[CW] Alexanderson Alternator

[Richard Knoppow]

     There seems to be some interest here in these ancient 
machines. I have a copy of "Principals of Radio Communication" 
(1921) J.H.Morecroft. This was a classic in its day.  In it he 
has a minimal discussion of both the Alexanderson Alternator and 
the arc converter type transmitters and also mentions the 
Goldschmidt alternator. The Alexanderson machines would have been 
very new then. In particular Morecroft talks about the relative 
efficiency of these machines. He states that there is very little 
information available about the efficiency and estimates it at a 
pretty low value, less than 50% for all of these CW sources. I am 
led to wonder if there was later information about efficiency. In 
particular, he assumes very high core losses in the Alexanderson 
machine.
    I suspect there is much better information in later books but 
I wonder if anyone on this list has made a study of early CW 
transmitters and can give a reasonably accurate of the 
efficiency. Both types of alternators and the arc-converter were 
built in very large sizes, up to a megawatt for the arc and at 
least 200KW for the alternators.
     This is the machine efficiency and doesn't count the antenna 
losses. One advantage of the Alexanderson machine is the multiple 
tuned antennas used with them which was considerably more 
efficient than the various other types used with the arc and 
Goldschmidt machines.

-- 
Richard Knoppow
1oldlens1 at ix.netcom.com
WB6KBL