of module A5200 can be tested. The signal
under test or the TS-1777/VRM-l 16-volt
is connected through inductor L7301, cou-
line can be tested.
pling capacitor C7503, and attenuating re-
a. When the TS-1777/VRM-l 16-volt
sistor R7903 to the audio amplifier. The
line is tested, the test probe tip is inserted
rectified output of the audio amplifier is
in test jack A. The regulated output of the
applied to the Schmitt trigger circuit. If
+16-volt dc regulator circuit is applied
the signal voltage is above the minimum
through rf choke L7301 and level-adjusting
limit, GREEN indicator DS7902 will light.
rheostat R7501 to the voltage supply limits
If the signal voltage is below the minimum
sensing circuit. The output from this cir-
limit, insufficient voltage will be applied
cuit is applied to the Schmitt trigger cir-
to the Schmitt trigger circuit, and RED
cuit. If the regulated voltage is within
indicator DS7901 will light. The operating
limits, GREEN indicator lamp. D67902
power to the audio amplifier and Schmitt
lights. If the regulated voltage is not within
trigger circuit are supplied from the +16-
the minimum and maximum limits, in-
volt dc regulated line.
sufficient voltage will be applied to the
Schmitt trigger circuit, and RED indicator
16. Selector Switch Positions 4, 5, and 6
lamp DS7901 lights. The voltage supply
(c, fig. 9)
limits sensing and Schmitt trigger circuits
are supplied from the +16-volt dc regulated
a. Position 4. When the selector switch -
line.
is in position 4, the audio output from
b. When a +16-volt dc point is tested in
module A5100 can be tested. Operation of
a unit under test, the test probe tip is
the circuit is similar to that of position 3
i n s e r t e d in the appropriate test point
( A 2 1 0 0 - 6 , TP3002, TP3005, TP3012,
has a resistance of 511K ohms, is used in
TP4006, TP4008, TP5010, or TP8001).
place of R7903.
The test voltage is then connected through
b. Position 5. When the selector switch
rf choke L7301 and the remainder of the
is in position 5, the audio output of module
test circuit functions as described in a
A4300 or A5200 can be tested. Operation
above.
--
of the circuit is similar to that of position
3 (para 15) except that resistor R7905,
14. Selector Switch Position 2
which has a resistance of 10K ohms, is
(B, fig. 9)
used in place of R7903.
c. Position 6. When the selector switch
When the selector switch is in position
is in position 6, the audio output of the
2, a +25.5-volt dc point on the unit under
module A5100 monitor amplifier or a
test can be tested. The test voltage is
sawtooth output from module A8400 can be
connected through rf choke L7301 and
tested. Operation of the circuit is similar
across voltage divider network consisting
to that of position 3 (para 15) except that
of resistors R7902 and R7917 to the Schmitt
resistor R7906, which has a resistance of
trigger circuit. If the test voltage is above
26.lK ohms, is used in place of R7903.
the minimum limit, GREEN indicator
DS7902 will light. If the test voltage is
17. Selector Switch Position 7
below the minimum limit, insufficient volt-
(D, fig. 9)
age will be applied to the Schmitt trigger
circuit, and RED indicator DS7901 will
When the selector switch is in position
light. Operating voltage for the Schmitt
7, the 11.5-mc output of a module A8300
trigger circuit is supplied from the +16-
can be tested. The test signal from the test
volt dc regulated line.
probe rf preamplifier is connected through
coupling capacitor C7901 and attenuating
15. Seiector Switch Position 3
resistor R7907 to the 11.5-mc amplifier.
(C, fig. 9)
The rectified output of the 11.5-mc ampli-
fier is applied to the Schmitt trigger cir-
When the selector switch is in position
cuit. If the signal voltage is above the
3, the 150-cycle-per-second (cps) output
12
