Spy sets
Burst encoders
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R-353 (Proton)   ПРОТОН
Russian spy radio set

The R-353 is a Russian spy radio set that was developed in the USSR in the early 1960s, at the height of the Cold War. It features an advanced built-in tape-based burst transmitter for sending coded messages in morse code at very high speed, in order to minimise the risk of detection and direction finding by the enemy. The R-353 is also known by its codename PROTON (Russian: ПРОТОН). Radios like the R-353 are extremely rare and are highly wanted by collectors.
The R-353 is one of the most beautiful and sophisticated valve-based spy radio sets around. It is completely self-contained and has a built-in power supply unit that can be connected to virtually any mains voltage in the world.

Contrary to many other Cold War era radios, the R-353 is a true spy radio set, that was used by Soviet (and other) spies and agents, to send messages to the countries behind the Iron Curtain. Therefore, most of the R-353 sets have their markings and controls in English, as that would reduce the risk of being exposed.

The transceiver has a modular design. On the left is the receiver, whilst the transmitter is on the right. In between these two units, is the burst transmitter: a small unit that can play back the metal tape cassette (see below). At the bottom is the power supply unit (PSU) which connects directly to the mains. The PSU can be detached and replaced by a power inverter, so that the R-353 can also be powered from a battery source.

A metal lid protects the controls and the tape reader. When opened, the top lid acts as a stand, holding the transceiver in operational position. Inside the top lid are some of the accessories. On the left is a white plastic plate, behind which some fuses and spare light bulbs are stored.

To the right of it is a dial, which resembles the dial on an old telephone set. The dial enables the operator to send numbers directly in morse code, without any knowledge of morse code whatsoever. To the right of the dial is a small work light attached to a flexible arm, and a small morse key that can be 'lifted' into position. To the right of the morse key are the user instructions and frequency tables; all in English.

Like most Russian equipment of the era, the R-353 was finished with Hamerite paint. Two colours are known to have been used for this: grey (most common) and green-blue Hammerite. The purpose of the different colours is unknown.
The complete unit with closed lid The complete unit viewed from the left Two doors in the body of the radio allow ventilation for the transmitter PA Looking inside the frequency table Close-up of the burst transmitter. The rubber roller drives the tape The cassette mounted on the transmitter Another view of the cassette mounted on the transmitter Frontal view of the unit in action

Sending messages in morse code
The R-353 was used to send messages in morse code (CW) in a variety of manners. The usual manner of operating the radio was by using the burst encoder to send pre-coded messages at very high speed, in order to minimise the risk of being detected. This method is further described in the next section below.
In case of emergency, the operator could also send messages directly in morse, using a small morse key that was folded away in the top lid of the radio. By pulling the morse key upwards, it locks into position allowing normal hand operation.

A small connector, sitting in a small bay inside the top lid, should be connected to the socket marked KEY on the radio's front panel. This way, both the morse key and the number dial (see below) are connected to the radio.

After use, the morse key needs to be stowed away before the lid can be closed again. This is done by pusing a spring-loaded lever at the underside of the key backwards and then pressing the key down.
The morse key is only of use to an experienced radio operator, who is capable of giving morse at a reasonable speed. If the operator is totally unexperienced with morse, an alternative method to send a numerical message is available in the form of a telephone-style dial.

Once the radio link with headquarters is established, all the user needs to do is dial the appropriate numbers on the circular disc. A clever mechanism hidden under the disc, translates each number directly into the appropriate morse code.

Burst encoder
The R-353 was supplied with one of the most advanced burst encoders of its time. It is based on a small cassette with a metal tape, on which the message are recorded, much like the American AN/GRA71.

A small metal box with a telephone-like dial was used to record the message on the tape, without using batteries!

 More information

Spare parts
The R-353 is completely valve-based. It contains many miniature valves and one rather large power valve, for the PA-section of the transmitter. In order to repair R-353 units in the field, a small metal box with spare parts was supplied.
The box contains virtually anything a technician needs to repair a faulty unit: fuses, light bulbs, valves (tubes), tools (screwdriver and pliers), spare metal tape, soldering iron, solder and raisin.

Spares boxes for the R-353 are very rare and unfortunately most of them have already been 'canibalised' in the past. The one shown here was discovered in a former East-German spares facility and according to the enclosed checklist, it is still complete. It even contains some brown envelopes with additional spares.

There are two variants of this box that have only minor differences. The one shown here has a spool with spare metal tape (for the burst encoder) in the top left of the top lid, whilst in the other variant it is stored in a small metal container.
A good look at the PA valve inside the box The toolkit in the bottom part and some small miniature valves inside the top lid The toolkit unvolded Close-up of some of the tools The soldering iron with a small box of raisin Perspective look at the contents of the box Front view of the contents of the box A very rare green/blue variant

Battery unit
By default, the R-353 was main powered, using the standard PSU attached to the bottom of the unit. The standard PSU could also be replaced by a power inverter, so that it could be powered from an external battery source.

The standard battery unit that was used with the R-353 is shown here. It's a small box that houses a number of common Russian wet batteries. The connector is on the right.

Battery charger
When an external battery was used (see above) this separate power supply unit was used to charge the batteries. It has two fixed wires: one that connects to the battery case (left) and one for connection to the mains (right).   

The R-353 in use
The R-353 has been in use in many Western European countries from the early 1960s, well into the 1970s and was captured by western agencies on a few occasions. One documented event was the capture of an East-German agent in The Netherlands (i.e. a Dutch person) in the early 1960s. When he was finally exposed, the Dutch security agency BVD (now AIVD) found a fully operational R-353 in his home [1] (see also [2] ).
  1. AIVD Website
    Short impression of the capture of an R-353 in The Netherlands (Dutch)

  2. Chris Vos, et al. De geheime dienst: verhalen over de BVD
    ISBN: 90-8506-181-4 (Dutch, book with DVD)

Further information

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