The following three undated photographs with annotations from New Zealand Post Office files appear to have been used in plans to replace the two original Oregon Pine masts with a single steel lattice tower plus secondary masts in 1923. The photos also show the original stone building and the small stone hut.
1923: A new 165-foot steel lattice tower was erected to replace the original 150-foot Oregon Pine masts which had rotted.
By the mid-1920s Wellington and some other coastal radio stations were using the new ‘beam’, short-wave radio technology for improved, long-distance communication with shipping, even as far away as the Ross Sea…[Engineers of the Marconi Company] had refined the so-called ‘beam’ system using special directional antennae that allowed short-wave radio signals to be beamed along clear paths rather than radiated out in more diffuse and thus less effective signals.1
1926: On 13 May, the winds on Tinakori Hills proved too strong for the steel lattice tower erected just three years earlier and it collapsed after all four legs sheared off their bases.
1927: On 26 November, VLW changed to ZLW, as part of new international agreement on callsign allocation.
1929: Wellington Radio got a second short-wave transmitter in late 1929.2
1 Wilson, A.C. (1994). Wire and wireless: A history of telecommunications in New Zealand 1890-1987, (p 115-116), Palmerston North, New Zealand: Dunmore Press.
2 Wilson, A.C. (1994). Wire and wireless: A history of telecommunications in New Zealand 1890-1987, (p 116), Palmerston North, New Zealand: Dunmore Press.