Scully 280B Series - Page 199

Model 285B Electronics Maintenance
fully clockwise. With reproducer in Stop mode, ACVM should indicate a
level less than -26 dBm. Repeat f or channel 2.
6.21 LINE OUT PU T Distortion
6.22 Connect LINE O UT P UT C HAN 1 to the distortion analyzer. Repro-
duce a 500-Hz signal recorded at standard playback fluxivity (250 nWb / m
and less than 0.6 % total ha~monic distortion for 7.5-15 in / s f ull
track and 2-channel 2-track machines and 200 nWb / m for all other
reproducer tape speeds and track-channel configurations). The third
harmonic distortion of the reproducer should be less than 0.6 %. Repeat
for channel 2.
6.23
S PEAKER OUT PU T Distortion
6.24 Connect distortion analyzer across S PEAKE R O UT P UT CH AN 1 with
the 8-ohm load in parallel. Adjust V OL UM E control to 3W output.
Third harmonic distortion should be less than 1% more than measured in
paragraph 6.22.
6.25 Flutter
6.26 Connect LI NE OU TPU T CH AN 1 to flutter meter. Install flutter
test tape. Set the flutter meter to (ANSI S4.3-19 7 2; IEC 386-1972)
PEAK WEI GH TED . Start the machine. Flutter should be less than the
values listed below. Repeat for channel 2.
SPEED in / s MA XI MUM FLUTTER
3.75 0.2 %
7.5 0.1%
15.0
0.08 %
6-7 / 6-8