I have been wondering if the 0v path from the FEE64s to the MACB where they are joined is a possible problem.

I have been contemplating an isolated LVDS interface for the 50Mhz clock to test the idea.

Fortunately i recalled the 50Mhz internal oscillator in each FEE64.

I have disconnected the FEE64s from the MACB and run them using their internal 50Mhz clok.

No apparent change in performance.....

With Detector on. Using 'little block' HV supply. 11&12 with pre-amp ref set at 0x30.

The rates are as follows:-

nnaida11: 19k

nnaida12: 52k

nnaida13: 10k

nnaida14: 10k

The stat spectra of 13 & 14 look ok.

The stat spectra of 11 and 12 are strange and noisy but not "mad".

Maybe when the power supply filters are in place this can be revisited