[Ron Ramirez]

The 52-A models were. A model designated simply "52" (not 52-A) would have been designed for 60 cycles. There were some Philcos produced in Canada which were made for 60 cycle AC, but 25 cycle AC sets seem to have been the majority for Canadian-built Philcos prior to WWII.

And starting in 1939, Philco of Canada completely revamped their model numbering scheme, so some late prewar as well as postwar models sometimes reused model numbers of prewar USA Philcos, causing great confusion today.