TM
11-6625-821-45
set that is to be used. Detailed functioning of
binations of received rf signals to
both sections is described in paragraph 1-4
determine its bearing, the test set
and 1-5.
can simulate rf signals of any bear-
ing.
signal generator connected to SIG-
Section
NAL GENERATOR connector J8
a. General. The receiver section of the test
provides the rf signal for the loop
set consists of Test Set, Radio TS-2502/ARM
antenna simulator circuit. From
93, the control unit, the inverter, and the ca-
connector J8, the rf signal is ap-
bles. The TS-2502/ARM-93 applies simulated
plied to the rotor of resolver B1
antenna signals to the receiver and provides
through a converter circuit com-
an indication of the receiver's response to such
prised of resistors R1 through R5
signals. It also provides interconnection be-
and capacitor C1. Resistor R1 fixes
tween the control unit and the receiver and be-
the input impedance at J8 to 50
tween the inverter and the receiver. The con-
ohms to match the output imped-
trol unit provides all the control information
ance of the external signal genera-
required by the receiver, and the inverter pro-
tor. Resistors R2 through R5 and
vides the ac power required by the receiver.
capacitor C1 form a network that
The cables interconnect the receiver, the test
converts the indication on the sig-
set, and external test equipment. Subpara-
nal generator output meter from
graphs b through d below describe the de-
microvolt to microvolt per meter.
tailed functioning of the circuits contained in
The microvolts per meter is the
the three units, and e describes the cables.
field strength of the signal at the
b. Test Set, Radio TS2502/ARM93.
simulated loop antenna in resolver
B1.
(1) Loop antenna simulator circuit. The
loop antenna simulator circuit pro-
vides the receiver with a signal that
simulated loop antenna signal from
is normally provided by the fixed
the stator windings of resolver B1
loop antenna in an aircraft installa-
is applied to LOOP ANTENNA
connector J9 through a cable sim-
tion.
ulator. In normal operation of the
receiver, a specific amount of im-
of the loop antenna simulator cir-
pedance is required between the
cuit is resolver B1. The two stator
fixed loop antenna and the re-
windings in resolver B1 simulate
ceiver. Capacitors C2 through C5
the two pairs of coils mounted at
and inductors L1 through L10 sim-
right angles to each other in the
ulate a part of this impedance. The
fixed loop antenna. The rotor wind-
remaining impedance is simulated
ing induces an rf signal into each
in the 5-foot cable (Cable Assem-
of the two stator windings. The
bly, Special Purpose, Electrical
phase and amplitude of the two in-
CX-11570/ARM-93)
that con-
duced stator voltages depend on
nects LOOP ANTENNA connector
the coupling between the rotor and
J9 to the receiver. Variable induc-
each stator winding. This coupling
tors L3 and L8 are connected across
can be varied by rotating the rotor
the resolver stator windings so
winding with the LOOP SIMULA-
the impedance at the end of the 5-
TOR control. Therefore, any com-
foot cable can be adjusted to the
bination of phase and amplitude
correct value.
of induced voltage can be obtained
(2) Sense antenna simulator circuit. The
from resolver B1 stator windings.
sense antenna circuit provides the
Since the receiver, in nomnal use,
receiver with a sense antenna signal
utilizes phase and amplitude com-
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