Tape head demagnetization

  • Thread starter hr(bob) hofmann@att.net
  • Start date
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hr(bob) hofmann@att.net

Guest
My car (built-in) tape player seems to be getting strange in its
volume. Associated radio is fine, tape volume is down. I thought
that I should demag the tale head. But, the opening is only barely
big enough to insert a tape, and my 120V 60Hz demagger has a 1/2" long
tip at 1/3" diameter, affixed on the end of a tube that is at least 1"
diameter so there is no way to get the demagger tip anywhere near the
tape head. I could maybe tape a large nail to the end of the existing
tip, and reach the vicinity of the head, but I don't think that will
so anything. I don't know what the magnetic structure is under/inside
the head, but assume it is shaped to deliberately have flux going
outside the head. It's not worth it to make a coil small enough to
fit into the opening. I understand there are demagnetizing tapes
available, but I am cheap and don't want to spring for the $$ unless I
am reasonably (66+%) sure it will work.

Thoughts, ideas, polite suggestions.
 
A magnetized head will cause loss of high frequencies long before there's a
drop in volume.

The deck probably has some other problem.
 
"hr(bob) hofmann@att.net" <hrhofmann@att.net> wrote in message
news:2f185192-5175-4698-a6bd-d9ecc6b2acdf@jj5g2000pbc.googlegroups.com...
My car (built-in) tape player seems to be getting strange in its
volume. Associated radio is fine, tape volume is down. I thought
that I should demag the tale head. But, the opening is only barely
big enough to insert a tape, and my 120V 60Hz demagger has a 1/2" long
tip at 1/3" diameter, affixed on the end of a tube that is at least 1"
diameter so there is no way to get the demagger tip anywhere near the
tape head. I could maybe tape a large nail to the end of the existing
tip, and reach the vicinity of the head, but I don't think that will
so anything. I don't know what the magnetic structure is under/inside
the head, but assume it is shaped to deliberately have flux going
outside the head. It's not worth it to make a coil small enough to
fit into the opening. I understand there are demagnetizing tapes
available, but I am cheap and don't want to spring for the $$ unless I
am reasonably (66+%) sure it will work.

Thoughts, ideas, polite suggestions.
Click to expand...

My initial thoughts are that tape heads that need demagnetising do not
generally exhibit the kind of extreme symptoms you are experiencing.

I would forget demagnetising as a solution right now, and try and establish
the real cause of the dramatic loss of level.



Gareth.
 
On 11/24/2012 11:27 PM, hr(bob) hofmann@att.net wrote:
My car (built-in) tape player seems to be getting strange in its
volume. Associated radio is fine, tape volume is down. I thought
that I should demag the tale head. But, the opening is only barely
big enough to insert a tape, and my 120V 60Hz demagger has a 1/2" long
tip at 1/3" diameter, affixed on the end of a tube that is at least 1"
diameter so there is no way to get the demagger tip anywhere near the
tape head. I could maybe tape a large nail to the end of the existing
tip, and reach the vicinity of the head, but I don't think that will
so anything. I don't know what the magnetic structure is under/inside
the head, but assume it is shaped to deliberately have flux going
outside the head. It's not worth it to make a coil small enough to
fit into the opening. I understand there are demagnetizing tapes
available, but I am cheap and don't want to spring for the $$ unless I
am reasonably (66+%) sure it will work.

Thoughts, ideas, polite suggestions.
Click to expand...
First check the tape on a known good tape player.
Or use a original prerecorded tape.

Tapes recorded on a machine with bad aligned heads will play good on
that machine, but not on others.

Clean the head. Clean the tape guides.
Demag if you can.
Adjust the head in height for maximum output.
Adjust the head azimuth to maximize high frequency.
And repeat the last two.

A magnetized head will destroy all your tapes (bad signal to noise
ratio). And can not be undone.
 
"hr(bob) hofmann@att.net" <hrhofmann@att.net> wrote in message
news:fef985fd-faef-42d8-a5b4-d937725a9aa7@ah9g2000pbd.googlegroups.com...
On Nov 24, 5:05 pm, "Gareth Magennis" <sound.serv...@btconnect.com
wrote:
"hr(bob) hofm...@att.net" <hrhofm...@att.net> wrote in message

news:2f185192-5175-4698-a6bd-d9ecc6b2acdf@jj5g2000pbc.googlegroups.com...





My car (built-in) tape player seems to be getting strange in its
volume. Associated radio is fine, tape volume is down. I thought
that I should demag the tale head. But, the opening is only barely
big enough to insert a tape, and my 120V 60Hz demagger has a 1/2" long
tip at 1/3" diameter, affixed on the end of a tube that is at least 1"
diameter so there is no way to get the demagger tip anywhere near the
tape head. I could maybe tape a large nail to the end of the existing
tip, and reach the vicinity of the head, but I don't think that will
so anything. I don't know what the magnetic structure is under/inside
the head, but assume it is shaped to deliberately have flux going
outside the head. It's not worth it to make a coil small enough to
fit into the opening. I understand there are demagnetizing tapes
available, but I am cheap and don't want to spring for the $$ unless I
am reasonably (66+%) sure it will work.

Thoughts, ideas, polite suggestions.

My initial thoughts are that tape heads that need demagnetising do not
generally exhibit the kind of extreme symptoms you are experiencing.

I would forget demagnetising as a solution right now, and try and
establish
the real cause of the dramatic loss of level.

Gareth.- Hide quoted text -

- Show quoted text -

Thanks Bill and Gareth,

OK - that's two votes against demagnetizing, plus I was skeptical
myself. So, now I have to decide whether to move my tapes to CD's, or
tear into a 10 year old car radio/tape player /cd player. I think it
will be easier to move a few tapes to CDs than tear up the car radio.
Click to expand...
You could of course convert your tapes to high quality mp3, and fit them all
on a single CD or SDcard, which could then be played on just about any cheap
slot-in replacement for your original car player with far better results
than you have now.


Gareth.
 
On Nov 24, 5:05 pm, "Gareth Magennis" <sound.serv...@btconnect.com>
wrote:
"hr(bob) hofm...@att.net" <hrhofm...@att.net> wrote in message

news:2f185192-5175-4698-a6bd-d9ecc6b2acdf@jj5g2000pbc.googlegroups.com...





My car (built-in) tape player seems to be getting strange in its
volume.  Associated radio is fine, tape volume is down.  I thought
that I should demag the tale head.  But, the opening is only barely
big enough to insert a tape, and my 120V 60Hz demagger has a 1/2" long
tip at 1/3" diameter, affixed on the end of a tube that is at least 1"
diameter so there is no way to get the demagger tip anywhere near the
tape head.  I could maybe tape a large nail to the end of the existing
tip, and reach the vicinity of the head, but I don't think that will
so anything.  I don't know what the magnetic structure is under/inside
the head, but assume it is shaped to deliberately have flux going
outside the head.  It's not worth it to make a coil small enough to
fit into the opening.  I understand there are demagnetizing tapes
available, but I am cheap and don't want to spring for the $$ unless I
am reasonably (66+%) sure it will work.

Thoughts, ideas, polite suggestions.

My initial thoughts are that tape heads that need demagnetising do not
generally exhibit the kind of extreme symptoms you are experiencing.

I would forget demagnetising as a solution right now, and try and establish
the real cause of the dramatic loss of level.

Gareth.- Hide quoted text -

- Show quoted text -
Click to expand...
Thanks Bill and Gareth,

OK - that's two votes against demagnetizing, plus I was skeptical
myself. So, now I have to decide whether to move my tapes to CD's, or
tear into a 10 year old car radio/tape player /cd player. I think it
will be easier to move a few tapes to CDs than tear up the car radio.
 
On Nov 24, 3:27 pm, "hr(bob) hofm...@att.net" <hrhofm...@att.net>
wrote:
My car (built-in) tape player seems to be getting strange in its
volume.  Associated radio is fine, tape volume is down.  I thought
that I should demag the tale head.  But, the opening is only barely
big enough to insert a tape, and my 120V 60Hz demagger has a 1/2" long
tip at 1/3" diameter, affixed on the end of a tube that is at least 1"
diameter so there is no way to get the demagger tip anywhere near the
tape head.  I could maybe tape a large nail to the end of the existing
tip, and reach the vicinity of the head, but I don't think that will
so anything.  I don't know what the magnetic structure is under/inside
the head, but assume it is shaped to deliberately have flux going
outside the head.  It's not worth it to make a coil small enough to
fit into the opening.  I understand there are demagnetizing tapes
available, but I am cheap and don't want to spring for the $$ unless I
am reasonably (66+%) sure it will work.

Thoughts, ideas, polite suggestions.
Click to expand...
loss of volume? doesn't that mean gunk building up that keeps the tape
too far away form the head? Or, mean some component is lost? like a
coupling cap that has seen better days? Or, something as simple as
one of the wiring connections in the cabling has gone high resistance.

Sadly, my favorite tapes were made during the era of poor mylar
coating and have all turned 'squeaky' and unplayable! I wish I could
have transferred them before they died, but hindsight.
 
On 11/24/2012 4:35 PM, Robert Macy wrote:
On Nov 24, 3:27 pm, "hr(bob) hofm...@att.net"<hrhofm...@att.net
wrote:
My car (built-in) tape player seems to be getting strange in its
volume. Associated radio is fine, tape volume is down. I thought
that I should demag the tale head. But, the opening is only barely
big enough to insert a tape, and my 120V 60Hz demagger has a 1/2" long
tip at 1/3" diameter, affixed on the end of a tube that is at least 1"
diameter so there is no way to get the demagger tip anywhere near the
tape head. I could maybe tape a large nail to the end of the existing
tip, and reach the vicinity of the head, but I don't think that will
so anything. I don't know what the magnetic structure is under/inside
the head, but assume it is shaped to deliberately have flux going
outside the head. It's not worth it to make a coil small enough to
fit into the opening. I understand there are demagnetizing tapes
available, but I am cheap and don't want to spring for the $$ unless I
am reasonably (66+%) sure it will work.

Thoughts, ideas, polite suggestions.

loss of volume? doesn't that mean gunk building up that keeps the tape
too far away form the head? Or, mean some component is lost? like a
coupling cap that has seen better days? Or, something as simple as
one of the wiring connections in the cabling has gone high resistance.

Sadly, my favorite tapes were made during the era of poor mylar
coating and have all turned 'squeaky' and unplayable! I wish I could
have transferred them before they died, but hindsight.
Click to expand...
I'd give up on head demagnetizing. It's not likely the problem.
And you're more likely to magnetize it with the demagnetizer
unless you disassemble the thing so you can get at it.

Tape players don't last in cars.
I've only had two CD players and they were worse.
The heat, outgassing of plastics, dirt, etc. get all over the optical
and mechanical stuff.
Luckily, my last player has a USB slot and a Flash Card slot.
It won't play a CD any more, but the SD card works fine.

As for old tapes...
If you have rare music, you're pretty much screwed.
If you have popular stuff, there's an option.
Go to the library, check out a CD. Copy it back to the tape.
If you bought the tape, you own the license to play it.
The nitpickers will argue about it, but I think you're
on solid moral and legal ground to refresh the media.
 
"hr(bob) hofmann@att.net" <hrhofmann@att.net> wrote in message
news:2f185192-5175-4698-a6bd-d9ecc6b2acdf@jj5g2000pbc.googlegroups.com...
My car (built-in) tape player seems to be getting strange in its
volume. Associated radio is fine, tape volume is down. I thought
that I should demag the tale head. But, the opening is only barely
big enough to insert a tape, and my 120V 60Hz demagger has a 1/2" long
tip at 1/3" diameter, affixed on the end of a tube that is at least 1"
diameter so there is no way to get the demagger tip anywhere near the
tape head. I could maybe tape a large nail to the end of the existing
tip, and reach the vicinity of the head, but I don't think that will
so anything. I don't know what the magnetic structure is under/inside
the head, but assume it is shaped to deliberately have flux going
outside the head. It's not worth it to make a coil small enough to
fit into the opening. I understand there are demagnetizing tapes
available, but I am cheap and don't want to spring for the $$ unless I
am reasonably (66+%) sure it will work.

Thoughts, ideas, polite suggestions.
Click to expand...

Sounds like very dirty heads , or head alignment has gone out of whack. This
happens when one or both head mounting screws loosen. Happens occasionally.

Mark Z.
 
On Sat, 24 Nov 2012 16:35:30 -0800 (PST), Robert Macy
<robert.a.macy@gmail.com> wrote as underneath my scribble :

A trick I found for this squeaky problem to do a one time transfer was
to play them as cold as possible, unfortunately just freezing the tapes
doesnt last long enough - always thaught a head heatsink to a
deepfrozen al or cu block might do the trick but I never tried it!! I
just caught mine early enough! Mine were BASF :(

Sadly, my favorite tapes were made during the era of poor mylar
coating and have all turned 'squeaky' and unplayable! I wish I could
have transferred them before they died, but hindsight.
Click to expand...
 
On Sat, 24 Nov 2012 14:27:55 -0800, hr(bob) hofmann@att.net wrote:

Thoughts, ideas, polite suggestions.
Click to expand...
As others have said, this does not appear to be a magnetised head but it
could be that particles from your tapes has collected in the gap(s) on
the the tape head(s). The gap(s) need to be magnetically open so that the
passing tape completes the magnetic circuit and it is a very small gap on
a playback head (of the order of 0.0001 inch).

BTW, if you are using a head demagnetiser never switch it on or off
anywhere near the heads. Move a few feet away before switching off. One
spike and you will have magnetised them!

Many years ago I worked in the dev lab of Marriott Magnetics one of the
original makers of tape heads in the UK. Long gone.



Charlie.



--
M0WYM
www.radiowymsey.org

Sales @ radiowymsey
http://stores.ebay.co.uk/Sales-At-Radio-Wymsey/
 
"Charlie+" <charlie@xxx.net> wrote in message
news:0so3b8th8pa17oglfphnb1047pggkv42js@4ax.com...
On Sat, 24 Nov 2012 16:35:30 -0800 (PST), Robert Macy
robert.a.macy@gmail.com> wrote as underneath my scribble :

A trick I found for this squeaky problem to do a one time transfer was
to play them as cold as possible, unfortunately just freezing the tapes
doesnt last long enough - always thaught a head heatsink to a
deepfrozen al or cu block might do the trick but I never tried it!! I
just caught mine early enough! Mine were BASF :(


Sadly, my favorite tapes were made during the era of poor mylar
coating and have all turned 'squeaky' and unplayable! I wish I could
have transferred them before they died, but hindsight.
Click to expand...

Try this method. Put a "squeaky" tape on a metal tray, and put it in a 150
degree oven (NO HOTTER!!) for about
1 hour. It will reactivate the binders and lubricants and when you play it,
TRANSFER it to another medium on first play. Works for old reel to reel
tapes. Google is your friend.
http://en.wikipedia.org/wiki/Tape_baking
 
"hr(bob) hofmann@att.net" <hrhofmann@att.net> wrote:
My car (built-in) tape player seems to be getting strange in its
volume. Associated radio is fine, tape volume is down. I thought
that I should demag the tale head. But, the opening is only barely
big enough to insert a tape, and my 120V 60Hz demagger has a 1/2" long
tip at 1/3" diameter, affixed on the end of a tube that is at least 1"
diameter so there is no way to get the demagger tip anywhere near the
tape head. I could maybe tape a large nail to the end of the existing
tip, and reach the vicinity of the head, but I don't think that will
so anything. I don't know what the magnetic structure is under/inside
the head, but assume it is shaped to deliberately have flux going
outside the head. It's not worth it to make a coil small enough to
fit into the opening. I understand there are demagnetizing tapes
available, but I am cheap and don't want to spring for the $$ unless I
am reasonably (66+%) sure it will work.

Thoughts, ideas, polite suggestions.
Click to expand...
I'd clean the head and capstan first, then worry about degaussing things.
 
On Sat, 24 Nov 2012 14:27:55 -0800 (PST), "hr(bob) hofmann@att.net"
<hrhofmann@att.net> wrote:

My car (built-in) tape player seems to be getting strange in its
volume. Associated radio is fine, tape volume is down. I thought
that I should demag the tale head. But, the opening is only barely
big enough to insert a tape, and my 120V 60Hz demagger has a 1/2" long
tip at 1/3" diameter, affixed on the end of a tube that is at least 1"
diameter so there is no way to get the demagger tip anywhere near the
tape head. I could maybe tape a large nail to the end of the existing
tip, and reach the vicinity of the head, but I don't think that will
so anything. I don't know what the magnetic structure is under/inside
the head, but assume it is shaped to deliberately have flux going
outside the head. It's not worth it to make a coil small enough to
fit into the opening. I understand there are demagnetizing tapes
available, but I am cheap and don't want to spring for the $$ unless I
am reasonably (66+%) sure it will work.

Thoughts, ideas, polite suggestions.
Click to expand...
Once upon a time i had a battery powered cassette sized tape head
demagnetizer. Sounds like just the trick for your situation, to determine
if it is head magnetization (perhaps unlikely) or some other problem.

?-)
 
On Sat, 24 Nov 2012 15:21:52 -0800 (PST), "hr(bob) hofmann@att.net"
<hrhofmann@att.net> wrote:

Thanks Bill and Gareth,

OK - that's two votes against demagnetizing, plus I was skeptical
myself. So, now I have to decide whether to move my tapes to CD's, or
tear into a 10 year old car radio/tape player /cd player. I think it
will be easier to move a few tapes to CDs than tear up the car radio.
Click to expand...
Lucky you are, over 200 to transfer have i.

?-)
 
On Sat, 24 Nov 2012 16:35:30 -0800 (PST), Robert Macy
<robert.a.macy@gmail.com> wrote:

On Nov 24, 3:27 pm, "hr(bob) hofm...@att.net" <hrhofm...@att.net
wrote:
My car (built-in) tape player seems to be getting strange in its
volume.  Associated radio is fine, tape volume is down.  I thought
that I should demag the tale head.  But, the opening is only barely
big enough to insert a tape, and my 120V 60Hz demagger has a 1/2" long
tip at 1/3" diameter, affixed on the end of a tube that is at least 1"
diameter so there is no way to get the demagger tip anywhere near the
tape head.  I could maybe tape a large nail to the end of the existing
tip, and reach the vicinity of the head, but I don't think that will
so anything.  I don't know what the magnetic structure is under/inside
the head, but assume it is shaped to deliberately have flux going
outside the head.  It's not worth it to make a coil small enough to
fit into the opening.  I understand there are demagnetizing tapes
available, but I am cheap and don't want to spring for the $$ unless I
am reasonably (66+%) sure it will work.

Thoughts, ideas, polite suggestions.

loss of volume? doesn't that mean gunk building up that keeps the tape
too far away form the head? Or, mean some component is lost? like a
coupling cap that has seen better days? Or, something as simple as
one of the wiring connections in the cabling has gone high resistance.

Sadly, my favorite tapes were made during the era of poor mylar
coating and have all turned 'squeaky' and unplayable! I wish I could
have transferred them before they died, but hindsight.
Click to expand...
Depending on your tastes, some might be available now in CD or MP3 format.
You may have to buy a lot more than what you have to get all you want. I
have a lot of old music of the 1950s to 1970s range and an interesting bit
outside that range. Not all digital yet. You know how to find me.

?-)
 
On Sat, 24 Nov 2012 23:33:26 -0600, "Mark Zacharias"
<mark_zacharias@labolgcbs.net> wrote:

"hr(bob) hofmann@att.net" <hrhofmann@att.net> wrote in message
news:2f185192-5175-4698-a6bd-d9ecc6b2acdf@jj5g2000pbc.googlegroups.com....
My car (built-in) tape player seems to be getting strange in its
volume. Associated radio is fine, tape volume is down. I thought
that I should demag the tale head. But, the opening is only barely
big enough to insert a tape, and my 120V 60Hz demagger has a 1/2" long
tip at 1/3" diameter, affixed on the end of a tube that is at least 1"
diameter so there is no way to get the demagger tip anywhere near the
tape head. I could maybe tape a large nail to the end of the existing
tip, and reach the vicinity of the head, but I don't think that will
so anything. I don't know what the magnetic structure is under/inside
the head, but assume it is shaped to deliberately have flux going
outside the head. It's not worth it to make a coil small enough to
fit into the opening. I understand there are demagnetizing tapes
available, but I am cheap and don't want to spring for the $$ unless I
am reasonably (66+%) sure it will work.

Thoughts, ideas, polite suggestions.


Sounds like very dirty heads , or head alignment has gone out of whack. This
happens when one or both head mounting screws loosen. Happens occasionally.

Mark Z.
Click to expand...
(+1) on the dirty heads. I had forgotten.

?-)
 
On Nov 25, 11:09 am, "Klaatu" <which...@today.org> wrote:
"Charlie+" <char...@xxx.net> wrote in message

news:0so3b8th8pa17oglfphnb1047pggkv42js@4ax.com...

On Sat, 24 Nov 2012 16:35:30 -0800 (PST), Robert Macy
robert.a.m...@gmail.com> wrote as underneath my scribble :

A trick I found for this squeaky problem to do a one time transfer was
to play them as cold as possible,  unfortunately just freezing the tapes
doesnt last long enough - always thaught a  head heatsink to a
deepfrozen al or cu block might do the trick but I never tried it!!  I
just caught mine early enough!   Mine were BASF :(

Sadly, my favorite tapes were made during the era of poor mylar
coating and have all turned 'squeaky' and unplayable!  I wish I could
have transferred them before they died, but hindsight.

Try this method.  Put a "squeaky" tape on a metal tray, and put it in a 150
degree oven (NO HOTTER!!) for about
1 hour.  It will reactivate the binders and lubricants and when you play it,
TRANSFER it to another medium on first play.  Works for old reel to reel
tapes.  Google is your friend.http://en.wikipedia.org/wiki/Tape_baking
Click to expand...
Wow! Great tidbit!
 
Sadly, my favorite tapes were made during the era of poor mylar
coating and have all turned 'squeaky' and unplayable! I wish I could
have transferred them before they died, but hindsight.

A trick I found for this squeaky problem to do a one time transfer was
to play them as cold as possible, unfortunately just freezing the tapes
doesnt last long enough - always thaught a head heatsink to a
deepfrozen al or cu block might do the trick but I never tried it!! I
just caught mine early enough! Mine were BASF :(
Click to expand...
I don't know if it's the same problem you're referring to, but I do
know that a lot of reel-to-reel tapes made several decades ago suffer
from a problem known as "sticky-shed syndrome".

http://en.wikipedia.org/wiki/Sticky-shed_syndrome

There's no permanent cure, but it's often possible to restore such
tapes to playability (at least temporarily) by removing moisture from
the tape/binder. This can be done by "baking" the tape at an elevated
temperature, or by storing the tapes in a temperature-and-humidity-
controlled environment for a period of time.

Some people have tried lubricating the tape just before playing it
(with alcohol, and I think I've heard of people using a light silicone
oil as well).

You might want to select one or two "sticky" tapes, and then doing a
gentle bake (possible heat-and-time schedules are in the Wikipedia
article), or put them in a sealed Tupperware container with several
large (and recently-baked) silica-gel moisture-absorbing packs for a
month or two. See if getting the absorbed moisture out of the binder
restores the tapes to a playable condition... if so, play them and
digitize them!

I had the master and mix tapes for an album my wife recorded in the
late 1970's baked and transcribed, some years ago... the process
worked and we were able to recover the album and transfer it to CD.
Without baking, it would have been a lost cause, I think.

--
Dave Platt <dplatt@radagast.org> AE6EO
Friends of Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!
 
On Sat, 24 Nov 2012 14:27:55 -0800 (PST), "hr(bob) hofmann@att.net"
<hrhofmann@att.net> put finger to keyboard and composed:

My car (built-in) tape player seems to be getting strange in its
volume. Associated radio is fine, tape volume is down. I thought
that I should demag the tale head. But, the opening is only barely
big enough to insert a tape,...
Click to expand...
Just to offer a different perspective, I onced repaired a Fujitsu Ten
auto-reverse car cassette player with the same symptom as yours. The
problem turned out to be a small dirty multipole switch. I'm a bit
hazy on the details, but ISTR that there were two head circuits, and a
different circuit was selected in forward and reverse mode.

As for demagnetising the head, I have a cassette tape with a built-in
battery powered demagnetiser that automatically activates when you
press the play button while the player is unpowered.

It looks something like this ...
http://farm3.static.flickr.com/2023/2183255937_ee2ffb7d96.jpg

- Franc Zabkar
--
Please remove one 'i' from my address when replying by email.
 
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