Return-Path: Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by mtain-dk03.r1000.mx.aol.com (Internet Inbound) with ESMTP id E54A0380000A5; Wed, 28 Mar 2012 18:13:02 -0400 (EDT) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1SD15w-0007av-JR for rs_out_1@blacksheep.org; Wed, 28 Mar 2012 23:11:56 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1SD15v-0007am-Lv for rsgb_lf_group@blacksheep.org; Wed, 28 Mar 2012 23:11:55 +0100 Received: from imr-da06.mx.aol.com ([205.188.169.203]) by relay1.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1SD15s-00007w-VA for rsgb_lf_group@blacksheep.org; Wed, 28 Mar 2012 23:11:55 +0100 Received: from mtaomg-da06.r1000.mx.aol.com (mtaomg-da06.r1000.mx.aol.com [172.29.51.142]) by imr-da06.mx.aol.com (8.14.1/8.14.1) with ESMTP id q2SMBe6h031150 for ; Wed, 28 Mar 2012 18:11:40 -0400 Received: from core-msa003a.r1000.mail.aol.com (core-msa003.r1000.mail.aol.com [172.29.233.73]) by mtaomg-da06.r1000.mx.aol.com (OMAG/Core Interface) with ESMTP id 15821E000084 for ; Wed, 28 Mar 2012 18:11:40 -0400 (EDT) References: <8CEDA76E04F70F0-1B04-5AAF@webmail-d082.sysops.aol.com> <8CEDAC636CB654A-A18-4C57@webmail-d159.sysops.aol.com> <4F72B8EB.5060402@dsl.pipex.com> <4F72E74B.8010300@iup.uni-heidelberg.de> To: rsgb_lf_group@blacksheep.org In-Reply-To: <4F72E74B.8010300@iup.uni-heidelberg.de> X-MB-Message-Source: WebUI MIME-Version: 1.0 From: Markus Vester X-MB-Message-Type: User X-Mailer: AOL Webmail 35810-STANDARD Received: from 77.7.53.125 by webmail-d032.sysops.aol.com (205.188.167.97) with HTTP (WebMailUI); Wed, 28 Mar 2012 18:11:40 -0400 Message-Id: <8CEDB46E28419A5-C48-D722@webmail-d032.sysops.aol.com> X-Originating-IP: [77.7.53.125] Date: Wed, 28 Mar 2012 18:11:40 -0400 (EDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=mx.aol.com; s=20110426; t=1332972700; bh=nH4WlYCzMx0rnM0EmvecZZXr22LptYVjzzX2Kej5Vk0=; h=From:To:Subject:Message-Id:Date:MIME-Version:Content-Type; b=xG8bBbCgNmDNPtLLvEpwV68SlT9t+fOoEvfv4FzHz8yPOw6EDpwaE1k+x51dPMu9G iPLNp+B4PO3l1qrhFDtXBwxSjp+mPvbueL2PgVnp9/CPwPvt2D87Ms8hrOwvm92IO3 at/cXAAOMSszwp50dny8ukInXOPztNpO5/Z2UUt0= X-AOL-SCOLL-SCORE: 0:2:509176992:93952408 X-AOL-SCOLL-URL_COUNT: 0 X-Spam-Score: 0.3 (/) X-Spam-Report: autolearn=disabled,FORGED_AOL_TAGS=0.281,HTML_MESSAGE=0.001,UNPARSEABLE_RELAY=0.001 Subject: Re: VLF: DF6NM on 8970.002 - again tonight Content-Type: multipart/alternative; boundary="--------MB_8CEDB46E29724D5_C48_34D23_webmail-d032.sysops.aol.com" X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.1 required=5.0 tests=FORGED_AOL_TAGS, HTML_FONTCOLOR_UNKNOWN,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-global-disposition: G X-AOL-SCOLL-SCORE: 0:2:513977440:93952408 X-AOL-SCOLL-AUTHENTICATION: mail_rly_antispam_dkim-d017.2 ; domain : mx.aol.com DKIM : pass x-aol-sid: 3039ac1db4074f738cee156c X-AOL-IP: 195.171.43.25 X-AOL-SPF: domain : blacksheep.org SPF : none This is a multi-part message in MIME format. ----------MB_8CEDB46E29724D5_C48_34D23_webmail-d032.sysops.aol.com Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Thanks very much for the interest, and to Chris 'WCD for the excellent capt= ure. As the WX is still dry and calm here, I have put the TX back on at 21 = UT for another night, with the same parameters as before. My ERP is a bit uncertain, as I haven't measured the effect of environmenta= l shielding on antenna height at VLF. My best guess is somewhere around 7 t= o 9 meters, which would give around 90 microohms radiation resistance, or 1= 0 =C2=B5W EMRP at 0.34 A.=20 The notion of corona being responsible for the noise was suggested by the t= hreshold-like onset of both visual and acoustical emissions. I currently ha= ve only very rudimentary "corona rings", by bending the insulated wire into= a couple of little loops at each end. I like Wolf's idea of hanging up gar= den decoration balls, but I'm not sure whether the landlady would find that= an acceptable view ;-) Maybe I should look for clear semi-transparent ones= , or even partly evacuate them to let them glow real pretty ;-) BTW working back from the corona brightness one gets an optical power of ab= out 1 =C2=B5W in the visual range. Assuming that at this level the partial = discharges are consuming on the order of 10% of the TX power, we find that = the efficiency of light generation is only some 0.1 ppm - similar to te eff= iciency of the whole antenna for VLF radiation ;-) Regarding the noise from the coil, I had originally thought that it might b= e caused by Lorentz forces in Earth's static field. This gave the idea to c= ancel the field and thus the noise by permanent magnets mounted appropriate= ly in the coil's vicinity. But this never worked, the magnetic effect turne= d out to be much too weak to explain the level of 9 kHz noise. Now I think = that it is more likely an electrostatic effect from the large AC voltage, c= ombined with static charge buildup on the plastic surfaces. And there is a = strong smell of ozone inside of the dustbin after transmitting a while, so = there is certainly some degree of partial discharges around the coil bucket= s. Best 73, Markus (DF6NM) -----Urspr=C3=BCngliche Mitteilung-----=20 Von: Stefan Sch=C3=A4fer An: rsgb_lf_group Verschickt: Mi, 28 Mrz 2012 10:27 am Betreff: Re: VLF: DF6NM on 8970.002 Hi Markus,=20 Nice work! I can see you in 424 uHz, and traces in 4.5 mHz. You leave a str= ong trace in 47 uHz, at exactly 8970.0020 Hz! Very nice. I can see QSB on your signal in that 174 km distance. What is the ERP? Go on! :-) 73, Stefan/DK7FC http://www.iup.uni-heidelberg.de/schaefer_vlf/DK7FC_VLF_Grabber.html PS: Lubos, really an excellent Grabber!! Am 28.03.2012 09:08, schrieb Chris Dillon:=20 Hi Markus Good signals here too in 424uHz and 125uHz (peaking 10dB over the noise) al= ongside Henny and Uwe.=20 Nice to see VLF busy!=20 73 Chris G3WCD On 28/03/2012 07:50, Markus Vester wrote:=20 The carrier was on air continuously from 20:26 to 6:36 this morning. =20 Thanks very much to Lubos, as well as to all other live grabber operators. = As far as I can see, traces appeared at DK7FC, G3ZJO, OK2BVG, and Paul Nich= olson. Best 73, Markus =20 -----Urspr=C3=BCngliche Mitteilung-----=20 Von: Lubos OK2BVG An: _RSGB_LF Verschickt: Mi, 28 Mrz 2012 4:24 am Betreff: RE: VLF: DF6NM on 8970.002 Hello Markus, VLF!=20 Your signal is nice visible on my grabber in QRSS6000 and traces in QRSS600= . In the 6000 window is evident, that we did our VLF QSO in time, when the = noise conditions were not the best.=20 I have written an article about our qso in Czech. It will be publised in a = ham magazine "Radioamater", common known in The Czech and Slovak republic. = Some hams would be encouraged to find VLF band by the report. :-) 73! Lubos, OK2BVG To: rsgb_lf_group@blacksheep.org From: markusvester@aol.com Date: Tue, 27 Mar 2012 17:22:42 -0400 Subject: VLF: DF6NM on 8970.002 It's a beautiful night! At 20:25, I have started up a straight carrier on 8= 970.002 Hz (DHO locked). If all stays well I will leave it on until after s= unrise. =20 An interesting observation on the side: In the first few minutes, I drove t= he amp up to 400 mA antenna current. A little corona became visible near th= e ends of two of the three topload wires - it wasn't very bright, not unlik= e 3rd magnitude stars when viewed from the ground 10 m below. But the 9 kHz= sound from antenna itself could be heard quite loudly, which is a potentia= l cause for neighbourhood trouble.=20 =20 Then I reduced the drive to 350 mA where the corona disappeared completely.= So did the noise, the antenna became absolutely quiet! All that was left w= as a little noise from the coil in the dustbin on the balcony, and the tran= sformer indoors. Thus the predominant cause for a squeaking antenna must be= corona. The fact that it can be heard at 9 rather than 18 kHz demonstrates= that the discharge must have an asymmetric dependence on the voltage polar= ity. =20 At the same time, wideband electrical noise on the nearby LF grabber antenn= a went down by 20 dB.=20 =20 BTW If you like you can actually read my VLF frequency from an alias line o= n the LF TA grabber: It is created by the 24th VLF harmonic, intermodulatin= g with DCF 77, thus appearing on 24 x 8970.002 - 77500 =3D 137780.048 Hz. =20 Best regards, Markus (DF6NM) ----------MB_8CEDB46E29724D5_C48_34D23_webmail-d032.sysops.aol.com Content-Transfer-Encoding: quoted-printable Content-Type: text/html; charset="utf-8"
Thanks very much for the interest, and to Chris 'WCD for the exce= llent capture. As the WX is still dry and calm here, I have put the TX back= on at 21 UT for another night, with the same parameters as before.
 
My ERP is a bit uncertain, as I haven't measured the effect of environ= mental shielding on antenna height at VLF. My best guess is somewhere = around 7 to 9 meters, which would give around 90 microohms radiation r= esistance, or 10 =C2=B5W EMRP at 0.34 A. 
 
The notion of corona being responsible for the noise was sug= gested by the threshold-like onset of both visual and acoustical emissions.= I currently have only very rudimentary "corona rings", by bending the insu= lated wire into a couple of little loops at each end. I like Wolf's idea of= hanging up garden decoration balls, but I'm not sure whether the landlady = would find that an acceptable view ;-) Maybe I should look for clear s= emi-transparent ones, or even partly evacuate them to let them glow real pr= etty ;-)
 
BTW working back from the corona brightness one gets an optical power = of about 1 =C2=B5W in the visual range. Assuming that at this level the par= tial discharges are consuming on the order of 10% of the TX power, we find = that the efficiency of light generation is only some 0.1 ppm - si= milar to te efficiency of the whole antenna for VLF radiation ;-)
 
Regarding the noise from the coil, I had originally thought that it mi= ght be caused by Lorentz forces in Earth's static field. This gave the=  idea to cancel the field and thus the noise by permanent ma= gnets mounted appropriately in the coil's vicinity. But this never worked, = the magnetic effect turned out to be much too weak to explain the level of = 9 kHz noise. Now I think that it is more likely an electrostatic = effect from the large AC voltage, combined with static charg= e buildup on the plastic surfaces. And there is a strong smell of ozone ins= ide of the dustbin after transmitting a while, so there is certai= nly some degree of partial discharges around the coil buckets.
 
Best 73,
Markus (DF6NM)
= -----Urspr=C3=BCngliche Mitteilung-----
Von: Stefan Sch=C3=A4fer <Stefan.Schaefer@iup.uni-heidelberg.de>
An: rsgb_lf_group <rsgb_lf_group@blacksheep.org>
Verschickt: Mi, 28 Mrz 2012 10:27 am
Betreff: Re: VLF: DF6NM on 8970.002

Hi Markus,

Nice work! I can see you in 424 uHz, and traces in 4.5 mHz. You leave a str= ong trace in 47 uHz, at exactly 8970.0020 Hz! Very nice.
I can see QSB on your signal in that 174 km distance.
What is the ERP?

Go on! :-)

73, Stefan/DK7FC

http://www.iup.uni-heid= elberg.de/schaefer_vlf/DK7FC_VLF_Grabber.html

PS: Lubos, really an excellent Grabber!!




Am 28.03.2012 09:08, schrieb Chris Dillon:=20
Hi Markus
Good signals here too in 424uHz and 125uHz (peaking 10dB over the noise) al= ongside Henny and Uwe.
Nice to see VLF busy!

73 Chris G3WCD


On 28/03/2012 07:50, Markus Vester wrote:=20
The carrier was on air continuously from 20:26 to 6:36 this = morning.
 
Thanks very much to Lubos, as well as to all other live grabber o= perators. As far as I can see, traces appeared at DK7FC, G3ZJO, OK2BVG= , and Paul Nicholson.
Best 73,
Markus
 
= -----Urspr=C3=BCngliche Mitteilung-----
Von: Lubos OK2BVG <bvgbob@hotmail.com>
An: _RSGB_LF <rsgb_lf_group@blacksheep.org>
Verschickt: Mi, 28 Mrz 2012 4:24 am
Betreff: RE: VLF: DF6NM on 8970.002

Hello Markus, VLF!=20
Your signal is nice visible on my grabber in QRSS6000 and traces in QR= SS600. In the 6000 window is evident, that we did our VLF QSO in time, when= the noise conditions were not the best. 
I have written an article about our qso in Czech. It will be publised = in a ham magazine "Radioamater", common known in The Czech and Slovak repub= lic. Some hams would be encouraged to find VLF band by the report. :-)

73!

Lubos, OK2BVG

To: rsgb_lf_group@blackshee= p.org
From: markusvester@aol.com
Date: Tue, 27 Mar 2012 17:22:42 -0400
Subject: VLF: DF6NM on 8970.002

It's a beautiful night! At 20:25, I have started up a straight carrier= on 8970.002 Hz (DHO locked). If all stays well I will leave it on until af= ter sunrise.
 
An interesting observation on the side: In the first few minutes, I dr= ove the amp up to 400 mA antenna current. A little corona became visible ne= ar the ends of two of the three topload wires - it wasn't very bright, not = unlike 3rd magnitude stars when viewed from the ground 10 m below. But= the 9 kHz sound from antenna itself could be heard quite loudly, whic= h is a potential cause for neighbourhood trouble.
 
Then I reduced the drive to 350 mA where the corona disappeared comple= tely. So did the noise, the antenna became absolutely quiet! All that = was left was a little noise from the coil in the dustbin on the balcon= y, and the transformer indoors. Thus the predominant cause for a squea= king antenna must be corona. The fact that it can be heard at 9 rather= than 18 kHz demonstrates that the discharge must have = an asymmetric dependence on the voltage polarity.
 
At the same time, wideband electrical noise on the nearby LF grabber a= ntenna went down by 20 dB.
 
BTW If you like you can actually read my VLF frequency from an&nb= sp;alias line on the LF TA grabber: It is created by the 24th VLF harmonic,= intermodulating with DCF 77, thus appearing on 24 x 8970.002 - 7= 7500 =3D 137780.048 Hz.
 
Best regards,
Markus (DF6NM)

 ----------MB_8CEDB46E29724D5_C48_34D23_webmail-d032.sysops.aol.com--