Return-Path: Received: (qmail 8346 invoked from network); 30 Nov 2002 14:39:08 -0000 Received: from murphys.services.quay.plus.net (212.159.14.225) by mailstore with SMTP; 30 Nov 2002 14:39:08 -0000 Received: (qmail 29221 invoked from network); 30 Nov 2002 14:38:54 -0000 Received: from post.thorcom.com (193.82.116.70) by murphys.services.quay.plus.net with SMTP; 30 Nov 2002 14:38:54 -0000 X-SQ: A Received: from majordom by post.thorcom.com with local (Exim 4.10) id 18I8lI-0001Lx-00 for rsgb_lf_group-outgoing@blacksheep.org; Sat, 30 Nov 2002 14:38:28 +0000 Received: from [195.235.30.34] (helo=smtp.bankinter.es) by post.thorcom.com with esmtp (Exim 4.10) id 18I8lH-0001Lo-00 for rsgb_lf_group@blacksheep.org; Sat, 30 Nov 2002 14:38:27 +0000 Received: from BI57429bankinter (h028074.nexo.es [195.235.28.74]) by smtp.bankinter.es (8.9.2/8.9.2) with SMTP id PAA05528 for ; Sat, 30 Nov 2002 15:38:26 +0100 (MET) Message-ID: <002901c2987e$08e4aa60$4a1cebc3@BI57429bankinter> From: =?iso-8859-1?Q?Jos=E9_Manuel?= To: rsgb_lf_group@blacksheep.org References: <170.17d27e8b.2b1a181e@aol.com> Date: Sat, 30 Nov 2002 15:37:38 +0100 MIME-Version: 1.0 X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2600.0000 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 Subject: Re: LF: Osc drift (TCXO) Content-Type: text/html; charset=windows-1252 X-Spam-Status: No, hits=0.7 required=5.0tests=MAILTO_LINK,REFERENCES,SPAM_PHRASE_00_01,SUPERLONG_LINE, USER_AGENT_OEversion=2.42 Sender: Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group Content-transfer-encoding: 8bit
Hi All again:
 
Note about TCXO and DTCXO.
73, José - EA1PX
 
http://www.temex-components.com/temex/technote/dctcxo.html
----- Original Message -----
Sent: Saturday, November 30, 2002 2:33 PM
Subject: Re: LF: Osc drift (TCXO)

Hi,

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.


I think the idea of a numerically-controlled TCXO is having an internal ADC digitizing the NTC voltage, convert it in a calibrated nonvolatile lookup-table and then use a DAC for the varicap. Depending on digital resolution, this concept can be prone to a stepwise response to gradual temperature changes, possibly resulting in a sawtooth FM pattern.

73
Markus, DF6NM