Return-Path: X-Spam-DCC: paranoid 1233; Body=3 Fuz1=3 Fuz2=3 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 s8K83beQ010318 for ; Sat, 20 Sep 2014 10:03:37 +0200 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1XVFad-0004n7-CL for rs_out_1@blacksheep.org; Sat, 20 Sep 2014 09:00:19 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1XVFac-0004my-Tr for rsgb_lf_group@blacksheep.org; Sat, 20 Sep 2014 09:00:18 +0100 Received: from omr-m04.mx.aol.com ([64.12.143.78]) by relay1.thorcom.net with esmtps (TLSv1:DHE-RSA-AES256-SHA:256) (Exim 4.82) (envelope-from ) id 1XVFaa-0005eQ-IU for rsgb_lf_group@blacksheep.org; Sat, 20 Sep 2014 09:00:17 +0100 Received: from mtaout-mcd02.mx.aol.com (mtaout-mcd02.mx.aol.com [172.26.223.206]) by omr-m04.mx.aol.com (Outbound Mail Relay) with ESMTP id ABC59700000B2 for ; Sat, 20 Sep 2014 04:00:13 -0400 (EDT) Received: from White (unknown [95.91.239.181]) by mtaout-mcd02.mx.aol.com (MUA/Third Party Client Interface) with ESMTPA id 1046A38000088 for ; Sat, 20 Sep 2014 04:00:12 -0400 (EDT) Message-ID: <3E929CBB414342E58A4D58FCC0733312@White> From: "Markus Vester" To: References: <6830353EE87C4976A52C3E8B21B3E35B@White> Date: Sat, 20 Sep 2014 10:00:18 +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=1411200013; bh=O/TPz2ICJ9SkzoCkUFlQBuEbIXqqnS/GR9AHe2t3Qhs=; h=From:To:Subject:Message-ID:Date:MIME-Version:Content-Type; b=o+ZwuD8TrpLjrvX4VhzsZn8TDccum3hU11epvSRI7W9pnakqxfHOzL+6bJkNbX8hm lAX/5/CoOTMyQbjIIJwZuQGZ9WCUYpwqVRoww5ZRW+81SvCjYz8wpvssmNs7chC0n+ 5yMsb5gYh/NufCD/C12ri4W1+K4MAAImQ6SERRII= x-aol-sid: 3039ac1adfce541d340c3b93 X-AOL-IP: 95.91.239.181 X-Scan-Signature: 18c34d0630bd8a741008f8972a39cc18 Subject: Re: LF: DX with 472 kHz, earth electrode antenna, 25 Watts output :-) Content-Type: multipart/alternative; boundary="----=_NextPart_000_001C_01CFD4B9.AEC5F180" 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: 462 Dies ist eine mehrteilige Nachricht im MIME-Format. ------=_NextPart_000_001C_01CFD4B9.AEC5F180 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable PS: Forgot to mention that you may also need to consider directivity: = The broadcast station used for the measurement should preferably be = close to one of the main lobes (ie NE or SW). If there is significant = deviation, you could either correct the measurement using the cosine of = the azimuth difference, or simply orient the reference loop the same way = as your ground antenna. 73, Markus =20 From: Markus Vester=20 Sent: Saturday, September 20, 2014 9:25 AM To: rsgb_lf_group@blacksheep.org=20 Subject: Re: LF: DX with 472 kHz, earth electrode antenna, 25 Watts = output :-) 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_001C_01CFD4B9.AEC5F180 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
PS: Forgot to mention that you may = also need=20 to consider directivity: The broadcast station used for the=20 measurement should preferably be close to one of the main = lobes (ie NE=20 or SW). If there is significant deviation, you could either = correct=20 the measurement using the cosine of the azimuth difference, or = simply=20 orient the reference loop the same way as your ground = antenna.
 
73, Markus  

From: Markus Vester
Sent: Saturday, September 20, 2014 9:25 AM
Subject: Re: LF: DX with 472 kHz, earth electrode antenna, = 25 Watts=20 output :-)

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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