Return-Path: Received: (qmail 25909 invoked from network); 8 Dec 2001 15:42:55 -0000 Received: from unknown (HELO murphys-inbound.services.quay.plus.net) (212.159.14.225) by excalibur.plus.net with SMTP; 8 Dec 2001 15:42:55 -0000 X-Priority: 3 X-MSMail-Priority: Normal Received: (qmail 27381 invoked from network); 8 Dec 2001 15:42:50 -0000 Received: from unknown (HELO post.thorcom.com) (212.172.148.70) by murphys.services.quay.plus.net with SMTP; 8 Dec 2001 15:42:50 -0000 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 Received: from majordom by post.thorcom.com with local (Exim 3.33 #2) id 16CjZ8-0003zn-00 for rsgb_lf_group-outgoing@blacksheep.org; Sat, 08 Dec 2001 15:39:02 +0000 Received: from e21.nc.us.ibm.com ([32.97.136.227]) by post.thorcom.com with esmtp (Exim 3.33 #2) id 16CjZ3-0003zi-00 for rsgb_lf_group@blacksheep.org; Sat, 08 Dec 2001 15:39:01 +0000 Received: from southrelay01.raleigh.ibm.com (southrelay01.raleigh.ibm.com [9.37.3.208]) by e21.nc.us.ibm.com (8.9.3/8.9.3) with ESMTP id JAA24886 for ; Sat, 8 Dec 2001 09:34:51 -0600 Received: from usa.net (ss5.pok.socks.ibm.com [9.14.3.70]) by southrelay01.raleigh.ibm.com (8.11.1m3/NCO v5.01) with ESMTP id fB8Fc7T206588 for ; Sat, 8 Dec 2001 10:38:07 -0500 Message-ID: <3C12339E.5D4D6578@usa.net> Date: Sat, 08 Dec 2001 16:37:02 +0100 From: "Alberto di Bene" X-Mailer: Mozilla 4.78 [en] (Windows NT 5.0; U) X-Accept-Language: en MIME-Version: 1.0 To: rsgb_lf_group@blacksheep.org Subject: Re: LF: Mains hum References: <5.1.0.14.2.20011208143147.009fc590@mail.pncl.co.uk> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 8bit Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group Sender: Walter Blanchard wrote: > Apologise for this not being on the main thread, but: > Can anyone tell me how to get rid of mains hum on soundcards? > [...] Walter, do those lines disappear if you switch off the RX ? Even if they are not affected by the radio volume setting, they could indicate some residual AC on the DC power that supplies the final audio amplifier of the RX. If they persist even with the radio power off, then the hum is picked up somehow by the cable, otherwise the radio is the cuplrit. 73 Alberto I2PHD .