TELE-TECH & - AmericanRadioHistory.Com

STANDARD
True Hermetic Sealing
assures Maximum Stability
,AMPERITE
AMPERITE
DELAY
RELAY
PROBLEM? Send for
Bulletin No. TR -81
Simplest Most Compact Most Economical
Thermostatic DELAY RELAYS
2 to 180 Seconds
Actuated by a heater, they operate on A.C., D.C.,
or Pu:sating Current.
Hermetically sealed. Not affected by altitude,
{
moisture, or other climate changes.
SPST only - normally open or normally closed.
Amperite Thermostatic Delay Relays are compensated.
for ambient temperature changes from
-55° to +70° C. Heaters consume approximately
2 W. and may be operated continuously. The units
are most compact, rugged, explosion -proof, long -
MINIATURE
lived, and - inexpensive!
TYPES: Standard Radio Octal, and 9 -Pin Miniature
Also - Amperite Differential Relays: Used for automatic
overload, under -voltage or under -current protection.
BALLAST REGULATORS
Amperite Regulators are designed to keep the current in a circuit
automatically regulated at a definite value (for example, 0.5 amp.)
... For currents of 60 ma. to 5 amps. Operate on A.C., D.C., Pulsating
Current.
F I oo 1
3
MAX
MAX
r
0
0
VOLTAGE OF Ì4V
ATTERY 6 CHARGER
VARIES APPROA.
WITH AMPERITE
VOLTAGE VARIES
ONLY
TÓ ;L TB
50% 2% BULB
Hermetically sealed, they are no affected by changes in altitude,
ambient temperature ( -55° to +90° C.), or humidity ...Rugged,
light, compact, most inexpensive.
Write for 4 -page Technical Bulletin No. AB -51
AMPERITE CO., Inc.
561 Broadway, New York 12, N. Y.
Telephone: CAnal 6 -1446
In Canada: Atlas Radio Corp., Ltd.
560 King St., W., Toronto 2B
Individual inspection
and double- checking
assures top quality
of Amperite products.
Direction Finders
(Continued from page 193 )
by each antenna, determines which
antenna is furnishing the stronger
signal, and connects this antenna
through the receiver to the bearing
indicator circuits. A simplified
block diagram of this unit is shown
in Fig. 8. Comparison of the two
antenna RF outputs is accomplished
by switching the receiver periodically
from one antenna to the
other and comparing the corresponding
receiver output voltages.
w. ì---
Fig. 9: Block diagram of local station
The antenna furnishing the
stronger signal, called the "operating"
antenna, supplies directional
information for a period of approximately
three seconds. The
output of the other antenna called
the "sampled" antenna is sampled
for a period of 0.3 sec.
In analyzing the operation of the
comparator (Fig. 8), assume that
antenna #1 is furnishing the
stronger signal initially and is connected,
for approximately 3 sec. to
the input of the radio receiver by
means of the RF switching relay
which is controlled by the multi -
vibrator in the timing circuit. The
30 cycle demodulated D/F output
of the receiver is applied to the
indicator through the disabling
relay and also to the amplitude
comparison circuits where a DC
voltage proportional to the antenna's
signal voltage is stored. Simultaneously,
the antenna's corresponding
reference voltages are
applied to the azimuth indicator
194 For product information, use inquiry card on pages 209 -210.
Tele -Tech & ELECTRONIC INDUSTRIES June 1956