Hi, I'm curious to hear people's thoughts on the SRS FS740 (https://www.thinksrs.com/products/fs740.html) as a lab frequency standard. The phase noise performance of the OCXO and Rb options seem quite good (the same specs apparently apply during GPS disciplining too)
| offset | TCXO | OCXO/Rb | | (Hz) | (dBc/Hz) | (dBc/Hz) | |--------+----------+----------| | 1 | -90 | -108 | | 10 | -104 | -130 | | 100 | -125 | -144 | | 1k | -142 | -143 | | 10k | -147 | -148 | | 100k | -149 | -149 | | 1M | -153 | -153 | as does the Allan deviation (during GPS disciplining) | time interval (s) | TCXO | OCXO | Rb | |-------------------+-------+-------+-------| | 0.01 | 1E-10 | 2E-11 | 2E-11 | | 0.1 | 4E-11 | 4E-12 | 4E-12 | | 1 | 3E-11 | 2E-12 | 1E-11 | | 10 | 1E-10 | 2E-12 | 6E-12 | | 100 | 6E-11 | 2E-12 | 1E-12 | | 1k | 6E-12 | 3E-12 | 1E-12 | | 10k | 6E-13 | 6E-13 | 3E-13 | | 100k | 6E-14 | 6E-14 | 3E-14 | | 1M | 5E-15 | 5E-15 | 3E-15 | (I used the typical performance plots for the phase noise and Allan deviation data) The OCXO does not exhibit the the hump around 2s seen by the rubidium oscillator option (PRS10) and therefore could be seen as better in applications not requiring the better holdover performance by the Rb. It also provides a pulse output with jitter < 50 ps RMS that could be used as a PPS signal. It can also provide a low noise 100 MHz output signal and can act as a frequency counter and DDS with high resolution and accuracy. And it comes with the schematics! But.... it's definitely not cheap. Other thoughts/opinions? Matt _______________________________________________ time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an email to time-nuts-le...@lists.febo.com To unsubscribe, go to and follow the instructions there.