After Chris, Jax and Volker worked on PZT, we moved to WFS.
The first trouble we noticed was the issue with MC1 and MC3 model mentioned in the earlier alog.
The second trouble was that we didn't get any sensible signal from segment 2 of WFSB.
It turned out that the RF cable for that segment on ISCT2L was broken at the connector on the WFS head. The metal sleeve thing was loose and would rattle when touched, and it was really easy to gently pull the cable out of the connector jacket.
We left the broken cable on the table and put a temporary cable in, and the segment started behaving. After this, we set the demod phase of WFSA and WFSB correctly by wiggling MC3 PIT.
The cable must be the one I had made a long time ago. I am sorry about that.
This picture shows the broken cable dangling from the cable tray.