Nagra PORTABLE ANALOGUE AUDIO TAPE RECORDER Instruction Manual - page 11
5. PINCHWHEEL LIFTER (stop + test only)
6. LEVEL CONTROL (right) mic input 2
7. LEVEL CONTROL (left) mic input 1
These are the main level controls for the two microphone inputs.
8. REFERENCE OSCILLATOR (push button)
On the lower edge of the front panel, between the line and playback potentiometer and the mic 2
potentiometer, there is the reference generator push button. When this button is pressed, a
composite 1.1 kHz signal with a 10 kHz 9th harmonic at a level of approximately -8 dB is injected
into the "DIRECT" chain of the recorder.
The modulometer will show -8 dB. It is useful to record a short burst of this signal at the beginning
of each reel of tape so as to enable the level of the playback chain to be accurately calibrated
before the real recording is made. This also permits adjustment of the record head azimuth in the
field without test equipment. At this point the subject of print-through should be mentioned. After a
certain period of time, a recording may be copied (at reduced level) onto adjacent turns of a tape on
a reel. This produces a perceptible echo during the silences preceding or following a strong sound.
It is thus recommended to leave a pause of two or three turns of tape after recording the "REF"
signal.
9. LINE & PLAYBACK POTENTIOMETER
This potentiometer is used to adjust the line input level when using the machine to record a signal
from the line input (41).
10. MANUAL/AUTOMATIC SELECTOR
This switch allows selection of the sensitivity adjustment of the microphone inputs. In the MANUAL
position the sensitivity is adjusted by means of the potentiometers (6) and (7). In the AUTOMATIC
position 1 this gives ALC (automatic level control) to mic input 1 only and for both mic inputs in the
position 2.
11. LID CATCH
12. MODULOMETER MODE SELECTION SWITCH
This is an eleven position rotary switch allowing different information to be displayed on the
modulometer.
Each position is described below:
X
Position not used.
RX
Indicates the level of the RF signal picked up by the antenna of the QRR
receiver. (see note)
SYNCH
This indicates the phase shift between the pilot playback signal from the tape
and the reference signal. Synchronism is correct when the needle is
stationary.