Mi51 (Mi 51).
Portable lamp wire recorders. Made from
1951 to 1955. From 1951 to 1953, their company produced
"Monske & Co. GmbH", Hannover, and from 1953 to 1955 -
the company "Protona GmbH"; Hamburg, Germany. In 1955
began the production of the following model
I have a recorder, two Mi51, externally applied in these
different types of batteries. In fact, the differences
are much greater. If you remove the spool and carefully
consider the deck, you will see that there are
structural differences. If you look at the kinematics of the inside, it is
immediately obvious that, while maintaining the overall
layout, they differ not only structurally, but also the
quality of manufacture, the materials used. In the left
column there are photos of the recorder manufactured by
"Protona GmbH" and in the right one by "Monske & Co.
GmbH". The device manufactured by "Protona GmbH" inside
looks much better. Nevertheless, the mechanics of both
machines was fully working, break down there is just
nothing. To transfer motion from the engine used "eternal"
belt a coiled spring, and there is no detail, which
would have used rubber.
left column there are photos of the recorder
manufactured by "Protona GmbH" (1953 - 1955), and in the
right one by "Monske & Co. GmbH" (1951 - 1953).
can be enlarged
In the photo on the right, there is an
inscription on the cover latch "Monske & Co"
Dimensions recorder 170 x
110 x 37 mm, weight 750 g without batteries. Since
recorders lamp, for their nutrition requires three
different voltages. Filament voltage 1,5 v - AA
batteries, the power of the anode 30 v - battery type
413, and the power of the
engine - a special battery 12 v, or two to 9 v,
connected in parallel (of the company "Monske & Co. GmbH"). Engine speed of both recorders is stable in
the range of power supply 8 - 12 v, and today can be
used to replace the battery 9 v, type PP3.
To supply the anode, I made the right size pack of three
batteries MN, 12 v + 12 v + 6 v = 30 v. The electrical
collected on three subminiature vacuum tube type DF67 (2
pieces), and DL67 (1 item). Electronics board both
devices do not differ structurally.
Electrical circuit Minifon Mi51
(Mi 51). Photo
from the book by Roland Shellin "Minifon
The Spy in Your Pocket", (Roland
Schellin, "Minifon Der spion in der
is a photo of the electronics board of the device of the
company "Protona GmbH".
In the photofrom left to
and on the rightDL67.Actual
sizesDF67 -26 x7.8 mm,
DL67 - 34,5 x
anda magnetreplaces theerase head
The stamp on the underside of the
deck of the apparatus of the company "Protona
To reduce the
impact of volatility of the wire, take-up spool has a
noticeably larger diameter, and head while working
smoothly moves up - down, putting the wire in neat rows.
According to this principle at that time was done, most
stationary wire recorders. Minifon also was the first
truly portable recorder. Naturally, he was very popular,
not only from honest citizens, but also to detectives
and intelligence services around the world. In Germany
it is sold for a price of 730 DM. Our secret police may
also use them as such domestic recorders did not exist.
the late 50's, or early 60-ies in the USSR began to
produce an analog - a wire recorder "Собеседник"
the KGB. Photograph of such a device has sent me a
famous collector of espionage equipment Detlev
Vreisleben (Germany). This recorder is in the in the
Museum of the Czech Police in Prague.
Recorder "Собеседник"(Interlocutor) Unfortunately,
there is no such recorder in my collection, and the only
known copy is in the Museum of the Czech Police in
the upper photo of the "Sobesednik"
that Detlev Vreisleben sent me, this is an old
exposition. Below is a
photograph of the "Sobesednik",
which I personally made in 2017 in the Museum of the
Czech Police in Prague, this is a new exposition, the
recorder is placed vertically.
If you compare the designs of
"Sobesednik" and "Minifon Mi51", it is clear
that they have a similar mechanics, but the
electronics are completely different.
is assembled on 4 transistors Raytheon, two of
which are visible marking CK721.
Condensers are also foreign-made, and the
resistors are similar to Soviet-type MLT, but
Of the foreign components in the USSR, they made
special equipment intended for use in "Western"
countries for the depersonalization of the
producer's country. In any case, it is written in the article about
special equipment in the magazine
"Men's work" No. 49. This
photo was shared with me by Roland Schellin, a
well-known technology historian and writer from
Use wire in
Minifon Mi51as a magnetic carrier allowed to reach a very
large recording. At the coil diameter of 44 mm wire is
placed for 4 hours of work at a speed of 23 cm / sec.
The wire is very thin, diameter 0,05 mm, but tough
enough, and by itself is not broken. Truncations occur
only when it is detached from the reel and is wound on
the shaft beneath it. Truncations are eliminated by a
simple binding knot the ends. To prevent soskakivaniya
wire on the head there is a flat spring, and under the
coils, a well-designed brake system. All this really
works well, and problems with the cliffs, as a rule does
not arise. Office carried out two handles - buttons that
need pushing or pulling.
photo on the left of the stop mode, the right photo mode
"record - play."
the recording or playback, the lateral extension
includes a mode button rewind.
To switch between recording modes - play a special
switch is not. If the plug is inserted into the recorder
microphone, recording mode. Play mode is activated if
the recorder is inserted into the plug headphones. The
length of the microphone plug 15 mm and a length of 25
mm headphone plug. Longer plug headphones clicks on the
pushers, switching contact group on-board electronics in
the playback mode. Erasing a record is in rewind mode,
using a permanent magnet located near the head. The
holder of a magnet fixed on the axis, and fed - is given
manually. It has a pin, which stands out through the
arcuate slot in the lid body. The connectors for
connecting the power supply are found in the devices in
different places (photo below). Round lock housing cover is on top, next to
the battery compartment.
The photo on the left of the original
battery 12 v power of the engine and the original packing
box. The photo on the right original battery type 30 v
Mallory RM-413, a modern analogue Eveready 413, and a
homemade battery 30 v, collected from three batteries MN
(12 v + 12 v + 6 v).
A set of original
batteries for recorders Minifon Mi51
In the photo below a
homemade battery power engine 9 v.
Self-made batteries 12 v and 30 v.
Produced with different number of coils of wire, at 1 -
4 hours recording. One of the coils came with the
recorder, was new and sealed. On the seal there is a
A set of accessories for the device of
the company "Protona GmbH". In the set were, power supply,
microphone, headphones - stethoscope, a device for
recording telephone conversations, 5 rolls of wire, and
In the photo below, a spoiled mercury
battery of 1.4 V - "Mercury
Energizer" in the recorder of the company "Protona GmbH"
is visible. It was unusual. The shape and
dimensions are the same as in modern AA batteries, but
the polarity is reversed. Also in the apparatus was
perfectly preserved anode battery Mallory, 29 v, type
devices were sealed, that is, to me they no who did not
climb up. A piece of wire, mounted inside the body,
passed through a hole in the deck, went out into the cup
for filling, and pressed into her lead seals. Thus,
without violating the seal, remove the deck from the
hull can not. On the stamps have stamp "Minifon" and the
On the inside of the
cover of the device "Protona GmbH" there is a sticker
with warranty information. Covers also differ in the way
they are fastened. In the recorder "Monske & Co. GmbH"
instead of the rotary latch, a screw is used.
Recorder company "Monske
& Co. GmbH" was with a cover, but without accessories. 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
Minifon Mi51 (Mi 51). Photo from
the book by Roland Shellin "Minifon
The Spy in Your Pocket", (Roland Schellin,
"Minifon Der spion in der tasche").
for Minifon Mi51 (Mi 51) from "Protona GmbH".
fact, the documentation for these recorders does not
mention Mi51, it was simply called Minifon.
However, the binding to the
model year was still used, for example, the name Minifon
53 is used in advertising.