Magazine article American Cinematographer

The New Nagra T Studio Model Recorder

Magazine article American Cinematographer

The New Nagra T Studio Model Recorder

Article excerpt

A basically non-mobile (but transportable) recorder that fits onto a stand or rack and can accept either flat reels or spools up to 300mm (12 inches), the norm for non-mobile studio units in Europe

Up to now, the largest model Nagra recorder has been the Nagra IV which, without external accessories, takes 178mm (7") reels only but can still operate during transportation: thus it can be considered a portable recorder.

The Nagra T takes reels or flat spools up to 300mm (12") in diameter, this being the norm for non-mobile studio units in Europe.

As a fixed installation the Nagra T is mounted on a stand but it is transportable for outside work and can be fitted into a rack.

The Nagra T is a double capstan unit having a speed stability of a close loop system and a threading ease of an open loop one.

Two versions of the Nagra T are envisaged:

Nagra Tins (instrumentation) for laboratory use (measurements) Nagra TA (audio) for sound recording.

Depending on the guides, heads and stops, both versions can be adapted to take 3.8, 6.25 or 12.5mm (.15, .25, .5") tapes.

Description

1. General

The Nagra T is composed of two main parts: the body of the machine formed by a very rigid framework, and on top the tapedeck which opens like the lid of a chest.

On the tape deck are found five motors (2 capstans, 2 spool motors and the servo to engage and disengage), heads, guides, tensionmeters, etc.

However, since all the "logical" functions are electronically operated, the Nagra T has very few mechanical parts and few parts liable to wear, so that long life and reduced maintenance costs constitute major attributes.

The upper part of the body of the machine contains the logical circuits controlling the mechanical parts of the deck. The lower part is fitted with removable plug-in containing recording and reproduction circuits. In view of this structure, the Nagra T is very adaptable and can easily be modified to become a specialized version.

2. Size

The Nagra T is 399mm (15.7") wide, 389mm (15.3") deep and '167mm (6.57") high with the lid closed (quarter inch tape version).

3. Spools

The spools fit on to the spool-supports which are removable and thus variable to take European cores (AEG), NAB or classical spools (Cine 8). But the Nagra T has four reel-supports, the inner ones for 180mm (7") spools with the Md closed, the outer ones for 300mm (12") spools. Thus if 180mm (7") reels are sufficient, the machine can hardly be considered cumbersome.

The tension of the tape between reels is controlled by two tensionmeters with differential transformer. In contrast to potentiometers, the life of differential transformers is virtually unlimited. The control device is twodirectional. Thus, when the machine is switched on, the debiting spool motor is also activated instead of simply revolving by tape traction, and fast starts cannot stretch the tape. Thus the Nagra T does not even damage 3.8mm x 9 microns (15" x .0004") tapes when the spool core is only 28mm (1.1") (SN). However, in this case, the tension-meter must be adjusted, but this is a simple operation.

4. Tape transport

Nagra T has two capstans. Each has its own individual motor directed by a tachymetric loop. The average speed of the two capstans is either controlled by a quartz, or is variable; but on the other hand, the speed difference is subject to the interhead tensionmeter. …

Search by... Author
Show... All Results Primary Sources Peer-reviewed

Oops!

An unknown error has occurred. Please click the button below to reload the page. If the problem persists, please try again in a little while.