[time-nuts] Thunderbolt Supply

[Bob Camp]

Hi

The +12 volts is what you want to keep stable. You would like to keep them all reasonably clean. That's not to hard for -12 since there's next to no current on it. +5 is mostly digital logic, it generates it's own suprs and noise. +12 runs the OCXO and it's internal regulators, it's likely all analog. 

The issue here isn't as much ultra clean as stable. A well regulated supply on the +12 will give you better performance out of the TBolt. The OCXO does indeed change frequency when the +12 changes. I posted some data a while back. 

Bob
 
On Feb 15, 2011, at 7:40 AM, Brendan Minish wrote:

> On Tue, 2011-02-15 at 10:47 +0100, Magnus Danielson wrote:
> 
>> This has gone overboard. The T-bolt generates digital noise all by 
>> itself. It's the OCXO which would benefit most from a clean supply and 
>> isolation from the rest of the T-bolt except that temp-sensor.
> 
> Considering the T-bolt has 3 supplies which rail is the one that is most
> important to keep clean 
> My main interest is the best possible phase noise and spur performance
> as the 10MHz output is feeding a high quality SDR
> 
>> Providing ultra-clean supplies to the digital logic would be overkill, 
>> as it would mess it up itself anyway.
> 
> I guess what I am wondering, considering I already have a very low
> noise, stable, battery backed 12V (13.8V really) system in the shack can
> I use that along with a small dual rail DC-DC converter and still get
> very good performance 
> 
> 
> -- 
> 73
> Brendan EI6IZ 
> 
> 
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