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"FILTER DESIGN DATA FOR COM-
MUNICATION ENGINEERS" by J. H.
:Muir. Published by Job n Wiley & Sons,
l or., 440 Fourth Avenue, New York 16,
N. Y. 252 pages. $7.50.
This book is concerned mainly with
the Zobel filter. Brief accounts of a
number of recent extensions to the
Zobel theory have been included.
Heretofore, textbooks on filters have
concentrated on theoretical principles
and have given comparatively little attention
to the needs of the practical
designer; the present work is an attempt
to supplement such textbooks by
providing in a convenient form charts,
tables and formulae selected or constructed
so as to lighten the labor of
calculation as much as possible. With
their help, it should be possible to design
filters in a small fraction of the
time otherwise needed.
Derivations of formulae have been
omitted except where they clarify the
presentation, and attention has been
confined to the statement of results and
the explanation of design methods. It
has been assumed that the reader has
an elementary knowledge of the principles
of line transmission and of filters.
"PROCEEDINGS OF THE NATIONAL
ELECTRONICS CONFERENCE" -1952-
1'ilume 8. Published by the National
Electronics Conference, 852 East 83rd
Street, Chicago 19, III. 835 pages, including
charts, diagrams and tables.
Case bound. $5.00.
Included in this volume are all of
the papers which were presented at the
Eighth National Electronics Conference
held in Chicago on September 29,
30 and October 1. A program of the
three -day session is also given.
Topics covered by the 97 technical
papers include: electronic research, development,
and application; antennas;
the assembly and measurement of components;
audio; circuits; coding and
recording techniques; computers; delay
lines and h.f. test equipment; electronic
instruments; engineering management;
industrial measurements; magnetic amplifiers;
memory tubes; radar; radio
navigation; reliability of components
and equipment; semiconductors; servomechanisms;
television; transistors; and
wave guides.
The appendices contain a catalog of
the various exhibitors at the 1952 Conference
and contents of previous issues
of the Proceedings. Copies of Volumes
2, 4, 5, 6 and 7 may also be obtained
for $5.00 a copy.
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APRIL, 1953
New Products
(C'onti,,rid front page 18)
tape recorder combination, where the
CCR turns on the tape drive mechanism
only when there is a signal to be
recorded.
FERRAMIC CORES
Production of a new line of ferramic
cores for use in digital computers is
under way at the General Ceramics and
Steatite Corporation. These cores are
molded of Ferramic MF 1118, a soft
magnetic material featuring square hysteresis
loops, high volume resistivity
and a low loss factor.
As the response time of Ferramic MF
1118 is about 40 times faster than that
of other magnetic materials, the new
cores have a switching time of less than
one microsecond. They are available in
three sizes. Complete data will be supplied
promptly on request to: General
Ceramics and Steatite Corp., Keasbey,
N. J.
DECADE RESISTOR
Type 245S, a new 1 -watt precision
wire -wound resistor for decades and
other applications requiring low resistance
values with close tolerances, low
temperature rise, and low inductance,
has been announced by the Shallcroes
Manufacturing Company. It can be calibrated
to a tolerance of ±0.1% or better
and is available from 0.1 to 1000
ohms. The Type 245S resistor is 11/8"
long by %" in diameter.
A single layer bifilar winding protected
by a moisture- resistant lacquer
coating is used for all- values. The Steatite
bobbin and axial wire leads at the
same end make it easy to mount this resistor
directly on decade switch decks
or other similar equipment. Further
details may be secured by letterhead
request to Shallcross Manufacturing
Company, Collingdale, Pa.
ULTRASONIC DELAY LINES
A series of fused quartz ultrasonic
delay lines for radar and electronic
computer applications has been developed
by Andersen Laboratories, Inc.,
West Hartford, Conn. These solid delay
lines are available in bandwidths of
12 mc. or greater, and feature an extremely
low ratio of spurious to desired
signals -as low as -50 db for special
requirements. Insertion losses are also
kept to a minimum, 34 to 50 db being
characteristic, depending on the terminating
impedance necessary.
Andersen Laboratories is prepared to
offer advice and engineering help to
customers on all types of ultrasonic
delay line problems.
REASONS WHY
Pro cisiot
COIL BOBBINS
Improve your coils . . .
Quality Controlled
Greater Insulation
Better Heat Dissipation
Higher Moisture Resistance
15 to 20 % Stronger
Lighter Weight
More Winding Space
PRECISION Coil Bobbins are finished to
your exact specifications. Only the finest
dielectric materials are used.
Cores furnished in an infinite variety of sizes
and shapes- kraft, fish paper, acetate, or combinations.
Flanges cut to specifications -plain
or fitted with leads, slots or holes; embossed
or recessed.
Send specifications for
free sample and request
new Arbor List of over
1500 sires.
PRECISION PAPER TUBE CO.
2063 W. Charleston St., Chicago 47, III.
Plant No. 2, 79 Chapel SI., Hartford, Conn.
Also Mfrs. of Precision Paper Tubes
RADIO -ELECTRONIC ENGINEERING 29