I tested a number of LNBs regarding the quality of their ozillators. To do this I mounted the LNBs in the feed holder of a FUBA DAA 850 A offset dish, monitored the CW beacon with an SDRplay RSP2pro and the software SDRconsole and evaluated the signal in the waterfall diagram.
Out of 50 single LNB's GM-201 the oscillators of 7 pieces have wobbled.
Out of 10 single LNB's goobay 67269 the oscillators of 2 pieces have wobbled.
At 10 single LNB's OPTICUM LSP-02G none of the oscillators wobbled.
Of other LNB types, I only have one or two pieces to test, so I can not say anything about their Oszillaors. With a total of more than 80 LNBs examined, one was included with a remarkably frequency stable oscillator. So there are also outliers for the good side ...
73! Peter, DJ7GP