Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on lipkowski.org X-Spam-Level: X-Spam-Status: No, score=0.0 required=5.0 tests=FREEMAIL_FORGED_FROMDOMAIN, FREEMAIL_FROM,HEADER_FROM_DIFFERENT_DOMAINS,HTML_MESSAGE,SPF_PASS, T_DKIM_INVALID,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 X-Spam-DCC: wuwien: mailn 1290; Body=2 Fuz1=2 Fuz2=2 Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by lipkowski.org (8.14.4/8.14.4/Debian-8+deb8u2) with ESMTP id v7LCvmGG011171 for ; Mon, 21 Aug 2017 14:57:49 +0200 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1djmDP-0008Az-No for rs_out_1@blacksheep.org; Mon, 21 Aug 2017 13:53:59 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1djmDP-0008Aq-4v for rsgb_lf_group@blacksheep.org; Mon, 21 Aug 2017 13:53:59 +0100 Received: from omr-m018e.mx.aol.com ([204.29.186.17]) by relay1.thorcom.net with esmtps (TLSv1:DHE-RSA-AES256-SHA:256) (Exim 4.89) (envelope-from ) id 1djmDI-0001eO-Oc for rsgb_lf_group@blacksheep.org; Mon, 21 Aug 2017 13:53:57 +0100 Received: from mtaomg-aaf02.mx.aol.com (mtaomg-aaf02.mx.aol.com [172.26.127.100]) by omr-m018e.mx.aol.com (Outbound Mail Relay) with ESMTP id 8CEDA3800040 for ; Mon, 21 Aug 2017 08:53:50 -0400 (EDT) Received: from core-acb02c.mail.aol.com (core-acb02.mail.aol.com [172.27.24.2]) by mtaomg-aaf02.mx.aol.com (OMAG/Core Interface) with ESMTP id 49BB638000081 for ; Mon, 21 Aug 2017 08:53:50 -0400 (EDT) Received: from 188.192.44.165 by webjas-vab238.srv.aolmail.net (10.96.18.241) with HTTP (WebMailUI); Mon, 21 Aug 2017 08:53:50 -0400 Date: Mon, 21 Aug 2017 08:53:50 -0400 From: Markus Vester To: rsgb_lf_group@blacksheep.org Message-Id: <15e04db3b5a-c05-4e12@webjas-vab238.srv.aolmail.net> In-Reply-To: <15e04da1bc1-c03-90c@webjas-vad055.srv.aolmail.net> MIME-Version: 1.0 X-MB-Message-Source: WebUI X-MB-Message-Type: User X-Mailer: JAS STD X-Originating-IP: [188.192.44.165] x-aol-global-disposition: G DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=mx.aol.com; s=20150623; t=1503320030; bh=TueupcvhrFIWZKBp/aOSilkEGdW33fSAG/BpyK7TCkA=; h=From:To:Subject:Message-Id:Date:MIME-Version:Content-Type; b=ygcPeeAdNxbHMI4tdRNylMo5igvDA42FBq7l8CGft8jVUOYGk6KUYMSiRWdEy9JWH UN9lwP1VE0Mzlg0Af9xzUvaseIEDi/SggDhiiDC1HJL60e3rZjB2a3RiN1+BCREcQA sk8lao9vW0lwk0/xf2WxxD7srs9Eiv982C2JMCSI= x-aol-sid: 3039ac1a7f64599ad7de2a32 X-Scan-Signature: 14522a7d8bfffcae5e92e35059f18ae1 Subject: Re: VLF: Carrier on 4470.005 Hz! - fieldstrength comparison Content-Type: multipart/alternative; boundary="----=_Part_24603_646063697.1503320030041" 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 2.75 Status: O X-Status: X-Keywords: X-UID: 12423 ------=_Part_24603_646063697.1503320030041 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Comparing the peaks again in 31 uHz after 9 hours of carrier accumulation, = it looks like the level difference was only 7 to 8 dB, implying that the st= ated 2 dB propagation loss over 1/r is probably not true. The main source o= f error is the noise floor which is causing a significant uncertainty for a= mplitude measurements: Even for peak with 14 dB SNR ("five-sigma"), the sta= ndard deviation for the magnitude due to the in-phase noise component would= be 1/5/sqrt(2) =3D 0.14, implying an uncertainty range of -3 to +2 dB at 9= 5% confidence.=20 I also have some doubt now about my earlier result of +5.5 dB gain on 3675 = Hz, which was based on a 8270 Hz reference, more than an octave away. The l= evel of Stefan's peaks on 4470 and 3675 seemed to be quite similar, implyin= g that the difference between path losses would not be more than the ~ 2 dB= ERP difference.=20 Jim, any results yet from FDTD simulations of the 226 km W-E path? 73, Markus (DF6NM) =20 -----Urspr=C3=BCngliche Mitteilung-----=20 Von: Markus Vester An: rsgb_lf_group Verschickt: So, 20. Aug 2017 21:34 Betreff: Re: VLF: Carrier on 4470.005 Hz! - fieldstrength comparison This test is going surprisingly well. producing beautiful twin peaks on 447= 0.005 and 4470.0025 on the DL0AO grabber. It looks like my signal is about = 10 dB stronger there. Our antenna currents are similar today, but I guess t= he effective height and ERP are 5 to 6 dB higher at DK7FC. Thus propagation= between Heidelberg and Amberg would be 13.5 - 5.5 -10 =3D -2 dB with refer= ence to groundwave alone. This is somewhat surprising, given that a similar= (but probably less reliable) calculation for 3675 Hz had indicated a +5.5 = dB ionospheric gain. All the best, Markus (DF6NM) -----Urspr=C3=BCngliche Mitteilung-- Von: Markus Vester An: rsgb_lf_group Verschickt: So, 20. Aug 2017 15:37 Betreff: Re: VLF: Carrier on 4470.005 Hz! I have managed to resonate my antenna and started a carrier on 4470.0025 Hz= since 13:07 UT. Antenna current is 0.16 A into 8 m effective height. Hope = that it might also become visible on DL0AO, and perhaps provide an improved= calibration reference for propagation from Heidelberg. =20 Best 73, Markus -----Urspr=C3=BCngliche Mitteilung-----=20 Von: Markus Vester An: rsgb_lf_group Verschickt: So, 20. Aug 2017 11:11 Betreff: Re: VLF: Carrier on 4470.005 Hz! Hi Stefan, this morning, an unambiguous peak has come up on the DL0AO cardioid in 31 u= Hz:=20 http://df6nm.bplaced.net/dl0ao/VLFgrabber/vlfgrabber_dl0ao_test.htm The signal level (-140 dB) seems to be similar to that previously observed = on 3675 Hz (noting that the gain of the synthetic cardioid summation has si= nce been reduced by 6 dB to make it equal to the single antennas). We can = probably hope for improved SNR during the day. Well done again! Best 73, Markus (DF6NM) =20 -----Urspr=C3=BCngliche Mitteilung-----=20 Von: DK7FC An: rsgb_lf_group Verschickt: Sa, 19. Aug 2017 15:01 Betreff: Re: VLF: Carrier on 4470.005 Hz! ...Rather 5 uW. Am 19.08.2017 14:28, schrieb DK7FC:=20 Hello VLF,=20 I un-wound the defective stack of the large coil which was used for 2970 H= z. It took about 4 hours to carefully unwound about 1000 turns, or about 1 = km of wire. The wire will be used for new coils which are already planned. Now, the remaining 4 stacks should hold at least 15 kV. I connected the co= il to the antenna and found the resonance close to 4470 Hz.=20 Now i'm running (since 12 UTC) a carrier transmission on 4470.005 Hz. The = antenna current is just 150 mA. That's an ERP of about 3 uW. A first signal= on the 67 km band from here :-) Let's see how long it holds until there is the next fault :-/ Reports/Spectrograms welcome... As usual there is a monitoring of the signal in 3.5 km distance from my tr= ee grabber: http://www.iup.uni-heidelberg.de/schaefer_vlf/DK7FC_VLF_Grabber= 2.html 73, Stefan Am 13.08.2017 22:17, schrieb DK7FC:=20 The repetition of yesterdays message failed. At 15:38 UTC the safety functi= on tripped. I've just been on the roof, when re-starting the transmission i= can see a spark in the center of one of the stacks. So now there is anothe= r one which has a flash over! :-( It must be replaced, which is a lot of work. So the tranmissions on 3675 H= z will stopp for some time. At least we have some carrier detections and ev= en EbNaut decodes. I need to think about a different coil concept.... More current, more volt= age, more power, more more more! ------=_Part_24603_646063697.1503320030041 Content-Type: text/html; charset=utf-8 Content-Transfer-Encoding: quoted-printable
Comparing the peaks again in 31 uHz after 9 hours o= f carrier accumulation, it looks like the level difference was only 7 = to 8 dB, implying that the stated 2 dB propagation loss over 1/r is pr= obably not true. The main source of error is the noise floor which is&= nbsp;causing a significant uncertainty for amplitude measurements= : Even for peak with 14 dB SNR ("five-sigma"), the standard deviation = for the magnitude due to the in-phase noise component would be 1/= 5/sqrt(2) =3D 0.14, implying an uncertainty range of -3 to +2 dB = at 95% confidence. 

I also have some doubt now about= my earlier result of +5.5 dB gain on 3675 Hz, which was based on=  a 8270 Hz reference, more than an octave away. The level of= Stefan's peaks on 4470 and 3675 seemed to be quite similar, implying that = the difference between path losses would not be more than the ~ 2= dB ERP difference. 

Jim, any results yet from FDTD simula= tions of the 226 km W-E path?

73, Markus (DF6NM)
  &nbs= p; 


-----Urspr=C3=BCngliche Mitteilung-----
Von: Markus= Vester <markusvester@aol.com>
An: rsgb_lf_group <rsgb_lf_group@blacksheep.org>
Verschickt: So, 20. Aug 2017 21= :34
Betreff: Re: VLF: Carrier on 4470.005 Hz! - fieldstrength comparison=

This test is= going surprisingly well. producing beautiful twin peaks on 4470.005 and 44= 70.0025 on the DL0AO grabber. It looks like my signal is about 10 dB s= tronger there. Our antenna currents are similar today, but I guess the = ;effective height and ERP are 5 to 6 dB higher at DK7FC. Thus propagation&n= bsp;between Heidelberg and Amberg would be 13.5 - 5.5 -10 =3D -2 = dB with reference to groundwave alone. This is somewhat surprisin= g, given that a similar (but probably less reliable) calculation for 3675 H= z had indicated a +5.5 dB ionospheric gain.

All the best,
Markus = (DF6NM)


-----Urspr=C3=BCngliche Mitteilung--
Von: Markus Vest= er <markusvester@aol.com>
An: rsgb_lf_group <rsgb_lf_group@blacksheep.org>
Verschickt: So, 20.= Aug 2017 15:37
Betreff: Re: VLF: Carrier on 4470.005 Hz!

I ha= ve managed to resonate my antenna and started a carrier on 4= 470.0025 Hz since 13:07 UT. Antenna current is 0.16 A into 8 m effecti= ve height. Hope that it might also become visible on DL0AO, and perhap= s provide an improved calibration reference for propagation from Heide= lberg.  

Best 73,
Markus


-----Urspr=C3=BCngl= iche Mitteilung-----
Von: Markus Vester <markusvester@aol= .com>
An: rsgb_lf_group <rsgb_lf_group@blac= ksheep.org>
Verschickt: So, 20. Aug 2017 11:11
Betreff: Re: VL= F: Carrier on 4470.005 Hz!

Hi Stefan,

this morning, an unambiguous peak has come = up on the DL0AO cardioid in 31 uHz: 
http://df6nm.bplaced.net/dl0ao/VLFgrabber/vlfgrabber_d= l0ao_test.htm
The signal level (-140 dB) seems to be similar to= that previously observed on 3675 Hz (noting that the gain of the= synthetic cardioid summation has since been reduced by 6 dB to make it equ= al to the single antennas).  We can probably hope for improved SN= R during the day.

Well done again!

Best 73,
Markus (D= F6NM)   


-----Urspr=C3=BCngliche Mitteilung----- =
Von: DK7FC <selberdenken@posteo.de>
An: rsgb_= lf_group <rsgb_lf_group@blacksheep.org>
Ver= schickt: Sa, 19. Aug 2017 15:01
Betreff: Re: VLF: Carrier on 4470.005 Hz= !

...Rather 5 uW.

Am 19.08.2017 14:28, schrieb DK7FC:
=20 Hello VLF,

I un-wound the defective stack of the large coil which was used for 2970 Hz. It took about 4 hours to carefully unwound about 1000 turns, or about 1 km of wire. The wire will be used for new coils which are already planned.

Now, the remaining 4 stacks should hold at least 15 kV. I connected the coil to the antenna and found the resonance close to 4470 Hz.
Now i'm running (since 12 UTC) a carrier transmission on 4470.005 Hz= . The antenna current is just 150 mA. That's an ERP of about 3 uW. A first signal on the 67 km band from here :-)
Let's see how long it holds until there is the next fault :-/

Reports/Spectrograms welcome...

As usual there is a monitoring of the signal in 3.5 km distance from my tree grabber: http://www.iup.uni-heid= elberg.de/schaefer_vlf/DK7FC_VLF_Grabber2.html

73, Stefan

Am 13.08.2017 22:17, schrieb DK7FC:
=20 The repetition of yesterdays message failed. At 15:38 UTC the safety function tripped. I've just been on the roof, when re-starting the transmission i can see a spark in the center of one of the stacks. So now there is another one which has a flash over! :-(
It must be replaced, which is a lot of work. So the tranmissions on 3675 Hz will stopp for some time. At least we have some carrier detections and even EbNaut decodes.

I need to think about a different coil concept.... More current, more voltage, more power, more more more!
------=_Part_24603_646063697.1503320030041--