Performance Check and Calibration Procedures
5–8 760A / 760D / 760N
760N: "5 bar segments
d. Set S340 to Position 7 (expanded scale with offset).
e. Set the leveled audio signal generator output level so the LEFT bar
indicates:
760A: 0 dB
760D : 0 dB on white scale
760N : 0 dB on blue scale
f. CHECK – that when the audio signal generator frequency is varied from
20 Hz to 20 kHz each bar amplitude changes less than 0.5 dB. With
S340 set to position 7, this is:
760A: "10 bar segments (+4 to –4 scale marks)
760D: "4 bar segments
760N: "5 bar segments
g. Set S340 to Position 0 (normal scale).
13. Check Bar Gain Match
a. Connect the leveled audio signal generator output to the LEFT AUDIO
INPUT only, and set SELECT to AUX.
b. With the EXPAND SCALE push button depressed, set the audio signal
generator output level so the LEFT bar indicates:
760A: –8 dB (TEST)
760D: 0 dB
760N: –9 dB
c. Move the input from the LEFT to the RIGHT AUDIO INPUT.
d. CHECK – that with the EXPAND SCALE push button depressed, the
RIGHT bar amplitude matches the LEFT bar amplitude within 0.3dB:
760A: "3 bar segments
760D: "2 bar segments
760N: "3 bar segments
e. Move the input from the RIGHT to the AUXILIARY AUDIO INPUT.
f. CHECK – that with the EXPAND SCALE push button depressed, the
AUXILIARY bar amplitude matches the LEFT bar amplitude within
0.3 dB.