[time-nuts] Lady Heather numbers
lists at rtty.us
Sat Mar 2 21:52:24 EST 2013
If there was a file / image attached , it didn't make it through. North doesn't matter much, South is a very big deal. That of course assumes you are in the US or Europe.
On Mar 2, 2013, at 9:45 PM, Peter Gottlieb <nerd at verizon.net> wrote:
> 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".
>> From: "Garren Davis"
>> Subject: [time-nuts] Lady Heather numbers
>> 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.
>> 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.
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