TELE-TECH & - AmericanRadioHistory.Com

the solid curve shows the signal
strength required for a high quality
bearing. These figures represent
the statistical average for 16 systems
during pilot production run.
The pick -up factor of the individual
antennas compared to a
tuned dipole over the same frequency
range varies from -5.5db
to +2db as shown in Fig. 11.
GAIN
OF
AS - 449
TUNED DIPOLE
IN
DB
220-
+ + +
of A o,
240-
280-
300-
340-
360
Now you can save valuable replacement
or specification time with Johnson Panel
Indicators. Available in a wide variety of
types, Johnson "preferred" units are
immediately available at parts distributors
throughout the country. Careful
standardization, with an eye to replacement
as well as interchangeability, makes
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leading manufacturers.
NEW PILOT LIGHT
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±80-- -
4co-I
Fig. 11: Pick -up factor of D/F antenna
compared to tuned half -wave antenna
System instrumental accuracy
curves obtained at three frequencies
are shown in Fig. 6. The maximum
excursions are +4 degrees and -2
degrees resulting in a total spread
of 6 °. The system was calibrated at
a frequency of 230 Mc and was not
re- calibrated at the other frequencies,
therefore, the figures include
zero shift resulting from
frequency change. It is obvious that
greater accuracy can be obtained if
the antenna is specifically oriented
for the operating frequency. An
analysis of 350 bearings obtained
during a series of instrumental
accuracy tests indicated that 51%
of the observed bearings were
within one degree of the true
(Continued on page 2021
1
Available types include: continuous indication neon
types; models for high and low voltage incandes-
cent bulbs; standard or wide angle glass and
lucite jewels in clear, red, green, amber, blue or
opal. Specials, including those meeting
military
specifications are also available in production
quantities. For full information, write today!
KNOBS AND DIALS
Dramatic in appearance and functional in design, these rugged
knobs and dials are made of tough, scratch resistant block
phenolic (To MIL -P -14) with heavy, integral molded brass inserts.
Three basic diameters: 1'.é ", Pi" and Vs"- available
with matching skirts of black phenolic, calibrated nickel silver
finish skirts or chromium dial plates. Write for information, to
E. F Jol: nsom: Coi::p miw
. 2311 SECOND AVE. S.W. WASECA, MINNESOTA
CAPACITORS INDUCTORS KNOBS DIALS SOCKETS INSULATORS PLUGS JACKS PILOT LIGHTS
Tele -Tech & ELECTRONIC INDUSTRIES June 1956 For product information, use inquiry cord on pages 209 -210. 201