[bct] Re: Squealing tapes

  • From: "Neal Ewers" <neal.ewers@xxxxxxxxxxxxxx>
  • To: <blindcooltech@xxxxxxxxxxxxx>
  • Date: Mon, 2 Jan 2006 10:15:11 -0600

In the mid 70s, people lost a lot of the things they had on tape because
during the oil shortage, people used a different substance to bond the
metal filings to the tape.  It is these tiny metal pieces which the
recording head arranges in order to cause the recording to play exactly
what is being recorded.  You could open a box with a reel to reel tape
in it and there would be a little pile of metal peaces in the box.
After the oil shortage, the bonding substance used was better than it
had been during the shortage, but it never did work as well as the
original bonding substance.  So, there could be one or more of three
problems going on here.

1.  The tape has lost some of these filings and there is not much you
can do about it.

2.  Your tape heads need cleaning because each time you listen to a
tape, some of the small fragments of the tape comes off on the heads.
This begins to effect the frequency response and can also cause a
squeaking noise.  There are special liquids that can be used to remove
these particles.  Some people use rubbing alcohol, but this, in time,
leaves a film which can also begin to cause the same problems you are
experiencing.

3.  You need to demagnetize your heads.  After a certain point, tape
heads actually begin to have enough of the tape particles on them that
the heads themselves become slightly magnetized, thus making it almost
impossible to completely clean the heads.  I haven't had to look for a
tape head demagnetizer for a long time because I already have one, and
with tapes going out of use, it might be difficult.  I would start with
something like Radio Shack.

These are over simplified answers, but the basic points are there.  I
didn't over simplify it because I didn't think people would understand
the more complex version.  It's just that it would have taken much
longer to explain in its completeness.

If you can't find real tape head cleaning liquid, alcohol will work.  If
you use Q tips, however, try to get the ones often used in hospitals.
They have two properties that might be of help.  First of all, only one
end has the tip.  The other end is just a wooden end, but the stem of
the Q tip is much longer than normal and may make it easier to get to
the record and/or play back heads of the recorder.  Secondly, these Q
tips tend not to have some of the cotton come off in the cleaning
process because they are much more tightly compacted.

I hope this helps.

Neal


-----Original Message-----
From: blindcooltech-bounce@xxxxxxxxxxxxx
[mailto:blindcooltech-bounce@xxxxxxxxxxxxx] On Behalf Of Mary Emerson
Sent: Sunday, January 01, 2006 10:18 PM
To: blindcooltech@xxxxxxxxxxxxx
Subject: [bct] Re: Squealing tapes


Joni,

I'm not sure if this is correct, but I have heard that the tape
squealing is 
caused by the materials from which the tapes are constructed
degenerating 
and there isn't anything that can be done about the squealing. I've
heard 
that tapes, especially reel to real, that have been archived for decades

have the same problem. I had lots of problems with reel to reel tapes 
squealing which was particularly annoying when I had people reading my 
textbooks onto tape in college. I haven't had too many cassettes do it
but 
have experienced some NLS books with the problem, and they were usually 
books I wanted to read and had waited to get for years. It's a shame
nothing 
can be done about it.

Mary 



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