TURN Dynamic Systems FSA3011 Frequency Stability Analyser

[jpb]

I've just come across this Frequency Stability Analyser on ebay which looks like a lower spec TimePod 5330A
https://www.ebay.com/itm/OCXO-GPSDO-Atom-Clock-Frequency-stability-Analyzer-FSA3011/123728915157
Does anyone know anything about TURN Dynamic Systems and this measurement device? It doesn't seem to use IQ type processing in the same way as the TimePod but then I suspect there is patent protection on the TimePod and the block diagram is quite high level so doesn't give much detail.

The noise floor of < 10^-12 at 1 second is twenty or more times better than most counters making direct measurements but it is probably not good enough for measuring good OCXOs in the short term.

It is certainly cheaper than a TimePod but is rather too pricey for my budget (hobby use) but I would like to know more about it.

[LKM]

It's a Dual-Mixer Time Difference analyzer. Clocks being compared still have to be the same frequency by the time they get to the mixers, this one appears to have a configurable divider which is nice, but it's not arbitrary inputs like the TimePod.

W. J. Wriley (author of Stable32) built a DMTD and did a great write-up. His has a better ADEV floor but price will probably be comparable if you built it. At least you'll know how they work.
http://www.stable32.com/A%20Small%20DMTD%20System.pdf

[jpb]

It's a Dual-Mixer Time Difference analyzer. Clocks being compared still have to be the same frequency by the time they get to the mixers, this one appears to have a configurable divider which is nice, but it's not arbitrary inputs like the TimePod.

W. J. Wriley (author of Stable32) built a DMTD and did a great write-up. His has a better ADEV floor but price will probably be comparable if you built it. At least you'll know how they work.
http://www.stable32.com/A%20Small%20DMTD%20System.pdf

Thank you.

I am a fan of W.J.Riley and his web site and use Stable32 and also am very aware  of the traditional dual mixer with zero crossing detection and counters but I somehow thought that this was something different. The block diagram on the ebay item shows counters before the mixers (presumably for coarse measurements) and then the mixer outputs go to  a block simply labelled "Time interval measurement" -  you are probably right that this is a time interval count between zeros but I wondered if it was doing anything different especially as its output is shown going into the phase measurement.

I am also rather curious about "TURN Dynamic Systems" - I can't find anything on the web about them but a couple of their products (this and a GPSDO module) have turned up on ebay recently.

[5065AGuru]

Hi, A friend is buying one and sending it to me to characterize. I'll be sharing the results here and also at time-nuts. I have 3 different DMTD systems at this time and am very interested to see how it compares!

Cheers,

Corby

[jpb]

Hi, A friend is buying one and sending it to me to characterize. I'll be sharing the results here and also at time-nuts. I have 3 different DMTD systems at this time and am very interested to see how it compares!

Cheers,

Corby

That would be great. I look forward to reading the results.

[dekagon]

Hello Corby,

did you have time for checking / comparing the FSA3011 yet? I would especially know if the FSA3011 can measure phasenoise or only the timestamps
of the DUT oscillators...

Thank you in advance

Chris