It seems the lower the frequency, the longer the QSB. I'm not certain if that's the cause of the Alpha fade downs, but it's quite likely.

I would not think they would deliberately reduce their transmitter powers -with VLF, the more power, the better.

The 'Tesla' radio concept is a very difficult one to explain to anyone 'technical', because it requires a total 'mind clearance' of all previous 'learned' knowledge regarding radio transmission principles. Whenever I have got into discussion regarding the Tesla system, it always ends with arguments challenging the workings, and actually being 'banned' on a forum as a 'heretic'. It also led to the final demise of the Elfrad group some time ago. 

I don't think any Amateurs research stuff below 10 Hz, so I'm 'on my own' down there, with the exception of a German ELF receiving enthusiast who has contributed to the Radio Below 22 kHz website.

The plan here is to complete a VLF / LF transmitter working on the same principle, and join in the VLF TX experiments with other Amateurs.

That will be the best way to take this forward. Also the new VLF 'Tesla' transmitter will cover the LF 136 kHz amateur band, and the Long Wave broadcasting band, with suitable matching arrangements, so that could prove interesting.

With very kind regards, David