If this error occurs, check the ribbon cable connections going
from the
CPU
bO,ard
to the channel
board~
Also
run
the CPU timer
test.
Press
SELECT
to
exit the
CGP
test. I
4.29 - DIGITIZER
TEST
The digitizer test requires a 1/4" monural audio cable, similar
to
the one used for the SYNC IN/OUT loopback.
An
oscilloscope with
probe grounded to the instrument chassis ground, and a pair of
stereo headphones are the only other equipment required
in
addition
to
the K250.
SETUP PROCEDURE
1. Connect one end of the 1/4" monaural audio cable to the
LEFT
HI
audio output jack
on
the rear panel of the K250.
Connect the other end of the audio cable to the LINE
IN
jack
on
the rear panel of the K250.
2.
Set the
GROUP
A slider
to
the
leftmost position.
3.
Set the GROUP B slider
to
the
rightmost position.
4.
Set the
VOLUME
slider
to
the rightmost position (maximum).
TEST DESCRIPTION
The digitizer test will use the K250 channel 1 as the Signal
source
to
be
digitized. Channel 12 will be set
up
in
digitizer mode
and
will be used to sample the input signal coming
in
from the LINE
IN
jack. When the sampling is complete, the original channel 1
sinewave signal will be output
on
channel
1,
Group
A.
The digitized
sinewave signal will be output
on
channel
2,
Group B for comparison.
The channel 2 signal
will
be
lower
in
amplitude than the channel 1
signal, but should not have distortion or noise present. The audio
output has been enabled during the test
to
permit aural verification.
The channel 1 signal should be audible
on
the left headphone speaker,
and the channel 2 digitized signal should be audible
on
the right
headphone speaker, at a slightly lower volume.
Kurzwell
250
Service Manual, Chapter 4
4·54
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