The change in electrical power in Germany would not affect the
recordings of Hitler's speeches made here in the U.S. and in other
countries. I have some complete speeches I recorded directly off the
discs recorded by CBS in Philadelphia and NBC in Chicago, and excerpts
from many other albums. What about all those classical recordings
recorded on disc and tape in Germany during those years? They also
would be off-speed if Hitler is off-speed. It is quite true that many
78s were really recorded at 75 and 76, but this dates back into the
acoustical era when almost all recording machines were spring or falling
weight driven. Many companies continued to use the falling weight
turntables into the 30s. But there is one more factor. ALL of these
mechanical machines had their speed controlled by centrifugal governors,
and many electrical motors also were likewise controlled. The motors
were set to run fast and would then be reduced by the governor. If
governor control was used, mains voltage and frequency would have no
effect, even if it varied during the recording.
Mike Biel [log in to unmask]
-------- Original Message --------
Subject: [ARSCLIST] power line frequency
From: George Brock-Nannestad <[log in to unmask]>
Date: Tue, November 03, 2009 7:09 pm
To: [log in to unmask]
From: Patent Tactics, George Brock-Nannestad
Hello,
from time to time this crops up on ARSCLIST (although I can only locate
April
2004 at the moment), because it is highly relevant, both for recording
and
reproduction done with synchronous motor drive and when using
stroboscopes.
We are now so fortunate that we have a reasonable certainty of having
either
50Hz or 60Hz (not to mention 400 Hz in aircraft), but that was very far
from
the real world, say from the 1920s and until ca. 1965. I have a fairly
good
impression of what went on in the US and in the UK (and in central
Copenhagen, Denmark, they had DC until 1962!).
Ca. 1980 a Danish record collector who had started late in academia,
studying
the subject of contemporary history, decided to write his thesis for
B.Sc. on
historians' problems in using sound recordings as historical sources.
His
name was E. B. Mortensen, in the 1970s a frequent contributor to
Talking
Machine Review, and his thesis was huge. It was a rambling discussion
based
on a lot of misunderstood acoustics, but it impressed immensely his
non-
technical history-based supervisors. He took innumerable measurements
and
made innumerable calculations that were quite misleading, and he used
his
ears. He purported that most of the 78s we listen to were really
recorded at
75 rpm. He discovered that Hitler sounded much better if the speed of
his
recordings were reduced by 10%; the speech became much less hysterical
and
probably more threatening, cajoling, etc. Without any source he claimed
that
the Germans had reduced their power line frequency from 1935-1944 to
47.3 Hz
to save power, and that consequently, when we reproduce at 78 rpm we
get an
erroneous result.
I was given a copy of the thesis by someone who wanted an independent
review.
I thought the conclusions on Germany were utter nonsense, but how do
you
disprove such a statement? I worked my way through volumes of the
foremost
German electrotechnical journal, Elektrotechnische Zeitschrift, the
publication of which petered out in 1944, due to shortages and the fact
that
the pages were quickly filling up with obituaries and death notices.
Nowhere
did I find anything that could prove or disprove his statement, and
anyway,
all synchronous clocks would run slow. It was counter-intutitive to a
technician, because if heavy machinery needed more power at a lower
speed it
would simply draw a higher current, and the real saving only occurred
during
the actual run-down from 50 Hz to 40-something Hz, which could be
termed a
one-time flywheel effect. I did find papers on the instability of
frequency
and slow regulation of hydroelectric plants, but I also found the
frequency-
stabilised converters used for film cameras. Apparently no problems in
the
professional sector. As Allan Koenigsberg said a short while ago, "How
does
one prove a negative?"
Now, 26 years later I am finding material that seems to indicate that
there
may have been some truth to Mr. Mortensen's assumption: at least during
1944
they did lower the mains frequency to 45 Hz, and indeed it appears that
Germany towards the end of the war had been split into two sectors, one
using
43 Hz and the other 41 Hz. There is a strange logic to why this would
save
energy. You may skip the next if it is too detailed.
The frequency really only influenced operation of motors: all AC motors
would
run more slowly. This meant that e.g. rolling mills, overhead cranes,
elevators, etc. would have a lower throughput and thereby a lower power
consumption. The voltage was maintained, so lights, heating, vacuum
cleaners,
etc. would not be influenced. The only real problems would be in the
iron
used as cores: it would be more likely to saturate and hence the
efficiency
would fall and transformers would risk overheating. The heavy
electrical
industry had already optimised the balance of copper and soft iron, and
that
was for the specified frequency. By the way, house wiring was made with
iron
wire and small transformers used zinc wire in the last days of the
Reich.
Now, there are still a lot of open questions here: was any recording
and
reproduction done at all at mains synchronous speed at that time? And
what
was the timeframe: Hitler's speeches had been recorded from about 1932,
and
surely they could not suffer from this phenomenon before the terrible
shortages set in. But I am certainly no longer cocksure. But, as I have
said
on this list before, one of the German broadcasting houses had a
quartz-
controlled power line installed for their tape recorders and
gramophones in
the 1950s. Perhaps not to re-live life's complications.
I have also recently found via the website:
http://vwgc.org.au/VWGCGramNotes.htm
that Western Australia had 40 Hz until 1958, and they show a 40 Hz
78rpm
stroboscope.
The BBC was aware that there might be variations in the mains
frequency, and
on:
http://www.btinternet.com/~roger.beckwith/bh/grams/grams_4.htm
you may find calibration discs and a stroboscope "For use when mains
frequency at the time of recording differs from that at reproduction".
In
reality it was no more than 2 Hz either way, and the circles were
marked in
difference frequency, rather than rpm. The central German broadcast
archives
had actually informed Mr. Mortensen that the recordings of the German
radio
stations were marked on the label with the mains frequency! But he
obviously
did not believe them.
The story continues. I would not be surprised to learn that northern
Italian
records were cut with machines run off 14 Hz or 16 2/3 Hz, which were
in use
for traction purposes. Let us see if a type-wri-toon will work here:
;-) -
yes, it did.
Kind regards,
George
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