Return-Path: Received: (qmail 1598 invoked from network); 28 Jul 1999 01:54:52 +0100 Received: from magnus.plus.net.uk (HELO magnus.force9.net) (195.166.128.27) by guiness.force9.net with SMTP; 28 Jul 1999 01:54:52 +0100 Received: (qmail 9233 invoked from network); 27 Jul 1999 23:31:59 -0000 Received: from unknown (HELO post.thorcom.com) (212.172.148.70) by magnus.plus.net.uk with SMTP; 27 Jul 1999 23:31:59 -0000 Received: from majordom by post.thorcom.com with local (Exim 3.02 #1) id 119GYA-0005CI-00 for rsgb_lf_group-outgoing@blacksheep.org; Wed, 28 Jul 1999 00:22:22 +0100 X-Priority: 3 Received: from mailout05.btx.dtag.de ([194.25.2.153]) by post.thorcom.com with esmtp (Exim 3.02 #1) id 119GY8-0005C7-00 for rsgb_lf_group@blacksheep.org; Wed, 28 Jul 1999 00:22:20 +0100 X-MSMail-Priority: Normal Received: from fwd08.btx.dtag.de ([194.25.2.168]) by mailout05.btx.dtag.de with smtp id 119GY6-0005xS-00; Wed, 28 Jul 1999 01:22:18 +0200 Received: (087321565-0001(btxid)@[193.158.171.64]) by fwd08.btx.dtag.de id ; Wed, 28 Jul 1999 01:22:10 +0200 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 Message-ID: Date: Wed, 28 Jul 1999 01:22:10 +0200 To: rsgb_lf_group@blacksheep.org References: <3.0.1.16.19990727115808.2d4fe51e@mail.cc.kuleuven.ac.be> Subject: Re: LF: Loops indoor and outdoor X-Mailer: T-Online eMail 2.3 MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 8bit X-Sender: 087321565-0001@t-online.de From: "Hans-Joachim Brandt" Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org Sender: Rik Strobbe schrieb: > Few weeks ago I tested a small loopantenna indoor > and noise was awfull. The 1 meter loop produced about 6dB more noise level > than the big outdoor vertical and signals were about 20dB down on the > indoor loop. > So the overall S/N ratio was at about 26dB worse. > Placing the loop in the back yard at about 25m from the house resulted in > the same S/N on loop and vertical. I have not found time to try such a loop, but this is interesting and pleasing me. I have just tried an LF broadacast ferrite rod aerial and found it not sufficiently sensitive. But with this ferrite rod I discovered that in my home brew equipment voltage stabilizers such as 78LXX produce a noise at the input side if this is not blocked by a good 6,8 MFD or more. This noise may be radiated from the supply cable leading to another power supply and increase indoor noise. But when studying the QSL card of HB9DCE, he is mentioning a vertical loop antenna with three turns and a circumference of 50 meters! So You still have to do a lot to catch up with him. > My tip : try to place your RX-antenna as far away as possible from > 'civilisation' and use good coax between antenna and RX. I have bad > experience with the shielding of cheap RG58. ZL2CA also has emphasized: Note that I run all of my shack via a 5 kVA isolation transformer, including a multisection low pass filter on the mains side, in an attempt to keep mains noise out of my VLF/LF receiving gear. 73 Ha-Jo, DJ1ZB