TELECOM Digest OnLine - Sorted: Re: 25 cps Power, was: Tie Lines was Re: Foreign Exchange Lines

Re: 25 cps Power, was: Tie Lines was Re: Foreign Exchange Lines

Paul Coxwell (
Mon, 30 May 2005 22:28:48 +0100

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

It would be interesting to know just how widespead the use of 50Hz was
in California in earlier times.

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]

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