[time-nuts] Improving the stability of crystal oscillators

[Magnus Danielson]

From: Bruce Griffiths <bruce.griffiths at xtra.co.nz>
Subject: Re: [time-nuts] Improving the stability of crystal oscillators
Date: Fri, 12 Oct 2007 10:08:34 +1300
Message-ID: <470E90D2.6000304 at xtra.co.nz>

Hej Bruce and Neville,

> Neville Michie wrote:
> >
> > If you use a transistor as a heater, the full supply voltage is  
> > across the
> > element all the time, so heating is proportional to the current flowing.
> >
> > Neville
> >   
> Neville
> 
> However using a transistor has the disadvantage of a small area heat
> source rather than the large area heat source possible with a heater
> winding.
> Using a small area heat source produces significant temperature gradients.

Using a single transistor yes. Spread out transistors can provide significantly
less gradients.

Cheers,
Magnus