Wednesday, August 12, 2015

Focus on the South Pacific: Wireless Station ZLB


Alphabet Soup in New Zealand - Wireless Station ZLB

Back in the year 1908, there was a regional conference in Melbourne Australia for the purpose of establishing a wireless link between Australia and New Zealand as a parallel to the underwater cable link.  In those days, the Australian federal government offices were all in Melbourne, and this was before the federal capital was established in the yet unbuilt city of Canberra.  
        Two years later tenders were called for the construction of two large wireless stations in New Zealand: one at the very top tip of the north island, and the other at the very bottom tip of the south island.  Then in the third year, that is 1911, a site was selected for the southernmost station, an area of 2,800 acres of swampy farm land that was then drained and grassed. 
      The location for the new wireless station was on the Awarua Plain, midway between the city of Invercargill and the seaport known as Bluff, ten miles each way.
      The contract to construct the two stations was awarded to the Australasian Wireless Company in Sydney which was representing the Telefunken company in Berlin, Germany.  The German staff who came out to install the station in South New Zealand approved of the location for the new station, stating that it reminded them of the location of the German wireless station at Nauen, near Berlin.
     The main station building housed a 50 kW Telefunken spark transmitter and also a small wireless receiver, with a power generator in a separate and smaller building.  In addition to the wireless station buildings, three cottages were also constructed for the staff of the new station.
         The antenna mast weighed 120 tons, it stood 410 feet tall, and it rested on a large glass insulator.  The antenna system was an umbrella style, with the top part of each guy wire active, and insulated from the ground.
        While the station was under construction, no callsign had been officially allocated.  However, when the station was activated on December 18, 1913, it was on the air under the newly allotted callsign VLB, indicating station B, with the B also standing for The Bluff, a prominent landmark nearby.  The actual opening date was half a year in advance of the original planned date for completion, due to the fact that the German staff needed to return home before the commencement of the obviously looming warfare. 
    Wireless station VLB was now the third wireless station in New Zealand, with VLA at Awanui and VLD in Auckland, both in the North Island, already in use. 
     The equipment of the VLB station was changed from spark to valve in 1924, and the callsign was changed from VLB to ZLB on January 1, 1929, due to a change in international radio regulations.  Then in 1930, the original spark transmitter, though by then well and truly modified, was dismantled.  At this stage, additional electronic equipment was installed.
      The tall tower was dismantled in 1938, and three lattice towers at 150 feet each were installed during World War 2.  At this stage, the receivers in use were National brand, Model HRO, with removable plug- in coils for band changes.
    Major changes took place in 1978, with a total staff now numbering 54 personnel working at six hour shifts.  The shortwave transmitters in use were 5 kW units manufactured by Philips, and the antenna systems were three wire dipoles set on masts 70 feet tall.  In addition, there were two broadband monopoles, with more under consideration.
      At this stage also, Awarua Radio ZLB was connected by landline to the large multi-transmitter facility 600 miles distant at Himatangi in the North Island and they began to key their transmitters as needed.  This long distance transmitter arrangement ended nearly a dozen years later in February 1989, a few months after their 75th anniversary.  It was stated that shortwave station ZLB at Awarua in South New Zealand could be heard worldwide, though there was one blind spot in West Africa.

     Ultimately, the end came, and Awarua Radio VLB-ZLB was finally silenced forever on August 30 1991, after an illustrious 78 years of international communication service on longwave and shortwave.   Yes, these days there are still many reminders evident to the wondering visitor who travels way down to the bottom of the South Island in New Zealand.  One of the early buildings is now a radio museum, the original transmitter building is now a farmers homestead, and the three large antenna blocks are still in place.    
(AWR-Wavescan/NWS 337)