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Direction Finders
(Continued from page 197)
also...
Indicator lights
SOR-AcTiot/
SWITCHES
To Hetherington engineers, snap- action
Switch -in-
dicator light combinations
Relays Aircraft and
Electrical Equipment
Assemblies
in a switch means a whole lot
a led by a
a decent action
hus i in every. Hetherloud
"click"
whether for
ington snap action switch, operabutton,
toggle, or
tion, lion, patented
f
shown ere provides four definite advan-
tages:
snap- action
. an exceptionally
positive
to "tease" the
that makes it impossible
switch ON or OFF contact.
lightning -fast contact make or
break for reduced arcing. (Hetherington
switches are smaller, carry
higher ratings because of this un-
usually fast action.)
the "snap" and the contact
make or break are siio ulta
"snaps
Deceptive
"clicks'
just can't occur with the Hetherington
snap-action mechanism).
highest quality construction
J polished taper, beryllium copper
springs, contacts and copper
terminals
of
with heavy silver overlay-all
cycles under
for a minimum life of 50,000 cY
rated load.
Today more and more appliance and
that
equipment
depe dable, space- saving nHethert
switches is really far -sighted
isgton Send details of your applicaeconomy
prompt recommendation by
lion for a p
Hetherington switch sp ecialists.
ffflfYfR//YGTO/V
SHARON HILL, PA.
West Coast Division: El Segundo, California
phase reference voltage arriving
over the second balanced pair is
applied to a split phase RC network
comprised of two sections.
One section shifts the phase +45°
from the original and the other
-45 °, thereby providing two voltages
which are displaced in phase
by 90 °. These voltages are amplified
in separate high quality, low
distortion amplifiers to the proper
level for direct application to the
phase meter stators.
The control portion of the remote
control unit contains a power supply
which provides current for
operation of the relays in the local
control unit and a removable control
panel. The control panel contains
a bank of ten push button
switches corresponding to the channels
established at the local station
and toggle switches for the system
on -off function and target operation.
Operation of any one of these
switches selects and transmits the
proper current levels to perform
the desired function. A switch is
also provided to transfer control
of the system to any one of the
parallel stations when more than
one remote station is used.
When multiple remote operation
is desired, a junction box is used
at the master station to furnish the
bearing signal to all remote
stations simultaneously. Through a
method of sequential switching controlled
by the transfer switch on
the remote control unit, any one
station at a time is allowed to control
the system. Each additional
station requires a remote control
unit and azimuth indicator identical
to those employed at the master
remote station.
System Performance
Extensive engineering evaluation
and operational suitability tests
were conducted to determine the
performance parameters of the
system. System range in all cases
has been consistently better than
contemporary voice communication
equipment. Fig. 10 shows the system
sensitivity in microvolts per
meter as a function of frequency.
The dashed curve illustrates the
threshold bearing sensitivity and
200 For product information, use inquiry card on pages 209 -210.
Tele -Tech & ELECTRONIC INDUSTRIES June 1956