Return-Path: Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by klubnl.pl (8.14.4/8.14.4/Debian-8+deb8u2) with ESMTP id x04GgC3j013477 for ; Fri, 4 Jan 2019 17:42:23 +0100 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1gfSHe-0001ok-7p for rs_out_1@blacksheep.org; Fri, 04 Jan 2019 16:25:18 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1gfSFw-0001oT-Tq for rsgb_lf_group@blacksheep.org; Fri, 04 Jan 2019 16:23:32 +0000 Received: from mout02.posteo.de ([185.67.36.66]) by relay1.thorcom.net with esmtps (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.91_59-0488984) (envelope-from ) id 1gfSFt-0004eF-Vp for rsgb_lf_group@blacksheep.org; Fri, 04 Jan 2019 16:23:31 +0000 Received: from submission (posteo.de [89.146.220.130]) by mout02.posteo.de (Postfix) with ESMTPS id 50D032400E6 for ; Fri, 4 Jan 2019 17:23:28 +0100 (CET) X-DKIM-Result: Domain=posteo.de Result=Signature OK DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=posteo.de; s=2017; t=1546619008; bh=gbzXlpR4VaDK8Z8Vbb7qbzsplThlXqwiSAvrqU5JCoA=; h=Date:From:To:Subject:From; b=M5iwC+TOryBveSAgKwWGrH6dmUfQdkHcDjCA2J21ZVz5c1jsEQ2MffN+P0HD7inkR buprH4kg840bQUMnzSf3Cs2A29tw9+o5Zc2d23dmhzWMLhSiTb9ouAJ7rv4xbDUBaS NqWJexJZy6Qp7iMmJ/y7aX3aRBzqDr1EWe3/IE5TLzDDdNmYg2Bd9FZ/sJeyEbvOr9 RwfHuoamnnk7rPeQcvYTpNgu8PtDtV2MmfOlY8TUeNmAXmk6U/djnGpSqPg/XJ9DNZ 0CBEdio5t80BhRn2GXITXM5f45utPRcO5EQeSLViSXSfjpV44tKLR+ALtgj4nz9hu1 lDWR8YjR4yqIw== Received: from customer (localhost [127.0.0.1]) by submission (posteo.de) with ESMTPSA id 43WVTC51Qbz9rxK for ; Fri, 4 Jan 2019 17:23:27 +0100 (CET) Message-ID: <5C2F887F.6030705@posteo.de> Date: Fri, 04 Jan 2019 17:23:27 +0100 From: DK7FC User-Agent: Mozilla/5.0 (Windows; U; Windows NT 6.1; de; rv:1.9.1.8) Gecko/20100227 Thunderbird/3.0.3 MIME-Version: 1.0 To: rsgb_lf_group@blacksheep.org References: <82481776.12934664.1546608823719.ref@mail.yahoo.com> <82481776.12934664.1546608823719@mail.yahoo.com> In-Reply-To: <82481776.12934664.1546608823719@mail.yahoo.com> X-Spam-Score: -2.3 (--) X-Spam-Report: Spam detection software, running on the system "relay1.thorcom.net", has NOT identified this incoming email as spam. The original message has been attached to this so you can view it or label similar future email. If you have any questions, see @@CONTACT_ADDRESS@@ for details. Content preview: Hello Markus, Hm, skywave cancellation? Then this must happen quite quickly. I would rather expect a slower dSNR/dt, like we can see at the VLF MSK transmitters. But maybe you are right. So let's hope for some more [...] Content analysis details: (-2.3 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- -2.3 RCVD_IN_DNSWL_MED RBL: Sender listed at http://www.dnswl.org/, medium trust [185.67.36.66 listed in list.dnswl.org] -0.0 SPF_PASS SPF: sender matches SPF record 0.0 HTML_MESSAGE BODY: HTML included in message 0.0 T_DKIM_INVALID DKIM-Signature header exists but is not valid X-Scan-Signature: 479f887a0af49374011bd47f9dfa3263 Subject: Re: ULF: Carrier on 2470.01 Hz Content-Type: multipart/alternative; boundary="------------050406010707090208090501" X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.5 required=5.0 tests=HTML_20_30,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 This is a multi-part message in MIME format. --------------050406010707090208090501 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Hello Markus, Hm, skywave cancellation? Then this must happen quite quickly. I would rather expect a slower dSNR/dt, like we can see at the VLF MSK transmitters. But maybe you are right. So let's hope for some more weeks with such a low QRN levels. If you like, buy one of the accus i bought, then come here and we can connect them in parallel, to run the carrier for twice the time :-) Or we can do 3 dB QRO to see the fading more clearly, but then i need to build a stronger DC/DC converter. Maybe next weekend we can try 1.97 kHz. 73, Stefan Am 04.01.2019 14:33, schrieb Markus Vester: > Hi Stefan > > > The trace appears to be a bit shorter... > > This is interesting! The attached enlarged screenshot is a comparison > from DL0YHF (top) DL0AO (bottom), with same timescale. We find that > DL0AO was fading out towards the end, whereas the DL0AO trace seemed > to be becoming stronger. > > I suspect that this may again be due to skywave cancellation. During > the afternoon hours (13 to 15 h local time), solar elevation slowly > decreases and the height of the ionosphere goes up, increasing the > path difference to groundwave. Thus the null will be moving out > to larger distances where skywave is less steep, reducing path > difference again. However the numbers don't quite match: For 300 km > distance and 70 km iono height, Pythagoras calculates about 31 km or > 0.25 lambda difference. So we would need to assume an additional -90° > phase lag from the reflection. > > If I remember right, Jim's FDTD calculations also showed a sharp > minimum at 2.5 kHz and 200 km. Thus we may be optimistic and hope > that propagation will improve when you go to even lower frequencies. > > Best 73, > Markus (DF6NM) > > > > -----Ursprüngliche Mitteilung----- > Von: DK7FC > An: rsgb_lf_group > Verschickt: Do, 3. Jan. 2019 19:53 > Betreff: Re: ULF: Carrier on 2470.01 Hz > > Here is a spectrogram (attached) showing the reprocessed data of the > VLF stream of DL4YHF. > The 2470.01 Hz carrier leaves a clear trace, not as strong as on 2970 > Hz but clearly there. The trace appears to be a bit shorter, maybe due > to higher QRN levels which were blanked or due to a loss of the > reference signal (unlikely). > The first hour of the transmission produced a 18 dB SNR peak. Adding > the second hour of the transmission made the result even a bit worse. > 313 km distance on the 121 km band, that's ~ 2.6 wavelengths crossed... > > 73, Stefan > > > > > Am 01.01.2019 15:05, schrieb DK7FC: > Thanks Markus, ULF, > > Again, congrats to the DL0AO crew for the latest record. We are > operating on the *121 km band* and crossed a distance of 283 km, or > 2.3 wavelengths!! Certainly this has never been done before by amateurs. > DL0AO has now a new lowest frequency for a amateur signal detection :-) > > Unfortunately i slept too long this morning and so i started the > experiment to late. I see the QRN is already increasing now and it has > been lower in the early morning. Maybe, the next weekend we could try > 1.97 kHz but then with an earlier start time. > Here, the experiment is still running and i can hear the FETs beeping. > Due to the relatively low ambient temperature, the accu voltage > dropped to 11.5 V now and i have a remaining charge of 25.( AH or 21%. > The antenna current dropped to 2.6 A now. 5 minutes left, then i will > go QRT. > > 73 from the car, > Stefan > > > > Am 01.01.2019 13:55, schrieb Markus Vester: >> Again a very good signal at DL0AO, about 12 dB in 1.5 * 424 uHz: >> >> https://vlf.u01.de/ >> https://vlf.u01.de/VLFgrabber/vlf5.jpg >> >> We're also running a 47 uHz instance in the background, still >> showing yesterday's experiment: >> https://vlf.u01.de/VLFgrabber/vlf9.jpg >> >> What a splendid start into the New Year! >> >> Best wishes to all, >> Markus (DF6NM) >> >> -----Ursprüngliche Mitteilung----- >> Von: DK7FC >> An: rsgb_lf_group >> >> Verschickt: Di, 1. Jan. 2019 13:40 >> Betreff: ULF: Carrier on 2470.01 Hz >> >> Hi ULF, >> >> Due to the recent success on 2970 Hz i am now TXing again on my ground >> loop antenna. This time, since 12:08 UTC i am transmitting on 2470.01 >> Hz. Again the TX power is 520 W and i'm getting 2.75 A antenna current. >> This time i need 1.72 uF for series resonating the antenna. As usual, i >> intend to run the carrier for 2 hours. >> Reports are very much apprechiated :-) >> Unfortunately my own tree is shut down but i'm recording the stream of >> DL4YHF and IK1QFK again. Also the DL0AO crew is watching and recording. >> Maybe even Paul will get something significant? >> >> With some luck, 2.47 kHz may propagate even better than 2.97 kHz ?? >> Optimism is the key word for the year! >> >> Oh and attached is a spectrogram produced from the stream of DL4YHF, >> showing my signal on 2.97 kHz. The SNR is far better than i ever >> expected from such an antenna! See attachment. A long message could have >> been transferred over this 313 km path! >> >> >> Happy new year 2019 to all of you. >> >> 73, Stefan >> >> > --------------050406010707090208090501 Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: 8bit Hello Markus,

Hm, skywave cancellation? Then this must happen quite quickly. I would rather expect a slower dSNR/dt, like we can see at the VLF MSK transmitters. But maybe you are right.
So let's hope for some more weeks with such a low QRN levels. If you like, buy one of the accus i bought, then come here and we can connect them in parallel, to run the carrier for twice the time :-) Or we can do 3 dB QRO to see the fading more clearly, but then i need to build a stronger DC/DC converter.
Maybe next weekend we can try 1.97 kHz.

73, Stefan

Am 04.01.2019 14:33, schrieb Markus Vester:
Hi Stefan

> The trace appears to be a bit shorter...

This is interesting! The attached enlarged screenshot is a comparison from DL0YHF (top) DL0AO (bottom), with same timescale. We find that DL0AO was fading out towards the end, whereas the DL0AO trace seemed to be becoming stronger.

I suspect that this may again be due to skywave cancellation. During the afternoon hours (13 to 15 h local time), solar elevation slowly decreases and the height of the ionosphere goes up, increasing the path difference to groundwave. Thus the null will be moving out to larger distances where skywave is less steep, reducing path difference again. However the numbers don't quite match: For 300 km distance and 70 km iono height, Pythagoras calculates about 31 km or 0.25 lambda difference. So we would need to assume an additional -90° phase lag from the reflection.   

If I remember right, Jim's FDTD calculations also showed a sharp minimum at 2.5 kHz and 200 km. Thus we may be optimistic and hope that propagation will improve when you go to even lower frequencies. 

Best 73,
Markus (DF6NM)



-----Ursprüngliche Mitteilung-----
Von: DK7FC <selberdenken@posteo.de>
An: rsgb_lf_group <rsgb_lf_group@blacksheep.org>
Verschickt: Do, 3. Jan. 2019 19:53
Betreff: Re: ULF: Carrier on 2470.01 Hz

Here is a spectrogram  (attached) showing the reprocessed data of the VLF stream of DL4YHF.
The 2470.01 Hz carrier leaves a clear trace, not as strong as on 2970 Hz but clearly there. The trace appears to be a bit shorter, maybe due to higher QRN levels which were blanked or due to a loss of the reference signal (unlikely).
The first hour of the transmission produced a 18 dB SNR peak. Adding the second hour of the transmission made the result even a bit worse.
313 km distance on the 121 km band, that's ~ 2.6 wavelengths crossed...

73, Stefan




Am 01.01.2019 15:05, schrieb DK7FC:
Thanks Markus, ULF,

Again, congrats to the DL0AO crew for the latest record. We are operating on the 121 km band and crossed a distance of 283 km, or 2.3 wavelengths!! Certainly this has never been done before by amateurs.
DL0AO has now a new lowest frequency for a amateur signal detection :-)

Unfortunately i slept too long this morning and so i started the experiment to late. I see the QRN is already increasing now and it has been lower in the early morning. Maybe, the next weekend we could try 1.97 kHz but then with an earlier start time.
Here, the experiment is still running and i can hear the FETs beeping. Due to the relatively low ambient temperature, the accu voltage dropped to 11.5 V now and i have a remaining charge of 25.( AH or 21%. The antenna current dropped to 2.6 A now. 5 minutes left, then i will go QRT.

73 from the car,
Stefan



Am 01.01.2019 13:55, schrieb Markus Vester:
Again a very good signal at DL0AO, about 12 dB in 1.5 * 424 uHz:

https://vlf.u01.de/
https://vlf.u01.de/VLFgrabber/vlf5.jpg

We're also running a 47 uHz instance in the background, still showing yesterday's experiment: 
https://vlf.u01.de/VLFgrabber/vlf9.jpg

What a splendid start into the New Year!

Best wishes to all,
Markus (DF6NM)

-----Ursprüngliche Mitteilung-----
Von: DK7FC <selberdenken@posteo.de>
An: rsgb_lf_group <rsgb_lf_group@blacksheep.org>
Verschickt: Di, 1. Jan. 2019 13:40
Betreff: ULF: Carrier on 2470.01 Hz

Hi ULF,

Due to the recent success on 2970 Hz i am now TXing again on my ground
loop antenna. This time, since 12:08 UTC i am transmitting on 2470.01
Hz. Again the TX power is 520 W and i'm getting 2.75 A antenna current.
This time i need 1.72 uF for series resonating the antenna. As usual, i
intend to run the carrier for 2 hours.
Reports are very much apprechiated :-)
Unfortunately my own tree is shut down but i'm recording the stream of
DL4YHF and IK1QFK again. Also the DL0AO crew is watching and recording.
Maybe even Paul will get something significant?

With some luck, 2.47 kHz may propagate even better than 2.97 kHz ??
Optimism is the key word for the year!

Oh and attached is a spectrogram produced from the stream of DL4YHF,
showing my signal on 2.97 kHz. The SNR is far better than i ever
expected from such an antenna! See attachment. A long message could have
been transferred over this 313 km path!


Happy new year 2019 to all of you.

73, Stefan



--------------050406010707090208090501--