[Drake] AC-4 transformer

[Guillermo]

    Hello all, I'm new to the list; I've an old Drake TR-4 from a
friend, and the transformer of the AC-4 power supply takes a high
current from its primary, when connected to 120 Vac and with all
secondary windings disconnected; it was measured something about 1.7 A,
the core keeps warm (normal temperature I think) even after 40 minutes
of use in the above condition. All secondary voltages measures ok, 255,
95, 105 and 13.5 Vac.
Another thing I've noted is that at 110 Vac it takes only 0.9A of
current, the strange behaviour for me is that  when I raise input
voltage to 120 Vac  (with a Variac) primary current raises very
abruptly, �is this transformer performing as designed?.

TIA
Guillermo - LU8EYW.