“As far as I know, these 29.499 kHz VLF signals are the first amateur VLF transmissions to span the Atlantic — "
"His transmitter has a 3CX3000A7 tube in the final, running grounded grid and generating 800 W. The effective isotropic radiated power (EIRP), however, was estimated to be approximately 1 mW.
To operate on 10,000 meters, Raide has a 90 foot vertical antenna using a reconfigured Zepp, fed via a huge loading coil that is 4 feet tall, more than 1 foot across and comprised of some 2000 feet of #14 wire. He employs a few thousand feet of “chicken wire” for his radial system."
"Ziegler said German and UK experimenters have been experimenting at frequencies below 9 kHz, which is unregulated. "http://www.arrl.org/news/hams-experimental-vlf-signals-heard-in-the-uk-europe