Am I correct in saying that when the Fredericia started transmissions she was on 1511 kHz? Then due to interference from/to Belgium moved to 1520 kHz. This may have been because of the original plan for the ship to go to the zoom which she eventually did. The use of 1511 would not have been such an issue up north. Caroline South of course used the Atlanta frequency.
I hear Ray is preparing a new edition of his book to coincide with the 60th anniversary. That might be an opportunity to make amendments but then he would be accused of rewriting history!
I have always been baffled by why Simon Dee kept saying in interviews and articles that, just before the Caroline ship sailed north on 3-July-64, the transmitter crystals were exchanged between the two ships. Both stations continued broadcasting on their original frequencies of 1520 (north) and 1493 (south) so, although this may have been the plan, I don't see how it could have happened.
His claim has been repeated in various histories. For example, Ray Clark in his 2014 book says "the transmitter crystals were exchanged" (page 77) and frequency changes had taken place overnight (page 78).