Actually there is a row in the manual that says that after the
alignment the gain of the filter stage must be 30dB consistently on
all the positions, 40dB with zero bias. It is written in German and I
missed that row before. I will try to figure out what this means in
terms of IF output level.

1sec comes from 0.1sec per division by ten divisions. If I'm getting
it right, I should try to keep the gain as constant as possible for
the purpose of the alignment, this is the key point I missed before.

The fact is that, at the moment, with either AGC off or AGC on, the
filters are quite far from spec, sometimes the center freq is off,
sometimes the top is not flat and/or the width is twice or three times
than expected. There are ten trimmers per filter, sixty total.

Tomorrow, I will record the current conditions and try to make some
progress.

Thank you again and best regards
Paolo