TELE-TECH & - AmericanRadioHistory.Com

permeability is defined. Temperature effects
and loss and stability considerations are included.
A numerical example is presented. An
error of 10% to 15% may be incurred due to
the approximations in the computations. Source
6/6 -174
Temperature Dependence of the Loss Factor
and the Dielectric Constant of Solid Insulating
Materials at about 4000 Mc. by F. Gross.
"Nach. Z." Mar. 1956. 5 pp. An Em-mode resonator
is used to measure the temperature response
between 20 °C and 350 °C of the dielectric
constant and the loss factor of ceramics,
glass and plastic materials at about 4000 Mc.
The results are tabulated. Source 6/6 -175
MEASURING & TESTING
An Electrostatic Analyzer for the Absolute
Measurement of Proton Energies and the Establishment
of Fixed Points on the High Voltage
Scale, by S. Hunt, D. Petrie, F. Firth, and
A. Trott. "Proc. BIEE." Mar. 1956. 6 pp. An
electrostatic analyzer for measuring the energy
of proton beams from an electrostatic generator
is described. The energy measurements are
absolute and are referred finally to the voltage
of thermostatically controlled standard cells.
Source 6/6 -176
Eddy- Current Bridge for Measuring Skin
Losses, by Q. Kerns. "Tele- Tech" June 1956.
3 pp. Eddy -currents are excited in a sample by
induction from an energized loop. Signal which
is proportional to loss is coupled out by second
loop in close proximity to sample surface. Different
regions of a large sample or many different
samples may be tested at rate of several
per minute. Source 6/6 -247
An Electrolytic -Tank Equipment for the Determination
of Electron Trajectories, Potential
and Gradient, by D. Hollway. "Proc. BIEE."
Mar. 1956. 6 pp. A description is given of a
general purpose electrolytic -tank equipment of
simple design. Provision is made for testing
either axially- symmetric or 2- dimensional models,
and the associated circuits can be arranged
by switching: 1. to measure potentials; 2. to
mark equipotentials automatically; 3. to measure
potential gradients; and 4. to trace electron
trajectories. Source 6/6 -177
A Method of Tracing Electron Trajectories in
Crossed Electric and Magnetic Fields, by D.
Hollway. "Proc. BIEE." Mar. 1956. 5 pp. with
discussion. It is shown that Gabor's tangent
method of electron path tracing may be extended
to problems which include the determination
of paths in the presence of crossed
electric and magnetic fields. The magnetic field
may either be constant or it may vary with
position if the distribution is known. The possible
extension to time varying fields is indicated.
Source 6/6 -178
A Digital Differential. Simultaneous Bi- Directional
Counting Using a Dekatron, by W.
Leslie. "El. Eng." May 1956. 4 pp. Dekatron is
used to indicate the running difference in
count between 2 independent pulse trains. It is
applied to indicate frequency differences. to
generate difference frequency signals without
tuned circuits, to control frequency or speed
relative to a master signal which may originate
from a quartz oscillator, wide range oscillator.
or from a shaft whose speed must be copied.
Source 6/6 -179
Corona Testing, by T. Verbon. "El. Des." Apr.
15. 1956. 2 pp. Test set described gives an accurate
measure of the corona being generated
at any test voltage; it measures a component's
voltage breakdown point ; and it determines
the frequency where maximum corona noise is
generated. Source 6/6 -180
Testing Selenium Rectifiers, by E. Pagano. "El.
Des." Apr. 15, 1956. 4 pp. Advantages and limitations
of effective test procedures that can be
performed to determine the quality of selenium
rectifiers are given. The tests described are
primarily based on measuring the forward and
reverse characteristics. Source 6/6 -181
Metrological Basis For The Pi -Pulse Method Of
Measuring Nonlinearity, by V. Wolf. "Radiotek."
Jan. 1956. 10 pp. Relationships are derived
for the design of the basic elements of a
device designated for the measurement of nonlinearity
by means of Pi- pulses. Analysis includes:
1) effect of a blocking filter upon the
evaluation of the nonlinearity coefficient, 2l
selection of the frequency range and bandwidth
of the filters, 8) selectivity of the filters.
Source 6/6 -182
Fixed Heater- Current Source for Testing Series -
String Tubes, by W. Drummeter and R. Salzman.
"El. Des," May 1, 1956. 2 pp. Because of
the effect of change of heater resistance on
tube performance, satisfactory testing requires
a constant current source rather than a constant
voltage source. Design and application of
such a device is described. Source 6/6 -183
Video Measurements Employing Transient
Techniques, by H. Samulon. "Proc. IRE." May
1956. 12 pp. Suitable waveforms and equipment
are described, followed by methods of measurement
and evaluation of response curves. An attempt
is made to estimate the effect of small
variations in the transfer function on the transient
response. Source 6/6 -184
Techniques for Measuring Noise -Part III, by
W. Bennett. "El." May 1956. 4 pp. Noise figure
is determined for various networks, 9 different
scales for measuring noise are compared, and
noise effects in TV are discussed. Source 6/6 -185
Apparatus for the Measurement of Physical
Constants by the Elastic Vibration Method, by
A. Martin . "J. EIRE." Mar. 1956. 17 pp. A
general introduction is followed by the description
of ultrasonic test equipment adapted to
handle fluid or solid samples of from 1 to 5 cm.
A frequency range of from 0.5 to 50 MC, a
temperature range of from 0° to 100 °C and
pressures up to 10.000 kg/cm= can be handled.
Source 6/6 -186
An Ultra- High -Speed Oscillograph, by F. Connor.
"Proc. BIEE." Mar. 1956. 4 pp. Design
and construction details of an oscillograph for
observing and studying the build -up of r -f
oscillations of a pulsed magnetron, and other
phenomena in the millimicrosecond range are
given. A unit containing short lengths of 70
ohm cable for delay purposes is included. Calibrating
circuit provides a 1250 MC timing
waveform from a pulsed coaxial -line oscillat'n
which also checks the linearity of the time
base. Source 6/6 -187
Theory and Applications of the Synchronous
Rectifier in Modern Measurement Engineering,
by S. Koepp. "Hochfreq." Jan. 1956. 6 pp. The
performance of the synchronous rectifier for
measurements is compared with that of the
square and linear rectifiers. Two circuit diagrams
for additive and multiplicative push -pull
mixing are included. Source 6/6 -188
Electronic Accessories in Ultrasonic Material
Testing, by H. Krautkraemer. "El. Rund."
Apr. 1956. 2 pp. Electronic visual and acoustical
indicators and electronic recording apparatus,
as well as equipment for sorting are
considered. In particular, an apparatus for the
inspection of railroad tracks is described.
Source 6/6 -189
Measuring Techniques for Non -Linear Networks,
by H. Nottebohm. "El. Rund." Apr.
1956. 3 pp. The techniques presented are based
on the generation of harmonics and beat frequencies
due to the non -linear characteristics.
Theoretical aspects are included. Source 6/6 -190
Bevatron- Frequency Measurement System. by
W. Brobeck and W. Struven. "El." May 1956.
6 pp. Varying bevatron magnetic -field frequency
over 350 to 2500 KC range is measured
at 32 predetermined points using digital techniques.
Departures from calculated frequency
are seen on bar -graph CRT display to approximately
1% accuracy. Source 6/6 -191
On the Measurement of the Quality Factor of
Cavity Resonators with a Standing Wave Indicator,
by H. Urbarz. Nach. Z. Mar. 1956. The
unloaded and loaded Q factor of the effective
cavity resonator of a Reflex Klystron are compared
and the effect of the coupling element
is studied. Sources of possible errors are considered.
Voltage standing -wave ratio as well
as the shift of the minimum method are employed.
Source 6/6 -192
Insulation Tests, by H. Graves. "Insult May
1956. 2 pp. One of a series of articles explaining
the purpose, reasons, operation, meaning.
and interpretation of results, etc., behind various
electrical insulation tests. This article
covers the effects of elevated temperatures on
varnished glass fabrics. Source 6/6 -193
RADAR,
NAVIGATION
Microwave Vehicle -Speed Indicator, by G.
Court "Wirel. Eng." Mar. 1956. 9 pp. In this
radar speed meter using the Doppler principle,
a hybrid waveguide junction is used to provide
both transmitting and receiving channels so
that only a single aerial is required. The
klystron oscillator. by using the leakage between
opposite arms of the junction, provides
local oscillator power for the homodyne detection
process used. Source 6/6 -194
Beam Deflection Tube Simplifies Radio Compass,
by J. Tewksbury. "El." May 1986. 2 PP.
Two miniature 6AR8 beam deflection tubes
replace 7 tubes formerly used in a radio compass,
resulting in smaller, lighter unit for aircraft.
Source 6/6 -195
Radar PPI Display Uses Precision Interlace.
by A. Shulman. "El." May 1956. 4 pp. Interlacing
during radar dead time is used to display
marker signals which represent target position
data from auto -tracking computer. Source
6/6 -196
A Method of Increasing the Ambient Illumination
of Radar Operations Room Without
Reduction of Signal Detection Threshold, by
C. Barnard. "Proc. BIEF' Mar. 1956. 4 pp.
This is accomplished by the use of a narrow -
band optical filter superimposed on the face of
the CRT, and the use of an illuminant complementary
to the response of the tube. Experiments
have shown that it is possible, by the
use of a number of illuminants lying outside
the passband of the filter, to create an impression
of white ambient lighting in which
the color discrimination of the operations room
staff appears to be unimpaired. Source 6/6 -197
Radar Second Detector Filter Nomograph. by
C. Young. "El." May 1956. 2 pp. When upper
video cutoff frequency, i -f value, tube and
socket capacitances are known, nomograph
gives optimum circuit constants for second
detector and video circuits of radar receiver.
Source 6/6 -198
134
Tele -Tech & ELECTRONIC INDUSTRIES June 1956