trivial cassette question
 

looked at a recently made (last 2 or 3 years i suppose) tdk d90 audio
cassette the other day and noticed there was no metal plate behind the
pressure pad - seems this omission is widespread these days- why has it
disappeared and what was its original function? something to do with
stray magnetic fields??
regards, b.

trivial cassette question
 

"b" wrote in message
oups.com...
looked at a recently made (last 2 or 3 years i suppose) tdk d90 audio
cassette the other day and noticed there was no metal plate behind the
pressure pad - seems this omission is widespread these days- why has it
disappeared and what was its original function? something to do with
stray magnetic fields??
regards, b.

The original function of the metal plate was, as you surmised, a magnetic
screen. Usually, the plate was made into a strip which acted as a spring to
keep the pressure pad in contact with the head(s). Why it has changed, I
have no idea - cost?

S.

trivial cassette question
 

b wiffled:
looked at a recently made (last 2 or 3 years i suppose) tdk d90 audio
cassette the other day and noticed there was no metal plate behind the
pressure pad - seems this omission is widespread these days- why has it
disappeared and what was its original function? something to do with
stray magnetic fields??
regards, b.

It's a good question, which has been answered, but another occurred to me:
how does a cassttte compare to an MP3?

trivial cassette question
 

"Serge Auckland" wrote in message
...
"b" wrote in message
oups.com...
looked at a recently made (last 2 or 3 years i suppose) tdk d90 audio
cassette the other day and noticed there was no metal plate behind the
pressure pad - seems this omission is widespread these days- why has it
disappeared and what was its original function? something to do with
stray magnetic fields??
regards, b.

The original function of the metal plate was, as you surmised, a magnetic
screen. Usually, the plate was made into a strip which acted as a spring
to keep the pressure pad in contact with the head(s). Why it has changed,
I have no idea - cost?

S.

Serge, I don't think that this is the plate that b was asking about. The
pressure pad, on the phosphor bronze spring, is the same as it ever was.
What has disappeared, is the flat metal plate behind that. It's as big as
the head access hole, not a thin strip like the pressure spring. My
immediate thought was also that this was a magnetic shield, but thinking
more about it, what exactly is it shielding against, and which way round -
head to tape spools, or vice versa ? The other thing that bothers me about
it being a magnetic shield, is that it appears to be made of mild steel,
rather than mu-metal or some other decent shielding material.

The other possibility is that it was for static shielding purposes. There is
a lot of static generated by the moving tape. One particular answer machine
that I used to have dealings with, used to suffer very badly with static
discharge to the head, which manifested as loud clicks. It was corrected by
the manufacturer bringing out a revised tape. I never took any notice of
what the revision was, but may have been using a tape with a shield ?? I
still have one, and I took a look at it, and it has the metal plate, but as
to whether the originals did not have a plate, I really can't remember.
Perhaps the plate has disappeared because advances in tape composition, have
removed the static problem in the first place. Just a thought.

Arfa

trivial cassette question
 

"Arfa Daily" wrote in message
...

"Serge Auckland" wrote in message
...
"b" wrote in message
oups.com...
looked at a recently made (last 2 or 3 years i suppose) tdk d90 audio
cassette the other day and noticed there was no metal plate behind the
pressure pad - seems this omission is widespread these days- why has it
disappeared and what was its original function? something to do with
stray magnetic fields??
regards, b.

The original function of the metal plate was, as you surmised, a magnetic
screen. Usually, the plate was made into a strip which acted as a spring
to keep the pressure pad in contact with the head(s). Why it has changed,
I have no idea - cost?

S.

Serge, I don't think that this is the plate that b was asking about. The
pressure pad, on the phosphor bronze spring, is the same as it ever was.
What has disappeared, is the flat metal plate behind that. It's as big as
the head access hole, not a thin strip like the pressure spring. My
immediate thought was also that this was a magnetic shield, but thinking
more about it, what exactly is it shielding against, and which way round -
head to tape spools, or vice versa ? The other thing that bothers me about
it being a magnetic shield, is that it appears to be made of mild steel,
rather than mu-metal or some other decent shielding material.

The other possibility is that it was for static shielding purposes. There
is a lot of static generated by the moving tape. One particular answer
machine that I used to have dealings with, used to suffer very badly with
static discharge to the head, which manifested as loud clicks. It was
corrected by the manufacturer bringing out a revised tape. I never took
any notice of what the revision was, but may have been using a tape with a
shield ?? I still have one, and I took a look at it, and it has the metal
plate, but as to whether the originals did not have a plate, I really
can't remember. Perhaps the plate has disappeared because advances in tape
composition, have removed the static problem in the first place. Just a
thought.

Arfa
Arfa,
Thanks for the explanation. I haven't used cassettes for several years, but
I don't recall there being a metal plate behind the spring. I used to use
mostly "That's Tape" metal cassettes, (best formulation at the time) or only
slightly less good were TDK metal. Maybe they didn't have the plate, or more
likely, I never noticed.

S.

trivial cassette question
 

"Triffid" schreef in bericht
...
b wiffled:
looked at a recently made (last 2 or 3 years i suppose) tdk d90 audio
cassette the other day and noticed there was no metal plate behind the
pressure pad - seems this omission is widespread these days- why has it
disappeared and what was its original function? something to do with
stray magnetic fields??
regards, b.

It's a good question, which has been answered, but another occurred to me:
how does a cassttte compare to an MP3?

320 kbps MP3 can outperform most casette/player combinations but not all of
them. The MP3s don't wear out however.

gr, hwh

trivial cassette question
 

hwh wrote:
It's a good question, which has been answered, but another occurred to me:
how does a cassttte compare to an MP3?


320 kbps MP3 can outperform most casette/player combinations but not all of
them. The MP3s don't wear out however.

gr, hwh

Electric guitar (or keyboard) stereo 'phasing' effects sound squish on
MP3 or ATRAC (MD) when I'm really concentrating. I still use a cassette
walkman for the gym... I've got over 500 cassettes from the 80's to
re-discover.

--
Adrian C

trivial cassette question
 

"Adrian C" schreef in bericht
...
hwh wrote:
It's a good question, which has been answered, but another occurred to
me:
how does a cassttte compare to an MP3?


320 kbps MP3 can outperform most casette/player combinations but not all
of them. The MP3s don't wear out however.

gr, hwh

Electric guitar (or keyboard) stereo 'phasing' effects sound squish on MP3
or ATRAC (MD) when I'm really concentrating. I still use a cassette
walkman for the gym... I've got over 500 cassettes from the 80's to
re-discover.

Are they ok? I found that many of the old ones loose their magnetic layer
easily, so that you have to clean the heads every few minutes!
All this is not very good for their treble response of course.

gr, hwh

trivial cassette question
 

hwh wrote:
"Adrian C" schreef in bericht
...

hwh wrote:

It's a good question, which has been answered, but another occurred to
me:
how does a cassttte compare to an MP3?


320 kbps MP3 can outperform most casette/player combinations but not all
of them. The MP3s don't wear out however.

gr, hwh

Electric guitar (or keyboard) stereo 'phasing' effects sound squish on MP3
or ATRAC (MD) when I'm really concentrating. I still use a cassette
walkman for the gym... I've got over 500 cassettes from the 80's to
re-discover.


Are they ok? I found that many of the old ones loose their magnetic layer
easily, so that you have to clean the heads every few minutes!
All this is not very good for their treble response of course.

Some of the pre-recorded chart compilation tapes are a bit dodgy - yes,
the heads eventually clog, or the tape itself jams. Most of my own
recorded tapes have been either TDK-AD or TDK-SA - these have been fine,
with the exception of 'print through' echo audible before loud starts.
All most unnoticable when all around me people are dropping weights,
swearing and attempting to make polite conversation about how noisy and
unruly the gym has become....

--
Adrian C

trivial cassette question
 

hwh wrote:
"Adrian C" schreef in bericht
...
hwh wrote:
It's a good question, which has been answered, but another occurred to
me:
how does a cassttte compare to an MP3?


320 kbps MP3 can outperform most casette/player combinations but not all
of them. The MP3s don't wear out however.

gr, hwh

Electric guitar (or keyboard) stereo 'phasing' effects sound squish on MP3
or ATRAC (MD) when I'm really concentrating. I still use a cassette
walkman for the gym... I've got over 500 cassettes from the 80's to
re-discover.

Are they ok? I found that many of the old ones loose their magnetic layer
easily, so that you have to clean the heads every few minutes!
All this is not very good for their treble response of course.

gr, hwh

i think the whole line of tape auto destructing is mostly (but not
totally) a myth spred by industry and aided by the media they advertise
in to get us to consume the latest format and has very little to do
with truth. I have old reel to reel tapes, vhs cassttes from the early
80s and audio cassettes. Out of the hundreds I have, the only problems
I have had are with:
- many old prerecorded cassettes from the 60s to early 80s - tend to
shed easily
-basf ferro tapes (both open reel LH and cassette, vintage '78-80) -
shedding
-scotch 175 from the mid 70s reel - hydrolised
-scotch dynarange cassettes - squealing and tape pad deteriorated
-mid-80s vintage E180 samsung vhs tape - shedding
(all kept at room temperature and stored in drawers)

I have NEVER had even the slightest problem with any other named brand
of audio/video tape deteriorating seriously so can only assume that the
rumours, whilst having an element of truth, are greatly exaggerated!
anyone else care to share their experiences....?
-B-