[time-nuts] E1938A PN measurments

[Bruce Griffiths]

Magnus Danielson wrote:
> On 09/29/2012 02:45 PM, Bruce Griffiths wrote:
>> For those that have Timelab the link to the E1938A PN measurement 
>> data is:
>>
>> https://dl.dropbox.com/u/59708595/E1938A.tim
>
> Thank you. I will measure mine so that we can compare them.
>
> Cross-correlation with a pair of BVAs should do it.
>
> Cheers,
> Magnus
>
>
I'm still a little suspicious of the result, although measuring a second 
E1938A removed from a Z3815A produced similar results.
I'll measure one of them again with an isolation transformer to 
eliminate an LF earth loop to see if the earth loop was an issue.
Using a single reference (PN floor < -170dBc/Hz) should suffice for this.
I didnt have RF isolation transformers available at the time.
I have since found that using a single point LF ground (rather than 
floating the entire interferometer) reduces the interferometer PN floor 
substantially.

Bruce