Return-Path: Received: (qmail 1999 invoked from network); 16 May 2002 15:32:50 -0000 Content-Transfer-Encoding: 8bit Received: from unknown (HELO warrior.services.quay.plus.net) (212.159.14.227) by exhibition.plus.net with SMTP; 16 May 2002 15:32:50 -0000 X-Priority: 3 X-MSMail-Priority: Normal Received: (qmail 20415 invoked from network); 16 May 2002 15:32:35 -0000 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 Received: from unknown (HELO post.thorcom.com) (193.82.116.70) by warrior.services.quay.plus.net with SMTP; 16 May 2002 15:32:35 -0000 Received: from majordom by post.thorcom.com with local (Exim 3.33 #2) id 178N8W-0008NO-00 for rsgb_lf_group-outgoing@blacksheep.org; Thu, 16 May 2002 16:25:48 +0100 Received: from hestia.herts.ac.uk ([147.197.200.9]) by post.thorcom.com with esmtp (Exim 3.33 #2) id 178N8V-0008NJ-00 for rsgb_lf_group@blacksheep.org; Thu, 16 May 2002 16:25:47 +0100 Received: from gemini ([147.197.200.44] helo=gemini.herts.ac.uk) by hestia.herts.ac.uk with esmtp (Exim 3.22 #1) id 178N8U-0005RP-00 for rsgb_lf_group@blacksheep.org; Thu, 16 May 2002 16:25:46 +0100 Received: from [147.197.232.252] (helo=rsch-15.herts.ac.uk) by gemini.herts.ac.uk with esmtp (Exim 3.33 #1) id 178N8T-0000Mh-00 for rsgb_lf_group@blacksheep.org; Thu, 16 May 2002 16:25:45 +0100 Message-ID: <5.1.0.14.0.20020516141438.00a7dd28@gemini.herts.ac.uk> X-Sender: mj9ar@gemini.herts.ac.uk X-Mailer: QUALCOMM Windows Eudora Version 5.1 Date: Thu, 16 May 2002 16:24:51 +0100 To: rsgb_lf_group@blacksheep.org From: "James Moritz" Subject: LF: Re: USA 136kHz proposals In-reply-to: <001301c1fcc4$b6c8ff60$3d1e073e@dave> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group Sender: Dear Dave, LF Group At 11:28 16/05/2002 +0100, you wrote: >I see from yesterday's ARRL Letter that the proposal for the USA 136 band >is for 1W >ERP and bandwidth less than 100Hz. I am puzzled why they are putting this >stipulation on bandwidth, I suppose it makes sense - otherwise someone could decide to monopolise the entire band sending SSTV or something. > It could be a >disincentive for normal CW operation (although hopefully most CW will be >in this >bandwidth), and presumably will be difficult to enforce. It's very easy to measure the bandwidth of signals with spectrogram software, or a spectrum analyser. Some people would be surprised to see what their signals look like! How difficult it would be to maintain that bandwidth depends on the complete specification - how many dB down at 100Hz BW? If it is 20dB down, no problem, but if it is 60dB down, difficult in any mode - the mains hum sidebands are usually more than that. On a similar note, it would seem premature to start rushing in to band plans again - remember that the original reason for having the "transatlantic" signals at the bottom of the band was to avoid CFH on 137.0kHz in the middle of the band - It is still there, and in the north-east US states this will certainly have a very direct influence on operating frequencies for all modes, which could well end up rather different to those in Europe. Arbitrarily imposing a band plan at this stage would be less than helpful, and it would be better to wait until US amateurs have a chance to gain operating experience on the band. Cheers, Jim Moritz 73 de M0BMU