One Line
Crypto Museum recently restored a 1960s DDR 'Type 2' transmitter found underground in an exceptionally good condition, and encourages donations to support its website.
Key Points
- DDR Type 2 was a valve-based short-wave clandestine spy radio transmitter developed in the early 1960s during the Cold War.
- The transmitter was intended for use by East-German agents operating in West-European countries and was distributed by the Ministerium für Staatssicherheit (MfS).
- A West-European forest was the site of a secret underground cache containing a VARTA 6V car battery, two rectangular watertight containers, and a spy radio set.
- The cache contained socketet parts, three small reels of ¼" ferro tape, a large reel with additional tape, and spares to allow the agent to repair the PSU and the transmitter in case of a failure.
- The transmitter is suitable for the 3.15 to 8.5 MHz frequency range, delivering an output power of 10 or 20W in CW (morse).
- Wire antenna and a suitable counterpoise must be connected to banana sockets at the rear of the transmitter for proper operation.
Summaries
233 word summary
Crypto Museum's website has information on various spy radio sets, including a DDR 'Type 2' transmitter recently restored. It was found underground and in a well-preserved state, having been buried for nearly 60 years. The transmitter and power supply unit (PSU) were in excellent condition, with only minor traces of rust. Inside the PSU was a VARTA 6V battery, indicating the radio was from the 1960s.
The items were stored in a hermetically sealed plastic bag inside a watertight container. This particular cache find was in exceptionally good condition. It contained socketet parts, three small reels of ¼" ferro tape, a large reel with additional tape, antenna and counterpose wires wound onto a pertinax (paxolin) card, and spares to allow the agent to repair the PSU and the transmitter in case of failure.
The transmitter was designed for use by East-German agents operating in West-European countries and was distributed by the MfS. It was usually hidden in underground caches and messages were encrypted using One-Time Figure Pads (OTFP). It had a lever to wind the tape from the leftmost reel to the pickup reel at the right, and a knob to select a number (0-9). It measures 150 x 105 x 50 mm and is housed in a grey hammer paint metal enclosure. The kit included 30 quarz crystals spread over three metal storage boxes. Donations are encouraged to support Crypto Museum's website.
1079 word summary
Crypto Museum's website has information on spy radio sets, DDR spy radio sets, handschnellgeber, Stanze tape punchers, and other related topics. Donations are encouraged to support the website. Links in red are unavailable. Restoration of a DDR 'Type 2' transmitter was recently completed. Valves, valves, crystals, and other components were replaced, and minor rust removed from the mains transformer. The transmitter produces a strong signal at the fundamental frequency, and F2-F5 are only 3-20 dB down. A 4.230 MHz crystal was installed in the transmitter's crystal socket and powered up. No reform cycle was needed as there were no electrolytic capacitors. All components were free from corrosion. The radio station featured here was in a well-preserved state, considering it had been buried in the ground for nearly 60 years. The power supply unit (PSU) had a metal base frame that held all components, and a removable metal grey hamerite case shell. The mains transformer was tested and it was decided not to raise the mains voltage above 200V AC to prevent saturation and increase its life span. The transmitter consisted of an oscillator, a power amplifier, and an antenna tuning circuit with a seven-position rotary switch. After a few hours of testing, the PSU produced stable LT and HT output voltages, without running hot. Additionally, a VARTA 6V battery was found, indicating the radio was from the 1960s. In 2018, a Crypto Museum in Europe displayed a radio transmitter and power supply unit (PSU) that had been kept underground for nearly 60 years and still worked. The transmitter and PSU were well-built with parts made by British and German manufacturers. The DDR had its own electronics industry but the transmitter was made to appear as though it came from Western Europe.
To protect the delicate parts of the transmitter, the chassis was zinc-plated and packed in a hermetically sealed plastic bag, which was stored in a watertight container. The items of this particular cache find were in exceptionally good condition, with only minor traces of rust. The PSU was also well-protected by the plastic bag, with no corrosion found on the exterior. Inside, the mains transformer exhibited minor traces of rust that could easily be brushed off. A West-European forest was the site of a secret underground cache discovered by a fanatic amateur-archeologist in 2018 using a metal detector. It contained a VARTA 6V car battery from the 1960s, which had been there for nearly 60 years and showed only minor signs of corrosion.
Upon further investigation, it became clear that this was not a regular car battery, but a secret cache. It had two rectangular watertight containers inside, padded with sheets of lead to give the battery a more convincing weight. The containers featured a metal bracket with two hex bolts and a lid held in place by rubber, allowing it to be closed firmly.
The cache contained a spy radio set consisting of socketet parts, three small reels of ¼" ferro tape, a large reel with additional tape, and spares to allow the agent to repair the PSU and the transmitter in case of a faillure. It also included antenna and counterpose wires wound onto a pertinax (paxolin) card. Wire antenna and a suitable counterpoise must be connected to banana sockets at the rear of the transmitter for proper operation. The polarity of the 2-wire cable is irrelevant and neither wire is connected to the chassis. A DIN-DIN cable and a 2-wire cable were supplied for connection to the transmitter.
The keyer consists of a lever to wind the tape from the leftmost reel to the pickup reel at the right, and a knob to select a number (0-9). The number is punched into the tape as a series of holes that represent the morse code characters and stored onto a regular ¼" audio tape.
The transmitter is suitable for the 3.15 to 8.5 MHz frequency range, delivering an output power of 10 or 20W in CW (morse). It is crystal operated and has a socket for a HC-6U format crystal at the top left.
The PSU provides the 6.3V LT and HT voltages for the transmitter. It is suitable for 220V AC mains only and has two switches: one for enabling the HT voltage and one for selecting the desired RF power output.
The kit included 30 quarz crystals spread over three metal storage boxes that were copies of those supplied with West-German spy radio sets like the SP-15. The first two boxes contain 24 crystals for the 3.15 to 7 MHz frequency range, but the third box contains 6 crystals from 7.087 to 8.370 MHz, which is above the specified range. The image above shows a typical setup for sending a message. It consists of a transmitter, power supply unit (PSU), crystal for desired frequency, antenna and counterpoise, and three recessed knobs for adjusting the frequency. The transmitter measures 150 x 105 x 50 mm and is housed in a grey hammer paint metal enclosure. The diagram below gives an overview of the controls and connections on the body of the device.
The transmitter was intended for use by East-German agents operating in West-European countries and was distributed by the Ministerium für Staatssicherheit (MfS), better known as the Stasi. It was usually hidden in underground caches to avoid being caught with the transmitter. Messages were encrypted using One-Time Figure Pads (OTFP), and instructions were sent via One-Way Voice Link (OWVL), also known as a Numbers Station.
The agent generally had a receiver such as the Grundig Transistor Luxus and had printed instructions on how to use the set, with a high-speed hand-operated morse burst encoder. A tuning table on the top surface gave a rough pre-set for each frequency. Radio direction finding (RDF) could be used to determine the transmitter's location if intercepted. Based on manufacturing codes on some of the components, it was probably manufactured in 1962 and is known as 'DDR Type 2'. DDR Type 2 was a valve-based short-wave clandestine spy radio transmitter developed in the early 1960s during the Cold War. It was used by the Stasi, the East German secret police. It was linked to many countries, manufacturers, agencies, people, and technologies, including telephones, telex, PC, radio, covert intercept, burst encoders, Yugoslavia, USSR, USA, UK, Sweden, Poland, Norway, Netherlands, Japan, Italy, Hungary, Germany, France, Finland, Czechoslovakia, Belgium, Austria, and other countries. It was also used during World War II and is part of a larger spy radio crypto and glossary.