Hi:

Why do cassettes use FM recording?

Why not AM recording?

How would the artifacts differ?


Thanks in advance.

What do you mean? And what type of cassettes are you talking about???

--

Greetings,

Jerry Greenberg GLG Technologies GLG
=========================================
WebPage http://www.zoom-one.com
Electronics http://www.zoom-one.com/electron.htm
=========================================


"Curious" wrote in message
om...
Hi:

Why do cassettes use FM recording?

Why not AM recording?

How would the artifacts differ?


Thanks in advance.

What do you mean? And what type of cassettes are you talking about???

--

Greetings,

Jerry Greenberg GLG Technologies GLG
=========================================
WebPage http://www.zoom-one.com
Electronics http://www.zoom-one.com/electron.htm
=========================================


"Curious" wrote in message
om...
Hi:

Why do cassettes use FM recording?

Why not AM recording?

How would the artifacts differ?


Thanks in advance.

What do you mean? And what type of cassettes are you talking about???

--

Greetings,

Jerry Greenberg GLG Technologies GLG
=========================================
WebPage http://www.zoom-one.com
Electronics http://www.zoom-one.com/electron.htm
=========================================


"Curious" wrote in message
om...
Hi:

Why do cassettes use FM recording?

Why not AM recording?

How would the artifacts differ?


Thanks in advance.

"Curious" wrote ...
Why do cassettes use FM recording?
Why not AM recording?

They don't use "FM" or "AM" recording.
They use baseband (direct) recording with HF bias.

Assuming you are discussing conventional audio
"Compact Cassettes" (a-la Philips, et. al)

"Curious" wrote ...
Why do cassettes use FM recording?
Why not AM recording?

They don't use "FM" or "AM" recording.
They use baseband (direct) recording with HF bias.

Assuming you are discussing conventional audio
"Compact Cassettes" (a-la Philips, et. al)

"Curious" wrote ...
Why do cassettes use FM recording?
Why not AM recording?

They don't use "FM" or "AM" recording.
They use baseband (direct) recording with HF bias.

Assuming you are discussing conventional audio
"Compact Cassettes" (a-la Philips, et. al)

Curious wrote:

Hi:

Why do cassettes use FM recording?

Video cassettes CAN use FM recording for audio.

Why not AM recording?

All the malaises of the AM principle, including the problem of what
happens at max negative modulation, i. e. modulation related loss of
carrier wave.

How would the artifacts differ?

Interrupted audio in case of AM recording.

Thanks in advance.

--
************************************************** *************
* \\\\\\\ Quality Ascii handcrafted by Peter Larsen /////// *
* \\\\\\\ My site is at: http://www.muyiovatki.dk /////// *
************************************************** *******

Curious wrote:

Hi:

Why do cassettes use FM recording?

Video cassettes CAN use FM recording for audio.

Why not AM recording?

All the malaises of the AM principle, including the problem of what
happens at max negative modulation, i. e. modulation related loss of
carrier wave.

How would the artifacts differ?

Interrupted audio in case of AM recording.

Thanks in advance.

--
************************************************** *************
* \\\\\\\ Quality Ascii handcrafted by Peter Larsen /////// *
* \\\\\\\ My site is at: http://www.muyiovatki.dk /////// *
************************************************** *******

Curious wrote:

Hi:

Why do cassettes use FM recording?

Video cassettes CAN use FM recording for audio.

Why not AM recording?

All the malaises of the AM principle, including the problem of what
happens at max negative modulation, i. e. modulation related loss of
carrier wave.

How would the artifacts differ?

Interrupted audio in case of AM recording.

Thanks in advance.

--
************************************************** *************
* \\\\\\\ Quality Ascii handcrafted by Peter Larsen /////// *
* \\\\\\\ My site is at: http://www.muyiovatki.dk /////// *
************************************************** *******

Peter Larsen wrote in message ...
Curious wrote:

How would the artifacts differ?

Interrupted audio in case of AM recording.

Due to electrical intereference?

Peter Larsen wrote in message ...
Curious wrote:

How would the artifacts differ?

Interrupted audio in case of AM recording.

Due to electrical intereference?

Peter Larsen wrote in message ...
Curious wrote:

How would the artifacts differ?

Interrupted audio in case of AM recording.

Due to electrical intereference?

Curious wrote:
How would the artifacts differ?

Peter Larsen wrote ...
Interrupted audio in case of AM recording.

"Curious" wrote ...
Due to electrical intereference?

WHAT ARE YOU TALKING ABOUT???

There IS no "AM" or "FM" recording on "Audio Cassettes"!

Curious wrote:
How would the artifacts differ?

Peter Larsen wrote ...
Interrupted audio in case of AM recording.

"Curious" wrote ...
Due to electrical intereference?

WHAT ARE YOU TALKING ABOUT???

There IS no "AM" or "FM" recording on "Audio Cassettes"!

Curious wrote:
How would the artifacts differ?

Peter Larsen wrote ...
Interrupted audio in case of AM recording.

"Curious" wrote ...
Due to electrical intereference?

WHAT ARE YOU TALKING ABOUT???

There IS no "AM" or "FM" recording on "Audio Cassettes"!

Richard Crowley wrote:

Curious wrote:
How would the artifacts differ?

Peter Larsen wrote ...
Interrupted audio in case of AM recording.

"Curious" wrote ...
Due to electrical intereference?

WHAT ARE YOU TALKING ABOUT???

There IS no "AM" or "FM" recording on "Audio Cassettes"!

A few seconds devoted to reading the original question allows only the
option of recording audio on a video recorder as having been considered
because of this, so that was what I wrote about.

--
************************************************** *************
* \\\\\\\ Quality Ascii handcrafted by Peter Larsen /////// *
* \\\\\\\ My site is at: http://www.muyiovatki.dk /////// *
************************************************** *******

Richard Crowley wrote:

Curious wrote:
How would the artifacts differ?

Peter Larsen wrote ...
Interrupted audio in case of AM recording.

"Curious" wrote ...
Due to electrical intereference?

WHAT ARE YOU TALKING ABOUT???

There IS no "AM" or "FM" recording on "Audio Cassettes"!

A few seconds devoted to reading the original question allows only the
option of recording audio on a video recorder as having been considered
because of this, so that was what I wrote about.

--
************************************************** *************
* \\\\\\\ Quality Ascii handcrafted by Peter Larsen /////// *
* \\\\\\\ My site is at: http://www.muyiovatki.dk /////// *
************************************************** *******

Richard Crowley wrote:

Curious wrote:
How would the artifacts differ?

Peter Larsen wrote ...
Interrupted audio in case of AM recording.

"Curious" wrote ...
Due to electrical intereference?

WHAT ARE YOU TALKING ABOUT???

There IS no "AM" or "FM" recording on "Audio Cassettes"!

A few seconds devoted to reading the original question allows only the
option of recording audio on a video recorder as having been considered
because of this, so that was what I wrote about.

--
************************************************** *************
* \\\\\\\ Quality Ascii handcrafted by Peter Larsen /////// *
* \\\\\\\ My site is at: http://www.muyiovatki.dk /////// *
************************************************** *******

Curious wrote:

Peter Larsen wrote in message ...
Curious wrote:

How would the artifacts differ?

Interrupted audio in case of AM recording.

Due to electrical intereference?

Loss of carrier.

--
************************************************** *************
* \\\\\\\ Quality Ascii handcrafted by Peter Larsen /////// *
* \\\\\\\ My site is at: http://www.muyiovatki.dk /////// *
************************************************** *******

Curious wrote:

Peter Larsen wrote in message ...
Curious wrote:

How would the artifacts differ?

Interrupted audio in case of AM recording.

Due to electrical intereference?

Loss of carrier.

--
************************************************** *************
* \\\\\\\ Quality Ascii handcrafted by Peter Larsen /////// *
* \\\\\\\ My site is at: http://www.muyiovatki.dk /////// *
************************************************** *******

Curious wrote:

Peter Larsen wrote in message ...
Curious wrote:

How would the artifacts differ?

Interrupted audio in case of AM recording.

Due to electrical intereference?

Loss of carrier.

--
************************************************** *************
* \\\\\\\ Quality Ascii handcrafted by Peter Larsen /////// *
* \\\\\\\ My site is at: http://www.muyiovatki.dk /////// *
************************************************** *******

"Peter Larsen" wrote ...
A few seconds devoted to reading the original question
allows only the option of recording audio on a video
recorder as having been considered because of this,
so that was what I wrote about.

No. The original question says nothing about "video" in
any sense of the word. Go back and read it again.

The Subject clearly says "Audio Cassettes".
This is the rec.AUDIO.tech newsgroup.

If "Curious" were asking about VIDEO cassettes,
he/she would have surely responded to at least ONE
of the three different messages asking for clarification
of the question.

I believe that you have made an unwarranted assumption,
and that you have not explicitly stated the assumption to
"Curious", and that you are unintentionally misleading
him/her.

"Peter Larsen" wrote ...
A few seconds devoted to reading the original question
allows only the option of recording audio on a video
recorder as having been considered because of this,
so that was what I wrote about.

No. The original question says nothing about "video" in
any sense of the word. Go back and read it again.

The Subject clearly says "Audio Cassettes".
This is the rec.AUDIO.tech newsgroup.

If "Curious" were asking about VIDEO cassettes,
he/she would have surely responded to at least ONE
of the three different messages asking for clarification
of the question.

I believe that you have made an unwarranted assumption,
and that you have not explicitly stated the assumption to
"Curious", and that you are unintentionally misleading
him/her.

"Peter Larsen" wrote ...
A few seconds devoted to reading the original question
allows only the option of recording audio on a video
recorder as having been considered because of this,
so that was what I wrote about.

No. The original question says nothing about "video" in
any sense of the word. Go back and read it again.

The Subject clearly says "Audio Cassettes".
This is the rec.AUDIO.tech newsgroup.

If "Curious" were asking about VIDEO cassettes,
he/she would have surely responded to at least ONE
of the three different messages asking for clarification
of the question.

I believe that you have made an unwarranted assumption,
and that you have not explicitly stated the assumption to
"Curious", and that you are unintentionally misleading
him/her.

"Peter Larsen" wrote ...
A few seconds devoted to reading the original question
allows only the option of recording audio on a video
recorder as having been considered because of this,
so that was what I wrote about.

Actually the original question says NOTHING about
"video". Read the Subject line again. It says "Audio
Cassettes" on my server.

You assumed "video" in your response, but "Curious"
never (visibly) confirmed that is what he/she is asking
about.

I still insist that there is NO SUCH THING as
"FM recording on *Audio* Cassettes" unless we are
tallking about some obscure laboratory experiment.

"Peter Larsen" wrote ...
A few seconds devoted to reading the original question
allows only the option of recording audio on a video
recorder as having been considered because of this,
so that was what I wrote about.

Actually the original question says NOTHING about
"video". Read the Subject line again. It says "Audio
Cassettes" on my server.

You assumed "video" in your response, but "Curious"
never (visibly) confirmed that is what he/she is asking
about.

I still insist that there is NO SUCH THING as
"FM recording on *Audio* Cassettes" unless we are
tallking about some obscure laboratory experiment.

"Peter Larsen" wrote ...
A few seconds devoted to reading the original question
allows only the option of recording audio on a video
recorder as having been considered because of this,
so that was what I wrote about.

Actually the original question says NOTHING about
"video". Read the Subject line again. It says "Audio
Cassettes" on my server.

You assumed "video" in your response, but "Curious"
never (visibly) confirmed that is what he/she is asking
about.

I still insist that there is NO SUCH THING as
"FM recording on *Audio* Cassettes" unless we are
tallking about some obscure laboratory experiment.

"Peter Larsen" wrote in message
...
Curious wrote:

Peter Larsen wrote in message
...
Curious wrote:

How would the artifacts differ?

Interrupted audio in case of AM recording.

Due to electrical intereference?

Loss of carrier.

Assuming we are talking about video cassettes (and not
"Audio Cassettes" as the OP wrote)....

Loss of carrier in FM will ALSO cause interrupted audio.
Some might even say that it is worse because of the nature
of FM demodulation when no carrier is present (i.e.
"inter-station hiss")

The only thing that saves it (in the case of VHS "Hi-Fi" for
example) is that most VCRs will automatically revert back
to the linear (baseband) audio track upon loss of FM Hi-Fi
carrier.

"Peter Larsen" wrote in message
...
Curious wrote:

Peter Larsen wrote in message
...
Curious wrote:

How would the artifacts differ?

Interrupted audio in case of AM recording.

Due to electrical intereference?

Loss of carrier.

Assuming we are talking about video cassettes (and not
"Audio Cassettes" as the OP wrote)....

Loss of carrier in FM will ALSO cause interrupted audio.
Some might even say that it is worse because of the nature
of FM demodulation when no carrier is present (i.e.
"inter-station hiss")

The only thing that saves it (in the case of VHS "Hi-Fi" for
example) is that most VCRs will automatically revert back
to the linear (baseband) audio track upon loss of FM Hi-Fi
carrier.

"Peter Larsen" wrote in message
...
Curious wrote:

Peter Larsen wrote in message
...
Curious wrote:

How would the artifacts differ?

Interrupted audio in case of AM recording.

Due to electrical intereference?

Loss of carrier.

Assuming we are talking about video cassettes (and not
"Audio Cassettes" as the OP wrote)....

Loss of carrier in FM will ALSO cause interrupted audio.
Some might even say that it is worse because of the nature
of FM demodulation when no carrier is present (i.e.
"inter-station hiss")

The only thing that saves it (in the case of VHS "Hi-Fi" for
example) is that most VCRs will automatically revert back
to the linear (baseband) audio track upon loss of FM Hi-Fi
carrier.

Richard Crowley wrote:

You assumed "video" in your response, but "Curious"
never (visibly) confirmed that is what he/she is asking
about.

Indeed.

I still insist that there is NO SUCH THING as
"FM recording on *Audio* Cassettes" unless we are
tallking about some obscure laboratory experiment.

Indeed2

--
************************************************** *************
* \\\\\\\ Quality Ascii handcrafted by Peter Larsen /////// *
* \\\\\\\ My site is at: http://www.muyiovatki.dk /////// *
************************************************** *******

Richard Crowley wrote:

You assumed "video" in your response, but "Curious"
never (visibly) confirmed that is what he/she is asking
about.

Indeed.

I still insist that there is NO SUCH THING as
"FM recording on *Audio* Cassettes" unless we are
tallking about some obscure laboratory experiment.

Indeed2

--
************************************************** *************
* \\\\\\\ Quality Ascii handcrafted by Peter Larsen /////// *
* \\\\\\\ My site is at: http://www.muyiovatki.dk /////// *
************************************************** *******

Richard Crowley wrote:

You assumed "video" in your response, but "Curious"
never (visibly) confirmed that is what he/she is asking
about.

Indeed.

I still insist that there is NO SUCH THING as
"FM recording on *Audio* Cassettes" unless we are
tallking about some obscure laboratory experiment.

Indeed2

--
************************************************** *************
* \\\\\\\ Quality Ascii handcrafted by Peter Larsen /////// *
* \\\\\\\ My site is at: http://www.muyiovatki.dk /////// *
************************************************** *******

In , on 01/03/04
at 07:27 PM, (Curious) said:

Hi:

Why do cassettes use FM recording?

Why not AM recording?

How would the artifacts differ?

Common audio tape recording does not use AM or FM. In its original
concept, the audio signal is run through a coil that is pressed against
the moving tape. Since the coil current varies with the audio signal,
an magnetic impression of the audio signal is "recorded" onto the tape.
During playback, the moving tape is again pressed against the coil,
current is generated in the coil as the varying magnetic field passes
by, this current is amplified and eventually drives the speakers.

Unfortunately, the above simplistic process does not produce the low
distortion audio that we need. A high frequency (compared to the audio
signal) steady current is added to the audio current presented to the
recording head (coil). This "bias" signal reduces distortion to a
manageable level.

The physical process of tape bias is very different from the AM and FM
modulation used for broadcasting.

It is possible to introduce an AM or FM modulation layer to the tape
recording process, and this is done for certain industrial
applications, but these processes are not used for home audio tapes.

---

AC bias was discovered independently in Germany and the US during the
1920's, but deployment was interrupted by political events. (I don't
know who was first. I've seen claims both ways.)

During the Second World War the German generals' would broadcast
speeches. Early in the war these broadcasts would be live or
transcribed to records because there was no practical way to send high
quality audio over phone wires and microwave relay links were not yet
available. Recordings and broacasts had to originate in a studio
setting. Therefore, the allies could easily track the location of a
general by monitoring the quality of his broadcast voice. While many
transmitters might carry the speech, one had much higher quality and
exposed the live location of the general. Eventually the Germans
started using AC bias magnetic recordings that sounded good enough to
prevent the allies from tracking the location of generals.

-----------------------------------------------------------
spam:
wordgame:123(abc):14 9 20 5 2 9 18 4 at 22 15 9 3 5 14 5 20 dot 3 15
13 (Barry Mann)
[sorry about the puzzle, spammers are ruining my mailbox]
-----------------------------------------------------------

In , on 01/03/04
at 07:27 PM, (Curious) said:

Hi:

Why do cassettes use FM recording?

Why not AM recording?

How would the artifacts differ?

Common audio tape recording does not use AM or FM. In its original
concept, the audio signal is run through a coil that is pressed against
the moving tape. Since the coil current varies with the audio signal,
an magnetic impression of the audio signal is "recorded" onto the tape.
During playback, the moving tape is again pressed against the coil,
current is generated in the coil as the varying magnetic field passes
by, this current is amplified and eventually drives the speakers.

Unfortunately, the above simplistic process does not produce the low
distortion audio that we need. A high frequency (compared to the audio
signal) steady current is added to the audio current presented to the
recording head (coil). This "bias" signal reduces distortion to a
manageable level.

The physical process of tape bias is very different from the AM and FM
modulation used for broadcasting.

It is possible to introduce an AM or FM modulation layer to the tape
recording process, and this is done for certain industrial
applications, but these processes are not used for home audio tapes.

---

AC bias was discovered independently in Germany and the US during the
1920's, but deployment was interrupted by political events. (I don't
know who was first. I've seen claims both ways.)

During the Second World War the German generals' would broadcast
speeches. Early in the war these broadcasts would be live or
transcribed to records because there was no practical way to send high
quality audio over phone wires and microwave relay links were not yet
available. Recordings and broacasts had to originate in a studio
setting. Therefore, the allies could easily track the location of a
general by monitoring the quality of his broadcast voice. While many
transmitters might carry the speech, one had much higher quality and
exposed the live location of the general. Eventually the Germans
started using AC bias magnetic recordings that sounded good enough to
prevent the allies from tracking the location of generals.

-----------------------------------------------------------
spam:
wordgame:123(abc):14 9 20 5 2 9 18 4 at 22 15 9 3 5 14 5 20 dot 3 15
13 (Barry Mann)
[sorry about the puzzle, spammers are ruining my mailbox]
-----------------------------------------------------------

In , on 01/03/04
at 07:27 PM, (Curious) said:

Hi:

Why do cassettes use FM recording?

Why not AM recording?

How would the artifacts differ?

Common audio tape recording does not use AM or FM. In its original
concept, the audio signal is run through a coil that is pressed against
the moving tape. Since the coil current varies with the audio signal,
an magnetic impression of the audio signal is "recorded" onto the tape.
During playback, the moving tape is again pressed against the coil,
current is generated in the coil as the varying magnetic field passes
by, this current is amplified and eventually drives the speakers.

Unfortunately, the above simplistic process does not produce the low
distortion audio that we need. A high frequency (compared to the audio
signal) steady current is added to the audio current presented to the
recording head (coil). This "bias" signal reduces distortion to a
manageable level.

The physical process of tape bias is very different from the AM and FM
modulation used for broadcasting.

It is possible to introduce an AM or FM modulation layer to the tape
recording process, and this is done for certain industrial
applications, but these processes are not used for home audio tapes.

---

AC bias was discovered independently in Germany and the US during the
1920's, but deployment was interrupted by political events. (I don't
know who was first. I've seen claims both ways.)

During the Second World War the German generals' would broadcast
speeches. Early in the war these broadcasts would be live or
transcribed to records because there was no practical way to send high
quality audio over phone wires and microwave relay links were not yet
available. Recordings and broacasts had to originate in a studio
setting. Therefore, the allies could easily track the location of a
general by monitoring the quality of his broadcast voice. While many
transmitters might carry the speech, one had much higher quality and
exposed the live location of the general. Eventually the Germans
started using AC bias magnetic recordings that sounded good enough to
prevent the allies from tracking the location of generals.

-----------------------------------------------------------
spam:
wordgame:123(abc):14 9 20 5 2 9 18 4 at 22 15 9 3 5 14 5 20 dot 3 15
13 (Barry Mann)
[sorry about the puzzle, spammers are ruining my mailbox]
-----------------------------------------------------------

Rumor has it that a record amp broke into oscillation thus adding a bias to
the audio. I've heard that this "accident" was discovered by B&K.

big snip ------------

Rumor has it that a record amp broke into oscillation thus adding a bias to
the audio. I've heard that this "accident" was discovered by B&K.

big snip ------------

Rumor has it that a record amp broke into oscillation thus adding a bias to
the audio. I've heard that this "accident" was discovered by B&K.

big snip ------------