I raised the issue of non-60Hz power in North America in another forum just a couple of months ago. It was after I acquired a book dating from 1959 (3rd edition, the 1st being 1950) which stated that 25Hz power was still in use in parts of upstate NY, and that many West Coast cities had 50Hz power.
I know from previous discussions we've had that the Los Angeles area used 50Hz at one time, and converted over to 60Hz during the 1930s. Apparently there was a city-wide program to help everybody replace synchronous clocks.
Somebody else recalled that when his grandfather worked as an electrician in the West Virginia mines in the early 1950s that they had 25Hz power.
We also came up with the following link to an interesting article about frequency converters. This seems to confirm that 25Hz power was indeed generated in the Niagara/Buffalo region of New York, as well as elsewhere.
Here in England, 25Hz was used on some electrified railroads in the npast, although the high-voltage lines now in use take their power from our regular 50Hz power grid.
- Paul.
[TELECOM Digest Editor's Note: One of my earliest terminal monitors was the H-19 from Heathkit (also known as Z-19 if you bought it already put together from Zenith. There as a little switch on the back which allowed you to 'default into' 50/60 cps, and you could also switch between 50/60 cps mode using keystrokes. PAT]