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 v8MBYNJC028854 for ; Fri, 22 Sep 2017 13:34:26 +0200 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1dvM6h-0001Zn-4j for rs_out_1@blacksheep.org; Fri, 22 Sep 2017 12:26:55 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1dvM6e-0001Ze-Vy for rsgb_lf_group@blacksheep.org; Fri, 22 Sep 2017 12:26:52 +0100 Received: from mout02.posteo.de ([185.67.36.66]) by relay1.thorcom.net with esmtps (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.89) (envelope-from ) id 1dvM6Z-0006Fb-CM for rsgb_lf_group@blacksheep.org; Fri, 22 Sep 2017 12:26:51 +0100 Received: from submission (posteo.de [89.146.220.130]) by mout02.posteo.de (Postfix) with ESMTPS id 33C1E2099D for ; Fri, 22 Sep 2017 13:26:45 +0200 (CEST) Received: from customer (localhost [127.0.0.1]) by submission (posteo.de) with ESMTPSA id 3xzB5J1Zwvz101M for ; Fri, 22 Sep 2017 13:26:44 +0200 (CEST) Message-ID: <59C4F373.8050009@posteo.de> Date: Fri, 22 Sep 2017 13:26:43 +0200 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: <15ea03edd54-c07-2a33b@webjas-vab251.srv.aolmail.net>, , <59C428C3.7030709@posteo.de> <59C4DD5D.31182.228EA758@mike.dennison.ntlworld.com> In-Reply-To: <59C4DD5D.31182.228EA758@mike.dennison.ntlworld.com> X-Spam-Score: -0.0 (/) 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 the administrator of that system for details. Content preview: Hi Mike, Am 22.09.2017 11:52, schrieb Mike Dennison: > I would certainly like to try to receive you again on VLF, Stefan. > But I understand that EbNaut cannot be seen on a spectrogram. Is that > correct? Yes, correct. At least as long as the SNR is as weak as it usually is on RX sites a few 100 km distant. On my tree grabber which is just 3.5 km distant you can see the signal in the spectrogram: http://www.iup.uni-heidelberg.de/schaefer_vlf/DK7FC_VLF_Grabber2.html > I don't have GPS timing (though I expect to have it by the > New Year). I do have excellent frequency accuracy and the computer > clock is synched to an NTP server and is kept within 0.5mS. > That sounds good. Also you are locking SpecLab to GBZ which is normally a 24/7 available reference. So you are already now able to decode EbNaut. > Is there anything I can receive during this test? Or should I wait > for a simpler transmission? > A simpler transmission, i.e. a carrier is better for starting. Did you get a result from my recent carrier transmission? The current transmission is 6 dB weaker. But somehoe propagation wasn't really good during the last weekend... You said you wanted to buy a new PC. This is a good step: To have a permanent running spectrogram, or 2 or 3. I know you are having a blog where you post some reception results from time to time. So you seem to be skilled enough to build up a website and maybe even run a test wise VLF grabber, like Eddie does from time to time. A grabber is also helpful to check the current situation (QRM, QRN, availability) by other people. Also it would be helpful to build a separate antenna just for VLF reception. Just build an active vertical. A 5m or 8m pole for example will give you enough capacity and signal energy to observe the ultra low frequencies. [...] Content analysis details: (-0.0 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- -0.0 RP_MATCHES_RCVD Envelope sender domain matches handover relay domain X-Scan-Signature: 4d97240a623a26620214cd27feaa9f71 Subject: Re: VLF: 300 mA on 8270 Hz Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.0 required=5.0 tests=none 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 Hi Mike, Am 22.09.2017 11:52, schrieb Mike Dennison: > I would certainly like to try to receive you again on VLF, Stefan. > But I understand that EbNaut cannot be seen on a spectrogram. Is that > correct? Yes, correct. At least as long as the SNR is as weak as it usually is on RX sites a few 100 km distant. On my tree grabber which is just 3.5 km distant you can see the signal in the spectrogram: http://www.iup.uni-heidelberg.de/schaefer_vlf/DK7FC_VLF_Grabber2.html > I don't have GPS timing (though I expect to have it by the > New Year). I do have excellent frequency accuracy and the computer > clock is synched to an NTP server and is kept within 0.5mS. > That sounds good. Also you are locking SpecLab to GBZ which is normally a 24/7 available reference. So you are already now able to decode EbNaut. > Is there anything I can receive during this test? Or should I wait > for a simpler transmission? > A simpler transmission, i.e. a carrier is better for starting. Did you get a result from my recent carrier transmission? The current transmission is 6 dB weaker. But somehoe propagation wasn't really good during the last weekend... You said you wanted to buy a new PC. This is a good step: To have a permanent running spectrogram, or 2 or 3. I know you are having a blog where you post some reception results from time to time. So you seem to be skilled enough to build up a website and maybe even run a test wise VLF grabber, like Eddie does from time to time. A grabber is also helpful to check the current situation (QRM, QRN, availability) by other people. Also it would be helpful to build a separate antenna just for VLF reception. Just build an active vertical. A 5m or 8m pole for example will give you enough capacity and signal energy to observe the ultra low frequencies. 73, Stefan > Mike, G3XDV > ========== > > >> VLF, >> >> My new VLF coil is now in operation. It is designed to run 300 mA. The >> first station where i like to transmit some messages is 8270 Hz, just >> because 36 km it is the easiest band on the VLF frequencies available >> for us. The idea is to transmit at least 100 hours on each band down >> towards DC, just to proof the design. Does someone like to join the >> experiments, RX or TX wise? >> >> I'm going to start a first transmission tomorrow morning using EbNaut: >> >> *f = 8270.005000 Hz >> Start time: 22.September.2017 06:00:00 UTC >> Symbol period: 24 s >> Characters: 12 >> CRC bits: 16 >> Coding 16K21A >> Duration: 11h,31min,12sec >> Antenna current: 300 mA* >> >> >> 73, Stefan >> >> >> >> >> >> --- >> This email has been checked for viruses by AVG. >> http://www.avg.com >> >> > > >