Specifications
under test or the TS-1777/VRM-l 16-volt
line can be tested.
a. When the TS-1777/VRM-l 16-volt
line is tested, the test probe tip is inserted
in test jack A. The regulated output of the
+16-volt dc regulator circuit is applied
through rf choke L7301 and level-adjusting
rheostat R7501 to the voltage supply limits
sensing circuit. The output from this cir-
cuit is applied to the Schmitt trigger cir-
cuit. If the regulated voltage is within
limits, GREEN indicator lamp. D67902
lights. If the regulated voltage is not within
the minimum and maximum limits, in-
sufficient voltage will be applied to the
Schmitt trigger circuit, and RED indicator
lamp DS7901 lights. The voltage supply
limits sensing and Schmitt trigger circuits
are supplied from the +16-volt dc regulated
line.
b. When a +16-volt dc point is tested in
a unit under test, the test probe tip is
inserted in the appropriate test point
(A2100-6, TP3002, TP3005, TP3012,
TP4006, TP4008, TP5010, or TP8001).
The test voltage is then connected through
rf choke L7301 and the remainder of the
test circuit functions as described in a
above.
14. Selector Switch Position 2
(B, fig. 9)
When the selector switch is in position
2, a +25.5-volt dc point on the unit under
test can be tested. The test voltage is
connected through rf choke L7301 and
across voltage divider network consisting
of resistors R7902 and R7917 to the Schmitt
trigger circuit. If the test voltage is above
the minimum limit, GREEN indicator
DS7902 will light. If the test voltage is
below the minimum limit, insufficient volt-
age will be applied to the Schmitt trigger
circuit, and RED indicator DS7901 will
light. Operating voltage for the Schmitt
trigger circuit is supplied from the +16-
volt dc regulated line.
15. Seiector Switch Position 3
(C, fig. 9)
When the selector switch is in position
3, the 150-cycle-per-second (cps) output
of module A5200 can be tested. The signal
is connected through inductor L7301, cou-
pling capacitor C7503, and attenuating re-
sistor R7903 to the audio amplifier. The
rectified output of the audio amplifier is
applied to the Schmitt trigger circuit. If
the signal voltage is above the minimum
limit, GREEN indicator DS7902 will light.
If the signal voltage is below the minimum
limit, insufficient voltage will be applied
to the Schmitt trigger circuit, and RED
indicator DS7901 will light. The operating
power to the audio amplifier and Schmitt
trigger circuit are supplied from the +16-
volt dc regulated line.
16. Selector Switch Positions 4, 5, and 6
(c, fig. 9)
a. Position 4. When the selector switch -
is in position 4, the audio output from
module A5100 can be tested. Operation of
the circuit is similar to that of position 3
(para 15) except that resistor R7904, which
has a resistance of 511K ohms, is used in
place of R7903.
b. Position 5. When the selector switch
is in position 5, the audio output of module
A4300 or A5200 can be tested. Operation
of the circuit is similar to that of position
—
3 (para 15) except that resistor R7905,
which has a resistance of 10K ohms, is
used in place of R7903.
c. Position 6. When the selector switch
is in position 6, the audio output of the
module A5100 monitor amplifier or a
sawtooth output from module A8400 can be
tested. Operation of the circuit is similar
to that of position 3 (para 15) except that
resistor R7906, which has a resistance of
26.lK ohms, is used in place of R7903.
17. Selector Switch Position 7
(D, fig. 9)
When the selector switch is in position
7, the 11.5-mc output of a module A8300
can be tested. The test signal from the test
probe rf preamplifier is connected through
coupling capacitor C7901 and attenuating
resistor R7907 to the 11.5-mc amplifier.
The rectified output of the 11.5-mc ampli-
fier is applied to the Schmitt trigger cir-
cuit. If the signal voltage is above the
12