Also, if you look at the first column of graphs from the GPSDO monitoring, the TIC ADEV is the phase error of the GPSDOs LO against the GNSS 1PPS output, after correcting quantization error ("sawtooth correction"). The magenta trace is after removing the frequency offset against 10MHz and after correcting also the frequency drift - as mentioned, the 53132A was only recently switched on and it's reasonable to assume that it will drift for a while before settling. The blue trace in timelab is the unedited phase data out of the tinyDMTD. I've also attached a screenshot from the GPSDO monitoring program, covering the same time interval. I've attached a screenshot out of timelab after collecting 1 hour worth of data. Temperature was not controlled during the test and I was in the room the whole time. No special cables were used, I took some PTFE SMA cables, connected the timebase output of the 53132A to one channel and the GPSDO output to the other channel. The measurement setup was relatively primitive, I just put the tinyDMTD on my lab bench, connected it to my laptop via the supplied USB cable and started logging in Timelab. So, here are the first results after letting the 53132A warm up for a few hours. The nanoVNA-H4 HW does not have to be modified so after use as a tinyPFA, it can always be converted back into a VNA. A wiki containing all the information for creating and using your own tinyPFA can be found here: A support forum is available in case you have questions regarding the operation of the tinyPFA or want to share results As the FW is fairly new you can expect some bugs.
During testing and comparing to other frequency and phase measurement devices, the tinyPFA outperformed conventional frequency counters and delivered phase measurements identical to a PhaseStation when used above the noise floor. Accuracy of phase measurements is better then 1e-12 / (Tau in seconds) and the device support sending the phase measurements over USB to programs like TimeLab or writing to an internal SD card for later analysis. For those that want to do very accurate phase and frequency measurements, but are not willing or capable to buy a PhaseStation or Timepod a new FW has been made available for the nanoVNA-H4 HW that converts it into a mix between a DMTD and PhaseStation.
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