Required Test Equipmenl - Crown D-75 Service Manual

3 Required Test Equipment
Many of the service and repair problems
with
the D· 75
can be performed
with
a limited amount of test
Equipment Requi rements
Oscilloscope Capable of displaying a
IOMHz signal
Volt-Ohmmeter
Low-voltage resistance probe
lOOmv (range). High-voltage
resistance probe
(I.5V
range)
Frcq. Counter
Signal Generator Sine!Square wave available;
flat frequency responce.
TIlD .1% maximum
Circuit Breaker 15 ampere rating
AC Line Voltage Peak: reading meter (displays
Monitor rms equivalem
to
a
sinusoidal
peak
for any
waveform)
equipment. However, in order 10 return the unit to its
"factory new" specifications. the fol lowing list ofrequircd
test equipment is recommended. The "Requirements"
column provides information to allow intelligent selcctin
of substituleS
if the
"Suggcsted Supplier and Mode'" is
not available or is considered impractical to obtain.
Application Suggested Model
Monitoring output during
Telequipmcnt D54A or
service and testing
equivalent
Check resistance values
Auke 8024 or equivalent
(low voltage probe). Check.
semiconductor junctions for
opens or shorts
(high
voltage probe) Check DC
voltages
For accurate general Heath SM I 18A
monitoring
Provide
teSt
signals for Wavctek 130 -Series or
service and checkout
equivalent
In AC line
to
unit.;
proteCtS
circuitry from overload if
power supply has shorted
Monitor Line voltage Circuit available from
Crown
R9qired Test Equipmefll 3·1