Спросил.
Ответили:
"DL0HOT is located at JO60IS64RP on a small mountain near Chemnitz (Saxony).
Soil is rocky and dry and we got some hard difficulties regarding lightning and
bad ground conditions in past.
The T-antenne is about 40 m high (highest point) with about 75 m long roof capacity
(2 m width using 3 wires), 10 m above ground on the south end and about 30 m
above ground in north (like an inverted V antenna).
The radiating vertical part is made of two 10 mm² wires with 1 m distance. Calculated
radiating resistance a bit more than 1 mOhm.
Coil: diameter 1000 mm, hight 1300 mm, designed as a variable inductivity. At moment
about 300 mH used (maximum abt. 500 mH) to get the antenna in
resonance at 8270 Hz. The complete inductivity consists of about 3 km 1.3mm copper
wire on a glas fibre reinforced sewage pipe."