[time-nuts] is there a "best bet" advanced hobbyist buildableGPSDOdesign?

[Scott Burris]

phil wrote:
>> On Dec 13, 2007 12:00 PM, Scott Burris <slburris at gmail.com> wrote:
>>     
>>> Continuing the design discussions, anyone have opinions about powering
>>> the HP 10811 oscillator?
>>> I'm thinking that you want voltage regulators that are pretty quiet so
>>> as to minimize jitter introduced
>>> via the power supply.  To that end, I'm looking at a LT1761 for the +12v
>>> OSC voltage and an LT3080
>>> for the 24v heater supply..
>>>       
>
> You might try ebay for a +24 / +12 volt switching supply, problem/s solved.
> I have bought them for as little as 3 bucks.
> Phil
>
>   
Can you get switching power supplies with really low noise 
characteristics?  The LT3080
is rated for 40uV of noise, and the LT1761 is rated for 20uV.  The 10811 
manual
suggests less than 100uV of noise for the oscillator supply and less 
than 30mV for the
heater. 

I'm not saying you couldn't get down into the uV range with switchers 
with some aggressive
filtering of some sort, but I'm not sure why one would go that route 
over a linear supply,
which can hit those numbers with the right regulators.  Here I'm valuing 
noise characteristics
over efficiency and size.

Scott