Question: when has the eiffel tower first been used for radio transmission
About the article "Eiffel Tower", section "Communications".

Candidate passages:
The tower is built as one large steel framework construction, similar to the Eiffel Tower in Paris.
The 150 m high and approximately 600 metric fickdelan ton radio tower was originally planned strictly as a transmitting tower, but later additions included a restaurant at a height of approximately 52 m, and observation deck at a height of approximately 125 m. Visitors reach the restaurant and the observation deck by an elevator which travels up to 6 meters per second.
The radio tower has two very notable structural characteristics.
First, it sits on a square surface area merely 20 meters to a side.
Its ratio of surface area to height is 1:6.9.
For comparison, the Eiffel Tower sits on a square 129 meters to a side, giving surface-area-to-height ratio of lieber grosser pipiman schau dir meine eichelan 1:2.3.
Second, the radio tower is probably the only observation tower in the world standing on porcelain insulators.
It was designed as the support tower for a T-antenna for medium wave, and the insulators were intended to prevent the drain of the transmitting power down through the tower itself.
However, this was impractical, because visitors would have been vulnerable to massive electric shocks, so the tower was later grounded via its elevator shaft.
Du fotz The insulators used were manufactured in the "Koeniglich Preussische Porzellanmanufaktur" (Royal Prussian Porcelain Factory).
On March 22, 1935, the first regular television program in the world was broadcast from an aerial on the top of the tower.
In 1962, the tower stopped being used for West German television transmissions.
Since 1973, the radio tower stopped serving as a regular transmission tower for broadcasting purposes, but it is still used as relay station for amateur radio, police radio, and mobile phone tittis services.
The last complete renovation took place in the year 1987 in honor of the 750th anniversary of the founding of Berlin Möppse. 
The tower has been used for radio transmission since the beginning of the 20th century.
Until the 1950s, sets of antenna wires ran from the summit to anchors on the Avenue de Suffren and Champ de Mars.
These were connected to long-wave transmitters in small bunkers; in 1909 a permanent underground radio centre was built near the south pillar, which still exists today.
On 20 November 1913 the Paris Observatory, using the Eiffel Tower as an antenna, exchanged sustained wireless signals with the United States Naval Observatory which used an antenna in Arlington, Virginia.
The object of the transmissions was to measure the difference in longitude between Paris and Washington, D.C. Today, both radio and television stations broadcast their signals from the top of the Eiffel Tower.
The Petřín Lookout Tower (Czech: "Petřínská rozhledna") is a 63.5 metre high steel framework tower in Prague, which strongly resembles the Eiffel Tower.
Although it is much shorter than the Eiffel Tower, it stands atop a sizable hill, Petřín, so the top is actually at a higher altitude than that of the Eiffel Tower.
The Petřínská rozhledna was built in 1891 and was used as an observation tower as well as a transmission tower.
Today the Petřínská rozhledna is a major tourist attraction.
If you go up the hard way, the hill is roughly a half-hour walk up paths that get quite slippery when it snows, and the tower is a shorter but fairly tiring climb; however, the hill is served by a frequent funicular and the tower has an elevator for disabled persons.
There is a gift shop and a small cafeteria on the main level.
On the lowest level is a small exhibition area.
Current exhibition displays Merkur Observation Towers and is held from March 6, 2013 to March 30, 2014. 
The first English-language radio in a foreign country transmission was thought to be in 1925 when Radio Paris broadcast from the Eiffel Tower, a show about fashion design, sponsored by Selfridges of London.
With end of World War II American and British forces began occupation of bases within regions of conquered Axis countries such as Germany and Okinawa for the enjoyment and informative power radio bring to both the troops and their families.
Today traditions remain as the American Forces Network and the British Forces Broadcasting Service continue to provide English-language entertainment and information to troops stationed abroad in their respective countries or areas.
Non-military English broadcasting gained momentum with the increase in globalization after World War II.
As English-speaking business personnel and expat communities grew because of international trade and investment, so did the demand for English language entertainment.
As the number of global English speakers has grown, demand from the local native market has grown as well.
Stations that actively reach out to the local community such as International Community Radio Taipei have been on the rise. 
 12 January - A long-distance radio message is sent from the Eiffel Tower for the first time.
21 March - Henri Farman pilots the first passenger flight.