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
Hi Piotr,
 
congratulations on those results = from your=20 ground dipole!
 
In my opinion, it is somewhat difficult = to estimate=20 ERP directly from WSPR SNR figures, because the variations in skywave=20 sttenuation and receiver noise floor are difficult to predict. = I would probably go about it by using a = receiver to=20 measure the effective loop area Aeff of the ground dipole. This can be=20 done with some broadcast station in the lower medium wave band, = comparing=20 receive level with that from a simple nonresonant loop with eg. 1 = square=20 meter. Only the voltage ratio (dB difference) is required so you=20 don't need an absolutely calibrated receiver. Thus
 
 Aeff =3D voltage on ground = antenna / voltage on=20 reference loop * 1 m^2
 
If the frequency of the used broadcast = station was=20 significantly higher than your transmit frequency, you can make a = correction for=20 the increased skin depth:
 
 Aeff' =3D Aeff * sqrt = (f_broadcast /=20 f_amateur)
 
Then, during your transmissions you'll = only need to=20 measure the current to your ground antenna, and calculate ERP=20 as
 
 ERP =3D 1.83 * 62342 ohms * = Aeff'^2 / lambda^4=20 * current^2
 
Best 73,
Markus (DF6NM)
 

Sent: Saturday, September 20, 2014 8:32 AM
To: rsgb_lf_group@blacksheep.org= =20
Subject: LF: DX with 472 kHz, earth electrode antenna, 25 = Watts=20 output :-)



Hi,

I reached OH8HTG WSPR,  1414,  km with my earth electrode = antenna! TX is M1GEO project, DDS RN3AUS, electrodes are 20 meters = apart.=20 Antenna is directly connected to 50 ohm tx filter with serial 2,2 nF = capacitor.=20 SWR is about 1,1 to 1.4 according to weather. Direction of the antenna = is NE, 50=20 deg.

So far my WSPR was received in DL, OK, OE corner by=20 DH5RAE,  DJ0ABR and  DC1RJJ, about 650 km far. Also = closer=20 by SP2OVY and SQ5KLN.


Who can help me estimate EIRP power? I declare now in WSPR beacon 5 = mW.



2014-09-20 02:14   SP5XSB   0.475636   -30   0   KO02ld   0.005   OH8HTG   KP34   1414   12   2014-09-20 02:12   DK7FC   0.475684   -9   0   JN49ik   1   SP5XSB   KO02ld   911   66   2014-09-20 02:06   SP5XSB   0.475636   -33   0   KO02ld   0.005   OH8HTG   KP34   1414   12 

Piotrek, sp5xsb


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