Large antenna extension coil

This antenna extension coil Idzerda used along with its channel PCGG.
Description:
Antenna circuit of a high-frequency transmitter for longer wavelength (e.g., 150 kHz) to 2000 m, with an antenna smaller than a quarter lambda own wavelength, must be brought into resonance by means of an additional self-induction in order to be able to receive and radiate maximum energy. Radiant energy depends strongly on the antenna height (radiation level). Tuned to a wavelength of 1015 m (f = 2.86 x 10 Hz), in 1919 at 670 m.
Technical information:
48 turns brass band b.9 1mm thick, mounted on six ebony columns with a diameter of 50mm, with 800mm of height, between two oak end caps and a septum. Bottom flange on three porcelain insulators. 49 brass branch terminals are divided onto three columns.