Hello,

my old 3-head dual capstan cassette deck doesn't fully erase old recordings
any more, they are still audible but very quiet. Demagnetizing and cleaning
the heads didn't help. Unfortunately I forgot to turn off the power before
demagnetizing, could it be I damaged something? Any help is appreciated.

Regards Willem

"Willem Hansel" wrote in message
...
Hello,

my old 3-head dual capstan cassette deck doesn't fully erase old
recordings
any more, they are still audible but very quiet. Demagnetizing and
cleaning
the heads didn't help. Unfortunately I forgot to turn off the power before
demagnetizing, could it be I damaged something? Any help is appreciated.

Regards Willem



If the machine still works on playback you didn't damage anything. The AC
field produced by the demagnetizer would make a big hum through the playback
preamp, but you probably wouldn't hear it because of a muting circuit in the
player.

The erase head could still be dirty, or (less likely) worn, but there could
also be a lack of back-tension on the supply side, mainly if it's a
single-capstan design - a bad soft-brake for example - or the tape path may
have a problem such as skewing the tape somewhat, or the erase head could
have had a wire come unsoldered. The recorded music + bias would partially
erase the old music, but not completely. That's why the erase head is there
in the first place.


Mark Z.

"Willem Hansel" wrote in message
...
Hello,

my old 3-head dual capstan cassette deck doesn't fully erase old
recordings
any more, they are still audible but very quiet. Demagnetizing and
cleaning
the heads didn't help. Unfortunately I forgot to turn off the power before
demagnetizing, could it be I damaged something? Any help is appreciated.

Regards Willem


obtain a bulk tape eraser. a small hand held type will be adequate. similar
to one pictured in this e-bay auction
http://makeashorterlink.com/?U675416DC

to operate, plug in, press button, slowly rub the tape back and forth
against the electromagnet, slowly pull tape away. then release button.

demagnetizing will have no effect on the ability of a tape recorders erase
head to erase.

"Willem Hansel" wrote ...
my old 3-head dual capstan cassette deck doesn't fully
erase old recordings any more, they are still audible
but very quiet. Demagnetizing and cleaning the heads
didn't help.

There are several things that could cause this. One of the
more likely is that the head is physically not contacting the
tape (or contacting it in the right way/place). You might
try taking a cassette and cutting away some of the shell so
you can observe how the head and the tape interact.

The other possibility is that the bias/erase oscillator is not
putting as much signal into the erase head as it used to.
Have you noticed any change in how recordings sound
(other than the background sound because of the partial
erasure.)? Have high frequencies become diminished,
etc? This may be another indication that the bias signal
has weakened, etc.

Unfortunately I forgot to turn off the power before
demagnetizing, could it be I damaged something?

That has the significant potential of damaging the play-
back circuitry, but is unlikely to have any effect on
the erase functionality. Not recommended that you do
that again.

"Willem Hansel" wrote in message
...
Hello,

my old 3-head dual capstan cassette deck doesn't fully erase old
recordings any more, they are still audible but very quiet. Demagnetizing
and cleaning the heads didn't help. Unfortunately I forgot to turn off the
power before demagnetizing, could it be I damaged something? Any help is
appreciated.

**It is likely that the erase head is either buggered (unlikely) or the
wiring to the erase head is damaged. You probably did not damage anything by
demagnetising the heads, but it is good practice to shut of the power first.

And, before anyone asks, the bias signal on the record head will be
sufficient to effect a partial erasure of the tape.


--
Trevor Wilson
www.rageaudio.com.au