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: : mailn 1480; 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 v75JAWt1013181 for ; Sat, 5 Aug 2017 21:10:33 +0200 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1de4I0-0003iF-L3 for rs_out_1@blacksheep.org; Sat, 05 Aug 2017 19:59:08 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1de4Gv-0003i4-FT for rsgb_lf_group@blacksheep.org; Sat, 05 Aug 2017 19:58:01 +0100 Received: from resqmta-ch2-08v.sys.comcast.net ([2001:558:fe21:29:69:252:207:40]) by relay1.thorcom.net with esmtps (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.89) (envelope-from ) id 1de4Gn-0000ba-CP for rsgb_lf_group@blacksheep.org; Sat, 05 Aug 2017 19:57:58 +0100 Received: from resomta-ch2-06v.sys.comcast.net ([69.252.207.102]) by resqmta-ch2-08v.sys.comcast.net with ESMTP id e4GUdxVixc9BRe4GhdsFUG; Sat, 05 Aug 2017 18:57:47 +0000 X-DKIM-Result: Domain=comcast.net Result=Signature OK DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=comcast.net; s=q20161114; t=1501959467; bh=V90pOJ9mRMJMb74vbBiYXHwq4ccolYdCoN0t8YMRmaY=; h=Received:Received:From:To:Subject:Date:Message-ID:MIME-Version: Content-Type; b=Jwu+khrgCgxlAdOe4o/Hj9kp+cTvfUnP4XLvPXxJBC1I6QzmKzNI6UEv14RtkZj7o Lq8JNk6qVPUad1tjW7geU8y6AhIMjKO1bWK/vWDhrKRn0U2adByG6Xju30YIxBLKAt rHpkoSbh16v2bg4NJ5Gt3A0m5yFeLRRppOfacQ6YSWX4moeRfAgrOY4+bsnBlAuLDZ kuXIfUkiIKAfQGkGQpRQufQZFATlQ95sdNv2FDlisDIGEolDnIwSa9C3GRMKAK0qE0 YjEKIwKAWMOWSLYcqBKmCp3R+zuYjCjj2FDpE7ASS42Q023HW8cEc2V/tCN3nuIVG1 MBFZErrMQWJCQ== Received: from Owner ([IPv6:2601:140:8500:7f9f:78f6:dd:b547:d008]) by resomta-ch2-06v.sys.comcast.net with SMTP id e4GfdOh78rV3qe4Ggdm9Nc; Sat, 05 Aug 2017 18:57:46 +0000 From: To: References: <59858CB7.3000202@posteo.de> <15db2643c6f-5f13-23c2@webprd-m101.mail.aol.com> In-Reply-To: <15db2643c6f-5f13-23c2@webprd-m101.mail.aol.com> Date: Sat, 5 Aug 2017 14:57:22 -0400 Message-ID: <014301d30e1c$b777ef00$2667cd00$@comcast.net> MIME-Version: 1.0 X-Mailer: Microsoft Outlook 14.0 Thread-Index: AQI64EdckNeIHpQIiDs6ajr//MCSIqGmZGpQ Content-Language: en-us X-CMAE-Envelope: MS4wfG7P/hxXevw4AWSFbdqgT0M8UwYmw+s6X9lxTRA+EZokUnAwwe7YZPxeVbFjhSf9zEg5osT6e7iEYUO/tm7OmE2BdAgnXPqHUMeUURuveD2LJ7D6q//R mQL44NbDMvpFhMMFBlUpHs2qXPzgyp5lbVY= X-Scan-Signature: a5eebf1400afcbaf7aee821a75970899 Subject: RE: VLF: Carrier on 3675.005 Hz Content-Type: multipart/alternative; boundary="----=_NextPart_000_0144_01D30DFB.306898F0" 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: RO X-Status: X-Keywords: X-UID: 12338 This is a multipart message in MIME format. ------=_NextPart_000_0144_01D30DFB.306898F0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Congratulations Stefan, Markus and DL0AO team! =20 Is this the first far-field link between 3.000 kHz and 4.000 kHz? =20 Another great data point in the previously uncharted and rough terrain = of 2 kHz - 4 kHz, 100 km - 1000 km. =20 Analytical and computational estimates of path loss 2 kHz - 4 kHz, 100 = km - 1000 km are at best somewhat (to considerably) speculative for lack = of data, so I=E2=80=99d venture that the DK7FC/DF6NM/DL0AO team, and all = those who provided receivers, transmitters and processing for prior = tests 2 kHz - 6 kHz*, 100 km - 1000 km, have done valuable pioneering = work. =20 (great work in hardware and processing, and especially pioneering work = in characterization of propagation in a little-understood and = not-too-friendly propagation realm 2 kHz - 4 kHz, 100 km - 1000 km) =20 >From a spectator=E2=80=99s perspective this is very exciting. =20 =20 * (5 kHz and 6 kHz tests helping to assess an upper boundary for the = complicated 2 kHz - 4 kHz, 100 km - 1000 km space)=20 (Much credit also to transmitter, receiver and processing work at = 970 Hz making the interesting sub-kHz world accessible) =20 =20 =20 Jim AA5BW =20 =20 =20 From: owner-rsgb_lf_group@blacksheep.org = [mailto:owner-rsgb_lf_group@blacksheep.org] On Behalf Of Markus Vester Sent: Saturday, August 5, 2017 8:35 AM To: rsgb_lf_group@blacksheep.org Subject: Re: VLF: Carrier on 3675.005 Hz =20 Yes the signal is definitely making it to Amberg! This is a fine result = of mutual collaboration: Stefan DK7FC erecting the transmit facility and = posing the low frequency challenge, the DL0AO team (specifically Tom = DK1IS and Bernd DF9RB) laying out antennas in a quiet forest around = their club station and installing dedicated hardware, and myself trying = to tame 14 SpecLab instances without introducing too many errors. The first indication of a 3675.005 Hz peak appeared already a couple of = days ago on the E-probe antenna, and is still shown in the ultra-narrow = 9.3 uHz window (waiting to be updated later tonight). Since yesterday, = antenna and GPS connections have been greatly optimized, and the 31 uHz = peak appeared early this morning after "only" 9 hours of averaging.=20 Best 73, Markus (DF6NM) -----Urspr=C3=BCngliche Mitteilung-----=20 Von: DK7FC An: rsgb_lf_group Verschickt: Sa, 5. Aug 2017 11:17 Betreff: Re: VLF: Carrier on 3675.005 Hz VLF,=20 After nearly 8 days the carrier is still on the air without an = interruption, despite occasional thunderstorms :-) It looks like the SNR is suffering by summer QRN, as expected.=20 The stable carrier was good for doing local tests with my = Raspi+Octo-soundcard. The system is now completely configured including = system time setting via the GPS module. I recorded a few days from the = carrier, converted the data files into wav, reprocessed them in SpecLab: = The carrier is stable and on the expected frequency, so the sample rate = correction via vlfrx tools seems to work. Forthermore i corrected some bugs in the circuit of my portable RX loop = preamp for VLF (must have been late in the night when i built it up a = few months ago). Now the noise is much lower. It looks promising! So it = is time for a portable VLF experiment in the far field, just to check = the system more seriously. The crew of DL0AO has built up and optimised their VLF system to receive = the weak 3675.005 Hz carrier in abt 220 km distance. Looks like there is = something on their cardioidal spectrogram pointing to West,=20 http://df6nm.bplaced.net/dl0ao/VLFgrabber/vlfgrabber_dl0ao_test.htm Something like 10 dB SNR in 31 uHz. That's not so bad! I will run it for some more time until the trace is a bit longer. Then = in some days i like to start transmitting an EbNaut message on that = frequency which can be stacked until a decode appears. Markus has = developed a tool for windows to do the stacking, maybe it works in that = experiment... It will also be a test to see if i can decode the message = from my own recording using vlfrx tools, an important step to pass... So far so good. What are YOUR projects you are currently working on, = LF/MF/VLF related? 73, Stefan Am 28.07.2017 16:56, schrieb DK7FC:=20 Hi VLF,=20 I'm back from LF for a while and built up my large VLF coil which was = used on 2970 Hz in the beginning of the year. Actually it is under = maintenance, one of the six stacks has to be replaced. It is already = dismantled but the new wire is not yet wound on the 250 mm diameter PVC = tube again.=20 So now the resonance is higher! I didn't know where it is and just = connected the coil and scanned the frequency downwards. Near 3685 Hz i = found a maximum of the antenna. Since the Q is not extremely high, i = decided to tune to 3675 Hz and added the usual 5 mHz offset, to stay = away from multiples of 1 Hz.=20 So, now since 14:40 UTC a carrier is running on 3675.005 Hz. The antenna = current is 170 mA. I estimate the ERP is just 3 uW! I guess this is a first amateur radio transmission on the 82 km band and = that class of ERP (?). Hopefully the coil will hold the 15.5 kV with just 5 stacks of windings. = It's inductance is 3.9 H in the moment! I intend to run the carrier for at least a few days, depending on the = feedback. Good luck for the VLF experts! 73, Stefan PS: A 424 uHz RDF spectrogram is running at = http://www.iup.uni-heidelberg.de/schaefer_vlf/DK7FC_VLF_Grabber2.html = (First pixel appears in 30 minutes) ------=_NextPart_000_0144_01D30DFB.306898F0 Content-Type: text/html; charset="utf-8" Content-Transfer-Encoding: quoted-printable

Congratulations Stefan, Markus and DL0AO = team!

 

Is this the first far-field link between 3.000 kHz and 4.000 = kHz?

 

Another great data point in the previously uncharted and rough = terrain of 2 kHz - 4 kHz, 100 km - 1000 km.

 

Analytical and computational estimates of path loss 2 kHz - 4 kHz, = 100 km - 1000 km are at best somewhat (to considerably) speculative for = lack of data, so I=E2=80=99d venture that the DK7FC/DF6NM/DL0AO team, = and all those who provided receivers, transmitters and processing for = prior tests 2 kHz - 6 kHz*, 100 km - 1000 km, have done valuable = pioneering work.

 

(great work in hardware and processing, and especially pioneering = work in characterization of propagation in a little-understood and = not-too-friendly propagation realm 2 kHz - 4 kHz, 100 km - 1000 = km)

 

From a spectator=E2=80=99s perspective this is very = exciting.

 

 

=C2=A0=C2=A0 *=C2=A0 (5 kHz and 6 kHz tests helping to assess an = upper boundary for the complicated 2 kHz - 4 kHz, 100 km - 1000 km = space)

=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0(Much credit also to = transmitter, receiver and processing work at 970 Hz making the = interesting sub-kHz world accessible) =C2=A0

 

 

Jim AA5BW

 

 

 

From:= = owner-rsgb_lf_group@blacksheep.org = [mailto:owner-rsgb_lf_group@blacksheep.org] On Behalf Of Markus = Vester
Sent: Saturday, August 5, 2017 8:35 AM
To: = rsgb_lf_group@blacksheep.org
Subject: Re: VLF: Carrier on = 3675.005 Hz

 

Y= es the signal is definitely making it to Amberg! This is a fine result = of mutual collaboration: Stefan DK7FC erecting the transmit = facility and posing the low frequency challenge, the DL0AO team = (specifically Tom DK1IS and Bernd DF9RB) laying out antennas in a = quiet forest around their club station and installing dedicated = hardware, and myself trying to tame 14 SpecLab = instances without introducing too many errors.

The first = indication of a 3675.005 Hz peak appeared already a couple = of days ago on the E-probe antenna, and is still shown in = the ultra-narrow 9.3 uHz window (waiting to be updated later = tonight). Since yesterday, antenna and GPS connections have been = greatly optimized, and the 31 uHz peak appeared early this morning = after "only" 9 hours of averaging.

Best = 73,
Markus (DF6NM)


-----Urspr=C3=BCngliche Mitteilung----- =
Von: DK7FC <selberdenken@posteo.de>
= An: rsgb_lf_group <rsgb_lf_group@blacksheep.org= >
Verschickt: Sa, 5. Aug 2017 11:17
Betreff: Re: VLF: = Carrier on 3675.005 Hz

V= LF,

After nearly 8 days the carrier is still on the air without = an interruption, despite occasional thunderstorms :-)
It looks like = the SNR is suffering by summer QRN, as expected.

The stable = carrier was good for doing local tests with my Raspi+Octo-soundcard. The = system is now completely configured including system time setting via = the GPS module. I recorded a few days from the carrier, converted the = data files into wav, reprocessed them in SpecLab: The carrier is stable = and on the expected frequency, so the sample rate correction via vlfrx = tools seems to work.

Forthermore i corrected some bugs in the = circuit of my portable RX loop preamp for VLF (must have been late in = the night when i built it up a few months ago). Now the noise is much = lower. It looks promising! So it is time for a portable VLF experiment = in the far field, just to check the system more seriously.

The = crew of DL0AO has built up and optimised their VLF system to receive the = weak 3675.005 Hz carrier in abt 220 km distance. Looks like there is = something on their cardioidal spectrogram pointing to West,
http://df6nm.bplaced.net/dl0ao/VLFgrabber/vlfgrabber_dl= 0ao_test.htm
Something like 10 dB SNR in 31 uHz. That's not so = bad!

I will run it for some more time until the trace is a bit = longer. Then in some days i like to start transmitting an EbNaut message = on that frequency which can be stacked until a decode appears. Markus = has developed a tool for windows to do the stacking, maybe it works in = that experiment... It will also be a test to see if i can decode the = message from my own recording using vlfrx tools, an important step to = pass...

So far so good. What are YOUR projects you are currently = working on, LF/MF/VLF related?

73, Stefan


Am = 28.07.2017 16:56, schrieb DK7FC:

H= i VLF,

I'm back from LF for a while and built up my large VLF = coil which was used on 2970 Hz in the beginning of the year. Actually it = is under maintenance, one of the six stacks has to be replaced. It is = already dismantled but the new wire is not yet wound on the 250 mm = diameter PVC tube again.
So now the resonance is higher! I didn't = know where it is and just connected the coil and scanned the frequency = downwards. Near 3685 Hz i found a maximum of the antenna. Since the Q is = not extremely high, i decided to tune to 3675 Hz and added the usual 5 = mHz offset, to stay away from multiples of 1 Hz.

So, now = since 14:40 UTC a carrier is running on 3675.005 Hz. The = antenna current is 170 mA. I estimate the ERP is just 3 = uW!

I guess this is a first amateur radio transmission on the = 82 km band and that class of ERP (?).

Hopefully the coil = will hold the 15.5 kV with just 5 stacks of windings. It's = inductance is 3.9 H in the moment!

I intend to run the = carrier for at least a few days, depending on the feedback.

Good = luck for the VLF experts!

73, Stefan

PS: A 424 uHz RDF = spectrogram is running at http://www.iup.uni-heidelberg.de/schaefer_vlf/DK7FC_VLF= _Grabber2.html (First pixel appears in 30 = minutes)

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