[Laser] Re: Lunar Eclipse

[F1AVYopto at aol.com]

>Do the 50 Hz lines there in France or other areas of  Europe
>drift the same way our 60 Hz lines do?

All the alternators  are mandatory synchronic because their electrical 
properties.
They work like  adjustable power generators (E>U) or synchronic motors (E<U) 
but their  rotation speed defines strictetly their produced frequency and a 
shift in  frequency a one to the others is impossible.
An overload that should give a  bigger than 60° phase offset on a 3 ph 
alternator should produce its abrupt  de-synchronisation, an inter-phase short cut 
and the disjunction of this  alternator to off line.
In fact it is the summing of all the rotating  inertias that stabilizes the 
immediate frequency.
The long-term stability is  maintained by the accurate adjustement between 
the avelable power and the used  power.
Automatic devices add or remove the energie input by stations or  
sub-stations commutations. 
In all the modern countries the long  term-stability is quite good but the 
immediate frequency fluctuates a little  bitas you notice.

>Each power generation station would
>have its own frequency  at any particular time, only
>occasionally matching up with other stations  briefly.


All the lines in a network are synchronic on the same frequency but each  
phases are separated by T/3 (120°)
It is why on a perfectly equilibrate network the lamps should not deliver  
120 Hz light but mainly 360 Hz. 'In Europe 100 and 300 Hz)
In  Europe most of the networks are interconnected to exchange their  
energies so they are synchronous.
Is  it the same in USA  between states and the neighbour countries like 
Canada ?  
The advantage for us of a very  stable frequency is the efficiency in 
averaging and summing functions in a  FFTDSP program.
QRSS 120 s / dot allows a very high sensitivity but you are right  needs a 
very long time to detect the signal ! 
73 Yves  F1AVY