TM 11-6625-2616-14
variac output from 103.5 vac to 126.5 vac. There
should be no obvious change in any power supply
a. Test Conditions.
voltage.
(1) Instrument connected to 115 vac or 230
vac power source.
(2) PWR ON pushbutton in (no warmup
required).
(3) VDC pushbutton in.
b. Test Procedure.
(1) Connect the oscilloscope common to in-
Buffer Amplifier Test
strument SIG L.
a. Test Conditions.
(2) Connect the oscilloscope 10:1 probe to
TP12 on the main board assembly.
(1) Instrument connected to 115 vac or 230
vac power source.
(3) The oscilloscope should indicate a gated
clock frequency of approximately 500 KHz and
(2) PWR ON pushbutton in (allow 5 min-
from 3- to 4-volt amplitude.
utes warmup time).
(3) VDC pushbutton in.
b. Test Procedure.
a. Test Conditions.
(1) Connect the voltage standard output
(1) Instrument connected to 115 vac or 230
to instrument SIG H.
vac power source.
(2) Connect the voltage standard common
(2) PWR ON pushbutton in (no warmup
to instrument SIG L.
required).
(3) Connect the leads of the multimeter
(3) VDC pushbutton in.
between the voltage standard output and TP5
on the signal conditioning assembly.
b. Test Procedure.
(4) Set the voltage standard output to
(1) Connect the oscilloscope common to in-
+10.0000 volts.
strument SIG L.
(5) The multimeter should not show any
(2) Connect the oscilloscope 10:1 probe to
visible deflection.
TP3 on the main board assembly.
(3) The oscilloscope should indicate 200-
millisecond pulses at 3- to 5-volt amplitude.
a. Test Conditions.
NOTE
(1) Instrument connected to 115 vac or 230
The presence of a 200-millisecond pulse
vac power source.
confirms that the counters are operating
(2) PWR ON pushbutton in (no warmup
properly. The trailing edge of the 200-
time required).
millisecond pulse is formed by the end
of the one hundred thousandth count
(3) VDC pushbutton in.
which terminates the pulse.
b. Test Procedure.
(1) Connect the voltage standard common
to instrument SIG L.
Pulse Width Test
(2) Connect the leads of the multimeter
a. Test Conditions.
between the voltage standard output and TP5
(1) Instrument connected to 115 vac or 230
on the main board assembly.
vac power source.
(3) Set the voltage standard to +10.0000
(2) PWR ON pushbutton in (no warmup
volts.
required).
(4) The multimeter should not show any
(3) VDC pushbutton in.
visable deflection.
