Hi all, I would appreciate any help in understanding testing for microphonics.
We have following requirements on Oven Controlled Crystal Oscillator (OCXO) when subjected to the random vibration level of 0.01 G^2/Hz from 20 to 200 Hz and the sinusoidal level of 0.1 G peak to peak from 20 to 120 Hz.
1. overall frequency stability < +/- 3.5 ppm
2. short term frequency stability of 3 sigma limit allen variance measured over a minimum of 150 samples with the sample of 100 milliseconds or less. The unit shall not vary more than +/- 1E-7 per second
3. frequency pulling shall be the frequency variation measured with a load of a voltage standing wave radio (VSWR) as high as 2.0:1 and shall not exceed +/-0.02ppm.
I am a mechanical engineer and trying to understand the microphonics. Can anyone tell me the implications of carrying out the sinusoidal test (the sinusoidal level of 0.1 G peak to peak from 20 to 120 Hz.) at fixed frequency of 20, 40 and 60 Hz instead of continuous sine sweep from 20 to 120 Hz?
Thanks in advance.