And now for something completely different
Fun with TEA!
This is the setup: The TA520 Time Interval Analyzer, the dual channel Tek AWG, a scope, a thermometer, a roll of RG174, a splitter and a dual mixer time difference contraption
The DMTD contraption:
A simple power splitter, good enough for 10MHz
A convenient roll of RG174 cable:
For better results, some thermal shield was added to the setup:
So, fire it all up and wait for the measurement to settle. The TA520 shows a nice horizontal line (time difference between the mixer outputs at 100Hz offset frequency). So 100ns equals 1ps in real.
Doing the numbers from the readout, the DMTD contraption has 1.1ps peak-to-peak / 0.16ps rms noise floor.
Now, I've taken the heat gun and partially warmed the RG174 by maybe 5°C ... 10°C. Result is here:
There's a change in delay of the warmed up RG174 line of about 2.5ps within 12sec.