FYI - some results of testing the formation of the 25 MHz reference signal for the LNB PLL and 40 MHz reference (for the VHF SDR ADALM Pluto) based on the ICS512 chip (PLL CLOCK MULTIPLIER) at http://www.ra3apw.ru/proekty/ics512_reference/. Please use Google translator.
The 10 MHz OCXO with phase noise -154 dBc / Hz @ 10 kHz acted as the main source of the reference frequency.
As a result: 25 and 40 MHz signals are formed, stability is good but the phase noise value (-99 dBc/Hz @ 10 kHz) is not good enough.
Use for QO-100 is not recommended.
73 de Karen, ra3apw