Return-Path: X-Spam-DCC: paranoid 1480; 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=-0.7 required=5.0 tests=BAYES_00,DNS_FROM_AHBL_RHSBL, RATWARE_GECKO_BUILD,SPF_PASS 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 u9C9velm021628 for ; Wed, 12 Oct 2016 11:57:40 +0200 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1buGFU-0003r3-RZ for rs_out_1@blacksheep.org; Wed, 12 Oct 2016 10:54:56 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1buGFU-0003qu-I0 for rsgb_lf_group@blacksheep.org; Wed, 12 Oct 2016 10:54:56 +0100 Received: from smtpout.karoo.kcom.com ([212.50.160.34]) by relay1.thorcom.net with esmtp (Exim 4.87) (envelope-from ) id 1buGFT-00063G-5N for rsgb_lf_group@blacksheep.org; Wed, 12 Oct 2016 10:54:55 +0100 X-IronPort-AV: E=Sophos;i="5.31,333,1473116400"; d="scan'208";a="172973608" Received: from unknown (HELO [127.0.0.1]) ([109.176.246.47]) by smtpout.karoo.kcom.com with ESMTP; 12 Oct 2016 10:54:52 +0100 Message-ID: <57FE0811.5010206@lineone.net> Date: Wed, 12 Oct 2016 10:53:21 +0100 From: LineOne User-Agent: Mozilla/5.0 (Windows NT 5.1; rv:31.0) Gecko/20100101 Thunderbird/31.1.2 MIME-Version: 1.0 To: rsgb_lf_group@blacksheep.org References: <57FD3F9F.80409@lineone.net> <57FD52C8.1010401@posteo.de> In-Reply-To: <57FD52C8.1010401@posteo.de> X-Scan-Signature: 7001055fa59a9c23b9831ea6d317a074 Subject: Re: LF: Audio link 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 2.56 on 10.1.3.11 Status: O X-Status: X-Keywords: X-UID: 9029 Thank you Stefan. I could try two microphone transmitters back to back as I have only one 1:1 isolation transformer and again I might try a short range LED link although these tend to have linear modulation and the dynamic range of digital radio signals seems quite high. On 11/10/2016 21:59, DK7FC wrote: > Hi Hugh, > > Maybe there is some improvement when trying 2 isolation transformers > and grounding the TP cable in the center? > The other solutions will not work well i think, because the dynamic > range is not high enough. > > 73, Stefan > > Am 11.10.2016 21:38, schrieb LineOne: >> To avoid having laptop running in the shack, which occasionally >> produces some QRM, I can send received audio from the shack to a >> desktop computer in the house on a twisted telephone pair. This works >> but any wire connection between shack and this desktop introduces >> some spurious signals on 136khz even if I use an audio isolating >> transformer. >> >> 73, Hugh, M0DSZ >> > >