Return-Path: Received: (qmail 770 invoked from network); 3 May 2000 12:23:04 -0000 Received: from unknown (HELO post.thorcom.com) (212.172.148.70) by bells.core.plus.net.uk with SMTP; 3 May 2000 12:23:04 -0000 Received: from majordom by post.thorcom.com with local (Exim 3.02 #1) id 12my3D-0007b3-00 for rsgb_lf_group-outgoing@blacksheep.org; Wed, 03 May 2000 13:14:47 +0100 Received: from smtp-out1.bellatlantic.net ([199.45.39.156]) by post.thorcom.com with esmtp (Exim 3.02 #1) id 12my3A-0007ay-00 for rsgb_lf_group@blacksheep.org; Wed, 03 May 2000 13:14:45 +0100 X-Priority: 3 X-MSMail-Priority: Normal Received: from bellatlantic.net (client-151-200-117-132.bellatlantic.net [151.200.117.132]) by smtp-out1.bellatlantic.net (8.9.1/8.9.1) with ESMTP id IAA01002; Wed, 3 May 2000 08:14:20 -0400 (EDT) Message-ID: <391018C6.7DEFD53B@bellatlantic.net> X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 Date: Wed, 03 May 2000 08:17:11 -0400 From: "Andre' Kesteloot" X-Mailer: Mozilla 4.7 [en]C-CCK-MCD NSCPCD47 (WinNT; I) X-Accept-Language: en MIME-Version: 1.0 To: rsgb_lf_group@blacksheep.org Cc: "lf-amrad" Subject: Re: LF: beacon power control References: <3.0.1.16.20000503100301.2e77a8b0@mail.cc.kuleuven.ac.be> <4.1.20000502224757.020c4040@mailer.inrete.it> <3.0.1.16.20000503132834.2d4fcc54@mail.cc.kuleuven.ac.be> 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: Rik Strobbe wrote: > [...] > As the beacon is meant to be low-power (10mW and less) a relative small TX > power can be used (50 Watts and less), so it can easily be overdimensioned > to provide extra safety. Maplin has a small class A amplifier using a LM 1875 that easily puts out 25 watts at 136 Khz. It is stable, has automatic current limiting and overheating protection Because it operates in class A, the output can be controlled simply by a step attenuator at the _input_ of the amplifier. Just a thought 73 Andre' N4ICK