On 24 May, 13:37, "John Rowland"
wrote:

Thanks. At the risk of being pedantic, the pictured MSF broadcasting array
was about 100 miles away from the NPL which was, and is, in Teddington.

Just look at the size of the tuning coil needed for this very low
frequency!

http://www.subbrit.org.uk/sb-sites/s...o/index2.shtml