Minifon P55 L (1960)

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     Minifon P55 L      Portable lamp wire recorder. Made in Germany in 1960 by "Protona GmbH"; Hamburg. This model was produced from 1955 to 1960, and this modification, the latter after 1957. Dimensions recorder 177 x 102 x 42 mm. Weight 690 g without batteries. Housing cast from magnesium alloy. As the magnetic carrier used wire from a special magnetic alloy with a diameter 0,05 mm or 0,038 mm. Coil diameter 44 mm can hold the wire diameter 0,038 mm for 5 hours at a speed of 20 cm / sec (model L). They also produced a model of S, at a speed of 34 cm / sec, and a coil with different amounts of wire. Mechanics of the recorder is rather complicated, and made with real German quality. Everything was thought out so well that even in the later, the transistor model “Protona Special”, it is used almost without changes. More mechanics is described on page “Minifon Protona Special”. Circuit collected on three subminiature vacuum tube type XFW40 (2 pcs), XFY54 (1 pc), in connection with which to supply the required three different voltages. Engine 6 - 12 v, the anode voltage - 30 v, filament voltage - 1,5 v. The engine has electromechanical stabilization speed. On the shaft of the engine is a centrifugal regulator. Electric stabilizer consists of several parts, one of which - a diode protection for the engine. Active element of the stabilizer is a miniature incandescent lamp.
     As an accessory to recorders made Minifon desktop speakers with an amplifier, combining the functions as a microphone and transmitter for non-contact recording from the telephone. For more details about their designs on the pages can be Minifon P55-Speaker and Minifon Attache-Speaker

Video review

Demonstration of mechanics

Photos can be enlarged

     On the inner side of the housing cover glued brief instruction in German. It is known that the model P55 in 1955 sold for $ 289.50, which was at that time a considerable amount of money. All models Minifon were very popular, used by special services, and successfully sold in 80 countries. For recorders in this series were issued special spy accessories, such as a microphone, under the camouflage watches, a device for recording telephone conversations, a miniature microphone with a clip, and other accessories.

     Included with the tape recorder I got the original external speaker - microphone and a miniature microphone with a clip. Connector for connection of the right of the control keys. The diameter of the connector is not standard, - 5 mm. To the left of the keyboard is an external power connector, and above them the counter flow wire. Unlike “Protona Special” volume control - the recording level is on the left, and the turnout voltage and LED indicator lamp hitch - right.
     The device was bought complete with an external speaker, microphone, specification, and a wonderful leather bag shoulder mount. Now the unit is in working condition.

Miniature crystal microphone, which I got bundled with the device.

The device came to me in perfect cosmetic form, but not working. The factory seal appeared the whole, over the past years, it is not opened.

     During the unit head moves up - down uniformly laying wire on the coil. In combination with good stabilization of the rotational speed of the engine, it allows to minimize the distortion of records associated with the unstable speed wire. There hitchhiking. When the coil wire ends, she pressed the lever is released. This lever, in turn, presses the power circuit breaker, located under the coil. When firing hitch red signal lamp lights.

     The first autopsy revealed that everything inside is preserved in perfect condition, not including rubber parts. Belt from time turned into something like clay, and I had to literally scrub away from the engine and flywheel. Also completely damaged tires on the movies for a rewind. In the second, large roller, rubber was in good condition. Incidentally, the same picture I saw and the recorder “Protona Special”. It was destroyed the same spot. In a large rubber roller, and then indented, where it was pressed to the flywheel. Hide this dent was with a small section of wire, stuck in the rubber under the dent. Mechanics was not worn, and the reason was soon discovered. Was broken brake rod, made in the form of steel wire of about 5 cm long. Apparently, this draft was broken at a time when the recorder was still almost new, and for some reason do not have to repair, but simply put on the shelf.

On the right is an enlarged photo wire stuck in the rubber under the dent. Wire raised rubber, and completely leveled hump.

      Get an old machine in such good condition, very lucky. I urge repaired, belt replaced, but instead destroyed rubber on the roller, put on his rubber ring. In this form the mechanics properly earned. Electronics has been completely serviceable, but the input electrolytic capacitor I replaced all the same. Had trouble only with the power of the anode. Type battery 413 with a voltage 30 v now difficult to find. Therefore had to make their own design from two batteries of 12 v, and a 6 v. To power the glow of lamps came AA batteries, and the engine battery 9 v, type PP3. From 9 v engine is working properly, as the range of his power is in the range of 6 v to 12 v.

28 v battery type Mallopy RM-413

On the left the original mercury battery 1,4 v types Mallory Duracell ZM-9 (AA). Made in the USA. On the original photo on the right batteries for 12 v engine recorders Minifon.

A set of original batteries "Pertrix" for recorders Minifon P55

Left photo homemade batteries 30 v and 12 v. Right recorder with new batteries in the collection.

Power supply 12 v to type recorders Minifon.

Below you can see pictures of the internal structure of Minifon P55 from different angles

Operating Instructions Minifon P55 (1957 - 1960)

Electrical circuit Minifon P55 L. Photo from the book by Roland Shellin "Minifon The Spy in Your Pocket", (Roland Schellin, "Minifon Der spion in der tasche").

Minifon P55 L specification obtained with the device

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Specification and price Minifon P55