Wire recordings have an unknown life expectancy. I have played wire recordings
made in the 1940’s and they played just fine. I can’t say the same for audio tapes
from the mid 1970’s to the mid 1990’s. So, while wire recordings are indeed
magnetic recordings, the lifespan appears to differ greatly from those recordings
made on audio tape.
Playing a wire recording can be a daunting task but, if done carefully, one can
extract the contents. The wire is made of stainless steel and is very fine, averaging
approximately 0.005 inches, (about 0.012mm) or, approximately the diameter of a
strand of thick human hair. The average speed was quite fast, about 24 inches per
second (approximately, 61 cm/s).
Wire recorders were used for various tasks and popular with consumers as well
until audio tape came along and replaced the technology. The two most popular
types of wire recorders are those that used a spool having a small hole (about ¼”
in Dia.) to be used on a corresponding shaft and those that used a spool with a
much wider center hole (about 1-3/8” in Dia.). The later being the consumer model
which is more common. Both types typically use a record/play and a erase head.
The heads on most wire recorders are built into one assembly.
Because the wire is so thin, tangles and breakage are a real problem. When the
wire broke (and it will), I used to splice it by soldering about a 1/4” overlap which
would be hardly noticed because of the play speed, even if I had to trim some wire
to make a clean splice. However, that method is very tedious and time consuming
so, I defaulted to the standard method of tying a square knot, which is still tedious.
Knots and other anomalies seem to pass through the head just fine.
Because the wire is so old, the factory leader may have to be replaced. Light
fishing leader or sewing thread works well as a replacement. I will often tie a loop
around the supply spool to keep the leader from un-threading.
I have experimented with methods of cleaning the record-play head. Webster
Chicago’s owners manual recommends using a brush with the bristles soaked in
Trichloroethylene. Obviously, the owner’s manual was written in the 1940’s. I used
a fine bristled brush, with the bristles trimmed to about ¾”, soaked in denatured
alcohol, and it seemed to work. The method that I currently use is a dedicated reel
of sewing thread that I will soak with denatured alcohol and play for about 30
seconds. The cleaning spool also contains a couple of segments of recording wire
that has been pre-recorded with alignment tones which I use for level setting.
Before playing a wire, it’s best to advance the mechanism by hand in order to line
up the head with the spool of wire. Observe how the wire spool will unwind so that
the head travel will match the way the wire un-spools. You can do this by rotating
the take-up spool on most machines. The available user manuals recommend
starting the head at the top of the travel. This works however, in practice, I’ve found
that matching the position and direction of travel of the wire to be best.
Fidelity is poor by today’s standards, averaging from about 50Hz to 5kHz. You may
notice an unusual amount of hum that is baked into many wire recordings. This is
mainly due to the drive motor being poorly isolated, mechanical operation of the
machine while recording and playing and the electronic technology of the time.
I learned right away to take the play head direct into a modern microphone preamp
which produces much better fidelity. You will need a microphone preamp with
plenty of gain (more than 70 dB). Equalization (EQ) should not be a problem. As
far as I can tell, wire recorders didn’t use any EQ. However, use your ears to get
the best sound. I generally transfer flat, then do any EQ, editing, etc. on a copy of
the file. Many of the consumer recordings that I transferred were recorded by
holding a microphone up to a speaker which, is not the best method. Plus, the
average person doing the recording was generally unaware of good microphone
techniques. Most wire recorders used a crystal microphone which has it’s own
fidelity issues. That said, I have transferred some wire recordings that were very
well recorded. So, it’s possible to get good results.
Most wire recorders used mechanical switching for play and rewind. Rewind is
generally scary fast and the tension is often slack. This is where most of the
tangles happen. I have found that applying very light pressure to the supply reel
during rewinding (which was the take-up reel during playback) will vastly reduce
tangles. You can do this by gently laying a finger on the supply reel. The weight of
your finger is usually enough. Some machines have a turned up edge on the take-
up reel to facilitate threading so you have to watch out.
The wire needs to take the same path during rewind as it did during playback
because the head assembly moves up and down or in and out, to provide an even
wind. One would think that head wear would be a problem but I haven’t noticed a
decrease in fidelity over time. At first, I tried a number of things to avoid the
possibility of wearing the play head during rewind but they usually ended up in
disaster. So now, I just ‘let it rip’ and try to avoid tangles.
© Corey Bailey Audio Engineering
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