Supply is based on need. Not much of a requirement for VLF. Very limited number of "Customers", at least in the UK - albeit Anthorn, Criggion and Rugby were worldwide coverage. It was fun when we had the transmitter (agreed outage for maintenance with customer) to transmit a short 4 char message, wait around 1second and pick it up on the receiver after it had travelled the world! Anthorn I only visited a couple of times, I never visited Skelton, so no nothing about that site. Criggion had very good coverage to the Mediterranean, Rugby was more general. Rugby B was a good site, remember it well. Have you worked out the main characteristic of the sites? They all have one thing in common - other than being VLF stations. Took the Americans a number of years to work out why we could get the coverage with lower power transmitted than they used. To get the same coverage, they just throw more power at it - a lot more power! Also remember being up a mast a Criggion checking on something. Back in London the boss called me in and said have you seen your photo? (I was clearly recognisable). I said no, he said you should, its perfect! He wasn't referring to my looks, just as a manager I had to lead by example and use all the safety kit, the photo (taken by a American satellite) clearly showed I was fully compliant! Really enjoyed my time doing that work.