LISTSERV mailing list manager LISTSERV 16.0

Help for ARSCLIST Archives


ARSCLIST Archives

ARSCLIST Archives


ARSCLIST@LISTSERV.LOC.GOV


View:

Message:

[

First

|

Previous

|

Next

|

Last

]

By Topic:

[

First

|

Previous

|

Next

|

Last

]

By Author:

[

First

|

Previous

|

Next

|

Last

]

Font:

Proportional Font

LISTSERV Archives

LISTSERV Archives

ARSCLIST Home

ARSCLIST Home

ARSCLIST  November 2009

ARSCLIST November 2009

Subject:

Re: power line frequency

From:

Michael Biel <[log in to unmask]>

Reply-To:

Association for Recorded Sound Discussion List <[log in to unmask]>

Date:

Tue, 3 Nov 2009 17:53:06 -0700

Content-Type:

text/plain

Parts/Attachments:

Parts/Attachments

text/plain (193 lines)

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

Top of Message | Previous Page | Permalink

Advanced Options


Options

Log In

Log In

Get Password

Get Password


Search Archives

Search Archives


Subscribe or Unsubscribe

Subscribe or Unsubscribe


Archives

November 2020
October 2020
September 2020
August 2020
July 2020
June 2020
May 2020
April 2020
March 2020
February 2020
January 2020
December 2019
November 2019
October 2019
September 2019
August 2019
July 2019
June 2019
May 2019
April 2019
March 2019
February 2019
January 2019
December 2018
November 2018
October 2018
September 2018
August 2018
July 2018
June 2018
May 2018
April 2018
March 2018
February 2018
January 2018
December 2017
November 2017
October 2017
September 2017
August 2017
July 2017
June 2017
May 2017
April 2017
March 2017
February 2017
January 2017
December 2016
November 2016
October 2016
September 2016
August 2016
July 2016
June 2016
May 2016
April 2016
March 2016
February 2016
January 2016
December 2015
November 2015
October 2015
September 2015
August 2015
July 2015
June 2015
May 2015
April 2015
March 2015
February 2015
January 2015
December 2014
November 2014
October 2014
September 2014
August 2014
July 2014
June 2014
May 2014
April 2014
March 2014
February 2014
January 2014
December 2013
November 2013
October 2013
September 2013
August 2013
July 2013
June 2013
May 2013
April 2013
March 2013
February 2013
January 2013
December 2012
November 2012
October 2012
September 2012
August 2012
July 2012
June 2012
May 2012
April 2012
March 2012
February 2012
January 2012
December 2011
November 2011
October 2011
September 2011
August 2011
July 2011
June 2011
May 2011
April 2011
March 2011
February 2011
January 2011
December 2010
November 2010
October 2010
September 2010
August 2010
July 2010
June 2010
May 2010
April 2010
March 2010
February 2010
January 2010
December 2009
November 2009
October 2009
September 2009
August 2009
July 2009
June 2009
May 2009
April 2009
March 2009
February 2009
January 2009
December 2008
November 2008
October 2008
September 2008
August 2008
July 2008
June 2008
May 2008
April 2008
March 2008
February 2008
January 2008
December 2007
November 2007
October 2007
September 2007
August 2007
July 2007
June 2007
May 2007
April 2007
March 2007
February 2007
January 2007
December 2006
November 2006
October 2006
September 2006
August 2006
July 2006
June 2006
May 2006
April 2006
March 2006
February 2006
January 2006
December 2005
November 2005
October 2005
September 2005
August 2005
July 2005
June 2005
May 2005
April 2005
March 2005
February 2005
January 2005
December 2004
November 2004
October 2004
September 2004
August 2004
July 2004
June 2004
May 2004
April 2004
March 2004
February 2004
January 2004
December 2003
November 2003
October 2003
September 2003
August 2003
July 2003
June 2003
May 2003
April 2003
March 2003
February 2003
January 2003

ATOM RSS1 RSS2



LISTSERV.LOC.GOV

CataList Email List Search Powered by the LISTSERV Email List Manager