Sorry RVDT, I had to amend my post as the Rad Alt remains on.
(memo to self: don't pretend to understand the electrical diagrams in the engineers office!)
Double Generator Disconnect will see the loss of;
Comm/Nav 1, Strobe/Nav lts, TCAD, ANR,
Steerable LL, Role Kit, Pitot 1, ADF/DME,
Gooseneck lights, Aft Tx Pump, Air Blowers, ATT Trim,
(My thought was that with the engines chopped and the rad alt gone there would be little reference of height in the descent other than out the window. As it happens, the rad alt would still indicate, although any aural warning would depend on the bug setting and the setting of the preset height warning system. Of course over a built up area the rad alt would be an area weapon!)