Nagra IV-S User manual

CHAPTER I"INSTRUCTION MANUAL"
TABLE OF CONTENTS
Please refer to your instruction manual:
May 1991
•
•
Nagra IV-S
Nagra IV-S TIME CODE
No 20 06 004 161
No 20 06 007 161

June 1988
CHAPTER I"INSTRUCTION MANUAL"
TABLE OF CONTENTS
Page No.
1.1 Introduction I1.1-1
1.2 Power supply:
1.2-1
External power supply
1.2-1
1.3 Danger of reverse polarization
1.3-1
1.4 Controls: Description and use 1.4-1 to
1.4-8
1.5 Connectors 1.5-1 to
1.5-4
1.6 Tape speed and standard selection
1.6-1
1.7 Loading atape on the recorder
1.7-1
1.8 First time operation: 1.8-1 to
1.8-2
Recording 1.8-1
Recording with microphone 1.8-1
Recording a line signal
1.8-2
Playingback a recorded tape
1.8-2
Working with headphones 1.8-2
1.9
Specifications 1.9-1 to 1.9-5

1.1 INTRODUCTION
The Nagra IV-S was introduced originally in 1971. It is a portable 6.35 mm (1 /4") analogue audio
tape recorder designed for high quality music recording, cinema and television applications.
Many mechanical and electronicmodifications have been made to the machine sin
ce its release, to
adapt it according to modern day requirements. Despite all these modifications, the machine
remainsremarkably similar to the original. The last major development was made in 1964 when the
SMPTE IEBU 80 bits centre-track time code was added.
The Nagra
IV- S can be delivered in three different v er sions all of which are available in eith er NAB
or CCIR equalization. These versions are as follows:
N05-L SP
N05-L
N05-T C
Non pilot
Pilot
Time code
Each version has three speeds: 38 crtvs, 19
cmJ s and 9.5 c mJs (15, 7i and 3 -1 ips) with the
following standards: NAB, CCIR and NAGRAMASTER (at 15 ips only).
The Nagra IV
-S is a stereo recorder with two 2 mm audio tracks (2.75 mm tracks on the
NQ8-lSP non-pilot machines) and a central track for pilot or time code uses, depending on the
machine type.
The two audio channels may be used with either the two internal mi cr ophone pre-amplifiers
(switchable between Dynamic, T power and Phantom power) or with a current line input. via the
QCSE cable. The two potentiometers on the front panel may be mechanically "GANGE
D" together
for easier
co ntrol, by moving the small white lever located on the green control.
The NAGRA
IV-S also contains a switchable limit er , a built-in l oudspeaker ,prov ision f or
connection to an external noise reduction system and an internal reference generator for line up,
and calibration purposes.
Optionally the machine may
be fitted with either the NAGRASYNC pilot option or the SMPTElEBU
80 bits time code option.
The machine may also be powered from either an external supply
ATN-3 or internal batteries.
(See page I 1.2
-1 ).
The
IV-S may also be used with the DGB 10" reel adaptor, to allow the use of larger reels f or
longer recording and playback.
June 1988 I 1.1-1

1.2 POWER SUPPLY
All models of the NAGRA IV- S may be powered by an external power supply (ATN -3) or
alternatively by internal batteries. The I V-S will accept voltages ranging from -, 1 V to -3 0 V with
peaks of up to -3 5 V.
The batteries are placed in the bott om of the machine and the polarity is marked inside the
compartment which is opened by turning the two fasteners with a screwdriver or a small co in. All
the batteriesMUST be orientated in the same direction as indicated on the base of the battery
compartment.
The NAGRA
IV-S houses twelve 1.5 V ce lls having a maximum diameter of 33.5 mm and a length
of between 59 .5 and 62.5 mm. The cells manufactured under the following standards are generally
acceptable: CEI R-200. ASA "D " and L9D .
It is important to remember that corrosive material can leak out of flat batteries, causing severe
damage to the recorder, and therefore it is recommended not to leave batteries in the
ma chine
during periods of storage.
The external supply is led into the machine via connector (48) on the right-hand side of the
machine. Rechargeable batteries may also
be used and can be charged using the ATN-3 C (order
no 14376) which includes the charger circuitry.
To check the state of the batteries or the external supply, set modulometer switch (12) to the
MSA TT
Mposition: in this case the red needle of the modulometer indicates the battery voltage on
the (volts Icell) scale and the green needle indicates the voltage needed by the motor.The
difference between these two readings shows the battery reserve.
When the power supplied to the machine is insufficient for normal operation of the recorder, the
rotary indicator "SPEED AND POWER" on the front panel of the machine will turn bla
ck . The
IV-S will function when the power is as low as 12 V (at 15 ips 138 cm/s) and down to as low as
10.5 V at the lower speeds. (These figures correspond to a machine in perfe
ct condition and
working at room temperature).
NOTE :Time Code machines will stop recording Time code when the batteriesbecome flat
before the audio recording is affected.
When using an external supply, selector switch (3) must
be in the "EXT" position. It mu st be in the
"SA TT "position when internal batteries are in use. It is not necessary to r em ove the batteries
when working with an external supply (and vi ce versa).
NOTE: For information on power supply to the time code circuits of the
IV-S TC refer to page
IV6 .1 -1 .
EXTERNAL POWER SUPPLY
On the right-hand side of the machine there is a 6 pin Tuchel-type T 3403 connector marked
"POWER PACK". The
co rresponding plug is the T 3400 /1 .
The connections are as follows:
pin 1 =Battery negative
pin 2 - Chassis (positive)
pin 3 =Pilot playba
ck output
pin 4 =Speed correction signal input
pin 5 =Negative external supply
pin 6 =-1 a vstabilized output.
June 1988 I1.2-1

1.3 DANGER OF REVERSE POLARIZATION
A reverse polarized power supply (negative to the chassis) WILL damage the machine. To reduce
the risk of serious damage a diode is placed in parall~ with the supply which will be short-circuited
in the event 01 reverse polarization. tf such an event occurs with normal "dry cells".they will be
raptdty exhausted and no further damage will oc cur.
On the other hand. certain accumulators are capable 01supplying suttictenl curr en t (in exc es s of 8
amperes) s uch that the intemal wiring of the machine will become hot enough to ca use its
insulation to decompose .This wil lthen Iiberats hydrochloric acKf gas which causes considerable
corrosion. " thi shappens,contact your nearest NAGRA agent immediat~y .
June 1988 I 1.
3- 1

NAGRA
IV-S TC
24 26 ® ® 28
23
19 18 17 15 16 14 12
13
50
11 4321

1.4 CONTROLS: DESCRIPTION AND USE
FRONT
PANEL
1. TAPE I DIRECT SWITCH (line and phones)
Wh en in "TAPE" pos ition, the signal is reproduced dire ctly fr om the tape.
When in "DIRECT" position, there are two posibilmes:
A. When recording. the signal is available before arriving on the tape.
B. When playing back. the signal may be adjusted by means of the level co ntrols and
co r rec ted by filter swi tc h (13).
2. TAPE I DIRECT (snap switch)
This switch affects the meter in the same way that the previous switch affects the outputs. Thus
when it is held to the left, the meterwill display the WOFF TAPE" signal whereas normally it
displays the "DIRE CT" signal.
3. POWER
SELECTION SWITCH (EXT IBATT)
The NAGRA
IV-S may be powered by either internal batteries or by an external source whi ch may
be sel ec ted using this switch. See also the "POWER SUPPLY" section of this chapter. (Page
11.2 -1).
4. MAIN FUNCTION SELECTOR (six position rotary)
STOP
TEST
RECORD
RECORD
(no limiter)
PLAYBACK
PLAYBACK
(with loudspe ak er)
June 1988
Stops the machine completely from any function. and will slightly move the
pinch wheel away from the capstan to prevent a flat being ca
us ed on the pin ch
roller. In this mode no circuits are powered (with the exception of the RAM and
REAL TIME CLOCK in machines fitted with SMPTE /EBU
lim e co de). See
section IV "TIME CODE AND PILOT" of this manual for further details.
Will power all circuits and allow level adjustment by means of rever co ntrols (6)
and (7). In this mode the motor is n ot powered. All indications of the
modulometer will be of the DIRECT input, irrespective of the position of tape I
dire ct switch (1).
Is the first of the two RECORD positions and corresponds to REC ORD WITH
LIMITER where the recording level is limited to
-+ 4dB. This level remains
constant when the input level is between
-+ 4dB and -+ 10 dB . Thus in this
position tape saturation cannot occur and distortion is avoided.
The limiter is inactivated in this position so that recordings that should be
saturated can be made. (e.g. Gun shots or explosio
ns ).
Is the first
of the two playback possibilities and corresponds to playback of the
tape to the headphones and line outputs only.
This position is exactly as above, only it allows monitoring via the internal
loudspeaker at the same time. This is also the only position of the main
function selector that permits the FAST FORWARD fu
nc tion to be perfor me d
(see page I 1.4--6).
I1.4-1