Return-Path: X-Spam-DCC: paranoid 1290; 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=-1.7 required=5.0 tests=BAYES_00,DNS_FROM_AHBL_RHSBL, HTML_40_50,HTML_MESSAGE,HTML_TITLE_EMPTY autolearn=no 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 t5QMgx4i000651 for ; Sat, 27 Jun 2015 00:43:00 +0200 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1Z8cHs-0001eV-Ov for rs_out_1@blacksheep.org; Fri, 26 Jun 2015 23:39:56 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1Z8cHs-0001eM-6u for rsgb_lf_group@blacksheep.org; Fri, 26 Jun 2015 23:39:56 +0100 Received: from omr-m1.mx.aol.com ([64.12.224.134]) by relay1.thorcom.net with esmtps (TLSv1:DHE-RSA-AES256-SHA:256) (Exim 4.85) (envelope-from ) id 1Z8cHp-0008CO-NR for rsgb_lf_group@blacksheep.org; Fri, 26 Jun 2015 23:39:55 +0100 Received: from mtaout-aaj01.mx.aol.com (mtaout-aaj01.mx.aol.com [172.27.3.205]) by omr-m1.mx.aol.com (Outbound Mail Relay) with ESMTP id 9E7F838000065 for ; Fri, 26 Jun 2015 18:39:51 -0400 (EDT) Received: from White (ipb21bee4a.dynamic.kabel-deutschland.de [178.27.238.74]) by mtaout-aaj01.mx.aol.com (MUA/Third Party Client Interface) with ESMTPA id 95BA338000085 for ; Fri, 26 Jun 2015 18:39:48 -0400 (EDT) Message-ID: From: "Markus Vester" To: References: <8D27C7D3E7D6748-14A8-F71B3@webmail-vm149.sysops.aol.com> <558D8FEC.2090102@posteo.de> <7D39EA36066C485998744D9E994DAC52@White> <558DC2A1.2040608@posteo.de> Date: Sat, 27 Jun 2015 00:39:46 +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=20150623; t=1435358391; bh=4Nh+nqWn3Qp9LrBuCg/64lTu5E0M58m4MWHqksW9XAM=; h=From:To:Subject:Message-ID:Date:MIME-Version:Content-Type; b=Oo+Sm5c7NmtuZyTbN2geSSYSKVtQt2hiuwb7BqJJmW1g1ZGbTPO52MFVqBSk99mbr Vl8OZDNeh6dvjF5Inw7WCuilePH2pNgZBKzOFjMjrqZLBtiJgeJq2WAgmEY9+e17W1 fTQNJC0+X6JDcQoQBT+jG66mWagHOY3hrXfwAV+4= x-aol-sid: 3039ac1b03cd558dd4b4046a X-AOL-IP: 178.27.238.74 X-Scan-Signature: 059065dc6500ac08f691f2dd07d4538f Subject: LF: Heidelberg remote MF receiver Content-Type: multipart/alternative; boundary="----=_NextPart_000_0006_01D0B071.C48B4940" 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: 3537 Dies ist eine mehrteilige Nachricht im MIME-Format. ------=_NextPart_000_0006_01D0B071.C48B4940 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Hi Stefan, it looks like signals are consistently better on your remote receiver, = perhaps around 6 dB or something in that ballpark. So it seems that all = your work is finally paying off! I'm looking forward to see a daytime = comparison tomorrow. My guess is that the main contributor to frequency variation would be = the 461 kHz LO crystal rather than the soundcard samplerate. Anyway = exchanging the 12 MHz crystal may possibly have no effect at all, = because the samplerate of USB soundcards is usually derived from the bus = master clock (ie the RasPi) and not from the internal crystal on the = dongle.=20 Best 73, Markus (DF6NM) From: DK7FC=20 Sent: Friday, June 26, 2015 11:22 PM To: rsgb_lf_group@blacksheep.org=20 Subject: Re: LF: 476.181 kHz from indoor loop Hi Markus,=20 Really? Wonderful! :-) And the stream is still running. I'll watch it = some days now to see if all Raspi problems are gone, then the next = part-project is the RX. Meanwhilethe sky wave is present and i can see you quite strong in = DFCW-30 with your 3 mW ERP from the loop. I missed watching you on the = remote grabber in daytime. What was the SNR ralative to the city = location? Same or better? I switched back to the T antenna in the = afternoon. It would be interesting so see you on my loop. On 21:19 i = switched to the loop! Ah and now you can see the drift of my RX which is quite visible, but = still uncritical for QRSS-30 or WSPR. I thought about changing the 12 MHz xtal of the soundcard. It is the = cheap SMD xtal which has 100 ppm/K but there are other versions with 30 = ppm/K. Maybe an idea, they are no expensive and still compact... 73, Stefan Am 26.06.2015 21:04, schrieb Markus Vester:=20 Hi Stefan, good to see the remote station working nicely now. >> but don't see you ...yes you do ;-) There is a slight frequency offset in the remote = grabber which had put me out of your QRSS-30 band. I now switched to my = "heritage" QRG 136172.5 ahem 476172.5 Hz, and voila there it is, loud = and clear. Currently still on the low Marconi, also about 2 mW EMRP. The = relatively strong coupling to the LF grabber E-field antenna produced = some aliases and noise there, which have been mitigated by a 475 kHz = Saugkreis (trap) - same as in old AM radios ;-)=20 73, Markus From: DK7FC=20 Sent: Friday, June 26, 2015 7:46 PM To: rsgb_lf_group@blacksheep.org=20 Subject: Re: LF: 476.181 kHz from indoor loop Hi Markus,=20 Thanks for your DFCW-30 transmission. I can see you clearly in daytime = on my RX in the city! However i can't see you on my RX is the garden! = The remote system seems to run stable now, at least for a longer time = then in the last 3 days :-)=20 = http://www.iup.uni-heidelberg.de/schaefer_vlf/DK7FC_remote_Grabber.html I switched between a T antenna and a loop beaming 300/120 deg but = don't see you. It appears that the hill between us is (my garden is on = the hill side, the city antenna is more distant to the hill) actually = reducing the SNR. So it also reduces QRN from the east and favours the = west. But i would prefer an omnidirectional pattern :-/ 73, Stefan Am 24.06.2015 12:11, schrieb Markus Vester:=20 I am currently running a DFCW-60 beacon on 476.181 kHz, using the = same 10m^2 indoor transmit loop as previously on LF. With 35 Watts of RF = input, estimated radiated power is around 2 mW, with lobes pointing west = and east. The daytime groundwave signal is visible in the bottom panel of the = DK7FC MF grabber. Going by the CCIR plots for 3 mS/m conductivity, the = groundwave attenuation for this distance would be about 23 dB in excess = off lossless 1/r propagation, resulting in approximately 0.2 uV/m in = Heidelberg.=20 Best 73, Markus (DF6NM) ------=_NextPart_000_0006_01D0B071.C48B4940 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Hi Stefan,
 
it looks like signals are = consistently better=20 on your remote receiver, perhaps around 6 dB or something in that = ballpark.=20 So it seems that all your work is finally paying off! I'm = looking=20 forward to see a daytime comparison tomorrow.
 
My guess is that the main contributor = to frequency=20 variation would be the 461 kHz LO crystal rather than the soundcard = samplerate.=20 Anyway exchanging the 12 MHz crystal may possibly have no effect at all, = because=20 the samplerate of USB soundcards is usually derived = from the bus=20 master clock (ie the RasPi) and not from the internal crystal on the=20 dongle. 
 
Best 73,
Markus (DF6NM)
 

From: DK7FC
Sent: Friday, June 26, 2015 11:22 PM
Subject: Re: LF: 476.181 kHz from indoor = loop

Hi=20 Markus,

Really? Wonderful! :-) And the stream is still running. = I'll=20 watch it some days now to see if all Raspi problems are gone, then the = next=20 part-project is the RX.
Meanwhilethe sky wave is present and i can = see you=20 quite strong in DFCW-30 with your 3 mW ERP from the loop. I missed = watching you=20 on the remote grabber in daytime. What was the SNR ralative to the city=20 location? Same or better? I switched back to the T antenna in the = afternoon. It=20 would be interesting so see you on my loop. On 21:19 i switched to the=20 loop!
Ah and now you can see the drift of my RX which is quite = visible, but=20 still uncritical for QRSS-30 or WSPR.

I thought about changing = the 12 MHz=20 xtal of the soundcard. It is the cheap SMD xtal which has 100 ppm/K but = there=20 are other versions with 30 ppm/K. Maybe an idea, they are no expensive = and still=20 compact...

73, Stefan

Am 26.06.2015 21:04, schrieb Markus = Vester:=20
Hi Stefan,
 
good to = see the remote=20 station working nicely now.
 
>> but don't see = you
 
...yes you do ;-) There is = a slight=20 frequency offset in the remote grabber which had put me out = of your=20 QRSS-30 band. I now switched to my = "heritage" QRG 136172.5 ahem=20 476172.5 Hz, and voila there it is, loud and clear.
 
Currently still on the low = Marconi, also=20 about 2 mW EMRP.  The relatively strong coupling to = the LF=20 grabber E-field antenna produced some aliases and noise there, = which have=20 been mitigated by a 475 kHz Saugkreis (trap) - same as in old AM = radios=20 ;-)
 
 73, Markus
 

From: DK7FC
Sent: Friday, June 26, 2015 7:46 PM
Subject: Re: LF: 476.181 kHz from indoor = loop

Hi Markus,

Thanks for your DFCW-30 = transmission. I can=20 see you clearly in daytime on my RX in the city! However i can't see = you on my=20 RX is the garden! The remote system seems to run stable now, at least = for a=20 longer time then in the last 3 days :-)
http://www.iup.uni-heidelberg.de/schaefer_vlf/DK= 7FC_remote_Grabber.html
I=20 switched between a T antenna and a loop beaming 300/120 deg but don't = see you.=20 It appears that the hill between us is (my garden is on the hill side, = the=20 city antenna is more distant to the hill) actually reducing the SNR. = So it=20 also reduces QRN from the east and favours the west. But i would = prefer an=20 omnidirectional pattern :-/

73, Stefan

Am 24.06.2015 = 12:11,=20 schrieb Markus Vester:=20
I am currently running a DFCW-60 beacon on 476.181 kHz, = using=20 the same 10m^2 indoor transmit loop as previously on LF. With = 35 Watts=20 of RF input, estimated radiated power is around 2=20 mW, with lobes pointing west and east.
 
The daytime groundwave signal is visible in the bottom panel of = the=20 DK7FC MF grabber. Going by the CCIR plots for 3 mS/m = conductivity, the=20 groundwave attenuation for this distance would be about 23 dB in = excess off=20 lossless 1/r propagation, resulting in approximately 0.2 uV/m in=20 Heidelberg. 
 
Best 73,
Markus (DF6NM)

 
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