[time-nuts] Re: problem with Trimble Mini-T

[Erik Kaashoek]

Hi Magnus
The ADEV was a separate measurement using the 10MHz output of the Mini-T 
against my most stable DOCXO using a tinyPFA
Erik.

On 6-11-2023 20:12, Magnus Danielson via time-nuts wrote:
> Hi Erik,
>
> Really happy to hear you got hold of the issue, and happy that my 
> little suggestions got you in the right track quick enough.
>
> With ADEV, do you mean the Lady Heather self-reports or that of a 
> separate reference measurement?
>
> Cheers,
> Magnus
>
> On 2023-11-06 16:47, Erik Kaashoek via time-nuts wrote:
>> Hi Magnus,
>> Thanks for telling me to check everything.
>> I turned out to be leakage from another 10MHz source with an output 
>> coax running close to the coax from the reference.
>> To ensure the PLL worked correctly I first validated in open loop 
>> mode the control range of the DAC, which turned out to have 10MHz 
>> correctly centered in the middle of the DAC range.
>> Then I enabled the PLL and after about 10 minutes the PLL was stable 
>> and within 1e-10 of a Rubidium reference.
>> The 0.1s ADEV without PLL active is just below 0.8e-11. With PLL 
>> active the 01. - 100 s ADEV is at about 3e-11 which is good enough 
>> for me. The active PLL ADEV can be further improved by making the 
>> loop time constant longer if needed (it is now at 100s)
>> Erik.
>>
>>