"Emmanuel Gustin" wrote in message ...

It was technically quite difficult to provide a smooth control
that had a more or less natural 'feel' for the gunner, was capable of
high speeds of rotation but also of accurate slow tracking, and had
no dead spots anywhere where movement wasn't linked correctly
to control input -- for example when passing the 0 degree line from
left to right, where the forces working on the turret reversed.

This I do not understand. The radar antennas of the era often used
synchro feedback systems - synchros do not have dead spots, they
provide a rotational signal from 0 to 360 with no interruptions when
making the 359 to 0 transition. What was the problem with the
control systems in the turrets?

Very hard. The electronics of the period used numerous
vacuum tubes which had a short lifetime.

Only hard working transmitter and radar tubes had short lifespans
(often just 50 hours). The tubes found in just about everything else
were quite hardy - most outlasted the war and are still good today.
Many small signal tubes often clocked lives well past 10,000 operating
hours.

William Donzelli