An octagonal concrete base with 0.8m x 0.48m apertures on the north, west, south and east sides; a hollow centre. Radial wooden strips and 3/8” (10mm) diameter threaded iron bolt protrusions remaining in a ring, 1.5m in diameter on the top. It has an external (flat face-to flat face) width of 2.1m (7 feet as built) is up to 1.1m high. Its inner width is 1.7m (66 ¾ inches as built) It supported an inductor, either for matching the elevated counterpoise or the antenna itself. Its installation may have been part of efforts to reduce significant problems with antenna interaction after a new antenna (‘GLJ’) was installed next to the existing, 1914 array in 1925.

Source: Rowlands, J., Marconi's Carnarvon Station 1912-1939: a journey into early commercial wireless in north Wales' Second Edition, 2023.

RCAHMW, 2023.