[time-nuts] Lady Heather numbers

Peter Gottlieb nerd at verizon.net
Sat Mar 2 21:45:22 EST 2013

I finally got the antenna outside, but just onto a deck railing and not yet up 
high on the roof.  Before I do that, does it look like I'm getting decent 
performance from it?  Here is the LH display:

Once up on the roof the Westerly exposure will be improved, but North East and 
South are pretty much clear right now.

Does anything else look suspicious or wrong?

Any hints greatly appreciated!

On 2/26/2013 1:53 PM, WarrenS wrote:
>> Can anyone comment on the picture.
>> I don't know if what I have would be considered good as far as accuracy and 
>> stability is concerned.
> The screen dump is way too short to give much detail.
> What can be said from what is there:
>> From a Ham standpoint it is all working fine and is much better than 1e-9.
>> From a time nut standpoint it is very poor.
> It is using the default setting (for the most part)
> Phase error at -100ns is ~50 times high for the 100 sec TC setting used, 
> (likely due to the high drift rate of the Osc)
> Frequency error is wondering around 1e-10 is about 50 times higher than what 
> is possible.
> Effect on freq and phase noise with sat changes is >>10 times more that what 
> is possible with good setup.
> Concerning your Dac comments, Yes makes sense, but your conclusing is wrong.
> Can't say or sure, because the 24 Hr + screen shot is not shown, but in general
> The Tbolt temperature reading has no direct effect on the Dac control voltage 
> unless the Tbolt is in hold over.
> The Dac voltage changes because the oscillator's freq is trying to change, not 
> the other way around.
> You can disable the Dac from changing with "dd".
> ws
> ********************
> From: "Garren Davis"
> Subject: [time-nuts] Lady Heather numbers
> Hi,
> I have been playing with my thunderbolt and Lady Heather over the weekend. I 
> hope it's ok
> that I attached a screen dump of what I have. Can anyone comment on the 
> picture. It's been
> running less than a day and I don't know if what I have would be considered 
> good as far as
> accuracy and stability is concerned.
> Thanks.
> Garren
> **************************
> Garren Davis garren.davis at qlogic.com
>> From looking at the graph over 24 hours it looks like the outer oven varies 
>> about +-.5C. This is
> from the tbolt temperature sensor as the tbolt is in the outer oven. The inner 
> oven where the
> oscillator is located holds at 66.4C. My concern is that it looks like the 
> tbolt algorithm controls
> the DAC voltage depending on the temperature that the tbolt reads. Temperature 
> goes up, the DAC
> voltage goes up. If the inner oven is holding steady then I don't want the DAC 
> voltage changing
> if the temperature in the outer oven is changing. Is there any way to tell the 
> tbolt algorithm to
> ignore the temperature in its DAC calculation?
> Wow, I hope this makes sense the way I explained it.
> Garren
> 888888888888888888888
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