Tape head demagnetization

[gregz]

"William Sommerwerck" <grizzledgeezer@comcast.net> wrote:

A magnetized head will cause loss of high frequencies long before there's a drop in volume.

The deck probably has some other problem.

Also true of a dirty head for the most part with possible left right
issues.
A magnetized head can ruin tapes HF.

Greg

 

[Wild_Bill]

If it's possible to see the head's tape surface from outside, a bright light
may be helpful to closely examine the surface.. any signs that the surface
is worn/wavy indicates that the head is worn out.

I never owned a radio/tape player where the volume was equal for both, but
if the volume is very limited for tapes, checking the head surface for
either dirt or wear would be worthwhile.

Extending the reach of a demagnitizer may be possible (there are some types
with numerous interchangeable tips) using a piece of steel rod (aligned
end-to-end if the existing tip isn't removable), but the head surface should
be protected from contact by the end of the rod (thick paint coating, nail
polish, thin tape etc).

--
Cheers,
WB
..............


"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.

 

[legg]

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.

Much of the audible 'squeek' noise may be the fault of the housing,
rather than the tape itself. Transfering the reels to a new case may
fix that. Labels can also be transfered, if the fix works.

In some instances, the case was defective on first transfer, so the
audible jitter was included in that transfer - no way around this.

RL

 

[Rene]

On 11/25/2012 08:52 PM, Cydrome Leader wrote:

"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.

I'd clean the head and capstan first, then worry about degaussing things.

You mention the capstan, I would also check the rubber roll very
carefully. After years it often gets little tears in the rubber and it
may be deformed and therefor not be guiding the tape correctly anymore.
They are cheap and relatively easy to replace.

Greetings,
Rene