Wikipedia says tests began 17 July 71, a week after the site had been completed. Another source says there were some tests in March that year.
Transmitter operated on clear channel frequencies between 6 and 40MHz. It's mentioned that at night time there were less frequencies available with the 6Mhz and 7Mhz bands being occupied by broadcast stations.
Scrolling through the broadcasts monitored for the purpose of trying to establish what the noise issues were being caused by many of them were in the 20 t0 25Mhz range.
Nothing to do with RNI when it was off the UK coast
