Rick, Based on your comments below, I would prefer a 75A-4. It has a product detector where the other receivers SP-600, R-390, R-390A, R-388, 51J-4 do not. There is some AM activity on 160, 80, and 40, but SSB activity is much more prevalent. Unless you like riding the RF gain control all the time when copying SSB or CW, you would really appreciate the product detector. However, you do give up "general coverage" capability with a 75A-4.
-- Ernie, k0occ Atlanta, GA -------------- Original message -------------- From: Rick Brashear <[EMAIL PROTECTED]> > Mark, > > Thanks for the reply. You brought up some interesting points. The bulk > of my listening activity is on 160, 75 and 40 meters. I seldom listen > to short-wave broadcasts, so that won't come into play. As for > fidelity, I'm no spring chicken and my ears are not as sharp as they > once were, (that's a bad place for an audio engineer to be) so I need > clean audio. I can always process it with outboard equipment to get the > exact sound these old ears prefer. I have at this time a great old > HQ-180 that I use as my primary receiver. However, it's more of a > communications receiver than a ham receiver, so it's lacking in areas, > but has beautiful audio. I also use a National NC-183 that has > fantastic audio. Even though I have gone through it completely and > spent hours getting the alignment exactly right, it still doesn't > perform as well as I'd like. I think it's doing all it was designed do, > but that's not enough. > > Thanks again for your questions and observations. In light of my reply, > what would you recommend? > > Rick/K5IZ > > W1EOF wrote: > > >Rick - I think this can only be answered depending on what you are looking > >for..... > > > > > > > > > ______________________________________________________________ > AMRadio mailing list > Home: http://mailman.qth.net/mailman/listinfo/amradio > Help: http://mailman.qth.net/mmfaq.html > Post: mailto:[email protected] > AMfone Website: http://www.amfone.net > AM List Admin: Brian Sherrod/w5ami, Paul Courson/wa3vjb From [EMAIL PROTECTED] Sat Jul 29 01:35:27 2006 Return-Path: <[EMAIL PROTECTED]> X-Original-To: [email protected] Delivered-To: [email protected] Received: from rrcs-mta-02.hrndva.rr.com (rrcs-mta-02.hrndva.rr.com [24.28.200.154]) by mailman.qth.net (Postfix) with ESMTP id 8DF06859C36 for <[email protected]>; Sat, 29 Jul 2006 01:35:27 -0400 (EDT) Received: from rrcs-fep-12.hrndva.rr.com (rrcs-fep-12b.hrndva.rr.com [172.28.200.150]) by rrcs-mta-02.hrndva.rr.com (8.13.5+Sun/8.12.10) with ESMTP id k6T5OG98003077 for <[email protected]>; Sat, 29 Jul 2006 01:24:16 -0400 (EDT) Received: from home1 ([68.89.47.126]) by rrcs-fep-12.hrndva.rr.com with ESMTP id <[EMAIL PROTECTED]> for <[email protected]>; Sat, 29 Jul 2006 01:24:16 -0400 From: "John Coleman ARS WA5BXO" <[EMAIL PROTECTED]> To: "'Discussion of AM Radio'" <[email protected]> Subject: RE: [AMRadio] Receivers Date: Sat, 29 Jul 2006 00:24:43 -0500 Message-ID: <[EMAIL PROTECTED]> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit X-Mailer: Microsoft Office Outlook 11 Thread-Index: AcayxG926ra4oCd9TOGvcSr0JsaIiQACEa7g In-Reply-To: <[EMAIL PROTECTED]> X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.2869 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: Sat, 29 Jul 2006 05:35:27 -0000 The 74A4 excels in stability, dial accuracy, and easy of tuning, but it is poor on fidelity. Not just in the audio stages but the conversion and IF stages add distortion as well. It's far from the worst of communication type receivers though, and some might say it's not bad at all, but it doesn't compare to the Superpros and that vintage of receiver. You might want to consider adding a double balanced product detector to one of the older receivers such as your NC183 for easy of tuning SSB and CW. There are a number of different designs that work well by sampling the IF before the detector. There is even a chip specially designed for the application and used in AM stereo radios. One advantage to this is the enhanced audio achieved while using the "carrier lock on AM" capability of the quadrature double balanced product detector. I used one that I built years ago on my HQ145, before the special chip was available. It was a real pleasure not having to listen to the distortion caused by selective QSB when the carrier phases out. It would how ever detect the 60 CPS FM/phase modulation of an old BC610 VFO where the diode detector did not. John
