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 vB5BMkXj024658 for ; Tue, 5 Dec 2017 12:22:48 +0100 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1eMB6p-000892-NS for rs_out_1@blacksheep.org; Tue, 05 Dec 2017 11:09:55 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1eMB6o-00088t-RQ for rsgb_lf_group@blacksheep.org; Tue, 05 Dec 2017 11:09:54 +0000 Received: from porthos.netcom.co.uk ([217.72.171.73]) by relay1.thorcom.net with esmtps (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.89) (envelope-from ) id 1eMB6i-00060k-5p for rsgb_lf_group@blacksheep.org; Tue, 05 Dec 2017 11:09:53 +0000 X-DKIM-Result: Domain=abelian.org Result=Signature OK DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=abelian.org ; s=default; h=Content-Transfer-Encoding:Content-Type:In-Reply-To: MIME-Version:Date:Message-ID:From:References:To:Subject:Sender:Reply-To:Cc: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help:List-Unsubscribe: List-Subscribe:List-Post:List-Owner:List-Archive; bh=DzWG81hsKbSetSJJ1zvgjiTslbhKlqJD04Ka+ADxnPo=; b=XXrYqzbVC7ggr8oJDR0mYofNYa +2qX2u+PbPn/gjtcSzuPP9TDf/mq3L3/pU1krGzOX43UthG4qT2L6/nMNMH7Fp1qPrq0mjzJsNDHn bf+RXjzLuMupmzIkFMmMiDo/wV7yheFsaHsCDpV1+ec1M0PfdWWonVAgIe9tZ6pWiecc=; Received: from i-194-106-52-83.freedom2surf.net ([194.106.52.83]:59902 helo=pn.abelian.org) by porthos.netcom.co.uk with esmtpsa (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.89) (envelope-from ) id 1eMB6g-0007BW-DD for rsgb_lf_group@blacksheep.org; Tue, 05 Dec 2017 11:09:46 +0000 Received: from [127.0.0.1] (localhost [127.0.0.1]) by pn.abelian.org (Postfix) with ESMTP id 7F6E040048A for ; Tue, 5 Dec 2017 11:09:45 +0000 (UTC) To: rsgb_lf_group@blacksheep.org References: <4d96a9d4-5f22-7650-872b-6344e9aea8e3@abelian.org> <00f901d36646$feda4e60$fc8eeb20$@comcast.net> <085dd850-9c10-16a0-70ef-fb2de079ffb8@abelian.org> <023201d367cf$8a5761b0$9f062510$@comcast.net> <579355A36AEE9D4FA555C45D556003AB9AAAF572@servigilant.vigilant.local> <2166618d-7238-0516-367c-2f917532eed2@abelian.org> <5A20A4EC.4060009@posteo.de> From: Paul Nicholson Message-ID: Date: Tue, 5 Dec 2017 11:09:45 +0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.3.0 MIME-Version: 1.0 In-Reply-To: <5A20A4EC.4060009@posteo.de> Content-Language: en-US X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - porthos.netcom.co.uk X-AntiAbuse: Original Domain - blacksheep.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - abelian.org X-Get-Message-Sender-Via: porthos.netcom.co.uk: authenticated_id: catchall@abelian.org X-Authenticated-Sender: porthos.netcom.co.uk: catchall@abelian.org 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: New H-field rx is coming along well. Design changes are completed - it has a lower system noise, wider bandwidth, significantly lower common mode response, and a much better line driver. Like the new E-field rx, it also has a built-in calibration port. [...] Content analysis details: (0.0 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- 0.0 T_DKIM_INVALID DKIM-Signature header exists but is not valid X-Scan-Signature: 086f3faad0220c9ae57a7913e711a86d Subject: Re: LF: RE: Todmorden receiver Content-Type: text/plain; charset=utf-8; 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=0.9 required=5.0 tests=FROM_ENDS_IN_NUMS 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 New H-field rx is coming along well. Design changes are completed - it has a lower system noise, wider bandwidth, significantly lower common mode response, and a much better line driver. Like the new E-field rx, it also has a built-in calibration port. Currently testing the design changes on breadboard and it performs just as per the Spice model, except for a higher than expected system noise. Should be just below 0.1fT in 1Hz but I'm measuring 0.46 fT. Maybe this specimen of LT1028 is a bit noisier than others? It's my last one but I've got more arriving hopefully today. I'll pick the best two. Even with this mysterious extra system noise, it's still 20dB below the natural noise floor after sferic blanking. Apart from that it is working perfectly, just as per design and looks very good at 137 kHz too. Hopefully will be able to start the cutting and drilling and filing and soldering this week. That's my least favourite part of the job. What I won't discover until it's finished and installed, is whether it actually cures the excess noise at 8kHz and 5kHz that we've seen lately. I haven't been able to identify the cause of the relatively (compared to E-field) poor S/N on the existing rx. Hopefully it is a low level of intermod in the line driver. If so the new rx will not suffer that problem and we'll see another step improvement in the 8270 spectrogram. -- Paul Nicholson --