The Cavite Peninsula on the edge of Manila Bay in the Philippines has played a pivotal role throughout the lengthy eras of Philippine history. The Cavite Peninsula is located on the edge of modern Metro Manila and the name comes into the Spanish language from an ancient word in the Tagalog language, Kawit, meaning a hook, which is the geographic shape of the peninsula.
The earliest settlers on Cavite came from Borneo Sulu some time during the dim distant past; and because of its deep water anchorage, this location became a moorage for ocean going Chinese junks involved in international trade. The Spanish began their rule of the Philippines at Cavite in 1571; and ¾ century later, the Dutch came and made their attack against the Philippines at this same location. The British followed in 1672 with an attack on the Philippines at Cavite, though their rule lasted for only two years.
The American era began on May 1, 1898 with an attack against the Spanish at Cavite. Nearly ½ a century later, the Japanese invaded the Philippines and their attack against Cavite itself began on December 10, 1941, just three days after Pearl Harbor. A little less than three years later, the Americans returned to Cavite; and ultimately the area was officially handed over to the Philippine government on September 1, 1971.
It was back in the Spring of 1903 that the American navy procured 20 sets of Slaby-Arco wireless equipment from Germany, both transmitters and receivers. One of these sets of wireless equipment was installed at the American navy base at Cavite, and a year later the station was taken into regular service for Morse Code traffic, on September 5, 1904.
The original callsign back then was UT, though this was changed on October 1, 1908 to the more familiar internationally recognized callsign NPO. Back then, the transmitter was described as a composite unit rated at 5 kW and radiating on 500 kHz.
During the year 1915, two tall towers were erected at the American navy base at Cavite and these were 141 feet and 134 feet tall. The operating power was increased from 5 kW up to 25 kW and station NPO identified as Radio Sangley, honoring the name of the American Naval Station, Sangley Point.
In the early 1920s, three new self supporting radio towers were erected at Cavite, each at 600 feet tall. When these came into use for supporting the antenna system at NPO, this naval radio station was sending out in Morse Code 2,000 words daily on longwave13900 metres (21.5 kHz) to the navy receiver station in San Francisco. It is stated that these three tall towers were visible from Manila City, ten miles distant.
The usage of shortwave for international radio communication was implemented at the Cavite radio station in the early 1920s. For example, it is recorded in the year 1926 that station NPO was utilizing two shortwave channels 3548 and 4283 kHz. Then, in 1929, an additional six shortwave transmitters were installed at NPO, each at 10 kW.
During the 1930s, the PanAm Seaplane Clippers, passenger and freight service, called at Cavite once each week in their flights between the United States and several Pacific locations. A color postcard from this era shows the PanAm Clipper moored at Cavite, with the skyline in the distance.
On December 10, 1941, a Japanese air raid badly damaged the radio station at Cavite setting the radio station building on fire, and damaging one of the tall towers.
Beginning just five days later, on December 15, 1941, eight daily special programs were beamed to the Philippines on shortwave for rebroadcast via 12 mediumwave and shortwave stations in Manila. Some of these relay programs were picked up at Cavite and rebroadcast on their transmitters also. Then when the Japanese took over Manila, Cavite continued to re-broadcast the program information from California for a few additional days, apparently from temporary facilities.
Soon afterwards, on January 2 of the next year, 1942, the order was given to evacuate Cavite. When the Americans returned three years later, they found the three towers still standing.
The famous wireless station at Sangley Point, the American navy base at Cavite in the Philippines, is an example of the widespread network of huge wireless stations established by America in strategic locations around our globe. As the well known writer and editor stated in Popular Communications a few years ago, “The Cavite station was a most historic wireless facility, a well known landmark.” That statement came from the pen (or maybe the typewriter) of the late Tom Kneitel, writing under the pseudonym Alice Brannigan.
(AWR Wavescan/NWS 260)