YE90PK, 90th Anniversary of Radio Malabar

On the 5th May 1923 Opened by : Mr. Dirk Fock, Governor General of Nederland Indie.The Radio Station on The Malabar for the Public Traffic

This station was designed and built by : Dr. Ir. Johannes Cornelis de Groot,on the Major Subdivision where under his Leadership

this Land was Built and for the First Time. the Mount Antenna, Devised by Him, was Made.

In the era just before the beginning ofWorld War I, twospark wireless stations were established in theDutch East Indiesfor naval communications. This was in the days before internationally recognized callsigns were in general usage and one of these stations, located at Sabang, was on the air in Morse Code under the irregular callsign SAB.

Immediately after the end of the war, there were four such stations in theDutch East Indies, and these were all designated withcallsignsin the new PK series:PKA Sabang,PKB Weltevreden,PKC Sitoebondo, and PKD Koepang’. Soon afterwards, theDutch government in Batavia announced that a huge arc transmitter station, usingTelefunken arc equipment, was under installation at Malabar, near Bandoeng. This massive 3.5 mega watt station was established for communication with the home office in theNetherlands.

The date for the official opening of this station was set at May 5, 1923. However, a tropical lightning strike destroyed some of the equipment and the opening was postponed until repairs were completed. By this time, however, arc transmitters were becoming obsolete, and valve or vacuum tube transmitters were soon afterwards installed at this same location on the island of Java.

Radio Kootwijkis a small town in theDutch municipality of Apeldoorn, with (in 2006) approximately 120 inhabitants. It is situated in a heather- and forest-rich territory in the Veluweregion, east of the sandhills of theKootwijkerzand and the town of Kootwijk.

The housing accommodations of Radio Kootwijk arose as a result of the building of a shortwave transmittersite with the same name, starting in 1918. The transmitters played an important role in the 20th century as a communication facility between the Netherlands and its then colony of Dutch East Indies. In 1923 Dutch PTT started trans-oceanic telegraphy using along wave transmitter (a 400KWhigh frequency alternator) from the German Telefunken company under the callsign PCG, in the 24kHz and 48kHz. By 1925 the longwave transmitter was changed by a shortwave tube based, electronic transmitter which had a much better performance due to the better propagation of shortwaves. With this new technology, in 1928 a radio-telephonic connection was established. At the end ofWorld War II, theGerman occupying forces blew up the transmitter. Afterward some of the radio towers were rebuilt

These devices served as the transmitters for most wireless telegraphy systems for the first three decades of radio(1887–1916) and the first demonstrations of practical radio were carried out using them. In later years somewhat more efficient transmitters were developed based on rotary machines like the high-speed Alexanderson alternators and the staticPoulsen Arcgenerators, but spark transmitters were still preferred by most operators. This was because of their uncomplicated design and because the carrier stopped when the telegraph key was released, which allowed the operator to “listen through” for a reply. With other types of transmitter, the carrier could not be controlled so easily, and they required elaborate measures to modulate the carrier and to prevent transmitter leakage from de-sensitizing the receiver. After WWI, greatly improved transmitters based on vacuum tubes became available, which overcame these problems, and by the late 1920s the only spark transmitters still in regular operation were “legacy” installations on naval vessels. Even when vacuum tube based transmitters had been installed, many vessels retained their crude but reliable spark transmitters as an emergency backup. However, by 1940, the technology was no longer used for communication. Use of the spark-gap transmitter led to many radio operators being nicknamed “Sparks” long after spark transmitters ceased to be used. Even today, the German verb “funken”, literally, “to spark”, also means “to send a radio message/signal”.