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=-2.2 required=5.0 tests=BAYES_00,HTML_30_40, 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 s8KFb0Ru011371 for ; Sat, 20 Sep 2014 17:37:00 +0200 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1XVMf4-0005Wo-Mw for rs_out_1@blacksheep.org; Sat, 20 Sep 2014 16:33:22 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1XVMf4-0005Wf-5S for rsgb_lf_group@blacksheep.org; Sat, 20 Sep 2014 16:33:22 +0100 Received: from mail-lb0-f178.google.com ([209.85.217.178]) by relay1.thorcom.net with esmtps (TLSv1:RC4-SHA:128) (Exim 4.82) (envelope-from ) id 1XVMf1-00077K-3s for rsgb_lf_group@blacksheep.org; Sat, 20 Sep 2014 16:33:21 +0100 Received: by mail-lb0-f178.google.com with SMTP id z12so2083755lbi.37 for ; Sat, 20 Sep 2014 08:33:17 -0700 (PDT) X-DKIM-Result: Domain=gmail.com Result=Good and Known Domain DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :content-type; bh=4YRLX59NmcJNgnRTMZAKDh/0B3hwTI0TCHoPSmk4B58=; b=XDRbCCCKxewE758GxGYAtcY3XeFJEpaE556fEEMJBdV8cZ75jIaDwUMyDIIo3rXvMf 3P4JfaGyA5zrOsdnQ5DN8SLUU5zqOvzXStKWf4n2s30PoUS+o/ohkZbObG3R0KjDHmL6 PsQEvR1jGRTi8Dsg9Wcw6A3+8duf7l421Vm6R0IKddd3HcrZlRFWKvAnMoHXT68uc2Hj 9qta3NZcvq64jioZ0WMKX83zEnpMFn5fHrYu6nzQvnaJb/v7+FbzSQiH7oHtHntKgQOt 5NVTwzzTnt8RYQ2G9dqnlXc8KwH0xqMhQNBQwZpyGWB+L6XaXevOut9lJ3MiS3xeYHGI C3Sw== MIME-Version: 1.0 X-Received: by 10.152.205.38 with SMTP id ld6mr3156800lac.97.1411227197563; Sat, 20 Sep 2014 08:33:17 -0700 (PDT) Received: by 10.114.217.97 with HTTP; Sat, 20 Sep 2014 08:33:17 -0700 (PDT) In-Reply-To: References: <6830353EE87C4976A52C3E8B21B3E35B@White> <3E929CBB414342E58A4D58FCC0733312@White> Date: Sat, 20 Sep 2014 17:33:17 +0200 Message-ID: From: Piotr Herko To: rsgb_lf_group@blacksheep.org X-Scan-Signature: 170d09a2454389e326e0caea8d7379f3 Subject: Re: LF: DX with 472 kHz, earth electrode antenna, 25 Watts output :-) Content-Type: multipart/alternative; boundary=001a11349bb2cee6b9050380ef3d 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: 466 --001a11349bb2cee6b9050380ef3d Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Mauro, I think that good explanation is in G0AKN document http://g0akn.joataman.net/site/EarthCurrentCommunications.pdf pages 15-18. Piotrek, sp5xsb On Sat, Sep 20, 2014 at 5:17 PM, IK1WVQ Mauro wrote: > > hi Piotrek, > thanks for your infos. > > only one question again: > I can try this in a field in the countryside .. this field is large (abou= t > 100 meters square) but no builds, then no ground bands in ground. > I can plant in the soil 2 to 4 rods (aligned along a side of the field) .= . > no problems for distance: up to 100 meters is ok .. > according to you experience, can this setup to be ok ??? > (for example: 2 or 3 rods near the TX (the "ground") and the fourth rod > placed 20 to 100 meters away (the "antenna") ... > > thanks , 73 de Mauro IK1WVQ > > > > At 10.59 20/09/2014, Piotr Herko wrote: > > Hi, > Tnx Marcus for methodology for EIRP level estimation. I try calculate! > Mauro, > =C3=82 Earthing =C3=82 connected to shack is from band around my home. Ba= nd in about > 1,5 meters deep in ground. It is connected to all my equipment. This band > is first for safety on home.=C3=82 > Electrode is about 20 meters far from nearest point of 'normal' earthing > point. Second electrode is simply 2 meters vertical =C3=82 rod pounded in= soil. > This electrode is directly connected to tx output with 2,2 nF capacitor i= n > serial. For connection I use isolated wire. Capacitance was selected to g= et > lowest SWR. I was using for it home made NWT-7, DK3WX project, simple > network analyser. It is simple observe on analyser where is minimum SWR, > then change capacitor to get low SWR. But it is no problem =C3=82 use SWR= meter > for it only. Output from tx is 50 ohm 5th order filter. =C3=82 Isolated w= ire lay > simply on ground. I dont see any significiant changes between wire on > ground and hanging on fence. SWR is 1.1 to 1.4 according to weather. > I dont =C3=82 know exatly =C3=82 what soil is in my garden! =C3=82 I thin= k it is sandy > clay. > > Piotrek, sp5xsb > > > > On Sat, Sep 20, 2014 at 10:00 AM, Markus Vester > wrote: > PS: Forgot to mention that you=C3=82 may also need to consider=C3=82 dir= ectivity:=C3=82 > The broadcast station used for the measurement should preferably be=C3=82= close > to=C3=82 one of the main lobes (ie NE or SW). If there=C3=82 is significa= nt > deviation,=C3=82 you could either correct the measurement using the cosin= e of > the=C3=82 azimuth difference, or simply orient the reference loop the sam= e way > as your ground antenna. > =C3=82 > 73, Markus=C3=82 =C3=82 > > From: Markus Vester > Sent: Saturday, September 20, 2014 9:25 AM > To: rsgb_lf_group@blacksheep.org > Subject: Re: LF: DX with 472 kHz, earth electrode antenna, 25 Watts outpu= t > :-) > > Hi Piotr, > =C3=82 > congratulations on those=C3=82 results from your ground dipole! > =C3=82 > In my opinion, it is somewhat difficult to estimate ERP directly from WSP= R > SNR figures, because the variations in skywave sttenuation and receiver > noise floor are difficult to predict. I would probably go about it=C3=82 = by > using a receiver to measure the effective loop area Aeff of the ground > dipole. This can be done=C3=82 with some broadcast station in the lower m= edium > wave band, comparing receive level with that=C3=82 from a simple nonreson= ant > loop with eg. 1 square meter.=C3=82 Only the voltage ratio (dB difference= ) is > required so you don't=C3=82 need an absolutely calibrated receiver. Thus > =C3=82 > =C3=82 Aeff =3D voltage on ground antenna / voltage on reference loop * 1= m^2 > =C3=82 > 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: > =C3=82 > =C3=82 Aeff' =3D Aeff * sqrt (f_broadcast / f_amateur) > =C3=82 > Then, during your transmissions you'll only need to measure the=C3=82 cur= rent > to your ground antenna, and calculate ERP as > =C3=82 > =C3=82 ERP =3D 1.83 * 62342 ohms * Aeff'^2 / lambda^4 * current^2 > =C3=82 > Best 73, > Markus (DF6NM) > =C3=82 > > From: Piotr Herko > Sent: Saturday, September 20, 2014 8:32 AM > To: rsgb_lf_group@blacksheep.org > Subject: LF: DX with 472 kHz, earth electrode antenna, 25 Watts output :-= ) > > > > Hi, > > I reached OH8HTG WSPR, =C3=82 1414, =C3=82 km with my earth electrode ant= enna! 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,=C3=82 =C3=82 = DJ0ABR and=C3=82 > =C3=82 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=C3=82 =C3=82 SP5XSB=C3=82 =C3=82 0.475636=C3=82 =C3= =82 -30=C3=82 =C3=82 0=C3=82 =C3=82 KO02ld=C3=82 =C3=82 > 0.005=C3=82 =C3=82 OH8HTG=C3=82 =C3=82 KP34=C3=82 =C3=82 1414=C3=82 = =C3=82 12=C3=82 > =C3=82 2014-09-20 02:12=C3=82 =C3=82 DK7FC=C3=82 =C3=82 0.475684=C3=82 = =C3=82 -9=C3=82 =C3=82 0=C3=82 =C3=82 JN49ik=C3=82 =C3=82 1=C3=82 > =C3=82 SP5XSB=C3=82 =C3=82 KO02ld=C3=82 =C3=82 911=C3=82 =C3=82 66=C3= =82 > =C3=82 2014-09-20 02:06=C3=82 =C3=82 SP5XSB=C3=82 =C3=82 0.475636=C3=82= =C3=82 -33=C3=82 =C3=82 0=C3=82 =C3=82 KO02ld=C3=82 =C3=82 > 0.005=C3=82 =C3=82 OH8HTG=C3=82 =C3=82 KP34=C3=82 =C3=82 1414=C3=82 = =C3=82 12=C3=82 > > > Piotrek, sp5xsb > > > --001a11349bb2cee6b9050380ef3d Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable
Mauro,

I think that good explanation is= in G0AKN document=C2=A0http://g0akn.joataman.net/site/EarthCurrentCommunica= tions.pdf=C2=A0
pages 15-18.

Piotrek= , sp5xsb



On Sat, Sep 20, 2014 at 5:17 PM, IK1WVQ Ma= uro <ik1wvq@stmb.it> wrote:

hi Piotrek,
thanks for your infos.

only one question again:
I can try this in a field in the countryside .. this field is large (about 100 meters square) but no builds, then no ground bands in ground.
I can plant in the soil 2 to 4 rods (aligned along a side of the field) .. no problems for distance: up to 100 meters is ok ..
according to you experience, can this setup to be ok ???
(for example: 2 or 3 rods near the TX (the "ground") and the fourth rod placed 20 to 100 meters away (the "antenna") ...

thanks , 73 de Mauro IK1WVQ



At 10.59 20/09/2014, Piotr Herko wrote:

Hi,
Tnx Marcus for methodology for EIRP level estimation. I try calculate!
Mauro,
 =C3=82 Earthing =C3=82 connected to shack is from band around my home. Band= in about 1,5 meters deep in ground. It is connected to all my equipment. This band is first for safety on home.=C3=82
Electrode is about 20 meters far from nearest point of 'normal' ear= thing point. Second electrode is simply 2 meters vertical =C3=82 rod pounded in soil. This electrode is directly connected to tx output with 2,2 nF capacitor in serial. For connection I use isolated wire. Capacitance was selected to get lowest SWR. I was using for it home made NWT-7, DK3WX project, simple network analyser. It is simple observe on analyser where is minimum SWR, then change capacitor to get low SWR. But it is no problem =C3=82 use SWR meter for it only. Output from tx is 50 ohm 5th orde= r filter. =C3=82 Isolated wire lay simply on ground. I dont see any significi= ant changes between wire on ground and hanging on fence. SWR is 1.1 to 1.4 according to weather.
I dont =C3=82 know exatly =C3=82 what soil is in my garden! =C3=82 I think = it is sandy clay.

Piotrek, sp5xsb



On Sat, Sep 20, 2014 at 10:00 AM, Markus Vester <markusvester@= aol.com> wrote:
PS: Forgot to mention that you=C3=82 ma= y also need to consider=C3=82 directivity:=C3=82 The broadcast station used f= or the measurement should preferably be=C3=82 close to=C3=82 one of the main lobes= (ie NE or SW). If there=C3=82 is significant deviation,=C3=82 you could either cor= rect the measurement using the cosine of the=C3=82 azimuth difference, or simply ori= ent the reference loop the same way as your ground antenna.
=C3=82
73, Markus=C3=82 =C3=82

From: Ma= rkus Vester
Sent: Saturday, September 20, 2014 9:25 AM
To: rsgb_lf_group@blacksheep.org
Subject: Re: LF: DX with 472 kHz, earth electrode= antenna, 25 Watts output :-)

Hi Piotr,
=C3=82
congratulations on those=C3=82 res= ults from your ground dipole!
=C3=82
In my opinion, it is somewhat diff= icult 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=C3=82 by using a receiver to measure the effecti= ve loop area Aeff of the ground dipole. This can be done=C3=82 with some broadcast station in the lower medium wave band, comparing receive level with that=C3=82 from a simple nonresonant loop with eg. 1 square meter.=C3= =82 Only the voltage ratio (dB difference) is required so you don't=C3=82 need a= n absolutely calibrated receiver. Thus
=C3=82
=C3=82 Aeff =3D voltage on ground = antenna / voltage on reference loop * 1 m^2
=C3=82
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:
=C3=82
=C3=82 Aeff' =3D Aeff * sqrt (= f_broadcast / f_amateur)
=C3=82
Then, during your transmissions yo= u'll only need to measure the=C3=82 current to your ground antenna, and calculat= e ERP as
=C3=82
=C3=82 ERP =3D 1.83 * 62342 ohms *= Aeff'^2 / lambda^4 * current^2
=C3=82
Best 73,
Markus (DF6NM)
=C3=82

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



Hi,

I reached OH8HTG WSPR, =C3=82 1414, =C3=82 km wit= h 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,= =C3=82 =C3=82 DJ0ABR and=C3=82 =C3=82 DC1RJJ, about 650 km far. Also closer by SP2OVY and SQ5KLN.


Who can help me estimate EIRP power? I declare no= w in WSPR beacon 5 mW.



2014-09-20 02:14=C3=82=C2=A0 =C3=82= SP5XSB=C3=82=C2=A0 =C3=82 0.475636=C3=82=C2=A0 =C3=82 -30=C3=82=C2=A0 =C3=82 0=C3=82=C2=A0 =C3=82 KO02ld=C3=82=C2=A0 =C3=82 0.005= =C3=82=C2=A0 =C3=82 OH8HTG=C3=82=C2=A0 =C3=82 KP34=C3=82=C2=A0 =C3=82 1414=C3=82=C2=A0 =C3=82 12=C3=82
=C3=82 2014-09-20 02:12=C3=82=C2=A0 =C3=82 DK7FC=C3=82=C2=A0 =C3= =82 0.475684=C3=82=C2=A0 =C3=82 -9=C3=82=C2=A0 =C3=82 0=C3=82=C2=A0 =C3=82 JN49ik=C3=82=C2=A0 =C3=82 1=C3= =82=C2=A0 =C3=82 SP5XSB=C3=82=C2=A0 =C3=82 KO02ld=C3=82=C2=A0 =C3=82 911=C3=82=C2=A0 =C3=82 66=C3=82
=C3=82 2014-09-20 02:06=C3=82=C2=A0 =C3=82 SP5XSB=C3=82=C2=A0 =C3= =82 0.475636=C3=82=C2=A0 =C3=82 -33=C3=82=C2=A0 =C3=82 0=C3=82=C2=A0 =C3=82 KO02ld=C3=82=C2=A0 =C3=82 0.005= =C3=82=C2=A0 =C3=82 OH8HTG=C3=82=C2=A0 =C3=82 KP34=C3=82=C2=A0 =C3=82 1414=C3=82=C2=A0 =C3=82 12=C3=82


Piotrek, sp5xsb



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