Return-Path: X-Spam-DCC: paranoid 1102; Body=2 Fuz1=2 Fuz2=2 X-Spam-Checker-Version: SpamAssassin 3.1.3 (2006-06-01) on lipkowski.org X-Spam-Level: X-Spam-Status: No, score=-1.6 required=5.0 tests=BAYES_00,NO_REAL_NAME autolearn=no version=3.1.3 Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by paranoid.lipkowski.org (8.13.7/8.13.7) with ESMTP id sB50e3Sj014631 for ; Fri, 5 Dec 2014 01:40:05 +0100 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1XwgpZ-0007Ob-Jr for rs_out_1@blacksheep.org; Fri, 05 Dec 2014 00:33:09 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1XwgpY-0007OS-VN for rsgb_lf_group@blacksheep.org; Fri, 05 Dec 2014 00:33:08 +0000 Received: from nina.ucs.mun.ca ([134.153.232.76]) by relay1.thorcom.net with esmtps (TLSv1:DHE-RSA-AES256-SHA:256) (Exim 4.84) (envelope-from ) id 1XwgpW-0005tl-Ee for rsgb_lf_group@blacksheep.org; Fri, 05 Dec 2014 00:33:07 +0000 Received: from plato.ucs.mun.ca (plato.ucs.mun.ca [134.153.232.153]) by nina.ucs.mun.ca (8.13.1/8.13.1) with ESMTP id sB50X1Uw007894 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO) for ; Thu, 4 Dec 2014 21:03:03 -0330 Date: Thu, 4 Dec 2014 21:03:01 -0330 (NST) From: jcraig@mun.ca X-X-Sender: jcraig@plato.ucs.mun.ca To: rsgb_lf_group@blacksheep.org In-Reply-To: <153268B9AC764888965D3815806715EC@White> Message-ID: References: <547C65A9.13517.C38DF3@mike.dennison.ntlworld.com> <153268B9AC764888965D3815806715EC@White> MIME-Version: 1.0 X-Scan-Signature: 290c8768709872f914a4ca71ad6bfe49 Subject: Re: LF: VO1NA on 477kHz last night Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed 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 2.56 on 10.1.3.10 Status: O X-Status: X-Keywords: X-UID: 1420 Hi Markus, Group. Thank-you for your interest in this enigmatic hissing dragon problem. The 630m class E TX worked well with the original AD8950 DDS, but when excited with the AD9851 clocked with the nice stable DOCXO, the hissing started. The hiss orginates with the drain choke (a 9 cm square core from a colour television) and persists even with a dummy load on the TX o/p. Putting 260pF across the TTL divider seems to reduce the hissing. Perhaps the DDS output has a spur? The DOXCO is fed to the dds via a shoddy npn stage which may be yielding a diry signal. In the mean time, a new VLF licence 10 mW 8.0-8.3 kHz arrived today. 73 Joe VO1NA On Thu, 4 Dec 2014, Markus Vester wrote: > Hi Joe, sounds like a fierce fire-spitting dragon... What is the nature of that hiss, and can you identify which component is actually producing the acoustic emissions? High voltage discharges at the antenna, instable current through a magnetrostrictive choke or transformer, or a singing ceramic capacitor? > > Best 73, > Markus > > > > From: jcraig@mun.ca > Sent: Thursday, December 04, 2014 12:08 AM > To: rsgb_lf_group@blacksheep.org > Subject: Re: LF: VO1NA on 477kHz last night > > > Hello Roelof, Andy and J-P, > > The TX was hissing furiuosly this morning while on the > wire aerial just before it was switched off. Thank-you > for the reports. > > The TX will be off tonight. > > 73 & MNI TNX > Joe > > > > >