[time-nuts] Low noise power supplies?

[Jim Lux]

On 1/30/13 8:28 PM, Chris Albertson wrote:

> For once the "best" is also cheap:  Batteries.
>
> But not all batteries are the same.  You want one with low internal
> resistance, so a lead acid flooded battery will be the best.

Most NiCd have very low internal resistance.. much lower than lead acid.

But aside from batteries, Rick's question is interesting, and I'd turn 
it around a bit.. What "off the shelf catalog product" has the lowest 
noise?  Do you go get a linear regulated supply from someone like Acopian?

And even more interesting.. if you're concerned about efficiency and 
want to use a DC/DC switcher to convert some ratty DC supply (12V 
vehicle power, or a solar panel, for instance) to something really 
quiet, what's the best strategy, using off the shelf bricks and modules.

That is, I'm sure someone could do a fabulous job with a box full of Ls 
and Cs and discrete components and a couple months to design, prototype, 
and build.. but if someone came to you and said, we want a mobile 
microwave system to study propagation in 3 weeks because they just got 
permission to go up on some mountain.  Something like a CW carrier at 
tens of GHz multiplied up from your very quiet oscillator, and they're 
going to look at turbulence and scintillation in the path, so time 
scales of milliseconds to 1000s of seconds are important.

What would you order from Newark, Allied, mouser, etc. (assuming you 
have your OCXOs and such sitting around).