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MEZON   МЕЗОН
Body-wearable wire recorder

MEZON 1 is a miniature stereo body-wearable covert audio recorder, developed and introduced in the early 1960s in the former Soviet Union (USSR) by Factory #19 in Poltava (Ukraine), for use by the KGB and other intelligence agencies. The device was in production throughout the 1960s and 1970s and records the audio from a microphone to a thin 0.05 mm metal wire instead of tape.

The recorder measures just 158 x 76 x 27 mm and weight less than 0.5 kg. It is powered by an internal 7.3V battery and can record for more than one hour on a single wire spool. The audio quality is excellent, but the motor makes some sound, which is why the device was often hidden under the clothing using a soft carrying case.

MEZON was supplied with a Neva microphone, a common TM-2 earphone, a remote control unit and several adapters and accessories, packed in two metal storage cases. Microphone and remote are connected to the 3 mm sockets at the right.
  
MEZON covert wire recorder with open lid

Although officially known as a dictaphone, MEZON was generally used by the KGB and the MVD for covert recording of conversations and wire taps. It is one of the smallest and most beautiful recorders of the era, and compares favourably with the Minifon P-55 (1955) and Minifon Special (1961), although the latter was capable of recording up to five hours rather than just one hour. The MEZON wire recorder is also featured in Keith Melton's excellent book Ultimate Spy [3 p.110]. In the late 1980s, MEZON was succeeded by the high-end miniature stereo tape recorder Yachta.

  1. In physics, MEZON (English: Meson) is a subatomic particle, intermediate in mass between an electron and a proton, that transmits the strong interaction binding nucleons together.

Storage case #1 MEZON in storage box MEZON seen from the front right Open MEZON seen from the front right T-65 microphone (front) Remote control unit (RCU) Eraser with wire spool installed Battery 'BOR'
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Storage case #1
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MEZON in storage box
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MEZON seen from the front right
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Open MEZON seen from the front right
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T-65 microphone (front)
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Remote control unit (RCU)
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Eraser with wire spool installed
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Battery 'BOR'

Features
The diagram below shows the MEZON recorder with its cover open, as seen from the front right. At the right are three 3 mm jack sockets, marked with coloured rings: white, blue and red. The white and blue sockets are for connection of the remote control unit (RCU). If the RCU is not used, a dummy plug (stub) should be inserted into the blue socket. The red socket at the right is used for connection of the microphone (when recording) or for the earphone (when playing back).


Note that the plugs for these sockets are very rare, as they have a a diameter of 3 mm (not the more common 3.5 mm) and they have a short piece of M4 thread that is used to fixate them in the socket. The actual recording wire is installed in the recording compartment, that is protected by a hinged lid. The recording wire is just 0.05 mm thick and runs between two spools, past an electomagnetic head at the front. Various cloth pads are present to keep the wire free from dust.

Note that when installing a wire spool, the spring-loaded cleaning pad and the spring-loaded bar can be interlocked, in such a way that the wire path stays open. This makes it easier to install a spool and guide the wire past the head. It can be released by pulling the bar further to the front.

When the device is running, the audio head and the wire guides, are slowly moved up and down by a slotted axle, to ensure that the wire is evenly divided over the height of the pick-up spool.

MEZON controls and connections Installing the stub MEZON controls and connections Operating the remote control unit Pulling the clean pad towards the front Spring-loaded bar and spring-loaded cleaning pad interlocked, to allow easy loading of the wire. Releasing the cleaning pad and the bar The recording wire guided past the audio head
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MEZON controls and connections
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Installing the stub
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MEZON controls and connections
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Operating the remote control unit
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Pulling the clean pad towards the front
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Spring-loaded bar and spring-loaded cleaning pad interlocked, to allow easy loading of the wire.
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Releasing the cleaning pad and the bar
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The recording wire guided past the audio head

Power supply
  • Battery BOR
    This was a standard rechargeable 7.3V battery known as BOR or BOR-1 (Russian: БОР-1). It is installed in the battery compartment at the left side. Two BOR-1 batteries were usually supplied with the kit, but as far as we know, they are no longer in production.

  • Button cells
    The set was supplied with a number of metal RC-63 cups that could hold OR-2K battery cells of 2.4V each (total: 7.2V). This solution could be used in place of the BOR-1 battery and fitted nicely in the existing battery compartment.

  • SATURN battery box
    Alternatively, the so-called 'SATURN' solution could be used, which is basically a metal box with five dry D-cell batteries. It connects to the battery compartment of the recorder, by means of a so-called SHUNT-adapter. The Saturn battery box was mainly used in an office environment, for example when transcribing covertly recorded conversations.

  • Shunt connector
    An external 7V DC power source could be used by installing the DC adapter (shunt) in the battery compartment (instead of a battery) and connecting a DC source to the two wires. A separate (fixed) shunt is supplied with the SATURN battery box (above).


Mezon with accessories

Parts
Storage cases MEZON wire recorder Microphone
Mic
Single earphone Pickup coil for recording telephone conversations Remote control unit Shorting plug (to be installed when remote control unit is not used) Adapter for connecting external audio source
Short wires with banana plugs for audio connections Spare wire spools Internal battery Alternative battery cells External battery box 'Saturn' Adapter for connection externbal DC power source De-magnetizer for erasing wire recording Soft leather belt carrying bag
Bag
Maintenance tools Wire pick-up tool Operating instructions
Storage cases
MEZON was supplied in two metal storage cases: a lower one, which contained the recorder and some accessories and tools in polystyrene foam, and a higher one with the additional equipment, spares and a covert carrying case.

The image on the right shows the lower case in which the foam interior has been replaced by felt. The higher storage case for the additional equipment and spares is currently missing from our collection.
  
Storage case #1

Wire recorder   MEZON
The actual recorder measures just 158 x 76 x 27 mm and weights 492 grams without batteries. It was painted either grey hammerite or black, and was usually carried in a special cloth holster, that could be hidden under the operative's clothing.

In such situations, the microphone was hidden elsewhere under the clothing, whilst the remote control unit was carried in one of the pockets.
  
MEZON covert wire recorder with open lid

Microphone   Neva
MEZON can be used with virtually any type of dynamic microphone, but was usually supplied with a so-called NEVA or a T-65 microphone. The microphone usually has a green wire with a red-marked 3 mm jack at the end. It should be connected to the rightmost socket of MEZON. The microphone has a safety pin at the rear, allowing it to be affixed to the clothing.

Note that when playing back a recording, the internal circuitry is reversed, as a result of which the microphone will act as a speaker. As it is a dynamic microphone element, this is possible.

  
NEVA microphone

Earphone   TM-2
For playing back the recorded audio, a standard TM-2 earphone was supplied, which had to be connected to the microphone socket (M).

In the absense of a suitable earphone, it was also possible to use the (dynamic) microphone element as a speaker, albeit with less privacy and a somewhat reduced audio quality.
  
TM-2 earphone

Telephone adapter
For recording a telephone conversation without physically connecting the recorder to the line, a special pickup coil was available. It should be placed in the vicinity of the internal transformer of the (analogue) telephone set.

In most cases, it was sufficient to place the pickup coil behind the telephone set in order to pick up a clear hum-free audio signal.
  
Telephone pickup coil

Remote control
A simple handheld remote control unit was supplied, to allow concealed operation of the recorder. For that purpose, the remote control unit could be carried in the pocket.

The device is made of (black) bakelite and has a shift-switch at the centre. It is connected to the recorder via an 80 cm cloth wire, with two screw-on 3 mm jacks at the end. The plugs are marked with a blue and a white ring, and should be inserted into the corresponding sockets on the right side of the body of the recorder.
  
Remote control unit with cable and two 3 mm plugs

Stub
Whenever the recorder is to be used without the remote control unit installed, A shorting plug should be installed into the blue-marked socket (i.e. the middle one).

This shorting plug is known as the stub, and ensures that the battery voltage is connected to the recorder. It effectively replaces the remote control unit. It the stub is missing, it is also possible to make a reproduction.
  
MEZON with shorting plug (stub)

External audio adapter
Apart from the supplied microphone, it was also possible to connect the recorder to an external audio source, such as an amplifier or a receiver, by using the audio adapter shown in the image on the right.

Likewise, this cable can also be used to connect the output of MEZON to the input of an external amplifier when playing back.
  
External audio adapter

Short wires
In order to connect the adapter above to an external audio device, two short blue wires with banana plugs at either end – shown in the image on the right – were supplied as part of the kit.

If these wires are missing, any other banana cables can be used, and it is also possible to make a suitable reproduction.
  
Short audio connection cables

Spare wire spools
Apart from the spools that are present inside the recorder, some spare ones were supplied with the kit. Two were stored in the smaller storage case, together with the recorder, whilst the remaining stock was held in the larger one.

The wire on these spools is just 0.05 mm thick and repairing a broken wire requires some skills, but with the right type of knot it can be done.
  
Two wire spools

Rechargeable battery   BOR-1
The recorder was usually powered by an internal (removable) battery of the type BOR-1 (Russian: БОР-1), that was installed in the battery bay at the left side. Alternatively, it was possible to replace the BOR-1 battery by an external battery box (Saturn) with five dry D-type batteries, or by a set of so-called button cells.

The image on the right shows an original BOR-1 rechargeable battery that was manufactured in May 1977. Many thanks to Atomic KGB Bunker for supplying it [1].

  
Battery 'BOR'

Cups for button cells   RC-63
As an alternative to the standard rechargeable BOR battery, it was possible to use a number of OR-2K buttons cells to get the required 7 Volts.

In order to fit the button cells in the available space, metal cups – known as RC-63 – were supplied, as shown in the image on the right .
  
RC-63 cups for OR-2K battery elements

External battery 'Saturn'
When using the recorder in playback mode, for example when transcribing a covertly recorded conversation, it was possible to replace the internal rechargeable battery by the external battery box shown in the image on the right.

This metal box is known as Saturn, and offers space for five large 1.5V D-type mono cells. The compartment towards the front holds a short cable with a SHUNT-adapter at the end. The SHUNT should be placed in MEZON's battery compartment instead of the regular battery.

  
Saturn battery box with lid removed

Shunt
It was also possible to power the recorder by an external 7V DC source, using the so-called SHUNT-adapter, which was installed instead of the internal battery. In that case, the two wires from the shunt adapter should be connected to the external DC power source.

A shunt adapter is also supplied as a fixed part of the external SATURN battery box, that was supplied in the larger storage case.
  
Shunt connector for external power source

Wire eraser
MEZON can only record and play-back. It has no facilities to erase a recording. In order to erase a recorded conversation the external eraser device shown in the image on the right, had to be used.

The spool with wire has to be installed in the bay at the top, after which the device should be connected to the mains. It contains a coil that produces an alternating magnetic field that is sufficiently strong to erase the wire, as soon as the black button at the front is pressed.

  
Eraser with wire spool installed

Soft carrying bag
Especially for carrying MEZON on the belt, a soft leather carrying case, or pouch, was supplied. It was available in several colours, including black and brown/red (as shown here).

The belt can be looped through the rear side of the carrying case. When replacing the batteries or swapping the wire spool, the recorder can be taken from the case, without the need to remove the case from the belt first.
  
MEZON with carrying case

Maintenance tools
The MEZON kit was supplied with a range of tools and materials to allow it to be serviced in the field. Tweezers and a pair of scissors were present to make installation of a wire spool easier, and to allow repair of a broken wire.

A plastic container with lubricant grease was supplied, along with a simple application tool.
  
Tools

Wire pick-up tool
When loading the spools and guiding the wire past the audio head, a metal grip with a very thin angled steel wire – shown in the image on the right – was used to handle the extremely thin recording wire.   
Wire pick-up tool

Operating instructions
MEZON came with a small booklet, at approx. A5-size, that acts as a checklist, but also contains a technical description of the device and and full operating instructions.

For the technically minded, it also contains the full circuit diagram of the recorder, which is built around 5 transistors.

 Download the booklet
  
Operating instructions

Storage case #1 MEZON in storage box Accessories Remote control unit (RCU) Remote control unit The remote control unit held in the hand External audio adapter Short audio connection cables
Alternative audio wiring NEVA microphone T-65 microphone T-65 microphone (front) T-65 microphone (rear) Telephone pickup coil Spare wire spools Spare wire spool
Wire spool Battery 'BOR' Production date (May 1977) written on the battery Additional text on the battery MEZON with rechargeable battery BOR Eraser with wire spool installed Eraser TM-2 earphone
Installing the stub MEZON with shorting plug (stub) installed for operation without remote control unit Using an alternative (home-made) shorting plug Shorting plug (stub) Shorting plug (stub) with blue ring Alternative home-made shorting plug Soft leather carrying case MEZON with carrying case
MEZON halfway in carrying case MEZON in carrying case Carrying case rear view RC-63 cups for OR-2K battery elements RC-63 cup (outside) RC-63 cup (inside) External battery box 'Saturn' Saturn battery box with lid removed
Shunt connector for external power source Close-up of shunt connector Battery compartment with shunt connector installed MEZON with cable for external power supply Oil application tool Wire pick-up tool Manual (detail)
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Storage case #1
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MEZON in storage box
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Accessories
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Remote control unit (RCU)
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Remote control unit
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The remote control unit held in the hand
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External audio adapter
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Short audio connection cables
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Alternative audio wiring
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NEVA microphone
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T-65 microphone
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T-65 microphone (front)
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T-65 microphone (rear)
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Telephone pickup coil
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Spare wire spools
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Spare wire spool
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Wire spool
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Battery 'BOR'
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Production date (May 1977) written on the battery
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Additional text on the battery
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MEZON with rechargeable battery BOR
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Eraser with wire spool installed
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Eraser
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TM-2 earphone
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Installing the stub
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MEZON with shorting plug (stub) installed for operation without remote control unit
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Using an alternative (home-made) shorting plug
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Shorting plug (stub)
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Shorting plug (stub) with blue ring
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Alternative home-made shorting plug
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Soft leather carrying case
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MEZON with carrying case
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MEZON halfway in carrying case
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MEZON in carrying case
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Carrying case rear view
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RC-63 cups for OR-2K battery elements
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RC-63 cup (outside)
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RC-63 cup (inside)
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External battery box 'Saturn'
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Saturn battery box with lid removed
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Shunt connector for external power source
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Close-up of shunt connector
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Battery compartment with shunt connector installed
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MEZON with cable for external power supply
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Oil application tool
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Wire pick-up tool
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Manual (detail)



Bottom view of the interior of MEZON. Click to enlarge.


Interior
Getting access to the recorder's interior is very straightforward and requires only the removal of 10 recessed miniature screws from the various metal panels. The diagram above shows the various parts of the recorder as seen from the bottom of the device, after removing the covers.

The recorder is build on a die-cast aluminium chassis, covered by a U-shaped metal panel at the rear, an L-shaped metal panel at the bottom front, and an arbitrary shaped panel that covers the controls at the right side of the device.

After removing the 10 recessed screws and the metal panels, the interior is exposed, as shown in the image on the right, where we see the device from the bottom front. The recording compartment is covered by a hinged lid that is just visible at the front edge. This grey lid is fixed in place and can not be removed easily.
  
Mechanism (bottom)

At the rear is the motor that has a rectangular shape. It is suspended between two rubber pads and has two rubber bands around its body to reduce the sound it makes when it is running. The motor has a built-in centrifugal switch that is mounted to the axle and acts as the governor. It ensures that the motor runs with a constant speed. The governor is bypassed when rewinding.

To the left of the motor is the audio amplifier that is encapsulated in a mu-metal enclosure, in order to reduce magnetic interference from the motor. The image on the right shows the audio amplifier after the cover has been removed.

The amplifier consists of two pertinax boards that are strongly glued together. Each of the board holds a number of parts, some of which are embedded in the board, whilst others – notably the electrolytic capacitors – are fitted in between the two boards. The board that is visible in the image, holds the 3 transistors.
  
Amplifier close-up

The other side holds the larger components, such as the 80µF capacitors and an inductor. This side also holds the rather complex purpose-built 4-pole function switch, that is used to select between record and playback. This lever-operated switch is actuated by the hinged cover. When the cover is open, playback mode is selected. When it is closed, the device is ready for recording.

When the amplifier is broken, it will be difficult to repair. It can not be removed easily, as it is held in place by its wiring. Furthermore, the circuit boards are glued together and most of the parts are covered by a strong conformal coating. More about this in the topic Restoration.

Another pertinax circuit board is present behind the control panel at the right side of the device. It becomes visible after removing the molded case shell from the control panel, and is shown in the image on the right. The large transistor at the right is part of the motor speed regulator.
  
Electronic circuit and jack sockets

This board also holds a single-transistor oscillator that produces the bias signal when recording. The inductor of this circuit is visible behind the big transistor. At the left side of this board are a few components that are actually part of the amplifier. They are fitted here as the volume selector switch is also located here. At the upper edge of the board are the three 3 mm jack sockets.

Cover over mechanism removed Mechanism (bottom) Mechanism (top side) Mechanism (bottom side) Electronic circuit and jack sockets Mechanism Function switch Wiring to the magnetic head
Motor Motor with centrifugal governor Motor flywheel detail Mezon with cover over motor compartment removed Metal cap removed from the amplifier Amplifier close-up Close-up of the amplifier Record/Playback function switch
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Cover over mechanism removed
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Mechanism (bottom)
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Mechanism (top side)
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Mechanism (bottom side)
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Electronic circuit and jack sockets
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Mechanism
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Function switch
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Wiring to the magnetic head
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Motor
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Motor with centrifugal governor
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Motor flywheel detail
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Mezon with cover over motor compartment removed
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Metal cap removed from the amplifier
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Amplifier close-up
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Close-up of the amplifier
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Record/Playback function switch

Circuit diagram
Below is the complete circuit diagram of the recorder. The upper half shows the audio amplifier, with T1 and T2 as pre-amplifiers and T3 as the power amplifier (PA). A 3-position volume switch (S4) is present between T2 and T3. The amplifier is used both for recording and playback, under control of a 4-pole switch (S2) that is actuated by the hinged top lid. When recording (rec), the microphone is connected to the input (T1), whilst the recording head is connected to the output (T3). At the same time, a bias signal is supplied to the audio head by the bias oscillator (T4).


When playing back (pb), the audio head is connected to the input, whilst the output signal is delivered to the microphone 1 (or speaker). In this position, the bias signal is not supplied to the audio head. At the bottom right is the motor control circuit (T5), which is basically an electronic switch that is driven by a centrifugal switch inside the motor. It is bypassed when rewinding (rew).


There are three 3 mm jack sockets, or busses, marked B1, B2 and B3. B1 is the socket for the microphone or speaker. B2 controls the power supply. When using MEZON without connecting the remote control unit (RCU), the dummy plug (stub) should be installed in this socket. When using MEZON with RCU (shown above), it should be connected to B2 and B3, in which case B2 controls the power, whilst B2 controls the motor circuit. The RCU effectively takes over the function of S1.

  1. As the NEVA microphone contains a dynamic element, it can be used as a speaker in playback mode. Alternatively, the earphones can be connected to this socket when playing back.

Restoration
When we received our MEZON recorder, it had several issues. The left arm of the lid over the wire spools was broken, a suitable battery was missing and the motor wasn't running when power was applied to the device. Its restoration took several weeks and is described in more detail below.

The most obvious problem was the broken arm of the hinged lid over the wire spools, as shown in the image on the right. This is actually a weak spot of the device, as the lid is made of very thin aluminium and the metal spring that keeps the lid in locked in position, is far too strong.

As a result, too much force has to be applied to the lid when opening it. This causes the thin area between the lid and the arm to bend and – after opening and closing it many times – eventually break. Once broken, it is difficult to repair this, as it can not be removed from the case frame.
  
Broken arm of the top lid

Before repair, the (too) strong spring was removed, so that the broken lid could be positioned correctly without any tension from the spring. The broken parts were sanded, cleaned, and held in position with a piece of duct tape, in such a way that the lid made a 90° angle with the body.

After several failed attempts it was found that the best results were obtained with a strong two-component metal glue, such as the EPOXY METAL from Bison [4]. It sticks very well to the metal, but takes several days to fully harden.

The metal glue was applied to the inside corners of the lid and a thin extra-hardened steel pin was embedded in the glue to add extra strength. Although the right arm was still intact, the same repair was applied there, as it was beginning to show the signs of a future crack. The metal glue was then left to fully harden for several days.
  
Mezon with open cover and open motor compartment

Once the glue was strong enough, the outside of the left arm was repaired in the same manner, by applying a small layer of metal glue over the crack. Again, it was left for several days to fully harden. After that, any excess glue was milled off and the repaired area was repainted in grey.

The results of the repair can be seen in the images below. A weaker spring was made to replace the old one. It was installed in the motor compartment, and works as expected.

The next thing to try was to apply a 7.3V DC 1 power source to the battery terminals to see if the motor would run. Unfortunately this was not the case as the motor bearings had dried out after several years of storage. Luckily, this was easier to fix than expected. After removing the blue tape from the square body of the motor, its interior and the bearings could be accessed.
  
Motor disassembled for repair

After applying a tiny drop of lubricant to the bearings, the motor started spinning straight away. The motor was then re-assembled, but the worn-out blue PVC tape was replaced by Maylar tape, which is more robust, temperature proof and sustainable, as it does not disintegrate over time.

Note the rectanglular brass shields that are held in place by the tape. They are used to cover the rectangular holes in the motor's frame and are necessary to reduce interference in the amplifier.

The image on the right shows the reworked motor re-installed in its bay at the rear side of the machine. The rubber bands are needed to reduce the sound of the spinning motor, which is particularly important for covert recordings. And after cleaning the driving gear and the rubber pads of the pick-up and supply reels, the wire and the spools are properly driven again.
  
Reworked motor with Maylar tape

Next, it was time to check the amplifier. Unfortunately, this part was not working as expected. In fact, it was not working at all. Although very faint cracks can be heard when altering the volume setting, no sound or noise from the audio head was heard at all, when playing back a recording.

As the amplifier is also used for recording, it was assumed that recording wasn't possible either. In order to address this problem, the metal cover has to be removed from the amplifier section.

The image on the right shows the amplifier after the metal cover has been removed. It consists of two pertinax board that are bonded together. Unfortunately, it is very difficult to remove the amplifier, as the teflon wires that connect it to the rest of the device, are very short. Using the circuit diagram and an external amplifier it was discovered that all coupling capacitor were dead.
  
Removing the amplifier

As these capacitors are not easily accessible – they are glued-in between the two boards – it was decided to connect modern alternatives in parallel to the old ones. The 6µF capacitor near T3, was replaced by a miniature 10µF alternative that was fitted aside the REC/PB function switch.

It was connected to the collector of T3 with a thin teflon wire, similar to the ones that are used in the rest of the circuit. In the same vein, the 2.2µF capacitor between T1 and T2 was replaced by a small tantalium type, as shown here. It is connected directly to the wiring of T1 and T2.

The third capacitor that had to be replaced, was the 10µF one between T2 an T3. Luckily, as it is connected in series with the volume control (S4), it is not part of the miniature circuit. Instead it is fitted externally, on the small PCB behind the control panel, close to the volume selector (S4).
  
Part of the front panel and the amplifier

The capacitor was removed from its protective teflon sleeve and replaced by a modern tantalium alternative, that nicely fits the sleeve. Capacitors of this type have the tendency to dry out over the years. After their replacement, the amplifier once again produces a strong and clear signal.

The adapter cable that is used for connecting an external audio source or an external amplifier, was also broken. Excessive solder inside the jack plug caused a full short-circuit of the audio line. This should be regarded as a manufacturing fault, with was easily fixed with a bit of rework.

The SHUNT-adapter, used for connecting MEZON to an external 7V power source, wasn't working either. This was caused by one of the two wires (inside the white cable) that was heavily corroded over the entire length and was not conducting anymore, probably due to the use of acid flux.
  
Both ends of the power cable. One of the wires is completely corroded over the entire length

Looking at the picture above more closely, we can see that the corroded wire even shines through the plastic insulation. As the cable was beyond repair, it was replaced by a similar plastic cable, from an old Soviet work light. The engraved aluminium ID tags on the wires, were removed from the old cable and refitted on the new one. The SHUNT was cleaned and refitted to the new cable.

The yellow foam inside the storage case had dis­integrated completely and had become sticky, to the point where its residues had started to cause damage to the parts stored inside the case. This means that it had to be removed. Furthermore, the white pre-shaped polystyrene, with cut-outs for the various parts, was missing completely and had probably been trown away earlier in life.

It was decided not to recreate the interior of the boxes – it would deteriorate again anyway – but instead replace it with something more practical that would still be suitable for the Cold War era.
  
Old deteriorated foam

The interior of the metal box was cleaned and the remains of the foam and its glue were carefully removed. Next the inside of the lid, the bottom and the sides were covered with 5 mm thick grey felt, as shown in the images above. Vertical dividers were added to keep everything in place.

The following has been repaired so far:

  • Left arm of top lid repaired
  • Motor repaired
  • Amplifier repaired
  • Belt and drive gear cleaned
  • Drive rubbers cleaned
  • Eraser repaired
  • External audio adapter repaired (short circuit)
  • Storage case interior renewed
  • Cable of SHUNT-adapter replaced
  1. Note that the shorting plug, or stub, has to be installed in the middle jack socket, in order to run the device without the remote control unit. Without the stub or the remote control, the device will not work.

Old deteriorated foam MEZON body-wearable wire recorder Broken arm of the top lid Broken arm of the top lid Mezon with open cover and open motor compartment Mezon with cover over motor compartment removed Motor disassembled for repair Close-up of motor under repair
Motor with centrifugal governor Reworked motor with Maylar tape Reworked motor re-installed Removing the amplifier Part of the front panel and the amplifier Amplifier with additional wire for new capacitor 10 uF capacitor added between function switch and inductor Capacitor in volume circuit replaced
Broken 10uF capacitor Eraser Plug with short-circuit causes bad bad soldering Felt padding detail Corner details Newly padded and compartmented storage case
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Old deteriorated foam
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MEZON body-wearable wire recorder
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Broken arm of the top lid
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Broken arm of the top lid
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Mezon with open cover and open motor compartment
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Mezon with cover over motor compartment removed
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Motor disassembled for repair
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Close-up of motor under repair
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Motor with centrifugal governor
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Reworked motor with Maylar tape
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Reworked motor re-installed
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Removing the amplifier
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Part of the front panel and the amplifier
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Amplifier with additional wire for new capacitor
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10 uF capacitor added between function switch and inductor
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Capacitor in volume circuit replaced
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Broken 10uF capacitor
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Eraser
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Plug with short-circuit causes bad bad soldering
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Felt padding detail
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Corner details
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Newly padded and compartmented storage case

Checklist
Below is a list of items that were originally supplied with each Mezon wire recorder, as printed in the first chapter of the original operating instructions. The items listed in red are currently missing from our collection. Any help in obtaining them would be greatly appreciated.

Box 1
  1. Metal storage case (low)
  2. Recorder MEZON
  3. Adapter
  4. Cups for OR-2K elements (RC-63)
  5. Connection cord for external source
  6. Earpiece TM-2
  7. Microphone 'Neva' or 'T-65'
  8. Remote control unit
  9. Recording wire (cartridge, spools)
  10. Telephone adapter TA-4
  11. Dummy connector (stub)
  12. Oil container
  13. Lubricating tool
  14. Wire pick-up tool
  15. Tweezers
  16. Scissors
  17. Screwdriver
  18. Head cleaning device
Box 2
  1. Metal storage case (high)
  2. De-magnetizer (for erasing the wire recording)
  3. Container for dry batteries (type 'Saturn')
  4. Containers with wire spools
  5. Shunt connector (for external DC power supply)
  6. Cups for OR-2K elements (RC-63)
  7. Carrying case (for recorder) 1
  8. Two batteries BOR-1 1
  1. These items are packed inside the Saturn battery container (box 2, item 3).

All items came in two metal boxes: a low one (box 1) and a higher one (box 2). The latter (box 2) is currently missing from our collection. Furthermore, we have altered the interior of box one, as the original foam had disintegrated completely. The images below shows an original MEZON kit with the original papers, from the collection of the Atomic KGB Bunker Museum in Lithuania [1].

MEZON kit in the collection of the Atomic KGB Bunker Museum [1] Complete set MEZON kit in the collection of the Atomic KGB Bunker Museum [1] Storage case #1 MEZON kit in the collection of the Atomic KGB Bunker Museum [1] Storage case #2 MEZON kit in the collection of the Atomic KGB Bunker Museum [1] Storage case #2
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MEZON kit in the collection of the Atomic KGB Bunker Museum [1] Complete set
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MEZON kit in the collection of the Atomic KGB Bunker Museum [1] Storage case #1
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MEZON kit in the collection of the Atomic KGB Bunker Museum [1] Storage case #2
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MEZON kit in the collection of the Atomic KGB Bunker Museum [1] Storage case #2

Wanted items
We are currently looking for the following items:

  • 3 mm jacks with 4 mm locking thread (several pieces)
  • High metal storage case (box 2)
  • Oil container
  • Screwdriver
  • Head cleaning device
Documentation
  1. Device 'Mezon', Technical description and operating instructions 1
    Аппарат Мезон, техническое описание и инструкция по эксплуатации (Russian).
    10 June 1968. Revision 6-e.

  2. Device 'Mezon', Technical description and operating instructions
    Аппарат Мезон, техническое описание и инструкция по эксплуатации (Russian).
    29 March 1974. Revision 9-e.

  3. Mezon Pasport No. 1002466 (export) 1
    24 November 1969.
  1. Document kindly supplied by Detlev Vreisleben [5].

References
  1. Atomic KGB Bunker, MEZON wire recorder on public display
    Lithuania, November 2017.

  2. Vintage Technics, Mezon
    Retrieved November 2017.

  3. H. Keith Melton, Ultimate Spy
    ISBN: 0-7513-4791-4. 1996-2002. p. 110.

  4. Bison, EPOXY METAL
    Retrieved December 2017.

  5. Detlev Vreisleben, Personal correspondence
    January 2018.
Further information
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Crypto Museum. Created: Friday 24 November 2017. Last changed: Monday, 29 January 2018 - 18:51 CET.
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