Hungary’s tallest tower since 1933 has been the Lakihegy transmitter tower. This iconic structure has become a symbol of Hungarian radio broadcasting over the past century. Located on the outskirts of Szigetszentmiklós, the octahedron-shaped tower, made up of eight triangles, reaches a maximum height of 307 meters — taller than the Eiffel Tower was.
The first Hungarian radio transmitter (which at the time still operated as a spark telegraph) was inaugurated in 1914. However, regular radio broadcasts have only been available to listeners since 1924. At that time, the legendary Reiss Henrik furniture delivery wagon and a mere 250-watt telegraph-telephone transmitter made by Huth served as the experimental transmitter of Magyar Rádió (Hungarian Radio).
When regular broadcasting began, the studio was relocated to the city center of Budapest, at 5–7 Bródy Sándor Street, and a new 20 kW Telefunken transmitter was installed near Lakihegy, on Csepel Island.
The First Telefunken Antenna
In the 1920s, antennas were typically envisioned as umbrella-shaped or T- and L-shaped wire antennas mounted on wooden or steel towers, which were built primarily to support these wire structures. The first spark telegraph transmitter on Csepel Island (which operated during World War I and was not yet located in Lakihegy but at the northern end of the island) also used an umbrella antenna.
The first antenna for Lakihegy transmitter was designed by Emil Fabinyi Fuchs and consisted of two 150-meter-tall steel towers manufactured by MÁVAG, with a 100-meter-long antenna stretched between them. This setup was already capable of delivering high-quality broadcasts in Budapest and its surroundings.
The growing number of subscribers during the 1920s clearly indicated the urgent need for a modern, long-range transmitter. By the end of the decade, plans had already emerged to build such a system—again in Lakihegy—capable of ensuring good reception throughout the entire country.
The Iconic Blaw-Knox Antenna
The first high-efficiency, half-wavelength, self-radiating antenna towers were built in the United States (in Boston and Wynne). Their use revealed that if their mechanical height slightly exceeds half the wavelength (between 0.5 and 0.55 times the wavelength), their radiation pattern becomes primarily horizontal, significantly increasing the area that can be covered without fading. In the UK, the BBC’s laboratory conducted the early experiments, while in the United States, the Blaw-Knox Company developed the diamond-shaped tower structure, which was statically favorable and uniformly strong.
The Tower’s Adaptation and Construction
The first European implementation of this type of antenna took place in Austria, near Vienna at Bisamberg. In the same year, based on the recommendation of Endre Magyari, planning began to install a similar tower in Lakihegy. As early as 1924, during his first study trip, Magyari had already suggested the idea of self-radiating antenna towers to the engineers at Telefunken. At the time, they laughed at the young man’s “idea” and, as he later recalled, jokingly tapped his foreheads — suggesting he should come to his senses. By this time, however, successful foreign examples and results already existed.
The “cigar-shaped” Blaw-Knox antenna was more expensive to build, but it resulted in significant power savings and increased the area that could be covered without fading at a given transmission power. According to tests verified by field strength measurements, to achieve a field strength of 50 mV/meter in, for example, Kecskemét, a self-radiating half-wavelength antenna tower required an input power of 100 kW. The same field strength could have been achieved with 150 kW using a 150-meter-high T-antenna (like the earlier Telefunken antenna at Lakihegy), or with 250 kW using a self-radiating quarter-wavelength tower. This is why Magyari chose the Blaw-Knox antenna.
The American design of the tower was adapted by engineer Pál Tantó to suit the sandy soil conditions of Csepel Island and the stronger wind loads expected in Hungary. A significant difference between the Vienna and Budapest towers is that Lakihegy received a half-wavelength tower, while the one in Vienna was only a quarter-wavelength. The design of the transmitter took nearly four years, and on July 1, 1933, MÁVAG’s assembly workers, under the direction of Károly Massányi, began construction of the 314-meter-high, Blaw-Knox system, elongated octahedral-shaped tower.
At the same time, as a joint investment by the Hungarian Post and the Hungarian Radio Corporation, a 120 kW medium-wave high-power broadcast transmitter was ordered from Standard Villamossági Rt. for the Lakihegy site. The first test broadcast took place on November 8, 1933. The official inauguration followed on December 2 of the same year, with the tower first transmitting a ceremonial speech by then-Prime Minister Gyula Gömbös on the Budapest I program.
At the top of the lattice structure sits a 36-meter-long extendable tuning element, which allows the effective length of the antenna to be adjusted (from the 36-meter-long tube, 30 meters can be extended upward). At the end of the tuning tube—at the very top of the antenna—there is a hollow steel sphere roughly the size of a basketball. During the renovation in 1968, this sphere was replaced, and the old one—heavily perforated by lightning strikes—was put on display at the Post Museum in Budapest.
Although everyone everywhere refers to it as being 314 meters tall, the antenna tower is “only” 284 meters high, and with the tuning extension properly adjusted it reached 307 meters. With this height, it held the world record for several years at the time, and it remains the tallest Blaw-Knox tower in the world to this day. The 314 meters represent the maximum achievable height if the tuning tube extension is fully extended to its maximum of 30 meters (284 + 30 = 314 m), which, however, has never actually been done.
The tower’s 30-meter tuning rod made it possible to change the transmission frequency. The Lakihegy transmitter broadcast on 549.5 kHz before 1931, then on 545 kHz, from 1938 on 546 kHz, and from 1954 on 539 kHz. The switch to 540 kHz had to be carried out later, when the high-power transmitter in Solt was put into operation.
Several novel engineering solutions had to be devised during construction, as the MÁVAG assembly team had never encountered such challenges when working on the previous straight towers at Lakihegy or Székesfehérvár, which were no taller than 150 meters. For example, an elevator had to be designed for transporting workers up and down, as climbing the tower resulted in significant time loss. Since the central section of the tower is 14 meters wide, it had to be bypassed by the elevator platform, so a crane arm extending from the tower was used in the upper section to assist with vertical transport.
At the time, the tower weighed 230 tons, while the pressure on the base insulator was 480 tons. This high load resulted from the tension in the supporting guy wires. To ensure better current distribution, a copper conductor was run along each of the four edges of the steel structure. The antenna’s grounding was achieved using a copper wire network buried in the soil over an area of approximately 10 hectares surrounding the tower.
The most technically interesting part of the antenna is the base insulation. The entire weight of the steel structure is supported by two specially reinforced truncated porcelain cones placed face to face, with steel hemispheres seated on top of them. These hollow ceramic components, only 9 cm thick, not only bear the structural load but also provide the necessary electrical insulation.
Except for the insulators, the entire tower was made of Hungarian-manufactured materials; its design involved significant Hungarian engineering work, and, as mentioned, construction was carried out by MÁVAG’s expert builder team. Hungarian industry and the nation’s engineering community had every reason to be — and still can be — proud of this facility.
Operation and Costs
From 1934 onward, the station had a total of three transmitters available for broadcasting:
- A 120 kW broadcast transmitter, call sign HAL, which transmitted the Budapest I program on a wavelength of 549.6 m. This transmitter was manufactured by Standard Villamossági Rt.
- A 20 kW broadcast transmitter, call sign HAL2 (in service since 1928, supplied by Telefunken, Germany), which from 1934 transmitted the Budapest II program on a wavelength of 833.3 m, and also served as a backup for the 120 kW transmitter.
- A 0.75 kW transmitter, built by the Post Experimental Station. This broadcast and telegraph transmitter, call sign HAL3, could operate in the 700–900 m wavelength range and served as a backup for the 20 kW unit.
The three transmitters had three corresponding antennas:
Two old 150 m towers supported two T-antennas, one each for the 20 kW and 0.75 kW transmitters. The 120 kW transmitter used the large Blaw-Knox antenna.
The 120 kW transmitter operated about 5,000 hours per year, the 20 kW unit about 1,500 hours, and the 0.75 kW transmitter was kept in reserve. The station’s power supply came from two 10 kV cables provided by the Budapest Metropolitan Electric Works. Its average annual electricity consumption was 2,700,000 kWh, costing exactly 266,000 pengő (today roughly €1.0–1.1 million).
The radio tubes were provided under a tube-hour purchase arrangement — essentially a tube rental system. Under this scheme, the station paid the supplying companies a set amount for every hour the transmitter operated; in return, the companies were obliged to replace all failed tubes and keep adequate spares in stock. This gave suppliers an incentive to provide long-lasting tubes. The 20 kW transmitter was operated entirely with domestically manufactured Philips-Vatea tubes, while the 120 kW unit used foreign-made tubes (French and British) as well as some Hungarian tubes. The average annual cost of tube-hours was 160,000 pengő (today approximately €610,000).
The Post leased the station’s 9-hectare site from the Imperial and Royal Family Estate for an annual rent of 2,195 pengő (about €8,400 today). The site contained a total of seven buildings: one station master’s residence, one staff residential building, one transmitter building, one gendarmerie barracks, one garage, one transformer house, and one coupling house. These buildings contained a total of 11 apartments — nine occupied by station staff and two by the gendarmerie. The station staff comprised 16 people: 1 chief engineer, 3 technical operating officers (instrument technicians), 7 hourly-paid technicians, 1 hourly-paid clerical assistant, 1 non-commissioned officer (caretaker/messenger), 1 mechanic (also a driver), and 2 hourly-paid laborers.
The number of radio subscribers in the country was steadily increasing, and by the end of 1935 exceeded 350,000. The station’s total annual operating cost, including wages and other expenses, was 453,000 pengő (about €1.6–1.7 million today). According to advertisements in the 1935 issues of the journal Radio and Electricity, the annual radio subscription fee was 4 pengő, which meant that subscription income totaled roughly 1.4 million pengő — about three times the station’s operating cost. Thus, radio broadcasting was profitable!
Politics Got Involved Too
In Germany, at the Königs Wusterhausen radio station in 1925, antenna towers taller than 280 meters could not be built due to the restrictions of the Treaty of Trianon. As a result, only a 243-meter tower was constructed. Reportedly, this rather absurd requirement was insisted upon by the French delegation during the peace negotiations following World War I, in order to maintain the world-record status of the 300-meter Eiffel Tower in Paris.
Indeed, when the Eiffel Tower was built in 1889, it stood at exactly 300 meters. An antenna was only added in 1957, which increased its height to 324 meters. However, its status as the tallest structure in the world had already been surpassed in 1930, with the completion of the Chrysler Building in New York, standing at 318.9 meters. Still, in 1925 the Eiffel Tower remained the tallest in the world, and even in 1933, it was still the tallest structure in Europe at 300 meters.
It is said that the Lakihegy tower’s steel structure was limited to 284 meters for the same reason: the French insisted that post-war Hungary should not build anything taller than their own. The transmission frequency called for a height of 307 meters, which would have exceeded that limit. The adjustable tuning extension had two advantages: first, it made it possible to retune the tower for different frequencies, and second, it kept the lattice structure’s height under 300 meters.
Thus, the Lakihegy transmission tower became the tallest structure in Europe at the time—because after the official inauguration, the top-mounted tuning tube was quietly extended to 307 meters.
The Tower Became a Symbol
The distinctive shape of the Blaw-Knox antenna became a symbol of Hungarian radio broadcasting. Standard even adopted it as its own emblem, commissioning a logo design featuring a symbolic image of the Lakihegy tower at its center. This emblem can still be seen today on the dials of old Standard radio sets.
A New Tower After the War
The Lakihegy tower served Hungarian Radio peacefully and effectively until the end of November 1944, when a technical unit of the German army, retreating before Soviet forces, was ordered to destroy the Lakihegy radio station. The tower was designed in such a way that it would remain standing even if any two of its guy wires were severed. On November 30, 1944, German demolition troops blew up six of the eight guy wires, and the tower collapsed toward the southwest. The central section of the tower—14 meters wide—drilled two meters into the ground upon impact, and the base of the tower was thrown eight meters away from its original position by the force of the fall. The base insulator shattered, and much of the steel structure was bent and deformed.
Reconstruction of the tower could only begin in January 1946, after the smaller 150-meter towers at Lakihegy had been rebuilt. About a quarter of the steel from the destroyed tower was still usable; the rest had to be newly manufactured. Spare base insulators had survived in a shelter, but all the guy wire insulators were broken and had to be replaced. Reconstruction of the tower was completed on December 14, 1946. The new tower was slightly lighter (approximately 225 tons), and the tension in the guy wires placed a pressure of about 420 tons on the base. One week after construction was completed, the old Telefunken transmitter—now upgraded to 50 kW—was connected to the antenna.
In 1967, alongside the 135 kW Standard transmitter, a new 2×150 kW EMV transmitter was installed. However, the antenna’s original insulators could not withstand the resulting 300 kW power output. Therefore, at the same time, all base and guy wire insulators had to be replaced with stronger ones. During this upgrade, a proper lightning protection system was also implemented, enabling continuous operation of the station even during thunderstorms, without needing to suspend broadcasting.
It Was Almost Demolished
In 1977, following the commissioning of the much more modern Solt radio transmitter, with its dual 1 MW capacity, the Lakihegy transmitter was downgraded to a backup role. Lakihegy’s importance steadily declined; the 307-meter tower was used less and less frequently, and broadcasting was increasingly done using the two smaller 117-meter towers instead. In 1983, the tower again faced serious danger: due to the high maintenance costs, the supervisory authority of the Post Office’s Directorate of Radio and Television Engineering decided to dismantle the large tower as redundant.
News of this plan sparked protests from private individuals, members of the Association of Telecommunications Engineers, museologists from the Post Museum, and veteran professionals who had taken part in the postwar reconstruction or were familiar with the tower’s history, unique characteristics, and fame. Ultimately, bowing to public pressure, the Lakihegy transmission tower was declared an industrial monument in 1985.
In the summer of 2006, the tower underwent a thorough renovation and was returned to service. It now operates on 135.6 kHz under the call sign HGA22, transmitting time synchronization signals similar to those of Germany’s DCF77. These signals are used by power providers to manage the switching between day and night service and to control public lighting.ű
Visiting the Lakihegy antenna
The Lakihegy transmitter tower Located in the outskirts of Szigetszentmiklós, on the northern part of Csepel Island. Exact coordinates: 47°22’23.0″N 19°00’17.0″E.
By Car
- From Budapest: Take the M0 motorway and exit at Szigetszentmiklós / Lakihegy, then follow Csepeli út or Lakihegyi út.
- From Csepel: Cross via the Gubacsi Bridge and continue along Csepeli út or II. Rákóczi Ferenc út.
There is no public parking directly next to the tower, as it is part of an operational industrial facility. You can park in the ALDI parking free across the street (47°22’31.0″N 19°00’11.7″E).
By Public Transport
- By HÉV suburban railway: Take the Budapest–Csepel line and get off at Szigetszentmiklós-Gyártelep station, then walk about 30 minutes.
- By Bus: BKK bus lines 38 and 238 stop at Lakihegy, adótorony (this is the closest bus stop to the facility). From the bus stop, it’s about a 5–10 minute walk.
Note: The tower site is an active technical installation and is not open to the public. It can only be viewed from outside the fence. The Post Museum occasionally organizes guided thematic visits, during which entry to the area is possible.
Sources
- György Dósa: Egy évforduló emlékére. Budapest, Rádiótechnika, 2003/1 and 2003/2.
- Béla Neuberger: Egy szemtanú visszaemlékezése: gravitációs jelenségek indikálása a lakihegyi 314 méteres antennatorony felhasználásával, 1961-ben. Budapest, Híradástechnika, 2000/12.
- Yearbook of the Postal and Telecommunications Museum Foundation 2001: https://download.postamuzeum.hu/Postamuzeum_Evkonyv/Postamuzeum_Evkonyv_2001.pdf
- Gusztáv Sugár: A magyar rádiózás története a felszabadulásig. Budapest, Posta Rádió és Televízió Műszaki Igazgatóság, 1985.
- Péter Vári (ed.): Az antennák világa. NMHH, 2023. https://nmhh.hu/dokumentum/243522/az_antennak_vilaga.pdf