Return-Path: Received: (qmail 18813 invoked from network); 29 Aug 2001 23:00:02 -0000 Received: from unknown (HELO warrior-inbound.services.quay.plus.net) (212.159.14.227) by excalibur.plus.net with SMTP; 29 Aug 2001 23:00:02 -0000 Received: (qmail 20450 invoked from network); 29 Aug 2001 22:58:16 -0000 Received: from unknown (HELO post.thorcom.com) (212.172.148.70) by warrior with SMTP; 29 Aug 2001 22:58:16 -0000 Received: from majordom by post.thorcom.com with local (Exim 3.16 #2) id 15cECf-00046U-00 for rsgb_lf_group-outgoing@blacksheep.org; Wed, 29 Aug 2001 23:52:57 +0100 X-Priority: 3 X-MSMail-Priority: Normal Received: from e34.co.us.ibm.com ([32.97.110.132] helo=e34.bld.us.ibm.com) by post.thorcom.com with esmtp (Exim 3.16 #2) id 15cECd-00046P-00 for rsgb_lf_group@blacksheep.org; Wed, 29 Aug 2001 23:52:56 +0100 Received: from westrelay01.boulder.ibm.com (westrelay01.boulder.ibm.com [9.99.140.22]) by e34.bld.us.ibm.com (8.9.3/8.9.3) with ESMTP id SAA127596 for ; Wed, 29 Aug 2001 18:50:03 -0400 Received: from usa.net (ss3.bld.socks.ibm.com [9.14.4.68]) by westrelay01.boulder.ibm.com (8.11.1m3/NCO v4.97.1) with ESMTP id f7TMovi345294 for ; Wed, 29 Aug 2001 16:50:58 -0600 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 Message-ID: <3B8D71CD.477AEF13@usa.net> Date: Thu, 30 Aug 2001 00:50:56 +0200 From: "Alberto di Bene" X-Mailer: Mozilla 4.76 [en] (Win95; U) X-Accept-Language: en MIME-Version: 1.0 To: rsgb_lf_group@blacksheep.org Subject: LF: Re: Receiver References: <001901c130be$0e72ab40$0eb51bca@xtr743187> 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: Vernall wrote: > Tom G3OLB, > > > Talking of TS-850s, does anyone know why my TS-850 changes gain at > > 500.000 KHz? Seems like an attenuator is switched in above 500 KHz. Is > > there a mod to defeat it? > > The TS-850 is manufactured with an attenuator for the MF AM broadcast band > (included within that band pass filter). The attenuator is made from > surface mount resistors, on the underside of the PCB, so it is a fairly > tricky job to rework. If you do a web search for TS-850 mods, you will find > a text and figures as to how to remove the attenuator. > Yes, that is typical for Kenwood, probably they fear their rigs get saturated in the MW band.... when modifying my TS-950SDX to improve its sensitivity in the LF band, as described in a past message, I eliminated that T-network attenuator. In my case it was rather easy, as Kenwood had kindly provided two test pins (???), just before and after the attenuator. So all it was needed was just a jumper. It looks like they had foreseen the need to bypass it. I have noticed no ill effects after its bypassing, probably in Japan they have much stronger MW transmitters than here :-) 73 Alberto I2PHD