What the Fuhrer said.........
 

When Field Marshall Mannerheim celebrated his 75 birthday on
4th June 1942, in a suite of first class railway carriages taken to
a secret location near Imatra in Finland, he had an unexpected guest -
Adolf Hitler.

YLE (Finnish Radio) had planned to broadcast the proceedings
and speeches of the birthday celebrations, and despite strict
instructions to the contrary, YLE sound recordist Thor Damen
recorded the discussions with Hitler by concealing a microphone
in the overhead hat-rack.

This is said to be the only recording of Hitler where he speaks like
a normal human being! Link below. Hitler begins to speak at: 03:20
He and Mannerheim discuss in German, and there is a Finnish voice
over.

To keep this thread on topic, at least as much as the discussions
on taxes and expensive watches, I would add that the recording
was made on a vintage 1941 AEG K4 tape recorder at 76cms.
(30 ips) This recorder was far ahead its time and included AC
bias, which only appeared some 6 yeas later on the American
Ampex 200 as the result technology acquired in the victory spoils.

Risto Syrjä also of YLE, had studied in Germany and
had been one of the team working on AC bias for tape
recording, which produced an improvement of 25dB
in signal-to-noise ratio compared with DC bias.

Iain

http://www.yle.fi/elavaarkisto/?s=s&g=1&ag=1&t=&a=376

What the Fuhrer said.........
 

Its quite funny as most of the cassette machines on sale now in the dying
era of tape use DC or permanent magnets for erase/bias.
Funny old world.

Brian

--
Brian Gaff....Note, this account does not accept Bcc: email.
graphics are great, but the blind can't hear them
Email:
__________________________________________________ __________________________________________________ __________


"Iain Churches" wrote in message
...
When Field Marshall Mannerheim celebrated his 75 birthday on
4th June 1942, in a suite of first class railway carriages taken to
a secret location near Imatra in Finland, he had an unexpected guest -
Adolf Hitler.

YLE (Finnish Radio) had planned to broadcast the proceedings
and speeches of the birthday celebrations, and despite strict
instructions to the contrary, YLE sound recordist Thor Damen
recorded the discussions with Hitler by concealing a microphone
in the overhead hat-rack.

This is said to be the only recording of Hitler where he speaks like
a normal human being! Link below. Hitler begins to speak at: 03:20
He and Mannerheim discuss in German, and there is a Finnish voice
over.

To keep this thread on topic, at least as much as the discussions
on taxes and expensive watches, I would add that the recording
was made on a vintage 1941 AEG K4 tape recorder at 76cms.
(30 ips) This recorder was far ahead its time and included AC
bias, which only appeared some 6 yeas later on the American
Ampex 200 as the result technology acquired in the victory spoils.

Risto Syrjä also of YLE, had studied in Germany and
had been one of the team working on AC bias for tape
recording, which produced an improvement of 25dB
in signal-to-noise ratio compared with DC bias.

Iain

http://www.yle.fi/elavaarkisto/?s=s&g=1&ag=1&t=&a=376

What the Fuhrer said.........
 

"Brian Gaff" wrote in message
...
Its quite funny as most of the cassette machines on sale now in the dying
era of tape use DC or permanent magnets for erase/bias.
Funny old world.

Brian

Yes, cheaper, when quality is not important.

No tape recorder of any quality used DC bias
from the late 40s onwnwards.

Iain

What the Fuhrer said.........
 

"Brian Gaff" wrote in message
...
Its quite funny as most of the cassette machines on sale now in the dying
era of tape use DC or permanent magnets for erase/bias.
Funny old world.


I'd be interested in knowing where your statistic that "most" of the
cassette machines on sale now use DC bias comes from. Personally I doubt it.
You may well find that although DC *erase* is common enough in cheaper
cassette recorders, bias is AC. It takes a lot less power from the
oscillator to provide bias than to erase a tape.

David.

What the Fuhrer said.........
 

"David Looser" wrote in message
...
"Brian Gaff" wrote in message
...
Its quite funny as most of the cassette machines on sale now in the dying
era of tape use DC or permanent magnets for erase/bias.
Funny old world.


I'd be interested in knowing where your statistic that "most" of the
cassette machines on sale now use DC bias comes from. Personally I doubt
it. You may well find that although DC *erase* is common enough in cheaper
cassette recorders, bias is AC. It takes a lot less power from the
oscillator to provide bias than to erase a tape.

David.

Agreed. I remember looking at an old Magnetofon 76cms deck with
AEG spools, just post WW2. The bias/erase oscillator was a separate
unit, an add-on with its own psu.

Iain

What the Fuhrer said.........
 

In article ,
Brian Gaff wrote:
Its quite funny as most of the cassette machines on sale now in the
dying era of tape use DC or permanent magnets for erase/bias.
Funny old world.

Do they really? The results would be appalling. And given most things
these days are a handful of chips I can't see why - the cost of providing
AC bias would be tiny.

--
*The early bird gets the worm, but the second mouse gets the cheese *

Dave Plowman London SW
To e-mail, change noise into sound.

What the Fuhrer said.........
 

In article ,
Iain Churches wrote:
Agreed. I remember looking at an old Magnetofon 76cms deck with
AEG spools, just post WW2. The bias/erase oscillator was a separate
unit, an add-on with its own psu.

Perhaps the best all round 1/4" machine ever was the EMI BTR2. Which was
in use for longer than any other model - and may still be used somewhere
even today. All the various amps were separate units. To make servicing
easier.

--
*Never put off until tomorrow what you can avoid altogether *

Dave Plowman London SW
To e-mail, change noise into sound.

What the Fuhrer said.........
 

In message , "Dave Plowman (News)"
writes
In article ,
Brian Gaff wrote:
Its quite funny as most of the cassette machines on sale now in the
dying era of tape use DC or permanent magnets for erase/bias.
Funny old world.

Do they really? The results would be appalling. And given most things
these days are a handful of chips I can't see why - the cost of providing
AC bias would be tiny.

From my limited experience with tape recording, I'm sure that DC
biassing (of any kind) is absolutely terrible.

I remember in the days when you could buy a cheap mono recorder from
Woolworths for around £5, but recordings made on it left an infinite
amount to be desired. However, a guy at work organised the production of
a small quantity of printed boards and an oscillator coil so that we
could modify some of these recorders from DC to AC bias. The improvement
was amazing. That recorder served me well when used in conjunction with
a ZX81 and a Spectrum.
--
Ian

What the Fuhrer said.........
 

"Dave Plowman (News)" wrote in
message
In article ,
Brian Gaff wrote:

Its quite funny as most of the cassette machines on sale
now in the dying era of tape use DC or permanent magnets
for erase/bias. Funny old world.

Do they really? The results would be appalling. And given
most things these days are a handful of chips I can't see
why - the cost of providing AC bias would be tiny.

I did a little study of available ICs for building cassette recorders. I
found no chips that included an on-chip bias oscillator. I found application
notes for building mono tape recorders with no bias oscillator, but all of
the ANs for stereo recorders showed an external bias oscillator.

The whole business of portable recorders seems to have gone almost
completely digital. Note that my Sansa Clip Plus includes a mono recorder
with a surprisingly effective microphone, along with the complete high
quality digital music player and FM tuner.

What the Fuhrer said.........
 

"Dave Plowman (News)" wrote in message
...
In article ,
Iain Churches wrote:
Agreed. I remember looking at an old Magnetofon 76cms deck with
AEG spools, just post WW2. The bias/erase oscillator was a separate
unit, an add-on with its own psu.

Perhaps the best all round 1/4" machine ever was the EMI BTR2. Which was
in use for longer than any other model - and may still be used somewhere
even today. All the various amps were separate units. To make servicing
easier.

Yes, excellent machine. The Decca redundancy store was full of them,
plus TR90s. The BTR2 never had the reputation or the sales of the
Studer C37, (which also had separate slide-in units) but was, in the
UK at least, considered to be far better than the 350 series Ampex.

Did you ever use a BTR4 Dave? They were very shortlived. It was
the last TR that EMI produced.


Iain