Russian Jammers

We, at the LPWS have often been accused of being jammers, but this is far from the truth. Admittedly, there is the playing of music on repeaters, but these are usually idle until one of our members comes along with a jolly tune (see the selection for download!).
An analogy of what occurs could be the following:- You stand on a river bridge calmly throwing stones into the water, a few anglers a mile or so away hear this and pack up and walk down to the area of the river beneath the bridge and set up their rods. They then complain that you are disturbing the fish!

The same is true for repeaters, there's no one on it until there is a break in the music, then everyone has come along to shout and swear or just key the mike, usually you can leave this repeater for minutes at a time and they will amuse themselves in the mistaken idea that they are jamming out your music. Whilst they are doing this, you can have a go on another frequency and start the whole process off again elsewhere. When the "sensible" hams monitoring the new repeater have joined in the jam the music, it is usually time to go back to the first one and give it a "top-up" as they might be getting tired. This can be kept going for ages, with LPWS input as low as 1% of the total traffic, with a quick visit to the other frequencies to keep the mayhem going.
This can be likened this to a circus act where the plate spinner keeps the plates going by tweaking the bamboo rods they are on, just as they are about to fall, a quick spin and they are back up to speed. An expert can keep as many as 5 repeaters blocked all at the same time with as much as 99% of the jamming coming from the so called "sensible" radio amateurs themselves.

When it comes to jamming though, we are quite plainly second division when compared to the world masters, the former Soviet Union.

Our friends in former Soviet Republics have quite kindly emailed the following material, for which we are most grateful!

This article deals with events which occurred in the Soviet Union after World War II. The Iron Curtain had been lowered. The peoples trapped in the Soviet Union were not to get any kind of information from abroad. The Communists were able to prevent people from moving through the Iron Curtain. But radio waves did not succumb to their regulations and penetrated the Curtain. This was a source of serious worry for the authorities – what would happen, now that info was coming in!? Something had to be done. And a solution was found.
Communists have always been frightened by radio receivers and photo cameras. If the taking of photos was always feared and forbidden, then the situation with listening to the radio was a bit different. In 1940-1941 it was forbidden, and radio receivers were confiscated. Later, radios were permitted. But in 1950-1951, the Soviets began to use special radio transmitters to jam the broadcasts which penetrated the USSR from abroad, in the languages of the nations which were trapped in the Soviet Union.
A special network of radio transmitters was constructed all over the Soviet Union for this very purpose. Jamming was done in the whole spectrum of broadcasting wavelengths, from long waves to short waves 13th meter. We know that jammers existed also in the “people’s democracies”, but we don’t have any information about them.
The jammers not only covered the nation which they were meant for, but their effect could be felt even in Europe, beyond the Iron Curtain (what insolence!). Just recently, a traveller from Germany told me how their short waves used to be full of the clutter from Russian jamming transmitters. But now their airwaves are clean.
One means of preventing the listening of foreign broadcasts was to limit the number of short wave bands that radio receivers could pick up. Radio receivers manufactured in the Soviet Union lacked part of the shortwave spectrum. They could not pick up the short waves used for transmitting during the day. If there are 8 shortwave transmission bands

11 13 16 19 25 31 41 49 m
25 21 18 15 12 9 7 6 MHz

and the most commonly used ones are 16-49m, then Soviet radio receivers could pick up only shortwave bands 25-49m.
The following article gives a picture of how radio broadcasts were jammed in Estonia during the Soviet era. A similar system functioned throughout the USSR.

This story gets its start from the fact that, in 1955, I graduated from the Tallinn Electromechanical Technical School, as a radio specialist. In those days, graduates were assigned to a job for three years, by a special government commission (we called the system a slave market). I was lucky to get a job in Tallinn, at the Estonian SSR Radio Centre, which was part of the Ministry of Communications.
I was assigned, along with a schoolmate, to Radio Centre site nr. 65, on Sitsi Hill. It was located on Kopli Street, at the Kopli-Tööstuse intersection, just before Kopli Street starts going downhill. Before the War, during independence, this had been the Ranna Radio Station. The antenna masts had been constructed by my teacher from the Technical School, engineer Albert Põdrus. In the foundation of one of the masts there was even a brass plate bearing Põdrus’s name.
The number 65 indicated that it was a secret broadcasting station, with the task of jamming foreign radio broadcasts. There were four such broadcasting stations in Estonia: nr. 602 in Tallinn, near Tõnismäe, on Luha Street, which had 3 distinctive pronged masts (one of which survives to this day); one in Tartu on Tiigi Street; and one in Pärnu. I no longer remember their code numbers. In addition to these, Estonian Radio’s existing broadcasting stations could also be used for jamming.
Of the Sitsi broadcasting station, only the main building still exists. Although we had been officially assigned to work there, for a whole month we weren’t permitted into the control room, which was the most secret spot in that building. In the course of that month, the KGB checked out our suitability for special assignments, as that kind of work was called in those days. They obviously couldn’t prove that we had committed any anti-Soviet crimes, and we were finally allowed to start working. It seems rather odd that a security check wasn’t done until after we were assigned to work there.

The jamming process itself was the following. The jamming of the Voice of America, Radio Free Europe, etc. was not just done through the aforementioned broadcasting stations. The whole process was much more complicated. The headquarters was of course in Moscow.
This is how it functioned in Estonia: every Estonian jamming center (Tallinn, Tartu, Pärnu) consisted of two departments – a so-called radio bureau and an objekt. The radio bureau was actually a monitoring centre, where the VOA and other broadcasts were listened to round the clock. When necessary, they gave the objekt (broadcasting station) instructions to start jamming.
The objekts were the aforementioned broadcasting stations (65, 602, etc.), which contained a wide assortment of short-, medium-, and long wave transmitting equipment.

The Tallinn radio bureau was located at 12 Kreutzwaldi Street, on the III floor of the Ministry of Communications building. On every table there was a large Russian Krot type shortwave receiver equipped with a sensitive panoramic oscillograph. At every receiver sat a female Russian operator, wearing headphones. There was also one medium- and long wave receiver, which was used only occasionally. In the radio bureau they had the broadcasting schedules of the Estonian and Russian programs of VOA, RFE, etc. These were listened to constantly, and when necessary, the objekts were told to turn on their jammers.

And now, a little bit about the objekts
These were nothing more than broadcasting stations which contained various transmitters. For instance, broadcasting station nr. 65 consisted of:
shortwave transmitters 1kW 10pcs
US military 1-1 transmitter SCR 1pc
medium wave transmitter Uragan 10kW 1pc (water cooled)
long wave transmitter Storm 3kW 1pc (air cooled)
and 2 smaller k-1 transmitters which were rarely ever used

Objekt nr. 65 was headed by a Russian woman named Gorelova, who had graduated from the Leningrad Communications Institute.
Objekt nr. 602 consisted of 10 4kW shortwave transmitters. This was also headed by a Russian woman.
The Tartu and Pärnu objekts consisted mostly of US military SCR type shortwave transmitters.
The objekts and transmitters were numbered in sequence. The numeration of the objekts was as follows:
the older type, equipped with 1-1 transmitters:
nr. 65 – in Tallinn, Sitsi Hill
nr. 66 – probably in Tartu
nr. 67 – probably in Pärnu
the rest of the objekts of this type were located outside of Estonia.
The newer type, equipped with more powerful transmitters:
nr. 602 – in Tallinn, on Luha Street. This was the only broadcasting station of its type in Estonia.

Numeration of transmitters: every transmitter had its own number. The numbers were assigned in sequence, within each city, irrespective of how many objekts there were in that city. Therefore, transmitters nr. 1-10 were located at objekt nr. 602, transmitters nr. 11-26 at objekt nr. 65. Nr. 1-10 were, for instance, 1-1 4kW transmitters, nr. 11, on the other hand, a Uragan transmitter.
The radio bureaus (Tartu and Pärnu had their own radio bureaus) communicated with the objekts via special direct telephone lines.

The Noise Generator.

The noise with which we jammed the incoming broadcasts was produced by a special generator. This was known as the GMD – generator meshajushtshego deitsvija, in direct translation, the interference activity generator. Each objekt had a GMD, and each radio bureau had one as a back-up. After every minute of producing interference noise, each generator would also transmit its call sign. For instance, objekt 65’s call sign was the Morse code letter for Y, objekt 602’s, the Morse letter for V.
A GMD unit actually consists of four separate generators, each one with a twin triode 6N7 (see diagram).
G1 gives the frequency 135Hz
G2 gives the frequency 320Hz
G3 gives the frequency 3Hz
G4 gives the frequency 5Hz
All of them are multivibrators, therefore, impulse current generators.
G1 and G3 are the basic generators, while G2 and G4 are the sub-generators, which modulate the frequency of the basic generators. G2 modulates G1’s frequency by +-3Hz, and G4 modulates G3’s frequency by +-5Hz. The noise produced by G1 and G3 are blended together to create the constant static and blaring with which the radio broadcasts were jammed, and which the radio listener finally heard. These Russian noise generators were actually quite cleverly made. Although all LW, MW, and SW broadcasts were always amplitude modulated (AM), amplitude modulation was not used for jamming, but rather frequency modulation (FM). And this, on such a narrow strip as is needed in a band for 1 station, that is, 9-10kHz. If the transmission bearing wave is viewed with an oscillograph, the modulation cannot even be observed, as if it didn’t exist.
The noise generator was regarded as the most secret device at the objekt. Outwardly, it didn’t differ in any way from a common amplifier. On photo nr. 3, a generator (on the bottom) can be seen on a stand together with common amplifiers.
The noise generator, or jammer, was the last device to be explained to a new employee at an objekt. Any other Estonian Radio Centre employee who came there and happened to ask questions about the device, was told that it was just one of the many amplifiers in the broadcasting station.
As a matter of fact, I had an experience like that when I was still going to Technical School and was doing my internship at Laitse radio broadcasting station. For some reason, they had a GMD there at the time. I stumbled upon it, and not knowing what it was, of course made inquiries. The response was, that this was a modulation amplifier.

Frequencies.

We were able to jam broadcasts in the long- and medium wave diapason, and shortwave broadcasts on bands 13, 16, 19, 25, 31, 41, 49m. I even remember some of the frequencies. In long wave, we worked on frequency 173kHz, and in medium wave, mostly on frequency 1195kHz – that was Munich.
Another episode illustrating the extreme secrecy surrounding the work. During work, we had to make notes. We had to jot down the frequencies that the radio bureau gave us, so that we could adjust the transmitters accordingly. After a 15 minute broadcast, we no longer needed these notes. But we weren’t allowed to write down the frequencies on a regular piece of paper, since those are thrown into the garbage, and could end up in the hands of enemy spies. Can you imagine – an American spy would be able to find out Voice of America’s broadcasting frequencies!
For making notes, we were given special notebooks with numbered pages, which were bound together with string, the ends of which were sealed together. When the notebook was filled, it had to be given to the superior, upon which it was destroyed, or even placed in the archives.

The jamming itself was done in the following fashion. The radio bureau operator informed us what frequencies to expect at what times. At the same time, she would be monitoring the broadcasts. When we were jamming Voice of America, the operator would maintain contact with us via the special telephone lines. Beside every transmitter, there was a telephone, so that the technician and operator could be in constant contact. Together they would try to get the jammer onto the exact frequency mode. We weren’t permitted to turn off the jammer until the operator said so. Since our transmitters at Sitsi were not of especially high quality, they would tend to wander off the frequency, and the Voice of America broadcast would come in clearly. But since the radio bureau was constantly monitoring the incoming broadcasts they would inform us of these shifts, so that we would have to make adjustments to the transmitters. Sometimes, friends who were trying to listen to VOA would phone us and ask us to turn the jammer off on some particular frequency. They would then be able to listen, undisturbed, until the radio bureau discovered the shift. Since Voice of America transmitted on several frequencies at the same time, it wasn’t easy for the radio bureau to monitor all the frequencies at the same time.
Besides the local jammers, there were also long distance jammers in Russia, Ukraine, and who knows where else. These directional antennas would be aimed towards Estonia. Since they were so far away, their jamming transmissions would reach us via atmospheric reflections. The effectiveness of these long distance jammers was very dependant on the weather and other factors affecting transmission.

Besides jamming, we also had the opportunity to transmit original broadcasts. Right nearby, just one tram stop towards the center of town, by the Heina Street railroad viaduct, was Tallinn Radio’s second program’s broadcasting station, the so-called “railroad transmitter”, so named because it was located in three railroad carriages. We could substitute for them with our medium wave transmitter, which was basically the same as theirs. And we actually did this when the “railroad transmitter” was being repaired.
In connection with this, we once had an interesting experience. We had to stand in, with our medium wave transmitter Uragan, for the “railroad transmitter”, since it needed to be overhauled. There was no direct link between us and the radio station. The station’s program was sent to us for transmission via the radio bureau. The radio station and the radio bureau were located in neighbouring buildings, at 12 and 14 Kreutzwaldi Street. The radio bureau sent us the program, to the Sitsi objekt, over the direct phone line. The radio program started at 6:55 in the morning. At the same time, 6:45 – 7:00, the Voice of America’s morning program was coming in on medium wave, and which we were supposed to jam. But this time the jamming was supposed to be done by the “railroad transmitter”, which was thereafter supposed to be taken away for repairs. I had already set our transmitter to the radio program’s frequency of 710kHz, the phone line with the radio bureau had been checked and commuted to the modulator, and the modulator had been adjusted to amplitude modulation. To check the transmission quality, we had a radio receiver on the table, tuned to 710kHz. But the radio bureau forgot that the transmission stations had been changed for that day. It was 6:50, when, over the table radio receiver, I could hear a Russian woman yelling and swearing in Russian – why isn’t transmitter Uragan switched on and jamming Voice of America! The radio bureau operator phoned us over the same modulation line, over which the radio program should have been sent. And all this was going onto the air, for all of Estonia to hear. When the operator finally got tired and stopped her tirade, so as to catch her breath, I was able to inform her as to who was, on that day, doing the jamming, and who was transmitting the radio broadcast. I knew that everything she had said had gone onto the air. For a moment, there was total silence, and then the radio show could be heard over the phone line. No one from radio bureau bothered us for some time.
Besides jamming, various other things were also done at the Sitsi station. The Tartu radio stations first post-War medium wave transmitter was built there, and then transported to Tartu. It was finally located in the Tiigi Street jamming station’s building. The transmitter was built from the same Uragan type of transmitter as we had. The constructor was Raul Pääro.
Both before and after me, many Electromechanical Technical School graduates ended up working at the Sitsi transmission station. For instance, the Minister of Communications Arvo Kaldma, and Kalju Kallikivi, the director of communications at Estonian Energy.
The Sitsi transmission station’s territory was surrounded by a high fence. No outsiders were allowed to enter, not even the militia (Soviet regular police). At the gate was a guard armed with a rifle. The security team consisted of both Estonians and Russians. Sometimes, when it got very boring, we would go into the basement with the guard and shoot the rifle. But this was of course done only in secret.
The Sitsi station operated round the clock, was run by four two man teams, with two technicians on duty during every 12 hour shift, during the day from 8:00 to 20:00, at night from 20:00 to 8:00.
One snowy winter we built a huge snowwoman in the station yard, which could even be seen from the other side of the fence, especially from the tram window. Since the snowwoman’s female anatomy was very visible, we received a written reprimand from the Estonian Radio Centre's Chief Engineer Gnipilt.
In 1958, my three compulsory years were up, and I left objekt nr. 65, and the Estonian Radio Centre altogether, so as to accept a better paying position at the Estonian Maritime Fishing Harbour's navigation centre.

Photos:
1/ Shortwave transmitters 1kW. There were 10 of them.
2/ The same transmitters.
3/ The transmission station’s switchboard.
4/ The medium wave transmitter Uragan.
5/ Transmission station technicians sitting inside the long wave transmitter Štorm.

These photos were made in the years 1956 and 1957. On photo nr. 3, on the right, at the bottom, is the GMD. The work that was done at the objekt was of course top secret. It was strictly forbidden to talk to any acquaintance or relative about the work. Needless to say, photographing the objekt was just as strictly forbidden. Getting caught could have brought with it a 25 year prison sentence. Nevertheless, we took pictures, talked about our work, and sometimes, at night, even brought in friends to show them the jammers. No one got caught.

We saw the construction of objekt nr. 602 with our own eyes, when we were attending the Technical School, in 1953 – 1955. We could clearly see the work in progress from the classroom windows. We asked teacher Arnold Isotamm what kind of transmission towers these were. He wouldn’t say, although he obviously knew. Now, 46 years later, I can’t say exactly what year that was. But it was most likely 1954. The general building of the jamming stations began about 1950 – 1951.

GSM Diagram

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The prongs on the transmission towers of objekt nr. 602.

 

The people were very curious about the reasons for the existence of the prongs on top of the Tõnismäe jamming transmission towers.

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There are four prongs on top of the tower. The prongs are nothing more than short wave transmission antennas.
View from above.

Two prongs, standing opposite each other, form one dipole antenna (half wave dipole). Some additions have been made to the only surviving jamming transmission tower.

Transmitting antennae

The whole Sitsi objekt territory was a triangular lot between Kopli and Tööstuse Streets. Now it has been built full of residential buildings. At one time, there were nothing but pastures there. Towards the city, the area ended with a church on Kopli Street. From behind that, a fence stretched to Tööstuse Street. As a matter of fact, the church was at first used as the control room for jamming transmitters. But quite soon, a new building was constructed for that purpose. And the church was converted into a residence for Radio Centre employees.
On the Sitsi site there were three masts. These weren’t actually antennas, just the supporting structures. Two of them dated back to the independence era, to the days of the Ranna Radio Station, in the sense that they had been constructed out of the waste materials that had been left over from the construction of the Türi broadcasting station antenna masts. During the building of the Türi transmitter, a section of one mast had been damaged while being unloaded in Tallinn harbour. This section was discarded, but the material was later used for the Sitsi site masts. Along with the jammers, a third mast was also constructed, which was about 30 – 40 meters high. The two original masts were higher. Unfortunately, I don’t recall the exact height, but it must have been about 60 meters. The antennas of all the transmitters were hung up between these masts. The shortwave aerials were symmetrically fed half wave dipoles; the medium- and long wave aerials, unsymmetrical antennas , which were shorter than ¼ wave. Theoretically, the masts were tall enough to put up a full ¼ wave antenna, but there just wasn’t enough space. Every transmitter had it’s own individual aerial, with the feeds coming out of the central building, through the windows.

Personnel

The objekt was under the authority of the Estonian SSR Radio Centre. They were also in charge of the radio broadcast transmission stations and the radio central studios. In those days, in 1955, there was no television yet.
I/ The objekt, or jamming station personnel consisted of the following:-

1) Supervisor – Russian (for some reason always a woman, special higher education in communications or radio technology, Party member (never a full engineer).
2) Senior technician – Estonian- graduate of the Tallinn Electromechanical Technical School - radio technician - not a Party member.
3) Shift personnel – the objekt operated round the clock - each shift worked for 12 hours straight - there were 2 technicians in each shift - since there were 4 shifts, then there was a total of 8 technicians.

Of the shift technicians, half were Estonians, half Russians. The Estonians, both the men and the women, were mostly radio technicians with a Technical School education. Not one of them was a Party member. Of the Russians, both the men and the women, no one had a special technical education. They had come to Estonia, after the War, with the Soviet army, some of them having been soldiers. Some were Party members, but not all. None of them could speak Estonian.

The radio bureau - worked round the clock with shifts:-

1) Supervisor - Estonian - man - Technical School educated radio technician - Party affiliation not known.
2) Shift personnel – 3 operators per shift - since there were 4 shifts, then there was a total of 12 operators, 1 Estonian man and 11 Russian women - none of them had a special technical education - none of the Russians could speak Estonian.

The wages in the transmitter stations and in the Radio Centre generally, were, at that time, the following. A radio technicians monthly wage was 640 Roubles. We have to keep in mind, that during the Soviet era (and also now, in independent Estonia) wages are quoted as the total amount from which taxes have not been subtracted. In other words, we are talking about gross earnings. 640 Roubles was a bit less than was needed to get by on for a whole month. Sometimes the money would run out before the next payday. During the last year of working at the jamming station, I became a top level technician, with a wage of 860 Roubles a month. But in comparison: when I went to work at the Tallinn Maritime Fishing Harbour, things changed noticeably. There I was paid 1540 Roubles, which was already quite adequate.

The LPWS would like to thank members of the press for their interest in this 100% genuine story and actual pictures emailed to us from Russia. We regret that the passage of time has made it impossible to contact our Russian friends, and it looks as if this is the only remaining copy of this report and pictures.