Hello All: Does anyone need a manual copy of a Heath SB 620? I have a copy of most of it. The manual covers the 455 KC IF frequency complete with diagrams and build information.
This is a good clear copy for cost of 5 bucks mailed in the US. First person to email me gets it. 73 Jim W5JO From [EMAIL PROTECTED] Mon Nov 22 20:29:47 2004 Return-Path: <[EMAIL PROTECTED]> Delivered-To: [email protected] Received: from imo-m25.mx.aol.com (imo-m25.mx.aol.com [64.12.137.6]) by mailman.qth.net (Postfix) with ESMTP id A36C7859BFC for <[email protected]>; Mon, 22 Nov 2004 20:29:34 -0500 (EST) Received: from [EMAIL PROTECTED] by imo-m25.mx.aol.com (mail_out_v37_r3.8.) id s.d7.1a38ec53 (4340); Mon, 22 Nov 2004 20:23:27 -0500 (EST) From: [EMAIL PROTECTED] Message-ID: <[EMAIL PROTECTED]> Date: Mon, 22 Nov 2004 20:23:27 EST Subject: Re: [AMRadio] AM Usage with Linear AMPS To: [EMAIL PROTECTED], [email protected] MIME-Version: 1.0 X-Mailer: Thunderbird - Mac OS X sub 208 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit X-Content-Filtered-By: Mailman/MimeDel 2.1.4 Cc: X-BeenThere: [email protected] X-Mailman-Version: 2.1.4 Precedence: list Reply-To: Discussion of AM Radio <[email protected]> List-Id: Discussion of AM Radio <amradio.mailman.qth.net> List-Unsubscribe: <http://mailman.qth.net/mailman/listinfo/amradio>, <mailto:[EMAIL PROTECTED]> List-Archive: <http://mailman.qth.net/mailman/private/amradio> List-Post: <mailto:[email protected]> List-Help: <mailto:[EMAIL PROTECTED]> List-Subscribe: <http://mailman.qth.net/mailman/listinfo/amradio>, <mailto:[EMAIL PROTECTED]> X-List-Received-Date: Tue, 23 Nov 2004 01:29:48 -0000 In a message dated 11/22/04 3:49:55 PM, [EMAIL PROTECTED] writes: > 50 watts AM output is surely not going to hurt a good ole 811A, > LOL! > Going to shorten it's life considerably. To properly adjust a linear amp for AM it is necessary to tune the thing up for the peak power level, i.e., 200 watts for a 50W carrier. The linear will be about 60% efficient at this output level. Then WITHOUT CHANGING THE TUNING adjust the output from the AM exciter to provide for 50W out of the linear with no modulation. The problem here is that the linear will now only be running about 30% efficiency under carrier-only conditions and the 811 would be dissipating something like 100+ watts. The 811A, of course, is only rated at 65 watts. Dennis D. W7QHO Glendale, CA
