Figure 1.--This is the Grman rdio detector van. Once this appeared one would expct that Station 506 might have shut down. But the 506 unit may hve beenso small that the opeatives involved did not see it. And those Resistnce members that saw it did not know who the German targets were so they could be informed.

The German Wehrmacht invaded Yugoslavia (April 1941). Yugoslavia was soon over run in a few days. The Germans set up a puppet government under Milan Nedic. Ugoslavs were shocked by the quick German vicyory. It seemed impossible to resit. And the Comminists were confused as the Soviet Union ar the time was a NAZI ally. Yugoslavs soon recovered ftom the shock and a substntial resistane movement was operating (by 1942). The building resistance soon movement communicated by radio. There was a German intelligence unit deoloyed whose whose purpose was to search for illegal radio transmissions. The Searching Communications unit uncovered a network of illegal radio stations throughout Sebia and in the city of Belgrade. The matter was so serious to the Germans that they called up experienced intelligence agents from Thessalonica in Greece to capture these radio locations. So began the Balkan war in the ether. The Nazi Special Intelligence unit set up their headquarters in the district of Belgrade called Dedinje. This area was then on the outskirts of Belgrade and was a fashionable area for wealthy families to live. This was the part of the city where many German soldiers were stationed. The district soon became used to the high ranking German officers who occupied the mansions left vacant after the pre-War owners had fled or had been arrested. When a new group of German officials arrived no-one paid much attention to them. A large number of trucks started to arrive at a secluded house. To be curious about what was happening could get one arrested and imprisoned. The next door neighbours moved away from their window when a German Sergeant shouted at them to stop watching them.

German Invasion (April 1941)

Yugoslavia unlike the rest of the region refused to knuckle under to Germany's diplomacy and threats. As a result, Hitler ordered the German Wehrmacht to invade Yugoslavia (April 1941). It was another in a series of brilliantly successful Blitkrieg campaigns. Unknown at the time, it would be Hitler's las military success. Yugoslavia was soon over run in a few days. While it was a huge success, most military historians regard it as a Phyric victory because it delayed Barbaross, the all imprtant effort to invade the Soviet Union ahd destroy the Red Army.

Puppet Regime

The Germans dismembred Yugoslavia. A NAZI controlled Government in Serbia was established headed by former royal Yugoslav army general Milan Nedich. He also initiated an ethnic cleansing campaign. Nedich operated concentration camps for Jews, non-Serbs, and his Serb political opponents. Some of these operations, especially aginst Jews were conducted for the NAZIs, other operations against non-Serbs were conducted to suppport Nedich's Serbian nationalist ideology. The first experiments in mass executions of camp inmates by poison gas were carried out by the NAZIs in one of Nedich's camps. Serbia became the first NAZI satellite to declare itself "Judenrein" ("cleansed" of Jews). Nedich's Serbian militia forces, which played a key role in this task, outnumbered both German security forces and resistance fighters within the wartime borders of Serbia.

Resistance

The Yugoslavs were shocked by the quick, almost efforless German victory. It seemed impossible to resist. And the Comminists were confused as the Soviet Union at the time was a NAZI ally. Communist parties throughout Europe followed orders from Moscow. Many European Communists sought refuge from the NAZIs in Moscow. Stalin conducted a purge of thse Cimmunists. Large numbers were killed. The survivors were men and women Stalin and his NKVD believed would unquestioining follow orders. Only 2 months after invading Yugoslavia, Hitler launched Barbarossa (June 1941). Suddenly Yugoslave Communists were free to resist.The survival of the Red Army changed the who dynamic in Yugoslavi, showing tht reistance was posible. Yugoslavs soon recovered from the shock and a substntial resistane movement was operating (by 1942).

Electronics

Electronics began to play a role in warfare for the first time in World War I. Electronic communications technology was still very limited. The situation at sea was different. Ships could have wireless facilities and thus could communivate with headqyarters, although there were distance limitations, especilly for the Germns. Land units could not transport bulky wireless statioins like ships at sea could. Front line units got instructions electroniclly, mostly by tlephone. But once on the move, especially an attack forward was launched, the units wer out of contact with headquarters, making followup orders very difficcult. World War II was very different. Electronics had made huge strides. A whole new industry had been created--radio, at the time often reffered to as wireless. Communictions with units on the move was now possible. Modern mobile warfare was only possible with directions to front line unit electronically. The German military understood this better than any other military establishment at the onset of the War. This gave rise to the Enigma Machine which the Germans believed was unbreakable. Thus during World War II the Allies set out to crack Enigma and the Germans set out to crack Allied codes as well as to monitor radio communications from the Resistance movements in occupied countries.

German Intelligence Units

The building resistance movement in Yugoslavia attempted communicated by radio. The Germans deployed a German radio intelligence unit to search for Reistance radio transmissions. The Searching Communications unit uncovered a network of illegal radio stations throughout Sebia and in the city of Belgrade. The matter was so serious to the Germans that they called up experienced intelligence agents from Thessalonica in Greece to identify these radio locations and capture the Resistance opertives involved. This began what one author describes as the 'Balkan War in the Ether'.

Dedinje

The Nazi Special Intelligence unit set up their headquarters in the district of Belgrade called Dedinje. This area was then on the outskirts of Belgrade and was a fashionable area for wealthy families to live. This was the part of the city where many German soldiers were stationed. The district soon became used to the high ranking German officers who occupied the mansions left vacant after the pre-War owners had fled or had been arrested. When a new group of German officials arrived no-one paid much attention to them. A large number of trucks started to arrive at a secluded house. To be curious about what was happening could get one arrested and imprisoned. The next door neighbours moved away from their window when a German Sergeant shouted at them to stop watching them. The neighbours knew that the security measures were high so concluded that a German general or his mistress was moving in. What puzzled them was why all the boxes and what could possibly be in them and why lots copper bars and wire? What were they for? The next surprise for the neighbours was to find that it was not a general moving in but a group of very young looking soldiers. The men were so young looking that it was hard to believe they were soldiers and not a youth group dressed in German uniforms.

Communications Search Unit

It was soon established that the platoon was under the command of a Sergeant Walney. He was very friendly to his men. He was head of the German �Communications Search Unit.� This was section in the German army�s Communications Department. Walney was head of a specialist unit whose expertise was in uncovering illicit radio signalling. They had been hastily brought from Thessalonica to track down the illegal radio operative. The equipment being unloaded was their radio devices surveillance equipment. The unit did not want their cover to be blown so the radio antenna became a washing line. No one would have any idea what was going because the physical features of a radio detection station were hidden. The antenna was stretched across the yard and looked like its only function was to be the washing line to dry the soldiers washed laundry. Sergeant Walney answered only to the Commander-in-Chief of German Forces in Serbia. His department�s role was to find out about the many illegal radio stations that had sprang up all over Serbia. They had to listen in to the illegal transmissions. Establish who was sending the radio messages. German agents had infiltrated Chetnik groups. Some agents were posted in cities. They also wanted to listen in on the Chetnik group radio traffic and learn what Draza Minolovic�s force was planning. They also wanted to know its relationship with the British. After 1943, the Germans wanted to know what the Partisan resistance was up to.

Operations

The German's Communications Search Unit�s task was to listen in to unidentified radio traffic. They also tried to track down the locations of the unidentified transmitors and find their code books and documents. This would allow Walney�s unit to read the radio traffic. Walney was not free to act against the illegal radios. He had to report to the Commander-in-Chief for permission to do this. The interrogations of the captured radio operatives had to be done in the presence of someone from Walney�s department. They worked in secret and were able to maintain their secret operations. Several months into the surveillance operation the unit had been able to monitor the traffic. It was mostly to do with sending orders and reports to the Resistance units. This was useful to the Germans.

Belgrade Chetnik Unit: Station 506

The Communications Search Unit began noticing a new illegal radio station had started transmitting in Belgrade. It was tied to Minolovic�s Chetniks units. The Germans initially was decided not to bother with the station. It did not pose a major threat to the Nazis. Had they gone after it and closed it down a new station would have appeared and the whole procedure would have had to start again. The station was listened to and it was soon realised that the radio traffic was more complex and dynamic than what was normally intercepted. What was even worse was that the radio code was very complex and the messages could not be deciphered. It turned out that the radio station communicated directly with British Intelligence and General Minolovic�s headquarters. The traffic was important because it was the latest detailed communiqu�s. Walney�s unit was alarmed. They had a name for it. They called it Station 506. The Chetniks were sending intelligence to the British about what they should bomb. Advnces in North Africa (November 1942) and then landings in Italy (September 1943) significntly increased Allied air capacity in the Balkans. The tramissions covered military trains, military transport, factories and airfields. There were orders to carry out sabotage against fuel reserves and rail tankers coming from the Rumanian Oil fields. When the German authorities compared this data with other information they realised that their transports were targeted by the Resistance movement. Transports going to Greece had been under constant attack. The Germans controlled the cities, but the rail lines crossed zreas in which German control a limited. Sometimes trains travelling along coastal railway lines could expect British Submarines to surface and fire upon them. There were also constant attacks by from the air. Railway trucks had been sabotaged. Wax balls wrapped in sand paper had put inside the wheels so that they screeched loudly when they moved. The Germans now realised that Station 506 was a dangerous adversary. It was one that had infiltrated the very top of the government in occupied Serbia. The technical reports transmitted were very accurate. Time and time again a mysterious name came up- �Ulman� The British thanked Station 506 for significant information it sent over.

German Response

The Germans called a special meeting to discuss Station 506. It was decided that the station was a very real threat and should be shut down and its operatives arrested. The first task was finding out which organisation was feeding it information. This line of enquiry failed. Walney�s unit were brought in. They soon established that Station 506 was located in Belgrade. Intercepting messages was possible from a fixed location. Locating transmission locations was a different matter. Soon a strange looking minivan appeared on the streets. It was a mobile radio detection finder vehicle. It drove around Belgrade trying to locate Statio 506. It seenms strange tht such a lrge znvhicle obviously involved in radio location ould not zleted the Sttion 506 opeators. Perhapsofonly a mll group was nvolved, they did not learn of the German efforts. The general location of Station 506 was believed to be somewhere to the right of Alexander Boulevard in the neighbourhood of Dyeram of Lyon. The Germans were not successful at first but they kept their radio detector van in the locality and eventually it picked up the transmission from Station 506 (December 28, 1942). The Germans soon surrounded the house. A man and woman came out of the house. They were quickly apprehended. They were Tihomir Yaksien and his fianc�. O nce the Gestapo moved in they found the Station 506 operative in the attic sending a message. He was also arrested. The radio operative turned out to be Branimir Thtga.

Plot Unravelled

The plot was soon unravelled. The leader was Dragamir Tomashevich. He was the senior employee of the Ministry of Post and Telegrams in the Serbian Givernment. He had put himself at the disposal of Nedic�s government. He spoke fluent German he was able to maintain his position to gather information. Tomashevich, had since 1942 been working with Draza Minaylev�s organisation. His minder was Major Zarko Todvrovich who had given him orders to set up a Belgrade radio Bureau which became Station 506. He hired Tihomir Yaksien and paired him with Branimir Thtga. Station 506 was set up and it operated from a house whose cover was that it was the love nest of Tihomir and his fianc�. The radio was in the attic so it would not draw attention. The information was gathered by Tomashevich. He gathered the radio parts from German suppliers in the name of the Ministry of Posts and Telegrams. Tomashevich essentiaaly was Station 506. This was his code name. He had a second network at the railway station. This unit collected information on rail transport and put the wax bearings in the wheels. The idea for this was Tomashevich�s. Tomashevich was interrogated and tortured ruthlessly, but he only gave away the identity of �Ulman�. Luka Shpataly was 'Ulman'. He was an industrialist who had bank rolled the radio station as well as running a network of saboteurs at the Zemun airport. His company made parts for the German Aircraft Industry. Both confessed to working for the British and along with Tihomir and his fianc�. They were executed by firing squad. Branimir Thtga was not executed. He was thought useful to the Nazi regime. Walney thought he could turn him into a rogue operative. When a station was shut down Thtga would operate it but feed the British with false information and luring in agents. They did not have the success they thought they would have using Thtga. They were successful in other places and were able to use rogue operatives to the German�s advantage. Thtga was released from custody in 1944. This was the end of the War in the Ether against Station 506.

Sources

Backuvich, Nemanja. "War in the Ether". Translated from Serbian into English by Natasha Draskovic. The Yugoslavian authorities in 1955 produced a 9 volume publication about Nazi intelligence gathering during the World War II occupation of Serbia. This is a full account of the Nazi Intelligence Service at this time. It was published by the Yugoslavian State Intelligence Bureau. In volume 6 is the story of Radio Station 506.

Created: 11:18 AM 6/30/2015
Last updated: 11:18 AM 6/30/2015