Return-Path: Received: (qmail 9729 invoked from network); 30 Nov 2002 11:39:13 -0000 Received: from marstons.services.quay.plus.net (212.159.14.223) by mailstore with SMTP; 30 Nov 2002 11:39:13 -0000 X-Priority: 3 X-MSMail-Priority: Normal Received: (qmail 26058 invoked by uid 10001); 30 Nov 2002 11:39:01 -0000 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 Received: from post.thorcom.com (193.82.116.70) by marstons.services.quay.plus.net with SMTP; 30 Nov 2002 11:39:01 -0000 X-SQ: A Received: from majordom by post.thorcom.com with local (Exim 4.10) id 18I5wm-0000Mw-00 for rsgb_lf_group-outgoing@blacksheep.org; Sat, 30 Nov 2002 11:38:08 +0000 Received: from [152.163.225.104] (helo=imo-r08.mx.aol.com) by post.thorcom.com with esmtp (Exim 4.10) id 18I5wl-0000Mn-00 for rsgb_lf_group@blacksheep.org; Sat, 30 Nov 2002 11:38:08 +0000 Received: from G0MRF@aol.com by imo-r08.mx.aol.com (mail_out_v34.13.) id l.136.17cb9e7c (4340) for ; Sat, 30 Nov 2002 06:37:35 -0500 (EST) From: G0MRF@aol.com Message-ID: <136.17cb9e7c.2b19fcff@aol.com> Date: Sat, 30 Nov 2002 06:37:35 EST To: rsgb_lf_group@blacksheep.org MIME-Version: 1.0 X-Mailer: AOL 6.0 for Windows UK sub 10512 Subject: Re: LF: Osc drift Content-Type: text/html; charset=windows-1252 X-Spam-Status: No, hits=1.4 required=5.0tests=BIG_FONT,EMAIL_ATTRIBUTION,NO_REAL_NAME,SPAM_PHRASE_05_08, USER_AGENT_AOLversion=2.42 X-Spam-Level: * Sender: Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group Content-transfer-encoding: 8bit In a message dated 11/29/02 7:03:23 PM GMT Standard Time, blanch@pncl.co.uk writes:



Layout of the IIG oscillator/synthesizer board is quite different from the
II, also the TCXO for the IIG is much bigger and a different part number.
The TCXO for the II is claimed to be a "numerically-controlled" type, that
for the IIG is not. Does anyone know the difference? I thought all tcxo's
were just thermistor-controlled varactor diodes in series with the crystal.



There is a remote possibility that you may have a PLL frequency synthesiser and not a crystal at the frequency that you think.
I recently tried to buy a crystal oscillator module at 70 something MHz only to be told that they were OK for everything except demanding communication applications.
It appears that they frequently have a standard PLL module and just programme it for whatever frequency the customer wants. It's then sold as an Oscillator module, which does contain a crystal, it's just the reference xtal for the internal PLL.
That may go some way to explain the jitter.......or not as the case maybe.

73

David  G0MRF   www.g0mrf.freeserve.co.uk