[R-390] Alternative to IERC tube shields?

[mikea]

On Mon, Aug 17, 2009 at 02:32:31PM -0400, Barry wrote:
> > An alternative is to put two of these in series; this also drops the
> > RPMnicely, but since you have two fans, you're moving twice as much air and
> > not having to put up with the heat from the resistor. 
> > 
> > -- 
> > Mike Andrews, W5EGO
> 
> A thermister, a couple of tubes, transformers, and an assortment of
> other components, and I'll bet someone could design a variable-speed
> fan that would regulate the temperature within a degree or two. Maybe
> it could use another 3TF7 to regulate the filaments on the circuit
> so that changes in the line voltage would not affect the temperature
> regulation.
>
> Barry - N4BUQ (duckin' and runnin')

I think that's an absolutely *GREAT* idea. While we're at it, we could
put the cold sides of some Peltier-effect coolers in the airflow from
the fans-in-series. I'll think about how to use some additional 3TF7s to
regulate the temps on the coolers.  

-- 
Mike Andrews, W5EGO
mikea at mikea.ath.cx
Tired old sysadmin