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Old 06-11-15, 19:10
Bruce MacMillan Bruce MacMillan is offline
a Canuck/Brit in Blighty
 
Join Date: Jul 2004
Location: Hell Fire Corner, Kent UK
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Quote:
Originally Posted by BCA View Post
I believe that the lower 25 hertz frequency required heavier transformers that for use with 60 hertz power. 400 hertz aircraft devices may have gone to a higher frequency to cut down weight. Can anyone clarify this? Also I suspect that a heavier 25 hertz device might work OK at a higher frequency, say 60 hertz. But not possible to go in the other direction.... Brian
Right on the money Brian. The older power generators around Niagara and other areas of the the northeast were 25 cycle. Because of that they needed a bit more iron. A 25 cycle transformer will work on 60 cycle except for synchronous motors like clocks. It doesn't work the other way around.

Aircraft went to 400 Hz to reduce weight. Modern supplies can work into the MHz range.

It's the weight of this equipment that coined the term "boatanchor" when referring to old radio equipment. Prior to moving I had to sadly give up a couple of Canadian Marconi CM11 sets weighing about 350 lbs each. The kicker was a pre war RCA RAB USN receiver. It weighed 460 lbs.
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