On 6/6/16 11:05 AM, Steven Smolian wrote:
> At least one source of cartridge magnetization is static electricity. I use a Zerostat to discharge static from records and the same device aimed at the cartridge. I've no idea how to measure theresults but suggest the process a part of your "good housekeeping" routine. That inexpensvic elittle device can really make a difference.
> It just occurred to me to wonder how it affects tapes, particularly in fast-forward and reverse which is where static electricity is most intensively generated. ? Might the discharge cause noises on the tape? Gotta try it.
My experience is that static discharge during fast wind rarely prints
anything onto the tape.
Static discharge while playing can print onto the tape if the discharge
occurs through one of the heads. Metal head cores should be grounded
(i.e. electrically connected to the transport chassis). As heads age,
this connection is sometimes interrupted, and the motion of the tape
across the head charges up the head until a spark jumps over the gap to
chassis. Heads with poorly grounded cores should be repaired or replaced.
On one occasion when playing an old tape that was not backcoated (on a
transport with heads that I confirmed were properly grounded) I had
periodic sparks jump from the metal reel to the transport. This put a
click in the audio, but did not permanently print anything to the tape.
With properly grounded heads and humidity maintained above 30%, I rarely
have problems with static electricity. Tapes which are not backcoated
may sometimes have static problems. (The backcoating is conductive,
which helps to discharge any static buildup.)
I don't think Zerostat will help with tape problems, because static
charge is continually generated during tape movement. Using Zerostat on
a reel of tape prior to playing won't help. Fortunately, there are
devices which continually discharge static buildup: air ionizers which
are used on static-free electronic assembly workstations. They produce
an airstream with equal numbers of positive and negative ions, which
will quickly discharge static from anything that's in the airstream.
One of the readily available models is SCS model 963E:
These used to be made by 3M. Apparently the brand has changed, although
the device seems exactly the same as the old 3M units. Similar devices
are available from many other manufacturers.
-- John Chester