First progress report on a multi-channel magnetic drum inner ...

V-3
coefficients, warpage, etc. t'.ost of these factors are quite amenable to
design calculations and quite definite upper limits are set by the
known properties of the materials involved« However, such questions
as bearing life at very high speed (12,000 or more R P M) present some
problems of prediction and do not have sharp boundary values.
4) In any such artificial separation of a complex interrelated
group of variables, the chief advantage is conceptual, and in arguing
about each group the others are assumed fixed and known.. Even to
manipulate within one of the three groups with the others fixed tacitly
assumes an interchangeability which is not strictly justified; for
example, the disposition of magnetic area "A" is unrestricted only if
the disposition of heads ajnong the naths scanned is completely fluidj
also the number of heads reading simultaneously only if the disposition
of "total amplifer capacity" in pulses per second is permutable. The
validity and signifigance of these points will be more carefully scru-
tinized later,
5) All of the variables of the three species indicated are being
studied; computationally where feasible; otherwise experimentally as the
design of the unit proceeds, and a summary of some of these experimental
results appears in the sections of this <strong>report</strong> which follow , The policy
adopted in the concurrent design is to provide ample margin of adjust-
ment so as to assure achievement of at least the limited performance
specified.