Nagra PORTABLE ANALOGUE AUDIO TAPE RECORDER Instruction Manual - page 55
MODULOMETER
Integration time for - 2 dB
7.5 ms
Usable scale
-30 to +5 dB
Frequency response
from 40 Hz to 20 kHz
±0,5 dB
RECORDING AND PLAYBACK CHAIN
Nominal recording level
0 dB= 320 nWb/m
Maximum peak level (M.P.L.)
+ 4 dB
Magnetic tape used for Calibration :
CCIR
LN
PEM 468
STD
PER 368
NAB
LN
3M 808
STD
3M 806
Erasing efficiency
CCIR
84 dB
NAB
88 dB
Frequency response, recording at 20 dB below M.P.L.
15 ips (38 cm/s) CCIR and NAB 30 Hz to 20 kHz ±1.5 dB
7½ ips (19 cm/s) CCIR and NAB 30 Hz to 15 kHz ±1.5 dB
3¾ ips (9,5 cm/s) CCIR and NAB 30 Hz to 8 kHz ±2.0 dB
Distortion at M.P.L :
CCIR
3rd harmonic
0,4%
2nd harmonic
0,3%
NAB
3rd harmonic
1,0%
2nd harmonic
0,4%
Signal-to-noise ratio of the playback chain only, with motor running and leader tape, ASA A
weighted, M.P.L 83 dB
Recording-playback signal-to-noise ratio at M.P.L at 7½ ips
ASA A
Linear
Weighted
LN
NAB
64 dB
73 dB
CCIR
62 dB
72 dB
STD
NAB
64 dB
70 dB
CCIR
62 dB
68 dB