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N A G R A     4.2 

 
 
 

PORTABLE ANALOGUE AUDIO 

 

TAPE RECORDER 

 

 

 
 
 
 

INSTRUCTION MANUAL 

 

(KSA code No. 20 04 004 151) 

 
 
 
 
 
 
 

Kudelski S.A. 
NAGRA Tape Recorder Manufacturer 
CH-1033 Cheseaux / SWITZERLAND 
phone (021) 732 01 01 

Copyright reserved for all countries

 

telex 459 302 nagr ch 

February 1991 Edition 

Printed in Switzerland 

telefax (021) 732 01 00 

http://www.nagraaudio.com

 

 

 
 

Summary of Contents for PORTABLE ANALOGUE AUDIO TAPE RECORDER

Page 1: ...KSA code No 20 04 004 151 Kudelski S A NAGRA Tape Recorder Manufacturer CH 1033 Cheseaux SWITZERLAND phone 021 732 01 01 Copyright reserved for all countries telex 459 302 nagr ch February 1991 Editio...

Page 2: ...aulty parts excluding all other indemnities All freight costs as well as customs duty and other possible charges are at the customer s expense Our guarantee remains valid in the event of emergency rep...

Page 3: ...14 MODULOMETER 13 15 PILOT INDICATOR 13 16 SPEED AND POWER INDICATOR 13 17 HEADPHONES OUTPUT 13 18 HEADPHONES VOLUME CONTROL 13 19 REEL FIXING NUT 13 TAPE DECK 14 20 SPEED AND EQUALIZATION SELECTOR 1...

Page 4: ...ON 27 RECORDING A PILOT SIGNAL 27 RECORDING THE INTERNAL CRYSTAL 27 RECORDING AN EXTERNAL PILOT SIGNAL 27 SYNCHRONIZING A RECORDED TAPE 28 FREQUENCY METER OPTIONAL ACCESSORY QFM 28 QUARTZ CRYSTAL PILO...

Page 5: ...sponse 43 Coloration Transient Reproduction Reverberation 43 Use at High Sound Levels 44 Signal to noise Ratio 44 Directional Characteristics 44 SECONDARY CHARACTERISTICS RELATED TO DIRECTIONAL CHARAC...

Page 6: ...R SUPPLY 52 TAPE TRANSPORT 53 WOW AND FLUTTER 53 AMPLIFIER CHAIN 53 MAGNETIC TAPE 53 AUTOMATIC LEVEL CONTROL 53 FILTERS 54 REFERENCE GENERATOR 54 OUTPUTS 54 BUILT IN LOUDSPEAKER 54 OPERATING CONDITION...

Page 7: ...s 19 cm s and 9 5 cm s 15 7 and 3 3 4 ips with the following standards NAB and CCIR The Nagra 4 2 is a mono recorder recording full track audio on 6 35mm tape and the Neopilot synchronization system T...

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Page 10: ...wheel away from the capstan to prevent a flat being caused on the pinch roller In this mode no circuits are powered TEST Will power all circuits and allow level adjustment by means of level controls 6...

Page 11: ...to 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 a...

Page 12: ...he V CELL scale of the meter and indicates the Volts per cell of the batteries COMPRESSION Compression reading in decibels on the ALC compression scale when switch 10 is in the AUTOMATIC position MOT...

Page 13: ...e It will turn black whenever any of the following conditions occur a The power supply voltage batteries or external becomes insufficient for correct operation of the machine b The motor current reach...

Page 14: ...with main function selector 4 in the playback with loudspeaker position and pinch roller lever 32 fully engaged The central position of this switch is OFF and this is the position that the switch shou...

Page 15: ...ne upon it When at the correct speed the bars on the roller should appear stationary 28 RECORDING HEAD Audio recording head 29 PILOT HEAD Neopilot head used for both recording and playback of pilot si...

Page 16: ...ng in place of the microphone preamplifiers preamplifiers type QPM 6 and using the corresponding potentiometer to control the input level 38 RX Antenna input for QRR receiver 39 ACC accessories 1 No c...

Page 17: ...in all modes except REWIND it is not recommended to use this remote method in REC as this will magnetize the recording head and reduce performance 7 Ground chassis 41 LINE INPUT Banana jack line inpu...

Page 18: ...impedance should be equal to or greater than 600 Ohm When the Line and Phones switch is in the position Tape the line output voltage is 4 4 V into 600 Ohm while playing back a tape recorded at 0 dB Th...

Page 19: ...ry compartment 3 PILOT PLAYBACK Pilot playback output 4 SPEED CORRECTION Tape speed correction input 5 EXTERNAL 12 to 30 Input for external power supply 12 to 30 V negative pole 6 10 R 10 V stabilized...

Page 20: ...When using an external supply selector switch 3 must be in the EXTERNAL position It must be in the BATTERIES position when internal batteries are in use It is not necessary to remove the batteries whe...

Page 21: ...o load running i e without tape and with the pinch wheel separated from the capstan but not in the rewind mode the needle should indicate between 0 2 and 0 3 V If this value is exceeded see paragraph...

Page 22: ...ter deflects with respect to the incoming signal without reaching the extreme right hand end of the scale 3 2 TAPE SPEED AND STANDARD SELECTION The NAGRA 4 2 is capable of running at three different s...

Page 23: ...witch to the left Depending on the position of TAPE DIRECT switch 1 it is possible to monitor either the input signal or the off tape signal on the headphones output during the recording This is possi...

Page 24: ...n Tape the signal coming from the tape can be heard In the position Direct a mixing of the signals coming from the microphones and from the tape can be heard The mixing of these signals can be control...

Page 25: ...readings of the playback signal while recording It always snaps back into the DIRECT position AUDIO INPUTS The Nagra 4 2 has 4 inputs a two microphone inputs b one asymmetrical line input transformabl...

Page 26: ...he signal is short the Automatic Level Control concludes that it is accidental and forgets it rapidly i e it returns to its previous sensitivity On the other hand a longer signal is considered useful...

Page 27: ...d to the machine This is a circuit that is located on the left hand end of the battery compartment inside the machine There are two operating frequencies for this circuit 50 or 60 Hz Check by means of...

Page 28: ...Hz and 60 Hz QFM 50 and QFM 60 QUARTZ CRYSTAL PILOT GENERATOR OPTIONAL ACCESSORY QGX 3 This accessory is designed for synchronous filming without a cable between the camera and the Nagra It supplies a...

Page 29: ...tape is grossly incorrect e g 100 Hz instead of 50 the needle will not be able to follow the beat and will remain stationary in the center of the dial If this is suspected switch to Playback The need...

Page 30: ...ING 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...

Page 31: ...ally used to measure the voltage per cell of the batteries 1 7 V corresponds to full scale deflection PILOT CONNECTORS On the Nagra 4 2 the pilot playback signal is to be found on the Power Pack conne...

Page 32: ...aced on X dB a sound of X dB captured by a normal microphone 0 2 mV bar into 200 and attacking a normal sensitivity preamplifier produces a recording at nominal level The modulometer will indicate 0 d...

Page 33: ...sensitivity in such a way that the fortissimo reaches 0 dB As the maximum level of the Nagra is 4 dB there is therefore a safety margin The compression can be done according to the needs in the studio...

Page 34: ...if the Nagra is not grounded but is connected to a camera which is not interference suppressed and the entire system is at a voltage above ground Hence the ground itself as seen by a cable is a potent...

Page 35: ...preamplifier to practically any value If the input impedance is high the microphone will not supply any current and only the voltage will be used to transmit the signal This is called a voltage feed I...

Page 36: ...adjusted azimuth it is perfectly possible to save the recordings it is sufficient to adjust the playback head in consequence This can be done by means of the ear by orienting the playback head to obt...

Page 37: ...rt of the magnetization curves the audio frequency signal is superimposed upon it The peaks of the high frequency signal always make an excursion into the linear region The low frequency signal determ...

Page 38: ...is universality is very important for if there is a pre emphasis in any link of a chain it is useless not to have it in the other links because in any case the high frequency peaks will be limited in...

Page 39: ...h the CCIR standards and gives good results General Procedure It is necessary to use a reference tape whose characteristics are well known above all in relation to other tapes on the market The normal...

Page 40: ...to sabring of the tape are hardly perceptible at the top of the curve and only become important on the sides Once the playback head has been correctly adjusted for azimuth it should not be touched ag...

Page 41: ...that by motor noise the normal noise of the motor due to the ball bearings and the friction of the brushes on the collector segments should be discounted only a squeaking produced by the vibration of...

Page 42: ...up reel The best grease to use is an Esso grease but if the recorder is not to be used at very low temperatures any mineral grease can be used For other oiling points use an oil designed for aviation...

Page 43: ...s unsuitable for capturing low level sounds Condenser microphones always have a preamplifier in the microphone casing otherwise their high impedance would not allow the signal to be transmitted along...

Page 44: ...nds can be disturbed by the combination of the microphone and its preamplifier The word combination is used because the background noise does not come only from the amplifier Take the case of a dynami...

Page 45: ...a microphone is used to balance the sound when a very loud source is placed around the null area of the microphone it is advisable to check the results The internal impedance of omni directional dynam...

Page 46: ...sound level is very low the gain has to be increased to a point where the microphone preamplifier combination noise level becomes greater than the tape noise level Under these conditions no advantage...

Page 47: ...e maximum voltage which they can receive is 20 mV for 200 Ohm and 10 mV for 50 Ohm For the application of these preamplifiers see Section 5 6 STATIC 5 Code QPM 3 5 This preamplifier is designed to rec...

Page 48: ...porated Static 5 preamplifier LOW FREQUENCY ROLL OFF ATTENUATORS Why Filter Sound engineers have long known that in certain cases an attenuation of the low frequencies can improve the subjective quali...

Page 49: ...exaggerated during the recording the damages are practically irreparable B In recording linearly the tape is loaded with signals which produce a certain modulation noise These signals will be eliminat...

Page 50: ...o stations still use them A VU meter is a simple rectifier voltmeter whose response time has been standardized If the signal to be measured is continuous e g a whistle the VU meter will indicate a val...

Page 51: ...orded on the Nagra and transmitted as recorded the operator can simply modulate the speech to 2 dB or even 4 dB and the limiter takes charge of any peaks and the music to 0 or even 2dB The VU meter is...

Page 52: ...5 to 12 V some performances are slightly reduced Current consumption in Test 95 mA in Line Playback 180 mA in Loudspeaker Playback average level 250 mA in Record 240 mA in Fast Rewind 280 mA Type of b...

Page 53: ...h QPSE 200 XOYO preamplifiers Overall frequency response 200 Ohm microphone input line output without load from 50 Hz to 20 kHz 1 dB Total distortion at 0 dB 10 mV input output load 600 Ohm 0 3 Input...

Page 54: ...t 15 kHz 24 Ohm Maximum output voltage on 600 Ohm for 1 distortion at 1 kHz 10 5 V at 5 kHz 10 5 V at 30 Hz 7 0 V Headphones output voltage on 50 Ohm adjustable from 20 to 500 mV Output voltage at MIX...

Page 55: ...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 7 ips 19 cm s CCIR and NAB 30 Hz to 15 kHz 1 5 dB 3 ips 9 5 cm s CCIR and NAB 30 Hz to 8 kHz 2 0 dB Distortio...

Page 56: ...m V Microphone input 2 200 Ohm 0 2 to 43 m V Unbalanced line input impedance 100 k Ohm admissible voltage 0 37 to 120 V Unbalanced line input at accessory connector admissible current 3 7 to 1 200 A...

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