Angie:

The discussion of various wire piqued my curiosity, so I did a little 
digging. I didn't find the exact reference I was looking for, but found 
a couple of similar citations. I think most of this research was done by 
Brush Magnetics and Marvin Camras at Armour Research, with similar 
research done by the Geramns.

The best reference I found was from "The Recording and Reproduction of 
Sound" (Oliver Read-Author; Howard Sams-Publisher; ©1952). In the 
section on wire recording, there is a reference to the use of medium 
carbon steel wire, which was produced from medium carbon steel rod. I 
think this was probably what some of the early Pierce wire stock was. 
There is also reference from a Fidelitone source which outlines 
differences between /"Regular Stainless Steel Wire"/ and /"Stainless 
Steel Recording Wire"/. It essentially outlines the fact that the 
Stainless Steel Recording Wire undergoes some specific QC and other 
treatments during manufacture. There was quite a bit of research that 
went into this at the time, and I haven't had a chance to look up all 
the references. I do recall that there tended to be a high rejection 
rate of the stainless steel rod used to produce the wire, and that it 
had to fall within specific limits on the B & H curve.

In the excellent book titled "Elements of Sound Recording" by John 
Frayne and Halley Wolfe (John Wiley & Sons, ©1949), there are references 
in a response chart from Brush Development to /"Carbon Steel Wire", "420 
Stainless Steel Wire", "Brush Wire Type BK-913",/ and /"Coated Paper 
Tape"/. (If you're curious, the paper tape beats them all!).

As I recall, the reference that I had previously seen wire stock 
referred to as "Type 1" and "Type 2" wire. Wish I could find the damn 
thing...

I think the part of oxidation problem is as a result of the pot metal 
that was used for making the wire spools, which in the case of 
Webster-Chicago, I believe are anodized aluminum, although I have 
frankly never researched it. I have seen problems in the past with 
various anodizing, where either the metal was contaminated, or the 
anodizing was not done quite properly, resulting a sort of white powder 
substance. I'm not a chemist, so I will leave it to someone else to 
speculate on exactly what the nature of this might be.

Your comments on print-through are interesting. It certainly would seem 
that wire would be prone to this-strange that it doesn't appear more 
often (on the other hand, the 40 db S/N ratio might have something to do 
with this!)

One of these days, in my spare time (yeah, right), I'm going to go down 
to the IIT archives and take a look at the Armour papers relating to the 
research on wire recording, although David Morton has already covered 
much of this in his dissertation on Webster-Chicago.

(BTW-the Webster-Chicago plant still stands at 5610 W. Bloomingdale in 
Chicago. I took some exterior photos a few years ago, and hope to make a 
tour of it sometime).

Scott D. Smith
Chicago Audio Works, Inc.


Angie Dickinson Mickle wrote:
> Scott D. Smith wrote:
>> I always thought all the wire made by W-C was stainless as well, but 
>> apparently there were at least couple of different grades (which I've 
>> seen reference to in some literature from the 1940s. Would have to 
>> dig for the source). 
>
> I would be very interested in your reference to this when you get a 
> chance.
>
>> I have seen some wire which has exhibited a crystalline type of 
>> oxidation (usually easily cleaned). 
>
> I've seen this also.  To me oxidation is rust, but this is definitely 
> some environmental reaction.  It does not seem to effect the recording 
> or the integrity of the wire in the least.  And I find it more often 
> on the metal spool itself than the actual wire.
>
>> I've never really experienced any issues with print-through on wires. 
>
> I hadn't either until very recently.  A very loud volume passage on a 
> wire definitely could be heard seconds later.  It could be argued that 
> that low level garbling that is frequently heard on wire could be 
> print-through.  On the other hand, it could be incomplete erasure of 
> previous recordings.  I could never tell.  Weighing tails out storage 
> to future playback equipment compatibility, I'd continue storing heads 
> out with a proper, even wind.  Because, here's my question.  After 
> being stored heads out for 50 or 60 years, how much worse can any 
> print-through get?
>
> Angie Dickinson Mickle
> Avocado Productions
> Broomfield, CO
> www.avocadoproductions.com
> 800-246-3811
>