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Before WWII, the Poles were already known for their compact and powerful spy radio sets, such as the Pipsztok (Peepshtock) developed by Thadeusz Heftman, a Polish radio engineer who had been educated in Germany. The sets were built at the AVA factory in Warsaw, where also the Enigma-replicas were built.

After the outbreak of WWII, the Poles successfully made their way to the UK, where they operated their own clandestine radio service and built their own spy radio sets. The Polish sets were of remarkable quality and were often better, smaller and more powerful than their British counterparts. They were used by the Polish Underground Army as well as by the British SOE at all theatres of the war, but mainly in Europe and the Pacific.

After the war, Poland was separated from the West when it became part of the Warsaw Pact, a collective defense treaty of eight communist states, lead by the Soviet Union (USSR). Follow­ing the collapse of the Soviet Union in 1991, Poland became a member of NATO in 1999, and of the European Union in 2004.

Polish spy radio sets on this website
AP-5 spy radio set, developed by the Poles in the UK
BP-3 spy radio set developed by the Poles in the UK
BP-5 spy radio set developed by the Poles in the UK
Polish OP-3 (Type 30/1) WW-II clandestine receiver. Produced in the UK during WW-II.
Also used by Poland
R-354 / Shmel (Bumblebee)
In the early days of WWII, a number of Poles managed to escape to the United Kingdom. There, the Polish soldiers were allowed to setup and train their own Army units within the UK, whilst the Polish engineers manned the Polish Military Wireless Unit (Polski Wojskowy Warsztat Radiowy) at Stanmore 1 , just north-west of London, between Edgware and Watford. They were responsible for the contact between their government in exile and the Polish Underground Army back in Poland.

Map of Greater London showing Stanmore (A) in the North-West (image via Google Maps)

At Stanmore Park, the Poles also manufactured their own spy radio sets, which were developed by Thadeusz Heftman, a Polish radio engineer who had been trained in Germany. In the late 1930s, Heftman had been working for AVA in Warsaw, a small company that built clandestine radio sets for the Polish Intelligence Service at the time. AVA was also the company who built the Polish Enigma Replicas in the early 1930s after the Poles had successfully broken the German Enigma cipher. Just before the outbreak of WWII, Heftman had developed and built a number of so-called Pipsztok (Peepshtock) radio sets that were both powerful and small – perfect for clandestine use.

When Germany invaded Poland in September 1939, the AVA company was first relocated to Romania and later to France, with the intention to manufacture the Peepshtock there. But when France was invaded by Germany in 1940, Heftman escaped to the UK, taking one of his Pipsztoki and the circuit diagrams with him. He was assigned to the Polish Military Wireless Unit, located at Stanmore Park, where he developed a wide range of superior spy radio sets, starting with the A1 (Nelka) in 1941, followed by the A2, A3, AP4 and AP5. These radios were mainly built for the SOE.

Alongside the A-series, Heftman also developed the so-called B-series (later: BP-series). Unlike the A-series, which had a built-in power supply unit (PSU), the B-series used an external PSU and were less prone to overheating, making them more suitable for operation in urban environments.

The B-series started with the B1 and B2 in 1942, followed a year later by the BP3, BP4 and BP5. At the time of their introduction, the BP radios were superior to the existing British spy sets, both in size and performance. It wasn't until 1943, with the introduction of the (much larger) British B2, that the British were able to match the performance of the Polish sets. And with the introduction of their A3, in 1944, they were finally able to match the size, albeit at a lower RF power output.

During WWII, the Poles made a significant contribution to the war effort, not only by building clandestine radio sets, but also by breaking the Enigma cipher machine. The Polish Government in Exile was led from London by General Sikorski. Under his command, the Polish Air Force played an important role in the Battle of Britain, the Polish Navy had 15 warships and 35 merchant ves­sels at sea, and the Polish Brigade fought at Narvik and Tobruk (North Africa). They also took part in the liberation of Italy (General Anders), Belgium and parts of the Netherlands (General Maczek), whereas the Parachute Brigade (General Sosabowski) was present at the Battle of Arnhem.

Once the war was over, the Poles could not return to their home country, as Poland had come under control of Stalin's Soviet Union — one of the outcomes of the Yalta Conference of February 1945 [3]. As a result, England still has a large Polish Community today (2014), such as the one in Letchworth [4]. Similar Polish communities were established in The Netherlands, for example in Breda where many of Maczek's people settled down after the war. The Polish contribution to the Allied Victory is often forgotten, but luckily we have museums like the Sikorski Institute in London (UK) [5] and the Maczek Museum 2 in Breda (Netherlands) [6], to remind us of their efforts.

  1. During WWII, Stanmore was home to the Radio Security Service (RSS) of MI6, the RAF (the Battle of Britain was controlled from here) and the Radio Workshop of the Polish Army in Exile, all of which were located at Stanmore Park. From 1942 onwards, Stanmore Park also became known as Outstation Stanmore (OSS), when Bletchley Park moved 49 of its Bombes to the site. They were used for breaking the German Enigma cipher.
  2. In 2011, Crypto Museum took part in the Enigma exhibition at the Maczek Museum in Breda (Netherlands) to commemorate the Polish code-breaking efforts before and during WWII.

Known Polish spy radio sets
Name Year Frequency Remark  
Pipsztok 1939 ? pre-WWII  
A-1 (Nelka) 1941 ? Prone to overheading  
A-2 1942 ?    
A-3 1943 ?    
AP-4 1943      
AP-5 1944 ? Introducing break-in keying  
AP-6 1945 ? Prototype  
AP-7 1945 ? Midget variant (prototype)  
B-1 1942 2-8 MHz    
B-2 1942 4-16 MHz    
BP-3 1943 2-8 MHz    
BP-4 1943 4-16 MHz    
BP-5 1944 2-8 MHz Introducing phone (voice)  
KR-1000 1943 3.5-16 MHz High power transmitter  
MR-2 1943 ? Based on AP-5  
MR-3 1944 2-8 MHz Based on MR-2  
NP-3 1944 3.5-9 MHz Miniature transmitter  
NS 1942 4.5-9.5 MHz Mains powered  
NSP 1942 4.5-9.5 MHz Mains and battery powered  
OP-3 1943 0.6-1.5 MHZ, 2-12 MHz Receiver  
OSB I 1942 3-9 MHz Battery powered receiver  
OSB II 1942 3-9 MHz Battery powered receiver  
UB ~1950 2-12 MHz Name suggested by Louis Meulstee in [1]  
Known users
During WWII
  • Armia Krajowa (Polish Home Army)
  • Bureau II and VI of the Polish General Staff
  • SOE (mainly in Europe and Asia)
  • BCRA (French resistance)
  • Czech Resistance
  • Yugoslav Resistance
  • Albanian Resistance
  • Resistance groups in Italy
  • OSS (probably used in the Pacific)
After WWII
  • SIS (UK)
  • Polish Clandestine Organisations WiN and NIE
  • Organisation Gehlen (predecessor of the German BND)
  • Ukrainian Organisation of Nartionalists (OUN)
  • CIA
  1. Louis Meulstee, Wireless for the Warrior, volume 4
    ISBN 0952063-36-0, September 2004

  2. Pierre Lorain, Secret Warfare
    1972. English adaption by David Kahn, 1983. ISBN 0-85613-586-0.

  3. Wikipedia, Yalta Conference
    Retrieved December 2014.

  4. RC Church of St Hugh of Lincoln (Letchworth), The Local Polish Community
    Retrieved December 2014.

  5. Wikipedia, Polish Institute and Sikorski Museum
    Retrieved December 2014. → Website.

  6. Website, Generaal Maczek Museum Breda
    Retrieved December 2014.

  7. Wikipedia, Polish government in exile
    Retrieved January 2015.
Further information
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Crypto Museum. Created: Wednesday 31 December 2014. Last changed: Monday, 12 February 2024 - 09:31 CET.
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