Message-ID: <002c01bfb096$06800760$9b1a073e@default>
From: "Alan Melia" <Alan.Melia@btinternet.com>
To: rsgb_lf_group@blacksheep.org
Subject: LF: Re: RE: High stability drive sources
Date: Thu, 27 Apr 2000 23:14:57 +0100
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Hi Andy, yes I have a toe in the microwave camp too! The Racal block has a
'tweaker' available through the rear panel but I am not sure whether it is a
pot or a cap yet. I have one of each here. Yep they are a bit big but look
to see what frequency you want to stablise before you throw the rest away
they will produce stabilised output from 2Mhz to about 32  MHz but not
continuously there are gaps. I believe the microwave boys are using them
with a 32MHz rock to give the 96MHz standard LO base frequency.
You mentioned the Murata heater tabs earlier.....have you any idea what
temperature these are supposed to stabilise at?? My data book doesn't quote
this. I have seen problems where the crystal used was not specified for a
turnover at the 'oven' temperature, leading to worse stability than without
using the tab. (crystals for use in ovened enclosure are usually cut at a
slightly different angle I believe) Used correctly they should give a order
of magnitude improvement for the guys with outside shacks! Particularly if
the 'tab' 12v supply can be left switched on. It is not a total cure and for
best performance crystals still need to be protected from direct draughts
even if only by a cornflake package.

Cheers de Alan G3NYK
Alan.Melia@btinternet.com

-----Original Message-----
From: Talbot Andrew <ACTALBOT@dera.gov.uk>
To: 'rsgb_lf_group@blacksheep.org' <rsgb_lf_group@blacksheep.org>
Date: 27 April, 2000 12:54 PM
Subject: LF: RE: High stability drive sources


>
>> Are more of these becoming available ?  A lot have been bought up by
>> microwave operators recently.
>>