Nagra PORTABLE ANALOGUE AUDIO TAPE RECORDER Instruction Manual - page 30

the Speed Varier and to allow the Synchronizer to make a final adjustment to 

ensure the slaving. 

This can be done as follows: 

Method A 

1. 

Play back the  tape to be transferred without slaving. When using the QSLI internal 

synchronizer, put the Nagra into "Playback" without loudspeaker. 

2. 

Adjust the speed with the aid of the Speed Varier QSV-2 in such a manner that the 

playback pilot signal and the mains are approximately synchronized. The needle of the 

Nagra meter (switch on "SYNC") will not swing. 

3. 

Rewind the tape and make the transfer in the usual manner. Under these conditions, 

the speed correction achieved by the Synchronizer will be very small. 

Method B 

Make the transfer in the classic manner and adjust the Speed Varier so that the needle 

(in the position SYNC) remains at the  center of the scale (QSLI). This method is less 

precise,  but it is sufficient in practice. It should be noted, however, that the 

interruptions of the pilot signal happen at the beginning of a sequence, and it is almost 

always necessary to make a trial playback, adjust the speed, rewind and then make 

the transfer. 

USE OF SPEED VARIER WHILST FILMING ON PLAYBACK 

Whilst filming on playback, it is possible that the camera may run at an incorrect speed. It will 

therefore be necessary to adjust the camera, if possible, to avoid any change in the tone of the final 

sound. If this is not possible, correction can be made with the Speed Varier (see above). 

RECORDING OF FACSIMILE AND SIMILAR SIGNALS 

A Nagra equipped with a Quartz Crystal Pilot Generator and a QSLI Synchronizer can reproduce, 

on playback, frequencies with a precision of the order of 0.001%, as any slipping or stretching of the 

tape is automatically compensated for. This applies to average frequencies for, inevitably, 

mechanical tolerances and longitudinal vibrations of the tape will affect the instantaneous speed 

(wow and flutter). 

Experience has shown that this precision is more than sufficient for the recording and reproduction 

of facsimile signals. Other telemetering applications are, of course possible. 

PILOT PLAYBACK USING A NAGRA 4.2 L NOT EQUIPPED WITH QSLI SYNCHRONIZER 

Output impedance: 47k Ohm ±20% 

Load impedance: from zero to infinity. 

Output voltage from tape recorded on Nagra 4.2 L: 330mV ±3 dB. 

PILOT PLAYBACK MADE BY NAGRA 4.2 L FITTED WITH QSLI SYNCHRONIZER 

Output impedance: 10 k Ohm ±20% 

Load impedance: from zero to infinity 

Output voltage from tape recorded on Nagra 4.2 L: 0.85 V nominal ±3 dB.