NAGRA IV MODELS
NAGRA IV D This model, without pilot facilities, has 3 speeds, 2 tape types, 2 microphone inputs, 1 line or accessory input, 1 mixer input. It also has switch for Manual/Automatic Level Control, Limiter against tape overload, "F" Device for automatic fading in and out, 4 position LF, Roll-Off Attenuator, Reference Generator, Line Output fully floating for terminating impedance of 800 ohm or more.
NAGRA IV L This model is similar to the Nagra IV D, but with the addition of the Neopilot system for synchronous recording in conjunction with a camera. The Nagra IV L could also be delivered completely wired for the Neopilot system but without the head or pilot recording circuit. These could be added (by plugging in and calibration) at a later date, for those who had no immediate need for the pilot facilities, but could require them later.
The Nagra IV L, along with all the Neopilot models, could also be equipped with certain accessories by plugging them into their respective sockets inside the box. These are:
Frequency Meter. To allow monitoring of the pilot frequency coming from a camera or an internal Pilot Generator (if installed). In addition, this circuit gives the "Alarm" signal if the frequency difference between the pilot signal and nominal exceeds +/- 5. Could be supplied for 50 Hz or 60 Hz.
Synchronizer and Pilot Playback Voltmeter. Allows playback of a tape with pilot track to be synchronized with a second external or internal pilot signal. Useful for filming on playback, transfer and recording facsimile signals (in conjunction with a Crystal Controlled Pilot Generator), etc. Gives "Alarm" signal if either pilot signal is lacking.
Crystal Controlled Pilot Generator. Allows synchronous recording without physical connections between camera(s) and Nagra, provided that the former has a speed stable to within +/- 0.01% to +/- 0.001% of the nominal speed, according to the sequence length required.
Start and Camera Identification H.F. Receiver. Completes the equipment necessary for filming without cables. Delivered with the equipment for the camera.
NAGRA IV B This is a simplified version of the Nagra IV D. Single speed (7.5"/sec.). The following useful but non-essential accessories have been suppressed: Automatic Level Control, LF Roll-off Attenuator, Reference Generator, "F" Device, and the Limiter. Normally fitted with single ended line output but the fully floating line output (as in the Nagra IV D) can be supplied.
NAGRA IV BL Similar to the Nagra IV B, but with Neopilot system.
NAGRA IV A Single speed (7.5"/sec.) with one microphone input, and exclusively Automatic Level Control. Level indication replaced by compression indication. Other characteristics as for Nagra IV B. The Nagra IV A allows recording of professional quality by non-technical personnel.
NAGRA IV DE This model is identical to the Nagra IV D, but with one single speed (7.5"/sec.) and without the Limiter and the "F" Device.
NAGRA IV LE This model is identical to the Nagra IV L, but with one single speed (7.5"/sec.) and without the Limiter and the "F" Device.
NAGRA IV AL This model is the Neopilot version of the Nagra IV A.
NAGRA M series: The M series of the Nagra IV was a range of recorders designed for use with the BU mixer (in preparation) or for installing in conjunction with other equipment, such as in studios, recording vans, etc. All facilities that are rendered unnecessary have been suppressed. These include input preamplifiers, line output amplifier, modulometer, voltmeter, etc. An electromagnetic indicator shows if the power supply voltage is within its correct limits.
NAGRA IV M This model is the version equivalent to the Nagra IV D. In the M series, it is a three speed machine, with the possibility of using both ordinary and low noise tapes. It incorporates the "F" Device and the Limiter. As in all the M series recorders, the only input is for a signal of 560 mV (corresponding to 0 db, 200mMax) with an input impedance of 2 kilohms. The output is at the same level, and has a source impedance of 5 kilohms, necessitating a load impedance of 50 kilohms or more. Both input and output are single ended.
NAGRA IV ML This is the Neopilot version of the Nagra IV M.
NAGRA IV ME This model is equivalent to the Nagra IV DE in the M series. It has a single speed (7.5"/sec.) and the "F" Device and the Limiter have been eliminated.
NAGRA IV MEL This model is the Neopilot version of the Nagra IV ME.