The ones available from the Microwave Component service were 35 - 40
deg units. These were just about OK. for the normal 20 deg
temperature crystal although a bit close to the turnover as you say.
Taking uWave equipment out portable on a hot day meant sunlight on the
RF box could raise the temp above this, upsetting the stability.
Some heaters Sam, G4DDK, had were 50 - 60 deg units and need a
specially cut crystal, where the perfomance was then excellent. Think
I have some of these decices, but haven't tried them yet as I haven't
any suitable high temp cut xtals in HC18U case.
Didn't know you were a Microwaver Alan ! I always maintained 73kHz
was a microwave band, where experimentation and homebrewing rather
than just operating was the norm. 137k just seems a DX chasing band
You mentioned the Murata heater tabs earlier.....have you any idea
temperature these are supposed to stabilise at?? My data book doesn't
this. I have seen problems where the crystal used was not specified
turnover at the 'oven' temperature, leading to worse stability than
using the tab. (crystals for use in ovened enclosure are usually cut
slightly different angle I believe) Used correctly they should give a
of magnitude improvement for the guys with outside shacks!
the 'tab' 12v supply can be left switched on. It is not a total cure
best performance crystals still need to be protected from direct
even if only by a cornflake package.
Cheers de Alan G3NYK
From: Talbot Andrew <[email protected]>
To: '[email protected]' <[email protected]>
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
>> microwave operators recently.
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