[ARC5] AN-Ranges

[Kenneth G. Gordon]

On 4 May 2018 at 11:29, bob at vanirmail.com wrote:

> Good morning Ken.
>  
> Did you really mean 60 RPM?

Yes. 60 RPM

>  Or perhaps 60 revs per second, I.E 
> 3,600 RPM?

Absolutely not. They wouldn't have run more than a week before failing at that speed. I had 
two military 5 kW generators at one time: a PU-286G which turned at 1800 RPM, and a 
different one which turned at 3600 RPM, both had 4 cylinder in-line engines in them. I never 
could figure out how the 3600 RPM job could be very reliable, but it did have 
positive-rotation valves in the engine and ran for a full 24 hours at one Field Day in which 
we used both of them. Talk about a screamer!

60 RPM. 

I was amazed.

A 2-pole alternator requires 3600 RPM for 60 Hz, a 4-pole, 1800 RPM, etc.

I have forgotten the mathematical relationship between poles and Hz output, but according 
to my quick and dirty figuring here, a 60 RPM generator would require something like 120 
poles.

Anyway, I assure you that Woody insisted that they were 60 RPM generators. I questioned 
him closely at the time, and he assured me it was so. And they were Kohler, too. Old ones.

Ken W7EKB

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