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=HEADER_FROM_DIFFERENT_DOMAINS, SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 X-Spam-DCC: EATSERVER: mailn 1166; 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 v79E6mt4029610 for ; Wed, 9 Aug 2017 16:06:49 +0200 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1dfRYm-0002m3-Ak for rs_out_1@blacksheep.org; Wed, 09 Aug 2017 15:02:08 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1dfRYl-0002lu-PU for rsgb_lf_group@blacksheep.org; Wed, 09 Aug 2017 15:02:07 +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 1dfRYi-0007i8-7w for rsgb_lf_group@blacksheep.org; Wed, 09 Aug 2017 15:02:06 +0100 Received: from submission (posteo.de [89.146.220.130]) by mout02.posteo.de (Postfix) with ESMTPS id E6E7F20CBE for ; Wed, 9 Aug 2017 16:02:02 +0200 (CEST) Received: from customer (localhost [127.0.0.1]) by submission (posteo.de) with ESMTPSA id 3xSCcm4rT6z10Hl for ; Wed, 9 Aug 2017 16:02:00 +0200 (CEST) Message-ID: <598B15D8.4040608@posteo.de> Date: Wed, 09 Aug 2017 16:02:00 +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: <15db2643c6f-5f13-23c2@webprd-m101.mail.aol.com> <5986259C.8020409@posteo.de> <598A1DBA.9040404@posteo.de> <31b55d24-5fc0-63cd-9e8d-e0b0d25af8c6@abelian.org> In-Reply-To: <31b55d24-5fc0-63cd-9e8d-e0b0d25af8c6@abelian.org> X-Scan-Signature: f38d515a9cad1e977fcfe251941a8120 Subject: Re: VLF: Carrier on 3675.005 Hz Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit 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: 12352 Hi Paul, Am 09.08.2017 15:39, schrieb Paul Nicholson: > > I'm measuring about 0.016 fT daytime, 0.045 fT nighttime. > > Daytime signal phase leads the night phase by about 67 degrees. > > Combining and normalising day/night signals and excluding > the terminator periods gives > > http://abelian.org/vlf/tmp/170809a.gif > > Still not significant, only about 3.5 sigma, 10.9 dB S/N > in 1.13 uHz. Thanks for that. I am happy with the result. It is not one of the main bands anyway, just a short trip to 82 km :-) So i will soon try some EbNaut with DL0AO. > The extra signal is raising the noise floor slightly > due to a tiny amount of distortion in the line driver and > isolating transformers. Did you ever try optocouplers instead of isolation transformers? For example an ADUM-4160 ? Could this be an alternative? > On the test bench the new rx does very > well: very low noise and low distortion. But with the full > signal from the antenna there is enough mixing to slightly raise > the noise floor. I just need that 0.1 dB and also to cure some > mechanical noises (microphonics) when the wind blows. > > PS, the new rx also also covers 137 kHz! The results on 137 kHz will be interesting. Will you publish the final schematic when the system is completed? 73, Stefan