Return-Path: Received: (qmail 17573 invoked from network); 19 May 2002 21:42:12 -0000 Received: from unknown (HELO marstons.services.quay.plus.net) (212.159.14.223) by excalibur-qfe1-smtp-plusnet.harl.plus.net with SMTP; 19 May 2002 21:42:12 -0000 Received: (qmail 12023 invoked by uid 10001); 19 May 2002 21:46:06 -0000 Received: from unknown (HELO post.thorcom.com) (193.82.116.70) by marstons.services.quay.plus.net with SMTP; 19 May 2002 21:46:06 -0000 Received: from majordom by post.thorcom.com with local (Exim 3.33 #2) id 179YOz-0000rN-00 for rsgb_lf_group-outgoing@blacksheep.org; Sun, 19 May 2002 22:39:41 +0100 Received: from 210-86-15-139.ipnets.xtra.co.nz ([210.86.15.139] helo=web4-rme.xtra.co.nz) by post.thorcom.com with esmtp (Exim 3.33 #2) id 179YOy-0000rI-00 for rsgb_lf_group@blacksheep.org; Sun, 19 May 2002 22:39:40 +0100 Received: from xtr743187 ([202.27.181.90]) by web4-rme.xtra.co.nz with SMTP id <20020519213903.OKCF12047.web4-rme.xtra.co.nz@xtr743187> for ; Mon, 20 May 2002 09:39:03 +1200 Message-ID: <005601c1ff7d$fb579360$5ab51bca@xtr743187> From: "Vernall" To: rsgb_lf_group@blacksheep.org References: <000c01c1ff5b$456a8480$8ce4fc3e@l8p8y6> Subject: LF: Re: pegelmesser Date: Mon, 20 May 2002 09:40:23 +1200 MIME-Version: 1.0 Content-Type: text/html; charset=windows-1252 X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 5.00.2919.6600 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group Sender: Content-transfer-encoding: 8bit

Mal,

The frequency stability of any selective level meter with a VFO for a local oscillator makes them suspect for staying tuned within a fraction of a Hz for long periods. The digital display on a Siemens D2019 I have merely counts the VFO (with a constant 100 kHz offset to give passband centre frequency) and numbers actually change with VFO warmup. The display is to 10 Hz, so it can not be used for pre-setting to a QRSS signal that is expected to be below the noise and therefore impractical to try tuning by "ear". As well, the BFO is a free-running RC oscillator so the recovered audio can have further drift of centre frequency.

There are some selective level meters with master oscillator arrangements for tuning and demodulation, and can have fractional Hz stability.

In saying the obvious, selective level meters are primarily intended for determining signal levels.

Bob ZL2CA